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Journal articles on the topic 'Mycobacterium species'
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1
Torkko, Pirjo, Marja-Leena Katila, and Merja Kontro. "Gas-chromatographic lipid profiles in identification of currently known slowly growing environmental mycobacteria." Journal of Medical Microbiology 52, no. 4 (2003): 315–23. http://dx.doi.org/10.1099/jmm.0.05113-0.
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Cellular fatty acid analysis by GLC is widely used in the species identification of mycobacteria. Combining mycolic acid cleavage products with shorter cellular fatty acids increases the informative value of the analysis. A key has been created to aid in the identification of all currently known slowly growing environmental species. In this scheme, the species are classified into six categories, each characterized by a combination of fatty markers shared by those species. Within each category, individual species may be distinguished by the presence or absence of specific marker substances, such as methyl-branched fatty acids or secondary alcohols. This study also describes earlier unpublished GLC profiles of 14 rare, slowly growing, environmental mycobacteria, Mycobacterium asiaticum, Mycobacterium botniense, Mycobacterium branderi, Mycobacterium conspicuum, Mycobacterium cookii, Mycobacterium doricum, Mycobacterium heckeshornense, Mycobacterium heidelbergense, Mycobacterium hiberniae, Mycobacterium kubicae, Mycobacterium lentiflavum, Mycobacterium scrofulaceum, Mycobacterium triplex and Mycobacterium tusciae. Though no single identification technique alone, even sequencing of an entire single gene such as 16S rRNA, can identify all mycobacterial species accurately, GLC has proven to be both reliable and reproducible in the identification of slowly growing mycobacteria. In cases of earlier unknown species, it generates useful information that allows their further classification and may lead to the description of novel species.
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Mohamed, Amr M., Peter C. Iwen, Stefano Tarantolo, and Steven H. Hinrichs. "Mycobacterium nebraskense sp. nov., a novel slowly growing scotochromogenic species." International Journal of Systematic and Evolutionary Microbiology 54, no. 6 (2004): 2057–60. http://dx.doi.org/10.1099/ijs.0.63126-0.
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The characterization of a novel slowly growing, scotochromogenic Mycobacterium species is reported. This previously undescribed mycobacterial species was isolated from five different patients with symptomatic pulmonary infections. All isolates were acid-fast-positive and the mycolic acid profiles were unique and supported placement into the genus Mycobacterium. Phenotypic characteristics of each strain included optimal growth after 3 weeks at a temperature range of 30–35 °C, yellow pigmentation after incubation in the dark and production of a heat-stable catalase. The 16S rRNA gene and internal transcribed spacer 1 sequences were identical for all five strains, but distinct from all known mycobacterial species. Phylogenetic analysis based on the 16S rRNA gene sequence placed the novel species within the slowly growing mycobacteria group in close proximity to Mycobacterium malmoense, Mycobacterium avium, Mycobacterium kansasii and Mycobacterium scrofulaceum. These data support the conclusion that the related five described organisms represent a novel Mycobacterium species, for which the name Mycobacterium nebraskense sp. nov. is proposed, with the type strain UNMC-MY1349T (=ATCC BAA-837T=DSM 44803T).
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Roth, Andreas, Udo Reischl, Anna Streubel, et al. "Novel Diagnostic Algorithm for Identification of Mycobacteria Using Genus-Specific Amplification of the 16S-23S rRNA Gene Spacer and Restriction Endonucleases." Journal of Clinical Microbiology 38, no. 3 (2000): 1094–104. http://dx.doi.org/10.1128/jcm.38.3.1094-1104.2000.
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A novel genus-specific PCR for mycobacteria with simple identification to the species level by restriction fragment length polymorphism (RFLP) was established using the 16S-23S ribosomal RNA gene (rDNA) spacer as a target. Panspecificity of primers was demonstrated on the genus level by testing 811 bacterial strains (122 species in 37 genera from 286 reference strains and 525 clinical isolates). All mycobacterial isolates (678 strains among 48 defined species and 5 indeterminate taxons) were amplified by the new primers. Among nonmycobacterial isolates, only Gordonia terrae was amplified. The RFLP scheme devised involves estimation of variable PCR product sizes together with HaeIII and CfoI restriction analysis. It yielded 58 HaeIII patterns, of which 49 (84%) were unique on the species level. Hence,HaeIII digestion together with CfoI results was sufficient for correct identification of 39 of 54 mycobacterial taxons and one of three or four of seven RFLP genotypes found inMycobacterium intracellulare and Mycobacterium kansasii, respectively. Following a clearly laid out diagnostic algorithm, the remaining unidentified organisms fell into five clusters of closely related species (i.e., the Mycobacterium aviumcomplex or Mycobacterium chelonae-Mycobacterium abscessus) that were successfully separated using additional enzymes (TaqI, MspI, DdeI, orAvaII). Thus, next to slowly growing mycobacteria, all rapidly growing species studied, including M. abscessus,M. chelonae, Mycobacterium farcinogenes,Mycobacterium fortuitum, Mycobacterium peregrinum, and Mycobacterium senegalense (with a very high 16S rDNA sequence similarity) were correctly identified. A high intraspecies sequence stability and the good discriminative power of patterns indicate that this method is very suitable for rapid and cost-effective identification of a wide variety of mycobacterial species without the need for sequencing. Phylogenetically, spacer sequence data stand in good agreement with 16S rDNA sequencing results, as was shown by including strains with unsettled taxonomy. Since this approach recognized significant subspecific genotypes while identification of a broad spectrum of mycobacteria rested on identification of one specific RFLP pattern within a species, this method can be used by both reference (or research) and routine laboratories.
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Chilima, Benson Z., Ian M. Clark, Sian Floyd, Paul E. M. Fine, and Penny R. Hirsch. "Distribution of Environmental Mycobacteria in Karonga District, Northern Malawi." Applied and Environmental Microbiology 72, no. 4 (2006): 2343–50. http://dx.doi.org/10.1128/aem.72.4.2343-2350.2006.
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ABSTRACT The genus Mycobacterium includes many species that are commonly found in the environment (in soil and water or associated with plants and animals), as well as species that are responsible for two major human diseases, tuberculosis (Mycobacterium tuberculosis) and leprosy (Mycobacterium leprae). The distribution of environmental mycobacteria was investigated in the context of a long-term study of leprosy, tuberculosis, Mycobacterium bovis BCG vaccination, and the responses of individuals to various mycobacterial antigens in Karonga District, northern Malawi, where epidemiological studies had indicated previously that people may be exposed to different mycobacterial species in the northern and southern parts of the district. A total of 148 soil samples and 24 water samples were collected from various locations and examined to determine the presence of mycobacteria. The detection method involved semiselective culturing and acid-fast staining, following decontamination of samples to enrich mycobacteria and reduce the numbers of other microorganisms, or PCR with primers specific for the mycobacterial 16S rRNA gene, using DNA extracted directly from soil and water samples. Mycobacteria were detected in the majority of the samples, and subsequent sequence analysis of PCR products amplified directly from soil DNA indicated that most of the products were related to known environmental mycobacteria. For both methods the rates of recovery were consistently higher for dry season samples than for wet season samples. All isolates cultured from soil appeared to be strains of Mycobacterium fortuitum. This study revealed a complex pattern for the environmental mycobacterial flora but identified no clear differences between the northern and southern parts of Karonga District.
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Chin, Kai Ling. "Molecular Characterization of Mycobacterium species Isolates from Patients with Pulmonary Tuberculosis in Sabah, Malaysia." Medicine & Health 17, no. 1 (2022): 198–210. http://dx.doi.org/10.17576/mh.2022.1701.15.
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Tuberculosis (TB) is one of the deadliest diseases worldwide, caused by members of Mycobacterium tuberculosis complex (MTBC), commonly by Mycobacterium tuberculosis (Mtb) and Mycobacterium bovis. In Malaysia, Sabah is one of the states of public health concern with the highest TB cases. Clinical presentations of TB and non-tuberculous mycobacteria (NTM) lung disease are similar, and mycobacteria appear to be identical under standard diagnosis with sputum smear microscopy, causing difficulty to diagnose TB. Identification of Mycobacterium species is essential for effective management of mycobacterial diseases treatment and their control strategy. Thus, this study aimed to identify the Mycobacterium species from suspected TB patients in Sabah using molecular methods. Sputum samples (n=595) were screened with GeneXpert MTB/RIF (Xpert), and positive TB samples (n=67) were processed and cultured in BACTEC MGIT. Forty-five isolates were successfully recovered in MGIT and characterisation of the mycobacterial isolates using PCR and/or sequencing with rpoB, RD9, hsp65, and 16S rRNA genes confirmed the presence of Mtb in 41 samples, and four non-mycobacteria, i.e. Microbacterium laevaniformans, Streptomyces sp., Streptomyces misionensis and Gordonia sp. These non-mycobacteria isolates showed negative results when tested directly with Xpert. In conclusion, Mtb is the predominant species of MTBC circulating in Sabah. The presence of non-mycobacteria in this study was due to bacterial contamination in MGIT, not bacterial cross-reactivity in Xpert, implying the high sensitivity and specificity of Xpert for diagnosis of TB.
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Julien, Coulibaly Kalpy, Vakou N’dri Sabine, Kouakou Luc Venance, et al. "Phylogenetic Profile of Nonulcerans and Nontuberculous Environmental Mycobacteria Isolated in Côte d’Ivoire." International Journal of Mycobacteriology 13, no. 2 (2024): 158–64. http://dx.doi.org/10.4103/ijmy.ijmy_96_24.
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Background: Environmental mycobacteria are involved in several infections ranging from lung to skin infections. In Côte d’Ivoire, apart from Mycobacterium ulcerans and Mycobacterium tuberculosis, little information exists on other species. The culture of these species, a real challenge, especially in developing countries like Cote d’Ivoire, limits their identification. However, there are reports in literature of infections caused by these mycobacteria, and few species have never been described in human or animal infections. These are difficult cases to treat because of their resistance to most antituberculosis antibiotics. The aim of our work was to study the diversity of potentially pathogenic mycobacterial species in wastewater drainage channels in different townships and in two hospital effluents in the city of Abidjan. Methods: Wastewater samples were cultured, followed by conventional polymerase chain reaction (PCR) targeting mycobacterial 16S ribonucleic acid (16S RNA) using PA/MSHA primers. 16 S RNA identified were sequenced by Sanger techniques. Sequences obtained were analyzed, and a phylogenic tree was built. Results: Fast-growing mycobacteria, including Mycobacterium fortuitum, Mycobacterium phocaicum, Mycobacterium sp., and others presence, were confirmed both by culture and molecular techniques. M. fortuitum strain was the same in effluents of the Treichville University Hospital and in the wastewater of the township of Koumassi. New species never isolated in Côte d’Ivoire, such as M. phocaicum, have been identified in wastewater of the township of Yopougon. Conclusion: This study showed that the sewer network in the city of Abidjan is colonized by both potentially pathogenic mycobacteria and saprophytic environmental mycobacteria.
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Aboagye, Samuel Yaw, Emelia Danso, Kobina Assan Ampah, et al. "Isolation of Nontuberculous Mycobacteria from the Environment of Ghanian Communities Where Buruli Ulcer Is Endemic." Applied and Environmental Microbiology 82, no. 14 (2016): 4320–29. http://dx.doi.org/10.1128/aem.01002-16.
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ABSTRACTThis study aimed to isolate nontuberculous mycobacterial species from environmental samples obtained from some selected communities in Ghana. To optimize decontamination, spiked environmental samples were used to evaluate four decontamination solutions and supplemented media, after which the best decontamination solution and media were used for the actual analysis. The isolates obtained were identified on the basis of specific genetic sequences, including heat shock protein 65, IS2404, IS2606,rpoB, and the ketoreductase gene, as needed. Among the methods evaluated, decontamination with 1 M NaOH followed by 5% oxalic acid gave the highest rate of recovery of mycobacteria (50.0%) and the lowest rate of contamination (15.6%). The cultivation medium that supported the highest rate of recovery of mycobacteria was polymyxin B-amphotericin B-nalidixic acid-trimethoprim-azlocillin–supplemented medium (34.4%), followed by isoniazid-supplemented medium (28.1%). Among the 139 samples cultivated in the main analysis, 58 (41.7%) yielded mycobacterial growth, 70 (50.4%) had no growth, and 11 (7.9%) had all inoculated tubes contaminated. A total of 25 different mycobacterial species were identified. Fifteen species (60%) were slowly growing (e.g.,Mycobacterium ulcerans,Mycobacterium avium,Mycobacterium mantenii, andMycobacterium malmoense), and 10 (40%) were rapidly growing (e.g.,Mycobacterium chelonae,Mycobacterium fortuitum, andMycobacterium abscessus). The occurrence of mycobacterial species in the various environmental samples analyzed was as follows: soil, 16 species (43.2%); vegetation, 14 species (38.0%); water, 3 species (8.0%); moss, 2 species (5.4%); snail, 1 species (2.7%); fungi, 1 species (2.7%). This study is the first to report on the isolation ofM. ulceransand other medically relevant nontuberculous mycobacteria from different environmental sources in Ghana.IMPORTANCEDiseases caused by mycobacterial species other than those that cause tuberculosis and leprosy are increasing. Control is difficult because the current understanding of how the organisms are spread and where they live in the environment is limited, although this information is needed to design preventive measures. Growing these organisms from the environment is also difficult, because the culture medium becomes overgrown with other bacteria that also live in the environment, such as in soil and water. We aimed to improve the methods for growing these organisms from environmental sources, such as soil and water samples, for better understanding of important mycobacterial ecology.
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De Groote, Mary Ann, Norman R. Pace, Kayte Fulton, and Joseph O. Falkinham. "Relationships between Mycobacterium Isolates from Patients with Pulmonary Mycobacterial Infection and Potting Soils." Applied and Environmental Microbiology 72, no. 12 (2006): 7602–6. http://dx.doi.org/10.1128/aem.00930-06.
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ABSTRACT High numbers of mycobacteria, including known pathogenic species such as Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium chelonae, were recovered from aerosols produced by pouring commercial potting soil products and potting soil samples provided by patients with pulmonary mycobacterial infections. The dominant mycobacteria in the soil samples corresponded to the dominant species implicated clinically. Profiles of large restriction fragments obtained by pulsed-field gel electrophoresis demonstrated a closely related pair of M. avium isolates recovered from a patient and from that patient's own potting soil. Thus, potting soils are potential sources of infection by environmental mycobacteria. Use of dust-excluding masks should be considered during potting or other activities that generate aerosol with soil.
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Issa, Rahizan, Hatijah Abdul, Siti Hasmah Hashim, Valentinus H. Seradja, Nurul ‘Aishah Shaili, and Nurul Akma Mohd Hassan. "High resolution melting analysis for the differentiation of Mycobacterium species." Journal of Medical Microbiology 63, no. 10 (2014): 1284–87. http://dx.doi.org/10.1099/jmm.0.072611-0.
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A quantitative real-time PCR (qPCR) followed by high resolution melting (HRM) analysis was developed for the differentiation of Mycobacterium species. Rapid differentiation of Mycobacterium species is necessary for the effective diagnosis and management of tuberculosis. In this study, the 16S rRNA gene was tested as the target since this has been identified as a suitable target for the identification of mycobacteria species. During the temperature gradient and primer optimization process, the melting peak (Tm) analysis was determined at a concentration of 50 ng DNA template and 0.3, 0.4 and 0.5 µM primer. The qPCR assay for the detection of other mycobacterial species was done at the Tm and primer concentration of 62 °C and 0.4 µM, respectively. The HRM analysis generated cluster patterns that were specific and sensitive to distinguished small sequence differences of the Mycobacterium species. This study suggests that the 16S rRNA-based real-time PCR followed by HRM analysis produced unique cluster patterns for species of Mycobacterium and could differentiate the closely related mycobacteria species.
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Gaber, Asaad, and Hazem Hamed. "Detection and identification of Mycobacterium species." EJMM-Volume 30-Issue 1 30, no. 1 (2021): 79–86. http://dx.doi.org/10.51429/ejmm30110.
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Background: Successful diagnosis and effective treatment for mycobacterial infections are mainly depending on a rapid and sensitive identification method. Objective: To detect and identify the Mycobacterium species. Methodology: PCR and LCD-microarry techniques were compared with the classical methods of Ziehl-Neelsen staining (ZN) and culturing. Two primers based on two conservative regions within the mycobacterium 16S rRNA gene were designed and amplified a DNA fragment of about 1350 bp for both complex of Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacteria (NTM). Results: Regarding to the standard method of culture, 57 positive individuals were identified out of 100 urine samples. The PCR showed 96.30 % sensitivity and 96.70% specificity, while ZN gave Se = 67.50 % and Sp = 100 %. The LCD-microarray analysis exhibited 100 % sensitivity and specificity. One species of MTB was determined as M. tuberculosis and positively represented by 12.3% (n=7). Five species of NTM were determined and represented as M. kansasii 36.8 % (n=21), M. celatum 21 % (n=12), M. gordonae 12.2% (n=7), M. chelonae 10.5 % (n=6), and M. phlei 7% (n=4). Conclusion: The results recommended utilizing the simple and rapid PCR method for early mycobacteria detection. Also, the fast LCD-microarray protocol is very beneficial for identification and differentiation between MTB and of NTM species.
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Malik, Richard, Carolyn O'Brien, and Janet Fyfe. "Infections of cats attributable to slow growing or ‘non-culturable’ mycobacteria." Microbiology Australia 30, no. 2 (2009): 92. http://dx.doi.org/10.1071/ma09092.
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Cats are susceptible to a range of different mycobacterial infections. Tuberculosis has not been seen in domestic species living in Australia (including the cat) for decades. Mycobacterial infections most commonly develop in cats subsequent to penetrating injuries (typically inflicted by other cats) that become contaminated with soil or dirt. Most of these infections are caused by rapidly growing mycobacteria, especially Mycobacterium smegmatis and related species, although occasionally other species such as Mycobacterium avium and Mycobacterium ulcerans are involved. In this report we briefly review infections caused by some novel mycobacterial species, which are either impossible or very difficult to grow in vitro using the usual range of liquid and solid media available in reference laboratories. Our understanding of these infections, sometimes referred to as ?feline leprosy-like syndromes?, has increased greatly since the application of molecular techniques and the systematic investigation of affected cats.
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Sharma, Megha, Bharti Malhotra, Jitendra Tiwari, and Shipra Bhargava. "Profile of Nontuberculous Mycobacteria in Patients Suspected of Tuberculosis and Drug-Resistant Tuberculosis." Journal of Laboratory Physicians 12, no. 03 (2020): 203–11. http://dx.doi.org/10.1055/s-0040-1721160.
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Abstract Objective Infections due to nontuberculous mycobacteria (NTM) is increasing globally and may present as drug-resistant tuberculosis (DRTB). In India, data on NTM prevalence and species diversity is limited. Present study was conducted to detect the prevalence and profile of NTM among patients suspected of DRTB using paraffin slide culture (PSC)and mycobacteria growth indicator tube (MGIT) culture methods for isolation of NTM. Material and Method A total of 2,938 samples suspected of TB/DRTB were cultured on PSC and MGIT960. Species identification of mycobacterial isolate was done by sequencing of 16s ribosomal RNA gene. Result Among 2938 samples, 35 (1.19%) were found positive for NTM by PSC and 9 (0.30%) were found positive by MGIT. The diversity of NTM species was high (13 species). Out of 35 NTM isolates by PSC, maximum 34.29% (12) isolates were found to be Mycobacterium fortuitum, followed by 11.43% (4) Mycobacterium abscessus and Mycobacterium chelonae, and 42.85% (15) were other species viz. 8.57% (3) were Mycobacterium intracellulare and Mycobacterium kansasii, 5.71% (2) were Mycobacterium peregrinum, and 2.85% (1) were Mycobacterium flavescens, Mycobacterium farcinogenes, Mycobacterium moriokanese, Mycobacterium wolinskyi, Mycobacterium simiae, Mycobacterium goodii, and Mycobacterium terrae each. Coinfection of Mycobacterium tuberculosis(MTB) and NTM was found in 60% (21) samples. Conclusion Prevalence of NTM was low among multidrug resistant tuberculosis/TB suspected patients, similar to other studies done in India. PSC was found better than MGIT for the isolation of NTM, though poor separation of NTM and MTB on subculture may have led to false negativity in cases of coinfection. About 13 species were isolated; M. fortuitum was the most common of all. Since coinfection of NTM and TB can also occur, samples of patients suspected of NTM should be cultured on PSC even if positive for MTB.
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Mah, Nancy, Carolina Perez-Iratxeta, and Miguel A. Andrade-Navarro. "Outer membrane pore protein prediction in mycobacteria using genomic comparison." Microbiology 156, no. 8 (2010): 2506–15. http://dx.doi.org/10.1099/mic.0.040089-0.
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Proteins responsible for outer membrane transport across the unique membrane structure of Mycobacterium spp. are attractive drug targets in the treatment of human diseases caused by the mycobacterial pathogens, Mycobacterium tuberculosis, M. bovis, M. leprae and M. ulcerans. In contrast with Escherichia coli, relatively few outer-membrane proteins (OMPs) have been identified in Mycobacterium spp., largely due to the difficulties in isolating mycobacterial membrane proteins and our incomplete understanding of secretion mechanisms and cell wall structure in these organisms. To further expand our knowledge of these elusive proteins in mycobacteria, we have improved upon our previous method of OMP prediction in mycobacteria by taking advantage of genomic data from seven mycobacteria species. Our improved algorithm suggests 4333 sequences as putative OMPs in seven species with varying degrees of confidence. The most virulent pathogenic mycobacterial species are slightly enriched in these selected sequences. We present examples of predicted OMPs involved in horizontal transfer and paralogy expansion. Analysis of local secondary structure content allowed identification of small domains predicted to perform as OMPs; some examples show their involvement in events of tandem duplication and domain rearrangements. We discuss the taxonomic distribution of these discovered families and architectures, often specific to mycobacteria or the wider taxonomic class of Actinobacteria. Our results suggest that OMP functionality in mycobacteria is richer than expected and provide a resource to guide future research of these understudied proteins.
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Slany, Michal, Petr Jezek, Vera Fiserova, et al. "Mycobacterium marinum infections in humans and tracing of its possible environmental sources." Canadian Journal of Microbiology 58, no. 1 (2012): 39–44. http://dx.doi.org/10.1139/w11-104.
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The low frequency of nontuberculous mycobacterial infections, nonspecific symptoms for individual mycobacteria, and the lack of specific identification methods could alter correct diagnosis. This study presents a combined microbiology and molecular-based approach for Mycobacterium marinum detection in four aquarists with cutaneous mycobacterial infection. Simultaneously, ecology screening for M. marinum presence in the aquarists’ fish tanks was performed. A total of 38 mycobacterial isolates originated from four human patients (n = 20), aquarium animals (n = 8), and an aquarium environment (n = 10). Isolate identification was carried out using 16S rRNA sequence analysis. A microbiology-based approach, followed by 16S rRNA sequence analysis, was successfully used for detection of M. marinum in all four patients. Animal and environmental samples were simultaneously examined, and a total of seven mycobacterial species were isolated: Mycobacterium chelonae , Mycobacterium fortuitum , Mycobacterium gordonae , Mycobacterium kansasii , Mycobacterium mantenii , Mycobacterium marinum , and Mycobacterium peregrinum . The presence of M. marinum was proven in the aquarium environments of two patients. Although M. marinum is described as being present in water, it was detected only in fish.
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To, Kimberly, Ruoqiong Cao, Aram Yegiazaryan, James Owens, and Vishwanath Venketaraman. "General Overview of Nontuberculous Mycobacteria Opportunistic Pathogens: Mycobacterium avium and Mycobacterium abscessus." Journal of Clinical Medicine 9, no. 8 (2020): 2541. http://dx.doi.org/10.3390/jcm9082541.
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Nontuberculous mycobacteria (NTM) are emerging human pathogens, causing a wide range of clinical diseases affecting individuals who are immunocompromised and who have underlying health conditions. NTM are ubiquitous in the environment, with certain species causing opportunistic infection in humans, including Mycobacterium avium and Mycobacterium abscessus. The incidence and prevalence of NTM infections are rising globally, especially in developed countries with declining incidence rates of M. tuberculosis infection. Mycobacterium avium, a slow-growing mycobacterium, is associated with Mycobacterium avium complex (MAC) infections that can cause chronic pulmonary disease, disseminated disease, as well as lymphadenitis. M. abscessus infections are considered one of the most antibiotic-resistant mycobacteria and are associated with pulmonary disease, especially cystic fibrosis, as well as contaminated traumatic skin wounds, postsurgical soft tissue infections, and healthcare-associated infections (HAI). Clinical manifestations of diseases depend on the interaction of the host’s immune response and the specific mycobacterial species. This review will give a general overview of the general characteristics, vulnerable populations most at risk, pathogenesis, treatment, and prevention for infections caused by Mycobacterium avium, in the context of MAC, and M. abscessus.
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Manguba, Alexander S., Jaime Alfonso M. Aherrera, Antonio L. Faltado, Melissa A. Llanto, and Raul D. Jara. "Cardiac Tamponade Complicating Disseminated Non-tuberculous Mycobacterial Infection Involving the Pericardium: A Case Report." Philippine Journal of Cardiology 41, no. 1 (2013): 7–10. http://dx.doi.org/10.69944/pjc.598ed10d2d.
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BACKGROUND: The most common mycobacterial species causing infection in the Philippines is Mycobacterium tuberculosis. Non-tuberculous mycobacteria (NTM) have not been reported in Philippine literature to disseminate to the pericardium. CASE: We present a case of disseminated mycobacterial (tuberculous and non-tuberculous co-infection) involving the pericardium, pleura, spleen and abdominal wall. This is the case of a 37-year old female who presented with dyspnea and multiple nodules within the abdominal wall. Computed tomography scan showed a thickened pericardium with minimal pericardial effusion, pleural effusion, and multiple abscesses within the spleen, and abdominal wall muscles. Pleural fluid and abdominal wall abscesses were positive for acid-fast bacilli. Mycobacterial cultures also later yielded growth of rapidly growing mycobacteria (Mycobacterium spp. growth within 24 hours). Pericardiostomy was performed to relieve tamponade. The patient was treated with quadruple anti-mycobacterials and a coarse of cefoxitin, amikacin, and clarithromycin. After six months of therapy, there was no recurrence of pericardial effusion. This case highlights the importance of a high index of suspicion in considering nontuberculous mycobacterial species in patients who do not show improvement with the standard quadruple anti mycobacterial regimen for M. tuberculosis. KEYWORDS: Cardiac tamponade, mycobacterium, pericardial effusion.
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Mignard, Sophie, and Jean-Pierre Flandrois. "Identification of Mycobacterium using the EF-Tu encoding (tuf) gene and the tmRNA encoding (ssrA) gene." Journal of Medical Microbiology 56, no. 8 (2007): 1033–41. http://dx.doi.org/10.1099/jmm.0.47105-0.
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The partial nucleotide sequences encoding the elongation factor Tu (tuf gene) (652 bp) and transfer-mRNA (tmRNA or ssrA gene) (340 bp) were determined to assess the suitability of these two genes as phylogenetic markers for the classification of mycobacteria, and thus as alternative target molecules for identifying mycobacteria. A total of 125 reference strains of the genus Mycobacterium and 74 clinical isolates were amplified by PCR and sequenced. Phylogenies of the two genes constructed by the neighbour-joining method were created and compared to a concatenated tree of 16S rDNA, hsp65, sodA and rpoB genes. The phylogenetic trees revealed the overall natural relationships among Mycobacterium species. The tmRNA phylogeny was similar to that of 16S rDNA, with low resolving power. The tuf gene provided better resolution of each mycobacterial species, with a phylogeny close to that of hsp65. However, none of these methods differentiated between the members of the Mycobacterium tuberculosis complex or the subspecies of the Mycobacterium avium complex. The correct identification of clinical isolates confirms the interest of these genes, especially tuf. It is suggested from these findings that tmRNA might be useful as another housekeeping gene in a polyphyletic approach to Mycobacterium species, but not as a first-line marker of species. tuf gene analysis suggests that this gene could be used effectively for phylogenetic analysis and to identify mycobacteria.
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Cayer, Marie-Pierre, Marc Veillette, Pascal Pageau, et al. "Identification of mycobacteria in peat moss processing plants: application of molecular biology approaches." Canadian Journal of Microbiology 53, no. 1 (2007): 92–99. http://dx.doi.org/10.1139/w06-105.
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Peat moss processing plant workers are exposed to high concentrations of bioaerosols. Although mycobacteria have been cultured from peat moss, no study has examined the workers' exposure to mycobacterial bioaerosols. We evaluated the presence of mycobacteria in air samples from peat moss processing plants using molecular biology approaches (cloning-sequencing and polymerase chain reaction (PCR)) and the workers exposure using immunoglobulin G (IgG) complexes to mycobacteria. In addition, species detected in air samples and in peat moss were compared. Two peat moss processing plants were chosen among 14 previously studied. A total of 49 clones were sequenced. Real-time PCR was also performed on the same air samples to evaluate the airborne concentration of mycobacteria and estimate exposure levels. Several Mycobacterium species were present in the air samples (M. malmoense, M. smegmatis, M. graceum, M. bohemicum, and M. interjectum). Mycobacterium avium was recovered by culture in peat moss but not in the air using the molecular approach. Total airborne Mycobacterium concentration was estimated at 8.2 × 108/m3. Workers had IgG against the mycobacterial mix and M. avium, suggesting significant exposure. The findings from air samples, supported by IgG measurements, demonstrate that peat moss processing plant workers are exposed to mycobacteria in addition to other biological agents.Key words: exposure, peat moss, airborne mycobacteria.
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Soini, Hanna, and James M. Musser. "Molecular Diagnosis of Mycobacteria." Clinical Chemistry 47, no. 5 (2001): 809–14. http://dx.doi.org/10.1093/clinchem/47.5.809.
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Abstract Tuberculosis is one of the leading infectious diseases in the world and is responsible for more than 2 million deaths and 8 million new cases annually. Because of the slow growth rate of the causative agent Mycobacterium tuberculosis, isolation, identification, and drug susceptibility testing of this organism and other clinically important mycobacteria can take several weeks or longer. During the past several years, many molecular methods have been developed for direct detection, species identification, and drug susceptibility testing of mycobacteria. These methods can potentially reduce the diagnostic time from weeks to days. Currently, two nucleic acid amplification methods, the Enhanced Mycobacterium tuberculosis Direct Test (Gen-Probe) and the Amplicor Mycobacterium tuberculosis Test (Roche Diagnostic Systems), have been approved by the Food and Drug Administration for direct detection of M. tuberculosis from clinical specimens. PCR-based sequencing has become commonly used to identify many mycobacterial species. DNA probes have been widely used for species determination of the most commonly encountered mycobacteria. High-density oligonucleotide arrays (DNA microarrays) also have been applied to simultaneous species identification and detection of mutations that confer rifampin resistance in mycobacteria.
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Lutsenko, A. V., A. L. Yasenyavskaya, and M. A. Samotrueva. "Mycobacterial infections: features of microbiological diagnosis." Сибирский научный медицинский журнал 43, no. 6 (2024): 34–44. http://dx.doi.org/10.18699/ssmj20230604.
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To date, more than 200 species of mycobacteria have been identified, in addition to the well-known Mycobacterium leprae and Mycobacterium tuberculosis. Among microorganisms belonging to the genus Mycobacterium, there are obligate pathogenic, opportunistic and saprophytic strains. The incidence of non-tuberculous or atypical mycobacteria, which cause opportunistic infections in humans and animals, is steadily increasing. Non-tuberculous mycobacteria are increasingly recognized as a source of healthcare-associated infections.Aim of the study was to analyze the literature on current methods of microbiological diagnosis of mycobacterial infections.Material and methods. A search and analysis of scientific literature in the Web of Science, PubMed, eLIBRARY.RU, Europe PMC databases was performed using the following key words: mycobacteriosis, non-tuberculous mycobacteria, mycobacterial infections, MALDITOF MS, atypical mycobacteria. Results and discussion. The review summarizes and presents the classification, morphological, cultural, genetic and ecological features of mycobacterial strains. Modern approaches in the diagnosis of mycobacterial diseases and identification of pathogens are analyzed; their advantages and disadvantages are indicated.Conclusions. Mycobacterial infections are often considered as diseases associated with the provision of medical care, requiring a detailed assessment of the situation with the definition of criteria for microbiological monitoring of objects of a medical organization, etc. The analyzed literature data demonstrate a variety of methods for laboratory diagnosis of mycobacterial infections with the need for further improvement of methodological approaches.
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Kim, Keun Ju, Yunhee Chang, Seung Gyu Yun, Myung-Hyun Nam, and Yunjung Cho. "Evaluation of a Commercial Multiplex Real-Time PCR with Melting Curve Analysis for the Detection of Mycobacterium tuberculosis Complex and Five Nontuberculous Mycobacterial Species." Microorganisms 13, no. 1 (2024): 26. https://doi.org/10.3390/microorganisms13010026.
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Background: Accurate and timely diagnosis of mycobacterial infections, including Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM), is crucial for effective disease management. Methods: This study evaluated the performance of the NeoPlex TB/NTM-5 Detection Kit (NeoPlex assay, Seongnam, Republic of Korea), a multiplex real-time PCR assay that incorporates melting curve analysis, compared with the line-probe assay (LPA). The NeoPlex assay could simultaneously detect and differentiate MTBC from five other NTM species: Mycobacterium intracellulare, Mycobacterium avium, Mycobacterium kansasii, Mycobacterium abscessus, and Mycobacterium massiliense. A total of 91 acid-fast bacillus culture-positive samples, comprising 36 MTBC and 55 NTM isolates, were collected from the Korea University Anam Hospital. Results: The NeoPlex assay successfully detected nucleic acids in 87 of the 91 isolates (95.6%). Notably, it identified additional mycobacterial nucleic acids not detected by the LPA in eight isolates. These findings were confirmed via DNA sequencing. The assay had 100% sensitivity and specificity for M. intracellulare, M. abscessus, M. massilense, NTM, and MTBC, whereas it had 100% specificity and sensitivity of 90.9% and 75.0% for M. avium and M. kansasii, respectively. Conclusions: These results highlight the potential of the NeoPlex assay to enhance rapid and accurate diagnosis of mycobacterial infections, particularly in settings in which prompt treatment initiation is essential.
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TURSUNOVA, NATALYA V., ELENA P. GUSELNIKOVA, and ELIZAVETA I. GORDEEVA. "NON-TUBERCULOSIS MYCOBACTERIA SPECIES CIRCULATING IN THE SIBERIAN FEDERAL DISTRICT OF RUSSIA." Bulletin of Contemporary Clinical Medicine 17, no. 5 (2024): 113–18. https://doi.org/10.20969/vskm.2024.17(5).113-118.
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Introduction. Non-tuberculous mycobacteria are ubiquitous; they are widespread in soil and water, including plumbing, aquariums, hot water supply systems, and air conditioning systems. Currently, more than 200 species of non-tuberculous mycobacteria are known, of which about 60 species have proven clinical significance, the rest are widespread in the environment, and little is known about their ability to cause diseases. Aim. The purpose of this study was to investigate the species diversity of non-tuberculous mycobacteria circulating in the Siberian Federal District of Russia. Materials and Methods. Two typical regions of the Siberian Federal District were selected for the study: Novosibirsk and Tomsk regions. Mycobacteria were cultured from patients’ sputum samples: 45 samples from the State Regional Clinical Tuberculosis Hospital and 106 from the Regional Department of Tomsk Phthisiopulmonology Medical Center. Further, non-tuberculous mycobacteria were identified by species, using the time-of-flight mass-spectrometry and the extraction with formic acid on an instrument according to the study protocol. Statistical processing of the study results was carried out using Microsoft Excel 2016 computer programs for Windows. Extensive indicators (the percentage of patients with detected pathogen drug resistance to the total number of patients, whose material was tested) were also calculated, and the boundaries of 95% confidence intervals (95% CI) were defined for the proportion (Fisher’s method). Statistical calculation of the research results was carried out in Microsoft Excel 2016. Results and Discussion. Among the slow-growing non-tuberculous mycobacteria species, Mycobacterium Avium complex is most common. Mycobacterium simie complex, Mycobacterium lentiflavum, and Mycobacterium parascorfulaceum were found less frequently. There were also Mycobacterium terrae complex and Mycobacterium nonchromogenicum found. The slow-growing mycobacteria, currently not grouped into a complex, include Mycobacterium Mycobacterium szulgae and Mycobacterium gordonae. Mycobacterium abscessus / Mycobacterium chelonae complex dominated among the fast-growing mycobacteria species. Mycobacterium fortuitum complex was a less common complex. Conclusions. For the first time, diversity was assessed and the dominant strains of mycobacteria circulating in the Novosibirsk and Tomsk regions were identified, which gives an idea of the main target strains, at which the main preventive and sanitizing measures should be targeted
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Szacawa, Ewelina, Nina Kozieł, Sylwia Brzezińska, et al. "Laboratory Diagnosis of Animal Tuberculosis in Tracing Interspecies Transmission of Mycobacterium bovis." Pathogens 14, no. 5 (2025): 459. https://doi.org/10.3390/pathogens14050459.
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Mycobacterium is one of the most dangerous pathogens of both animals and humans. Bovine tuberculosis (BTB) is a disease caused by mycobacteria belonging to the Mycobacterium tuberculosis complex (MTBC), which spreads mainly among domestic cattle but also to mammals other than cattle. The transmission of MTBC between different species requires research and epidemiological investigations to control its spread. When multiple species are a reservoir of infection, it poses a significant public health and veterinary concern. In this study, the diagnosis of alpaca, cattle, horses, dogs, a sheep and a cat from one farm suspected of bovine tuberculosis was performed. The animals (except for one horse, the dogs and the cat) were euthanised after the intradermal tuberculin tests. Mycobacterial isolation from animal tissue samples was performed. The obtained Mycobacterium strains were genotyped using spoligotyping and mycobacterial interspersed repetitive unit–variable number tandem repeat (MIRU-VNTR) methods. The isolates from a horse, two cows, a sheep and an alpaca were classified as Mycobacterium (M.) bovis. The single M. bovis spoligotype SB0666 pattern was isolated, and the MIRU-VNTR results presented the same 222632237401435 patterns. The molecular investigation uncovered information on the relationship of Mycobacterium bovis.
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Olsen, Randall J., Patricia L. Cernoch, and Geoffrey A. Land. "Mycobacterial Synovitis Caused by Slow-Growing Nonchromogenic Species: Eighteen Cases and a Review of the Literature." Archives of Pathology & Laboratory Medicine 130, no. 6 (2006): 783–91. http://dx.doi.org/10.5858/2006-130-783-mscbsn.
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Abstract Context.—Slow-growing nonchromogenic mycobacterial species are an infrequent cause of soft tissue infection. Because these organisms are rare, they are not often initially considered in the differential diagnosis of synovitis. Objective.—To evaluate the clinical and pathologic characteristics of patients with synovitis resulting from slow-growing nonchromogenic mycobacterial species. Design.—A 20-year retrospective review of records from The Methodist Hospital Microbiology Laboratory identified 18 culture-positive cases of synovitis that resulted from slow-growing nonchromogenic mycobacteria, including 14 caused by Mycobacterium avium complex, 1 caused by Mycobacterium malmoense, 1 caused by Mycobacterium haemophilum, and 2 caused by Mycobacterium nonchromogenicum isolates. In addition, a comprehensive literature search revealed an additional 48 cases of synovitis caused by slow-growing nonchromogenic mycobacteria. Results.—The historic literature described the majority of the 48 patients as previously healthy, elderly individuals with a several-month history of monoarticular pain and swelling in the small joints of the upper extremity. In contrast, the current series demonstrated the probable role of multiple chronic coexisting medical conditions in promoting disease susceptibility. These patients were also unique in their significantly younger age distribution and diversity of infection sites. Histologic examination and direct acid-fast bacteria stains generally did not aid the diagnosis. Amputation was performed in 2 patients because of delayed identification of disease. Conclusions.—The current series demonstrates that difficult identification and infrequent occurrence cause these organisms to be overlooked by physicians and laboratory personnel. A heightened clinical suspicion for slow-growing nonchromogenic mycobacterial species is necessary when routine culture and histopathologic findings do not readily isolate an organism, or when the patient does not respond to antibiotic and anti-inflammatory treatment.
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Muñoz-Muñoz, Lara, Carolyn Shoen, Gaye Sweet, et al. "Repurposing Avermectins and Milbemycins against Mycobacteroides abscessus and Other Nontuberculous Mycobacteria." Antibiotics 10, no. 4 (2021): 381. http://dx.doi.org/10.3390/antibiotics10040381.
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Infections caused by nontuberculous mycobacteria (NTM) are increasing worldwide, resulting in a new global health concern. NTM treatment is complex and requires combinations of several drugs for lengthy periods. In spite of this, NTM disease is often associated with poor treatment outcomes. The anti-parasitic family of macrocyclic lactones (ML) (divided in two subfamilies: avermectins and milbemycins) was previously described as having activity against mycobacteria, including Mycobacterium tuberculosis, Mycobacterium ulcerans, and Mycobacterium marinum, among others. Here, we aimed to characterize the in vitro anti-mycobacterial activity of ML against a wide range of NTM species, including Mycobacteroides abscessus. For this, Minimum Inhibitory Concentration (MIC) values of eight ML were determined against 80 strains belonging to nine different NTM species. Macrocyclic lactones showed variable ranges of anti-mycobacterial activity that were compound and species-dependent. Milbemycin oxime was the most active compound, displaying broad-spectrum activity with MIC lower than 8 mg/L. Time kill assays confirmed MIC data and showed bactericidal and sterilizing activity of some compounds. Macrocyclic lactones are available in many formulations and have been extensively used in veterinary and human medicine with suitable pharmacokinetics and safety properties. This information could be exploited to explore repurposing of anti-helminthics for NTM therapy.
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Fusco da Costa, Ana R., Tarcisio Fedrizzi, Maria L. Lopes, et al. "Characterization of 17 strains belonging to the Mycobacterium simiae complex and description of Mycobacterium paraense sp. nov." International Journal of Systematic and Evolutionary Microbiology 65, Pt_2 (2015): 656–62. http://dx.doi.org/10.1099/ijs.0.068395-0.
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Fourteen mycobacterial strains isolated from pulmonary samples of independent patients in the state of Pará (Brazil), and three strains isolated in Italy, were characterized using a polyphasic approach. Thorough genetic investigation, including whole-genome sequencing, demonstrated that the strains belong to the M. simiae complex, being most closely related to Mycobacterium interjectum . For 14 of the strains, evidence emerged supporting their inclusion in a previously unreported species of the genus Mycobacterium , for which the name Mycobacterium paraense sp. nov. is proposed (type strain, IEC26T = DSM 46749T = CCUG 66121T). The novel species is characterized by slow growth, unpigmented or pale yellow scotochromogenic colonies, and a HPLC mycolic acid profile different from other known mycobacteria. In different genetic regions, high sequence microheterogeneity was detected.
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Udhayabanu, Lakshmipriya, Kopula Sathyamoorthy Sridharan, and Tessa Antony. "Pitfalls in Using Matrix-assisted Laser Desorption Ionization-time of Flight Mass Spectrometry for the Identification of Mycobacterium." Biomedical and Biotechnology Research Journal 9, no. 1 (2025): 113–17. https://doi.org/10.4103/bbrj.bbrj_39_25.
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Background: Mycobacterial culture in solid or liquid medium remains one of the the gold standard methods for diagnosing mycobacterial infections. Identification of the correct species of mycobacteria is imperative for providing the appropriate treatment, as both tuberculous and nontuberculous mycobacteria can cause clinical infection. The current study was done to identify Mycobacterium species by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from both solid and liquid media. Methods: In this cross-sectional pilot study, 50 isolates were included: 25 from liquid culture-mycobacterium growth indicator tubes (MGIT) and 25 from solid culture-Lowenstein Jensen (LJ) media, that were positive for the presence of acid-fast bacilli. The protein extraction was performed using VITEK MS Mycobacterium/Nocardia Kit (bioMerieux, France) extraction protocol and was further identified using VITEK MALDI-TOF MS (biomerieux, France) machine version 3.2. The results obtained were compared with GeneXpert results from the direct clinical specimen. Results: Among 25 MGIT isolates, only one was identified as Mycolicibacterium fortuitum (4%). Among the 25 LJ isolates, nine (36%) were identified to belong to the Genus Mycobacterium. Eight isolates were identified as Mycobacterium tuberculosis complex and one was identified as Mycobacterium kansasii. Conclusion: The study showed that even though MALDI-TOF MS has the advantage of being cost-effective, technically easier to perform and the ability to provide rapid results, the number of isolates giving identification from primary culture of clinical samples was found to be low (10/50, 2.5%). The purity of the culture has to be ensured, even while using the rigorous protein extraction process.
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Brown-Elliott, Barbara A., Christopher J. Crist, Linda B. Mann, Rebecca W. Wilson, and Richard J. Wallace. "In Vitro Activity of Linezolid against Slowly Growing Nontuberculous Mycobacteria." Antimicrobial Agents and Chemotherapy 47, no. 5 (2003): 1736–38. http://dx.doi.org/10.1128/aac.47.5.1736-1738.2003.
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ABSTRACT MICs of linezolid in broth microdilutions were tested against 341 slowly growing nontuberculous mycobacteria (NTM) belonging to 15 species. The proposed linezolid susceptibility MICs for all Mycobacterium marinum, Mycobacterium szulgai, Mycobacterium kansasii, Mycobacterium malmoense, and Mycobacterium xenopi isolates and for 90% of Mycobacterium gordonae and Mycobacterium triplex isolates were ≤8 μg/ml. Linezolid has excellent therapeutic potential against most species of NTM.
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Wood, Hillary N., Ashelyn E. Sidders, Lauren E. Brumsey, Evgeny S. Morozkin, Yulia V. Gerasimova, and Kyle H. Rohde. "Species Typing of Nontuberculous Mycobacteria by Use of Deoxyribozyme Sensors." Clinical Chemistry 65, no. 2 (2019): 333–41. http://dx.doi.org/10.1373/clinchem.2018.295212.
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Abstract BACKGROUND Nontuberculous mycobacteria (NTM) species are a rising threat, especially to patients living with pulmonary comorbidities. Current point-of-care diagnostics fail to adequately identify and differentiate NTM species from Mycobacterium tuberculosis (Mtb). Definitive culture- and molecular-based testing can take weeks to months and requires sending samples out to specialized diagnostic laboratories. METHODS In this proof-of-concept study, we developed an assay based on PCR amplification of 16S ribosomal RNA (rRNA) rrs genes by using universal mycobacterial primers and interrogation of the amplified fragments with a panel of binary deoxyribozyme (BiDz) sensors to enable species-level identification of NTM (BiDz-NTMST). Each BiDz sensor consists of 2 subunits of an RNA-cleaving deoxyribozyme, which form an active deoxyribozyme catalytic core only in the presence of the complimentary target sequence. The target-activated BiDz catalyzes cleavage of a reporter substrate, thus triggering either fluorescent or colorimetric (visually observed) signal depending on the substrate used. The panel included BiDz sensors for differentiation of 6 clinically relevant NTM species (Mycobacterium abscessus, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium fortuitum, Mycobacterium kansasii, and Mycobacterium gordonae) and Mtb. RESULTS Using the fluorescent BiDz-NTMST assay, we successfully identified the species of 38 clinical isolates. In addition, a subset of strains was tested with visual BiDz sensors, providing proof-of-concept for species typing of NTM by the naked eye. CONCLUSIONS The BiDz-NTMST assay is a novel platform for rapid identification of NTM species. This method is highly specific and significantly faster than current tools and is easily adaptable for onsite diagnostic laboratories in hospitals or clinical laboratories.
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Wang, Chun Fang, Hua Rui Qi, Xiu Yun Jiang, Hong Xia Ma, Ai Dong Qian, and Chun Feng Wang. "Isolated Strains of Nontuberculous Mycobacterium Interfere with Immune Responses Associated with Mycobacterium Bovis BCG Vaccination." Advanced Materials Research 884-885 (January 2014): 450–54. http://dx.doi.org/10.4028/www.scientific.net/amr.884-885.450.
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Prior exposure of a vaccine to certain species of environmental mycobacteria can prime the immune system against common mycobacterial antigens, which can in turn reduce the subsequent efficacy of live attenuated mycobacterial vaccines (such as Mycobacterium bovis BCG), in both human and livestock vaccination programs. In this study, five strains of nontubeculous mycobacterium, all isolated from lymphonodi mandibulares and lymphonodi mesenterici samples of swine and cattle, were investigated to determine their growth characteristics and effects on the immune system in murine models. Markedly, different effects on the immune system were observed. The different results may be linked to the inherent growth characteristics of the five strains, The implications of these findings for BCG vaccination protocols are discussed.
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Singh, Amresh Kumar, Anand Kumar Maurya, Jyoti Umrao, et al. "Role of GenoType® Mycobacterium Common Mycobacteria/Additional Species Assay for Rapid Differentiation between Mycobacterium tuberculosis Complex and Different Species of Non-tuberculous Mycobacteria." Journal of Laboratory Physicians 5, no. 02 (2013): 083–89. http://dx.doi.org/10.4103/0974-2727.119847.
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ABSTRACT Background: Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM) may or may not have same clinical presentations, but the treatment regimens are always different. Laboratory differentiation between MTBC and NTM by routine methods are time consuming and cumbersome to perform. We have evaluated the role of GenoType® Mycobacterium common mycobacteria/additional species (CM/AS) assay for differentiation between MTBC and different species of NTM in clinical isolates from tuberculosis (TB) cases. Materials and Methods: A total of 1080 clinical specimens were collected from January 2010 to June 2012. Diagnosis was performed by Ziehl-Neelsen staining followed by culture in BacT/ALERT 3D system (bioMerieux, France). A total of 219 culture positive clinical isolates (BacT/ALERT® MP cultures) were selected for differentiation by p-nitrobenzoic acid (PNB) sensitivity test as and BIO-LINE SD Ag MPT64 TB test considering as the gold standard test. Final identification and differentiation between MTBC and different species of NTM were further confirmed by GenoType® Mycobacterium CM/AS assay (Hain Lifescience, Nehren, Germany). Results: Out of 219 BacT/ALERT® MP culture positive isolates tested by PNB as 153 MTBC (69.9%) and by GenoType® Mycobacterium CM/AS assay as 159 (72.6%) MTBC and remaining 60 (27.4%) were considered as NTM species. The GenoType® Mycobacterium CM/AS assay was proved 99.3% sensitive and 98.3% specific for rapid differentiation of MTBC and NTM. The most common NTM species were; Mycobacterium fortuitum 20 (33.3%) among rapid growing mycobacteria and Mycobacterium intracellulare 11 (18.3%) among slow growing mycobacteria. Conclusion: The GenoType® Mycobacterium assay makes rapid and accurate identification of NTM species as compared with different phenotypic and molecular diagnostic tool and helps in management of infections caused by different mycobacteria.
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Pagán-Ramos, E., J. Song, M. McFalone, M. H. Mudd, and V. Deretic. "Oxidative Stress Response and Characterization of theoxyR-ahpC and furA-katG Loci inMycobacterium marinum." Journal of Bacteriology 180, no. 18 (1998): 4856–64. http://dx.doi.org/10.1128/jb.180.18.4856-4864.1998.
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ABSTRACT Oxidative stress response in pathogenic mycobacteria is believed to be of significance for host-pathogen interactions at various stages of infection. It also plays a role in determining the intrinsic susceptibility to isoniazid in mycobacterial species. In this work, we characterized the oxyR-ahpC and furA-katG loci in the nontuberculous pathogen Mycobacterium marinum. In contrast to Mycobacterium smegmatis and likeMycobacterium tuberculosis and Mycobacterium leprae, M. marinum was shown to possess a closely linked and divergently oriented equivalents of the regulator of peroxide stress response oxyR and its subordinate geneahpC, encoding a homolog of alkyl hydroperoxide reductase. Purified mycobacterial OxyR was found to bind to theoxyR-ahpC promoter region from M. marinum and additional mycobacterial species. Mobility shift DNA binding analyses using OxyR binding sites from several mycobacteria and a panel of in vitro-generated mutants validated the proposed consensus mycobacterial recognition sequence. M. marinum AhpC levels detected by immunoblotting, were increased upon treatment with H2O2, in keeping with the presence of a functional OxyR and its binding site within the promoter region ofahpC. In contrast, OxyR did not bind to the sequences upstream of the katG structural gene, and katGexpression did not follow the pattern seen with ahpC. Instead, a new open reading frame encoding a homolog of the ferric uptake regulator Fur was identified immediately upstream ofkatG in M. marinum. The furA-katGlinkage and arrangement are ubiquitous in mycobacteria, suggesting the presence of additional regulators of oxidative stress response and potentially explaining the observed differences in ahpC andkatG expression. Collectively, these findings broaden our understanding of oxidative stress response in mycobacteria. They also suggest that M. marinum will be useful as a model system for studying the role of oxidative stress response in mycobacterial physiology, intracellular survival, and other host-pathogen interactions associated with mycobacterial diseases.
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Galassi, L., R. Donato, E. Tortoli, D. Burrini, D. Santianni, and R. Dei. "Nontuberculous mycobacteria in hospital water systems: application of HPLC for identification of environmental mycobacteria." Journal of Water and Health 1, no. 3 (2003): 133–39. http://dx.doi.org/10.2166/wh.2003.0016.
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Nontuberculous mycobacteria (NTM), ubiquitous in water environments, are increasingly recognized as nosocomial pathogens. Our study reports a one-year survey of the water system of two hospitals, A and B, in a small town near Florence, Italy. NTM were found throughout the study period in both settings, but B showed a significantly higher mycobacterial load. Mycobacterium gordonae and Mycobacterium fortuitum were the most frequent species isolated. Identification was carried out by conventional techniques and by high performance liquid chromatography (HPLC) analysis of cell wall mycolic acids. HPLC profiling could be used as a first-choice method for identification of environmental mycobacteria.
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Harth, Günter, Saša Masleša-Galić, and Marcus A. Horwitz. "A two-plasmid system for stable, selective-pressure-independent expression of multiple extracellular proteins in mycobacteria." Microbiology 150, no. 7 (2004): 2143–51. http://dx.doi.org/10.1099/mic.0.27113-0.
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Recombinant mycobacteria expressing Mycobacterium tuberculosis extracellular proteins are leading candidates for new vaccines against tuberculosis and other mycobacterial diseases, and important tools both in antimycobacterial drug development and basic research in mycobacterial pathogenesis. Recombinant mycobacteria that stably overexpress and secrete major extracellular proteins of M. tuberculosis in native form on plasmids pSMT3 and pNBV1 were previously constructed by the authors. To enhance the versatility of this plasmid-based approach for mycobacterial protein expression, the Escherichia coli/mycobacteria shuttle plasmid pGB9 was modified to accommodate mycobacterial genes expressed from their endogenous promoters. Previous studies showed that the modified plasmid, designated pGB9.2, derived from the cryptic Mycobacterium fortuitum plasmid pMF1, was present at a low copy number in both E. coli and mycobacteria, and expression of recombinant M. tuberculosis proteins was found to be at levels paralleling its copy number, that is, approximating their endogenous levels. Plasmid pGB9.2 was compatible with the shuttle vectors pSMT3 and pNBV1 and in combination with them it simultaneously expressed the M. tuberculosis 30 kDa extracellular protein FbpB. Plasmid pGB9.2 was stably maintained in the absence of selective pressure in three mycobacterial species: Mycobacterium bovis BCG, M. tuberculosis and M. smegmatis. Plasmid pGB9.2 was found to be self-transmissible between both fast- and slow-growing mycobacteria, but not from mycobacteria to E. coli or between E. coli strains. The combination of two compatible plasmids in one BCG strain allows expression of recombinant mycobacterial proteins at different levels, a potentially important factor in optimizing vaccine potency.
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Tzanatou, A., D. Papaventsis, G. Vrioni, and J. Papaparaskevas. "Applications of MALDI-TOF mass spectrometry in the diagnosis of mycobacterial infections." ACTA MICROBIOLOGICA HELLENICA 68, no. 4 (2023): 215–29. https://doi.org/10.5281/zenodo.10203252.
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The genus Mycobacterium includes species like the members of the pathogenic Mycobacterium tuberculosis complex, a major global public health burden, and an ever-increasing number of nontuberculous mycobacterial species, of which approximately 1/3 have been associated with infections linked to substantial morbidity and mortality. Therefore, the rapid and accurate identification of mycobacteria is crucial for disease management.MALDI-TOF MS technique was introduced for the identification of microorganisms as a common laboratory practice during the last decade. It utilizes the unique for each species, fingerprint-like, protein mass spectra and achieves rapid, easy, reliable and cost-effective identification of bacteria, yeasts, moulds and mycobacteria. As conventional methods for the identification of mycobacteria are time-consuming, MALDI-TOF MS offers a new alternative approach that reduces the turnaround time.Protocols for inactivation and sample preparation of mycobacteria for MALDI-TOF MS proteins' analysis have been described in detail and are used in clinical microbiology laboratories. The continuous upgrading of databases through incorporation of an increasing number of mass spectral profiles of mycobacterial species, as well as the development of more powerful software for the analysis with MALDI-TOF MS, are future key goals. Through them, it is believed that a reliable identification of a greater number of mycobacterial species will be achieved and an improved distinction between phylogenetically closely related species could be accomplished, as the latter remains the main limitation of the method. Finally, MALDI-TOF MS analysis of surface lipids, specific to each mycobacterial species, is a field of research which developments are expected and promises to further shorten the identification time of mycobacteria, and perhaps even achieving their typing.The prospects launched by the introduction of MALDI-TOF MS technology in the diagnosis of mycobacteria have had a spectacular impact on species identification and it is anticipated that they will have a similar impact on both typing and detection of antituberculosis drugs resistance.
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Daniel, Alexa K., Richard E. Lee, Francoise Portaels, and P. L. C. Small. "Analysis of Mycobacterium Species for the Presence of a Macrolide Toxin, Mycolactone." Infection and Immunity 72, no. 1 (2004): 123–32. http://dx.doi.org/10.1128/iai.72.1.123-132.2004.
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ABSTRACT Mycobacterium ulcerans is an environmental organism which is responsible for the disease Buruli ulcer, a necrotizing skin disease emerging in west Africa. M. ulcerans produces the polyketide-derived macrolide mycolactone, which is required for the immunosuppression and tissue damage which characterizes Buruli ulcer. We have extracted lipids from the cell envelope and culture filtrate from 52 isolates of Mycobacterium species, analyzed them with thin-layer chromatography, and tested them in a murine fibroblast cell line (L929) cytotoxicity assay to investigate whether these mycobacterial species produce mycolactone. For these studies chloroform-methanol (2:1, vol/vol) extracts were prepared from representative fast- and slow-growing mycobacterial species. Isolates tested included 16 uncharacterized, slow-growing, environmental mycobacterial species isolated from areas in which M. ulcerans infection is endemic. Although several strains of mycobacteria studied produced cytopathic lipids, none of these produced a phenotype on cultured cells consistent with that produced by mycolactone. Two mycobacterial species, M. scrofulaceum and M. kansasii, and eight of the environmental mycobacterial isolates contained cell-associated lipids cytopathic to fibroblasts at concentrations of 33 to 1,000 μg/ml. In contrast, mycolactone produces cytotoxicity at less than 2 ng/ml. Analysis of 16S rRNA sequences from the eight environmental isolates suggests that these are novel mycobacterial species. Results from these studies suggest that, although production of cytopathic lipids is relatively common among mycobacterial species, the production of mycolactone as a cell-associated or secreted molecule appears so far to be restricted to M. ulcerans.
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Seagar, A. Louise, Carmel Prendergast, F. Xavier Emmanuel, Alan Rayner, Susan Thomson, and Ian F. Laurenson. "Evaluation of the GenoType Mycobacteria Direct assay for the simultaneous detection of the Mycobacterium tuberculosis complex and four atypical mycobacterial species in smear-positive respiratory specimens." Journal of Medical Microbiology 57, no. 5 (2008): 605–11. http://dx.doi.org/10.1099/jmm.0.47484-0.
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A novel, commercially available reverse hybridization assay [GenoType Mycobacteria Direct (GTMD), version 2.0; Hain Lifescience] was evaluated for the direct detection of five clinically relevant mycobacterial species [Mycobacterium tuberculosis complex (MTBC), Mycobacterium avium, Mycobacterium malmoense, Mycobacterium kansasii and Mycobacterium intracellulare] from 54 smear-positive respiratory specimens and the findings were compared with culture results. Three approaches were used for specimen preparation using either whole or ‘split’ sample volumes and N-acetyl-l-cysteine/3 % NaOH or 4 % NaOH as decontamination chemicals. Forty-three out of 52 samples in which RNA amplification was successful gave GTMD results that concurred with the identification of the cultured isolate. All cases of MTBC were detected. Twenty-two samples contained M. tuberculosis complex, seven had M. kansasii, four had M. malmoense, seven contained atypical mycobacteria other than those detectable using the GTMD assay and three specimens contained no viable mycobacteria. The assay is easy to use and can be completed in one working day. Results interpretation is facilitated by the inclusion of an internal amplification control with each sample to allow identification of specimens containing amplification inhibitors. A positive GTMD result will quickly identify patients with MTBC infection or provide specific identification of four other atypical mycobacteria from the same specimen. This allows more rapid drug susceptibility testing, treatment, and public health and infection control decisions.
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Miller, Nancimae, Susanna Infante, and Tim Cleary. "Evaluation of the LiPA MYCOBACTERIA Assay for Identification of Mycobacterial Species from BACTEC 12B Bottles." Journal of Clinical Microbiology 38, no. 5 (2000): 1915–19. http://dx.doi.org/10.1128/jcm.38.5.1915-1919.2000.
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The LiPA MYCOBACTERIA (Innogenetics NV, Ghent, Belgium) assay was used to identify mycobacterial isolates using culture fluid from positive BACTEC 12B bottles. The LiPA method involves reverse hybridization of a biotinylated mycobacterial PCR fragment, a 16 to 23S rRNA spacer region, to oligonucleotide probes arranged in lines on a membrane strip, with detection via biotin-streptavidin coupling by a colorimetric system. This system identifies Mycobacteriumspecies and differentiates M. tuberculosis complex,M. avium-M. intracellulare complex, and the following mycobacterial species: M. avium, M. intracellulare, M. kansasii, M. chelonaegroup, M. gordonae, M. xenopi, and M. scrofulaceum. The mycobacteria were identified in the laboratory by a series of tests, including the Roche AMPLICOR Mycobacterium tuberculosis (MTB) test, the Gen-Probe ACCUPROBE, and a PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the 65-kDa heat shock protein gene. The LiPA MYCOBACTERIA assay detected 60 mycobacterium isolates from 59 patients. There was complete agreement between LiPA and the laboratory identification tests for 26 M. tuberculosis complex, 9 M. avium, 3 M. intracellulare complex, 3 M. kansasii, 4 M. gordonae, and 5 M. chelonae group (all were M. abscessus) isolates. Three patient samples were LiPA positive forM. avium-M. intracellulare complex, and all were identified as M. intracellulare by the PCR-RFLP analysis. Seven additional mycobacterial species were LiPA positive forMycobacterium spp. (six were M. fortuitum, and one was M. szulgai). The LiPA MYCOBACTERIA assay was easy to perform, and the interpretation of the positive bands was clear-cut. Following PCR amplification and gel electrophoresis, the LiPA assay was completed within 3 h.
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Padya, Leah, Nyasha Chin'ombe, Marcelyn Magwenzi, Joshua Mbanga, Vurayai Ruhanya, and Pasipanodya Nziramasanga. "Molecular Identification of Mycobacterium Species of Public Health Importance in Cattle in Zimbabwe by 16S rRNA Gene Sequencing." Open Microbiology Journal 9 (March 13, 2015): 38–42. https://doi.org/10.5281/zenodo.2591997.
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Mycobacterium species are naturally found in the environment as well as in domestic animals such as cattle. So far, more than 150 species of Mycobacterium, some of which are pathogenic, have been identified. Laboratory isolation, detection and identification of Mycobacterium species are therefore critical if human and animal infections are to be controlled. The objective of this study was to identify Mycobacterium species isolated in cattle in Zimbabwe using 16S ribosomal RNA gene amplification and sequencing. A total of 134 cow dung samples were collected throughout Zimbabwe and mycobacteria were isolated by culture. Only 49 culture isolates that were found to be acid-fast bacilli positive by Ziehl-Neelsen staining. The 16S rRNA gene was successfully amplified by PCR in 41 (84%) of the samples. There was no amplification in 8 (16%) of the samples. Out of the 41 samples that showed amplification, 26 (63%) had strong PCR bands and were selected for DNA sequencing. Analysis of the DNA sequences showed that 7 (27%) belonged to Mycobacterium neoaurum, 6 (23%) belonged to Mycobacterium fortuitum, 3 (12%) to Mycobacterium goodii, 2 (1%) to Mycobacterium arupense, 2 (1%) to Mycobacterium peregrinum or M. septicum and 1 isolate (0.04%) to Mycobacterium elephantis. There were 5 (19%) isolates that were non-mycobacteria and identified as Gordonia terrae, a close relative of Mycobacterium. The study therefore provided a molecular basis for detection and identification of Mycobacterium species in animals and humans.
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Whipps, Christopher M., W. Ray Butler, Fazel Pourahmad, Virginia G. Watral, and Michael L. Kent. "Molecular systematics support the revival of Mycobacterium salmoniphilum (ex Ross 1960) sp. nov., nom. rev., a species closely related to Mycobacterium chelonae." International Journal of Systematic and Evolutionary Microbiology 57, no. 11 (2007): 2525–31. http://dx.doi.org/10.1099/ijs.0.64841-0.
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Mycobacterial infections in fish are usually attributed to strains of Mycobacterium marinum, Mycobacterium chelonae and Mycobacterium fortuitum. Bacteria identified as M. chelonae have been isolated numerous times from salmonid fishes. Recently, this bacterium has been associated with salmon mortalities in the aquaculture industry. An M. chelonae-like species from salmon, ‘Mycobacterium salmoniphilum’, was described in 1960. However, the species name lost standing in nomenclature when it was omitted from the 1980 Approved Lists of Bacterial Names because the species could not be distinguished with confidence from M. fortuitum. In the 1980s, mycobacteria isolated from salmon were characterized as a distinct subspecies, ‘Mycobacterium chelonae subsp. piscarium’. Again, the uncertainty of the validity of the species resulted in the subsequent withdrawal of the name. Since then, most studies have considered isolates from salmon to be M. chelonae. Nucleotide sequence analysis of the small-subunit rRNA, hsp65 and rpoB genes was used to examine the taxonomic relatedness of type cultures and authentic isolates in our culture collection available from earlier studies. The M. chelonae-like strains from salmon were phylogenetically distinct from other Mycobacterium strains and members of the M. chelonae complex. Moreover, the cell-wall-bound mycolic acids were not representative of known mycolate patterns for M. chelonae-complex organisms. These results supported the status of the species as a separate taxon and effect the valid publication of the name ‘M. salmoniphilum’ as Mycobacterium salmoniphilum (ex Ross 1960) sp. nov., nom. rev., with the type strain SCT (=ATCC 13578T =DSM 43276T).
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Radulski, Łukasz, Monika Krajewska-Wędzina, Marek Lipiec, Marcin Weiner, Anna Zabost, and Ewa Augustynowicz-Kopeć. "Mycobacterial Infections in Invasive Turtle Species in Poland." Pathogens 12, no. 4 (2023): 570. http://dx.doi.org/10.3390/pathogens12040570.
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Over the last 30 years, the number of invasive turtle species living in the wild has significantly increased in Poland. This proliferation carries many threats, which mainly include the displacement of native species of animals from their natural habitats. Turtles can also be reservoirs for pathogens, including bacteria from the Mycobacterium genus. In order to confirm or rule out the presence of acid-fast mycobacteria in the population of invasive turtle species, samples from carapace, plastron, internal organs and mouth cavity swabs from 125 animals were tested. Twenty-eight mycobacterial strains were isolated in culture, which were classified as atypical following multiplex-PCR reactions. The GenoType Mycobacterium Common Mycobacteria (CM) test, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, PCR-restriction fragment length polymorphism (PRA)-hsp65 and DNA sequencing were used to identify the species of isolates. Of the 28 strains, 11 were identified as M. fortuitum, 10 as M. chelonae, 3 as M. avium ssp. avium, 2 as M. nonchromogenicum and 1 each of M. neoaurum and M. scrofulaceum. The results of the research will also strengthen the understanding that these animals can be vectors for pathogens when living in the wild.
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Suffys, Philip, Adalgiza da Silva Rocha, Adeilton Brandão, et al. "Detection of mixed infections with Mycobacterium lentiflavum and Mycobacterium avium by molecular genotyping methods." Journal of Medical Microbiology 55, no. 1 (2006): 127–31. http://dx.doi.org/10.1099/jmm.0.46218-0.
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Three mycobacterial isolates, one from the blood of an HIV-infected patient and two consecutive isolates from a woman with unknown HIV status, had been identified as belonging to the Mycobacterium avium complex by conventional procedures. In both patients, using genetic analysis procedures such as PCR–restriction enzyme analysis (PRA) of the hsp65 gene, a commercially available reverse hybridization-based assay (INNO-LiPA mycobacteria) and/or sequencing analysis of the 16S–23S internal transcribed spacer (ITS), the presence of Mycobacterium lentiflavum was also demonstrated. At the time of detection, both cases were also infected with M. avium, suggesting an underestimation of infection with M. lentiflavum and co-infection with different Mycobacterium species.
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Ad�kambi, To�di, Skandar Ben Salah, Mohamed Khlif, Didier Raoult, and Michel Drancourt. "Survival of Environmental Mycobacteria in Acanthamoeba polyphaga." Applied and Environmental Microbiology 72, no. 9 (2006): 5974–81. http://dx.doi.org/10.1128/aem.03075-05.
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ABSTRACT Free-living amoebae in water are hosts to many bacterial species living in such an environment. Such an association enables bacteria to select virulence factors and survive in adverse conditions. Waterborne mycobacteria (WBM) are important sources of community- and hospital-acquired outbreaks of nontuberculosis mycobacterial infections. However, the interactions between WBM and free-living amoebae in water have been demonstrated for only few Mycobacterium spp. We investigated the ability of a number (n = 26) of Mycobacterium spp. to survive in the trophozoites and cysts of Acanthamoeba polyphaga. All the species tested entered the trophozoites of A. polyphaga and survived at this location over a period of 5 days. Moreover, all Mycobacterium spp. survived inside cysts for a period of 15 days. Intracellular Mycobacterium spp. within amoeba cysts survived when exposed to free chlorine (15 mg/liter) for 24 h. These data document the interactions between free-living amoebae and the majority of waterborne Mycobacterium spp. Further studies are required to examine the effects of various germicidal agents on the survival of WBM in an aquatic environment.
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VanHeyningen, T. K., H. L. Collins, and D. G. Russell. "IL-6 produced by macrophages infected with Mycobacterium species suppresses T cell responses." Journal of Immunology 158, no. 1 (1997): 330–37. http://dx.doi.org/10.4049/jimmunol.158.1.330.
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Abstract The ability of Mycobacterium bovis Calmette-Guérin bacillus-infected bone marrow-derived macrophages to process and present exogenously added Ags to T cells and stimulate their growth and production of IL-2 was examined. The infected macrophages were inhibited in their ability to activate T cells, and this inhibition could be transferred to uninfected macrophages with filtered supernatants from mycobacteria-infected macrophages. The inhibition was not due to decreases in macrophage viability, Ag uptake, or cell surface expression of MHC class II or other accessory molecules necessary for Ag presentation. Other intracellular pathogens such as Listeria monocytogenes and Leishmania mexicana did not induce the soluble inhibitory factor, while Mycobacterium avium strain 101 did, suggesting the factor is specific to infection with mycobacteria. The inhibitory effect was reversed completely by preincubation with neutralizing Abs against IL-6, and rIL-6 partially restored the effect. Approximately 10,000-fold more IL-6 was produced by mycobacteria-infected macrophages compared with uninfected controls. Such sustained levels of IL-6 may account for the immune unresponsiveness apparent in both human and murine mycobacterial disease.
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Jiang, Qiang, Rong Hu, Feng Liu, Feng Huang, Lei Zhang, and Hua Zhang. "Characterization of a Novel Oxidative Stress Responsive Transcription Regulator in Mycobacterium bovis." Biomedicines 12, no. 8 (2024): 1872. http://dx.doi.org/10.3390/biomedicines12081872.
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The antioxidant defense is critical for the survival of intracellular pathogens such as Mycobacterium tuberculosis complex (MTBC) species, including Mycobacterium bovis, which are often exposed to an oxidative environment caused by reactive oxygen species (ROS) in hosts. However, the signaling pathway in mycobacteria for sensing and responding to oxidative stress remains largely unclear. In this study, we characterize a TetR-type transcription regulator BCG_3893c, designated AotM, as a novel redox sensor in Mycobacterium bovis that increases mycobacterial tolerance to oxidative stress. AotM is required for the growth of M. bovis in the presence of 1 mM hydrogen peroxide. Loss of the aotM gene leads to altered transcriptional profiles with 352 genes significantly up-regulated and 25 genes significantly down-regulated. AotM recognizes a 14-bp palindrome sequence motif and negatively regulates the expression of a FAD-dependent oxidoreductase encoded by bcg_3892c. Overexpression of BCG_3892c increases intracellular ROS production and reduces the growth of M. bovis. In summary, we propose that AotM enhances the mycobacterial resistance against oxidative stress probably by inhibiting intracellular ROS production. Our findings reveal a novel underlying regulatory mechanism behind mycobacterial oxidative stress adaptation.
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Hayes, S. F., and P. L. C. Small. "Evaluation of alternative fixatives/protocols for the ultra-structural preservation of fast and slow growing mycobacteria." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 814–15. http://dx.doi.org/10.1017/s0424820100166531.
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Various fixation formulas and protocols were examined to determine a routinely optimal fixation of Mycobacterial species in and out of tissues. These were evaluated by TEM and compared to results obtained using freeze substitution methods upon other Mycobacteria such as Mycobacterium aurum CIPT 1210005, M. fortuitum, M. phlei 425, M. kansasii and M. thermoresistible ATCC 19527Samples consisted of two slow growing mycobacterial species, both human pathogens; Mycobacterium tuberculosis, grown in M7H9 broth, and Mycobacterium marinum (1218 R & S variants), grown on M7H10 agar, with the latter also grown in tissue culture, and in guinea pig skin. Fixatives included: (1) glutaraldehyde/parafoimaldahyde/tannic acid in a phosphate/sucrose buffer, (2) paraformaldehyde/polylysine/periodate/glutaraldehyde (PLPG) in phosphate buffer followed by tannic acid and reduced osmium respectively, (3) PLP followed by tannic acid only without osmium, and (4) fixative 84-40 containing carbodiimide, glutaraldehyde and ruthenium red. Protocols varied in the length of time for fixation, types of buffers, solvents and in embedding schedules for Spurr's low viscosity resin.
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Zivanovic, Irena, Dragana Vukovic, Ivana Dakic, and Branislava Savic. "Species of mycobacterium tuberculosis complex and nontuberculous mycobacteria in respiratory specimens from Serbia." Archives of Biological Sciences 66, no. 2 (2014): 553–61. http://dx.doi.org/10.2298/abs1402553z.
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This study aimed to provide the first comprehensive report into the local pattern of mycobacterial isolation. We used the GenoType MTBC and CM/AS assays (Hain Lifescience) to perform speciation of 1 096 mycobacterial cultures isolated from respiratory specimens, one culture per patient, in Serbia over a 12-month period. The only species of the Mycobacterium tuberculosis complex (MTBC) identified in our study was M. tuberculosis, with an isolation rate of 88.8%. Ten different species of nontuberculous mycobacteria (NTM) were recognized, and the five most frequently isolated species were, in descending order, M. xenopi, M. peregrinum, M. gordonae, M. avium and M. chelonae. In total, NTM isolates accounted for 11.2% of all isolates of mycobacteria identified in pulmonary specimens. Our results suggest that routine differentiation among members of the MTBC is not necessary, while routine speciation of NTM is required.
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Wamalwa, Ronald, Bernard Guyah, and Nathan Shaviya. "Antibiotic Resistance in Mycobacterium Tuberculosis and Non-Tuberculous Mycobacteria." African Journal of Empirical Research 5, no. 4 (2024): 1001–10. http://dx.doi.org/10.51867/ajernet.5.4.83.
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Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacteria (NTM) antibiotic resistance presents an important challenge to the treatment of mycobacterial infections. The therapeutic approaches are complicated by the resistance of both MTB and NTM to a variety of antibiotics. Resistance to first-line drugs such as isoniazid, rifampicin, ethambutol, and streptomycin has been consistently increasing in MTB, underscoring the necessity of effective treatment strategies. Conversely, the necessity of species-specific treatment regimens is underscored by the high resistance rates of NTM species, such as Mycobacterium avium complex, M. kansasii, and M. abscessus complex, to commonly used anti-tuberculosis pharmaceuticals. A combination of intrinsic and acquired factors are involved in the mechanisms of antibiotic resistance in these mycobacteria. Features such as biofilm formation, thick cell walls, and reduced drug uptake are responsible for intrinsic resistance in NTM, whereas acquired resistance can develop as a result of protracted antibiotic exposure. Understanding these resistance mechanisms is essential for the development of new therapies and the prevention of the increasing prevalence of drug resistance in mycobacterial infections. The significance of continuous surveillance, species-specific treatment protocols, and the development of novel antimicrobial agents to effectively manage mycobacterial diseases is emphasized by the prevalence of antibiotic resistance in MTB and NTM. This review article focuses on the molecular mechanisms that have resulted in the development of resistance in both MTB and NTMs, as well as the extent to which various classes of antimycobacterial drugs act.
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Falkinham, Joseph O. "The Changing Pattern of Nontuberculous Mycobacterial Disease." Canadian Journal of Infectious Diseases 14, no. 5 (2003): 281–86. http://dx.doi.org/10.1155/2003/323058.
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Nontuberculous mycobacteria are human opportunistic pathogens whose source of infection is the environment. These include both slow-growing (eg,Mycobacterium kansasii and Mycobacterium avium) and rapid-growing (eg,Mycobacterium abscessusandMycobacterium fortuitum) species. Transmission is through ingestion or inhalation of water, particulate matter or aerosols, or through trauma. The historic presentation of pulmonary disease in older individuals with predisposing lung conditions and in children has been changing. Pulmonary disease in elderly individuals who lack the classic predisposing lung conditions is increasing. Pulmonary disease and hypersensitivity pneumonitis have been linked with occupational or home exposures to nontuberculous mycobacteria. There has been a shift fromMycobacterium scrofulaceumtoM aviumin children with cervical lymphadenitis. Further, individuals who are immunosuppressed due to therapy or HIV-infection are at a greatly increased risk for nontuberculous mycobacterial infection. The changing pattern of nontuberculous mycobacterial disease is due in part to the ability of these pathogens to survive and proliferate in habitats that they share with humans, such as drinking water. The advent of an aging population and an increase in the proportion of immunosuppressed individuals suggest that the prevalence of nontuberculous mycobacterial disease will increase.
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KRYSZTOPA-GRZYBOWSKA, KATARZYNA, SYLWIA BRZEZIŃSKA, EWA AUGUSTYNOWICZ-KOPEĆ, EWA AUGUSTYNOWICZ, and ANNA LUTYŃSKA. "PCR-Based Genomic Deletion Analysis of RD-Regions in the Identification of Mycobacteria Isolated from Adverse Events Following BCG Vaccination or TB Suspected Cases." Polish Journal of Microbiology 63, no. 3 (2014): 359–62. http://dx.doi.org/10.33073/pjm-2014-048.
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Early identification of mycobacterial species is crucial for early diagnosis. PCR-multiplex method performed on randomly chosen 54 mycobacteria isolates originating from clinical samples was found to be an inexpensive, quick and reliable alternative for commercially available diagnostics tests. Although the results of gene probes identification performed by NTLDR were generally consistent with multiplex PCR, two mixed Mycobacterium bovis BCG/Mycobacterium tuberculosis infections and a single misdiagnosis of M. tuberculosis with M. bovis were found. The routine application of multiplex-PCR has the potential to make diagnostics surveillance studies feasible.