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Kelly, Devin, Julie Rizzo, Heather Yun, and Dana Blyth. "Microbiology and Clinical Characteristics of Industrial Oil Burns." Open Forum Infectious Diseases 4, suppl_1 (2017): S109. http://dx.doi.org/10.1093/ofid/ofx163.111.
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Abstract Background Injured oil workers are exposed to a broad microbiome in hydraulic fracturing fluids (HFF) and oil wells at the time of injury. This includes Pseudomonas, Stenotrophomonas, Acinetobacter, and rare human pathogens which may be harder to culture. This study evaluates oil-related burn (ORB) microbiology. Methods Patients admitted to the USAISR burn center enrolled in the Epidemiology of Workplace Burns and Injuries in Texas registry from April 2011 to November 2016 were included as cases and controls. Patients hospitalized ≤2 days were excluded. ORB was defined as exposure to HFF (FORB), or non-HFF (NFORB). Controls were patients admitted with industrial burns (non-ORB). Patient demographics and clinical cultures (days 1–15) were obtained through the registry and electronic medical record. Results 149 industrial burns were included, of which 35 (23%) were ORB and 114 (77%) were non-ORB. Of the ORB, 11 (31%) were FORB and 24 (69%) were NFORB. ORB had a median age, TBSA, and Baux score of 31, 25, and 58 compared with non-ORB with 36, 4, and 44, respectively (P < 0.01). Twenty-five patients had positive cultures: 12 (48%) non-ORB and 13 (52%) ORB. Sixty Isolates identified from the ORB population included Flavobacterium, Pseudomonas, and Serratia. FORB accounted for three (25%) of the culture positive ORB. S. marcescens was isolated in 1 FORB (33%) compared with 0 NFORB and non-ORB (P < 0.05). Otherwise, there was no statistical difference in isolates. Median time to first positive culture differed among non-ORB (4 days), FORB (13 days), and NFORB (3.5 days, P = 0.03). Forty-six (31%) patients had cultures obtained during admission: three (7%) FORB, 12 (26%) NFORB, and 31 (67%) non-ORB. Of cultured patients, ORB had a median TBSA and Baux score of 44 and 90 compared with non-ORB with 11 and 47, respectively (P < 0.01). Comparing all cultured patients, ORB had more positive, negative, and total cultures compared with non-ORB with 2 vs. 0, 7 vs. 3, and 10 vs. 3, respectively (P < 0.01). Conclusion Within this cohort, ORB was associated with more severe injuries compared with non-ORB. They had more positive, negative, and total cultures, and recovery of S. marcescens was associated with FORB. Larger studies with non-culture based technology could help further define the microbiology of this uniquely exposed population. Disclosures All authors: No reported disclosures.
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Merlino, John. "Applications and integration of chromogenic culture media in clinical microbiology." Microbiology Australia 31, no. 3 (2010): 127. http://dx.doi.org/10.1071/ma10127.
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The ability to rapidly detect and identify micro-organisms is of paramount importance for many microbiology laboratories. The application of new classes of enzymatic-based chromogenic compounds has revolutionised traditional culture media, leading to the developments of a new generation of chromogenic media. Many studies have shown that the chromogenic agar has become more than an isolation media when compared to conventional culture media. A newer, faster, more cost-effective means in the presumptive identification or screening of microorganisms which are either genus, or in some cases species-specific, and allows superior differentiation of mixed micro-organisms in cultures. When supplemented with antibiotics or other agents, chromogenic media allows the screening for multidrug resistance and virulence in many micro-organisms and can be easily integrated with other automated and/or molecular-based methods.
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Connon, Stephanie A., and Stephen J. Giovannoni. "High-Throughput Methods for Culturing Microorganisms in Very-Low-Nutrient Media Yield Diverse New Marine Isolates." Applied and Environmental Microbiology 68, no. 8 (August 2002): 3878–85. http://dx.doi.org/10.1128/aem.68.8.3878-3885.2002.
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ABSTRACT Microbial diversity studies based on the cloning and sequencing of DNA from nature support the conclusion that only a fraction of the microbial diversity is currently represented in culture collections. Out of over 40 known prokaryotic phyla, only half have cultured representatives. In an effort to culture the uncultured phylotypes from oligotrophic marine ecosystems, we developed high-throughput culturing procedures that utilize the concept of extinction culturing to isolate cultures in small volumes of low-nutrient media. In these experiments, marine bacteria were isolated and cultivated at in situ substrate concentrations—typically 3 orders of magnitude less than common laboratory media. Microtiter plates and a newly developed procedure for making cell arrays were employed to raise the throughput rate and lower detection sensitivity, permitting cell enumeration from 200-μl aliquots of cultures with densities as low as 103 cells/ml. Approximately 2,500 extinction cultures from 11 separate samplings of marine bacterioplankton were screened over the course of 3 years. Up to 14% of the cells collected from coastal seawater were cultured by this method, which was 14- to 1,400-fold higher than the numbers obtained by traditional microbiological culturing techniques. Among the microorganisms cultured were four unique cell lineages that belong to previously uncultured or undescribed marine Proteobacteria clades known from environmental gene cloning studies. These cultures are related to the clades SAR11 (α subclass), OM43 (β subclass), SAR92 (γ subclass), and OM60/OM241 (γ subclass). This method proved successful for the cultivation of previously uncultured marine bacterioplankton that have consistently been found in marine clone libraries.
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Sansupa, Chakriya, Sara Fareed Mohamed Wahdan, Terd Disayathanoowat, and Witoon Purahong. "Identifying Hidden Viable Bacterial Taxa in Tropical Forest Soils Using Amplicon Sequencing of Enrichment Cultures." Biology 10, no. 7 (June 22, 2021): 569. http://dx.doi.org/10.3390/biology10070569.
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This study aims to estimate the proportion and diversity of soil bacteria derived from eDNA-based and culture-based methods. Specifically, we used Illumina Miseq to sequence and characterize the bacterial communities from (i) DNA extracted directly from forest soil and (ii) DNA extracted from a mixture of bacterial colonies obtained by enrichment cultures on agar plates of the same forest soil samples. The amplicon sequencing of enrichment cultures allowed us to rapidly screen a culturable community in an environmental sample. In comparison with an eDNA community (based on a 97% sequence similarity threshold), the fact that enrichment cultures could capture both rare and abundant bacterial taxa in forest soil samples was demonstrated. Enrichment culture and eDNA communities shared 2% of OTUs detected in total community, whereas 88% of enrichment cultures community (15% of total community) could not be detected by eDNA. The enrichment culture-based methods observed 17% of the bacteria in total community. FAPROTAX functional prediction showed that the rare and unique taxa, which were detected with the enrichment cultures, have potential to perform important functions in soil systems. We suggest that enrichment culture-based amplicon sequencing could be a beneficial approach to evaluate a cultured bacterial community. Combining this approach together with the eDNA method could provide more comprehensive information of a bacterial community. We expected that more unique cultured taxa could be detected if further studies used both selective and non-selective culture media to enrich bacteria at the first step.
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Libertin, Claudia R., Keith A. Sacco, and Joy H. Peterson. "Education and coaching to optimise blood culture volumes: continuous quality improvement in microbiology." BMJ Open Quality 7, no. 3 (July 2018): e000228. http://dx.doi.org/10.1136/bmjoq-2017-000228.
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The blood volume cultured in the detection of bacteraemia is a major variable in treating patients with systemic inflammatory response syndrome. The fact that drawing optimal volumes (8–10 mL) of blood for culture increases the sensitivity of the method is well established. This study aimed to optimise the mean blood volumes (mBVs) to that recommended level in a small rural hospital by implementing a continuous quality improvement programme in clinical microbiology. The education of phlebotomists, followed by monthly feedback and coaching sessions, can influence the blood volume drawn by phlebotomists and improve the sensitivity of blood cultures. Statistically significant increase (p<0.001) in both mBVs and median blood culture volumes occurred within 5 months compared with the baseline values obtained in the preceding 10 months. This quality improvement was sustained over 1 year. The mBVs inoculated into aerobic culture bottles met the manufacturer’s instructions of a fill volume of 8 to 10 mL of blood per bottle and optimised the yield of isolation of organisms from blood cultures.
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Simner, Patricia J., Kelly A. Doerr, Lory K. Steinmetz, and Nancy L. Wengenack. "Mycobacterium and Aerobic Actinomycete Culture: Are Two Medium Types and Extended Incubation Times Necessary?" Journal of Clinical Microbiology 54, no. 4 (February 10, 2016): 1089–93. http://dx.doi.org/10.1128/jcm.02838-15.
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Mycobacterial cultures are historically performed using a liquid medium and a solid agar medium with an incubation period of up to 60 days. We performed a retrospective analysis of 21,494 mycobacterial and aerobic actinomycetes cultures performed over 10 months to determine whether two medium types remain necessary and to investigate whether culture incubation length can be shortened. Specimens were cultured using Bactec MGIT liquid medium and Middlebrook 7H11/S7H11 solid medium with incubation periods of 42 and 60 days, respectively. Time-to-positivity and the identity of isolates recovered from each medium were evaluated. A total of 1,205/21,494 cultures (6%) were positive on at least one medium. Of the 1,353 isolates recovered, 1,110 (82%) were nontuberculous mycobacteria, 145 (11%) were aerobic actinomycetes, and 98 (7%) wereMycobacterium tuberculosiscomplex. Assessing medium types, 1,121 isolates were recovered from solid medium cultures, 922 isolates were recovered from liquid medium cultures, and 690 isolates were recovered on both media. Liquid cultures were positive an average of 10 days before solid cultures when the two medium types were positive (P< 0.0001). Isolates detected on solid medium after 6 weeks of incubation included 65 (5%) nontuberculous mycobacteria, 4 (0.3%) aerobic actinomycetes, and 2 (0.2%) isolates from theM. tuberculosiscomplex. Medical chart review suggested that most of these later-growing isolates were insignificant, as the diagnosis was already known, or they were considered colonizers/contaminants. This study reaffirms the need for both liquid medium and solid medium for mycobacterial and aerobic actinomycetes culture and demonstrates that solid medium incubation times may be reduced to 6 weeks without significantly impacting sensitivity.
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SCHIEMANN, DONALD A. "Examination of Enterotoxin Production at Low Temperature by Yersinia spp. in Culture Media and Foods." Journal of Food Protection 51, no. 7 (July 1, 1988): 571–73. http://dx.doi.org/10.4315/0362-028x-51.7.571.
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Sixteen of 27 (59%) cultures of Yersinia spp. produced enterotoxin measured by the suckling mouse assay at 25°C in aerated broth culture media. Only one of 15 of these cultures, which was identified as Yersinia kristensenii, produced enterotoxin at 6°C. No enterotoxin was detected in water and methanol extracts of 6 food slurries inoculated with this toxigenic culture after incubation at 9.8°C for 4 d.
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Balaji, S., A. Sujatha, and I. Kalyanasundaram. "A simple rapid procedure for obtaining axenic cultures from monoxenic cultures of myxomycete plasmodia." Canadian Journal of Microbiology 45, no. 10 (October 1, 1999): 865–70. http://dx.doi.org/10.1139/w99-080.
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Axenic culture of myxomycete plasmodia has been attempted from time to time by various authors, but with very little success. From over 500 known species of myxomycetes, fewer than 20 species have been reported in axenic culture to date, including axenic myxamoebal cultures. In these cultures, the plasmodia required either complex media, or a killed bacterial supplement for growth. Furthermore, the time required for attaining the axenic state varied from several months to years. In the present study, a simple, rapid procedure has been developed to render monoxenic plasmodial cultures axenic. This procedure is based on our discovery that plasmodia have certain unusual substrate preferences that are inhibitory to the associated bacteria using Physarella oblonga as a model. The presence or absence of the bacteria could be ascertained through incubation in four different bacteriological media and by the use of a differential staining technique.Key words: myxomycetes, axenic culture, hydrocarbon utilization, bacterial associates.
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Traynor, Peter. "Culture Media SIG." Microbiology Australia 33, no. 4 (2012): 000. http://dx.doi.org/10.1071/ma12903.
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The Culture Media Special Interest Group of the Australian Society for Microbiology was formed in 1991 by a group of interested individuals after an upsurge in interest in the issue of media quality and the appearance that no common standards or consensus existed in this area in Australia. Increased interest, especially amongst medical microbiologists, in what was being done, or should be done, by way of assuring the quality of microbiological media made the issue contentious.
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Huang, Felicia Scaggs, Andrea Ankrum, Cincinnati Hospital, Zheyi Teoh, Joshua Courter, Francesco, Mangano, Karin Bierbrauer, and Josh. "Learnings from a Cutibacterium acnes pseudo-outbreak in pediatric neurosurgical patients." Antimicrobial Stewardship & Healthcare Epidemiology 2, S1 (May 16, 2022): s57—s58. http://dx.doi.org/10.1017/ash.2022.166.
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Background:Cutibacterium acnes is normal skin flora as well as a common culture contaminant. It can cause infections in the setting of sterile implants, although clinical presentations can be subtle. Differentiating true infection from sample contamination is challenging and has implications for patient care. We describe an investigation of a cluster of 7 hospitalized pediatric patients with C. acnes isolated from anaerobic cultures of cerebrospinal fluid (CSF) over 3 weeks at a quaternary-care children’s hospital. Methods: An outbreak response was coordinated between the infection prevention and control (IPC), microbiology, and neurosurgery teams. We defined a case as a hospitalized patient with C. acnes isolated from a CSF culture beginning in November 2020. We reviewed charts of all cases and CSF culture collection on all case units, transport to and processing at the microbiology laboratory, and the IPC team measured adherence for all processes. Results: There were 8 positive cultures in 7 cases from November 10 to 27, 2020. The median case age was 2 months (range, 0–119). Cases occurred on 4 different units. All positive patients had at least 1 implanted neurosurgical device used for CSF drainage. There were no clear commonalities in surgeon responsible for device placement, hardware type placed, or staff collecting CSF samples. A standard protocol for CSF collection was followed for all cases. Overall, 3 patients cleared cultures without intervention, 2 received oral antibiotics, and 2 underwent surgical removal of their device. Specimen processing was unchanged, although due to supply issues, an alternative anaerobic culture media (Anaerobic Systems, Morgan Hills, CA) was used for 6 weeks, during which all cases were identified. Compared to routine media, the alternative is known to enhance organism detection. The company reported no concerns for media contamination or C. acnes outbreaks. Once routine media became available, CSF culture positivity for C. acnes returned to baseline (late November or early December) (Fig. 1). Conclusions: We identified a likely pseudo-outbreak related to temporary use of a more sensitive culture media. No direct patient harm was identified, although many had increased risk of harm by surgical intervention or prolonged length of stay. Technological advances may enhance organism identification but challenge existing paradigms of care. More studies are needed to better delineate the intersection of diagnostic advancements with patient care standards.Funding: NoneDisclosures: None
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Yarbrough, Melanie L., Meghan A. Wallace, Cynthia Marshall, Erin Mathias, and Carey-Ann D. Burnham. "Culture of Urine Specimens by Use of chromID CPS Elite Medium Can Expedite Escherichia coli Identification and Reduce Hands-On Time in the Clinical Laboratory." Journal of Clinical Microbiology 54, no. 11 (August 31, 2016): 2767–73. http://dx.doi.org/10.1128/jcm.01376-16.
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Urine is one of the most common specimen types submitted to the clinical microbiology laboratory; the use of chromogenic agar is one method by which the laboratory might expedite culture results and reduce hands-on time and materials required for urine culture analysis. The objective of our study was to compare chromID CPS Elite (bioMérieux), a chromogenic medium, to conventional primary culture medium for evaluation of urine specimens. Remnant urine specimens (n= 200) were inoculated into conventional media and into chromID CPS Elite agar (chromID). The time to identification and consumables used were documented for both methods. Clinically significant pathogen(s) were recovered from 51 cultures using conventional media, withEscherichia colibeing the most frequently recovered organism (n= 22). The rate of exact uropathogen agreement between conventional and chromogenic media was 82%, while overall categorical agreement was 83.5% The time interval between plating and final organism identification was decreased with chromID agar versus conventional media forE. coli(mean of 24.4 h versus 27.1 h,P< 0.001). Using chromID, clinically significant cultures required less hands-on time per culture (mean of 1 min and 2 s [1:02 min]) compared to conventional media (mean of 1:31 min). In addition, fewer consumables (2.4 versus 3.3 sticks and swabs) and rapid biochemical tests (1.0 versus 1.9) were necessary using chromID versus conventional media. Notably, antimicrobial susceptibility testing demonstrated good overall agreement (97.4%) between the chromID and conventional media for all antibiotics tested. chromID CPS Elite is accurate for uropathogen identification, reduces consumable usage, and may expedite the identification ofE. coliin clinical specimens.
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MARTYNIUK, STEFAN, and JADWIGA OROŃ. "Use of Potato Extract Broth for Culturing Root-Nodule Bacteria." Polish Journal of Microbiology 60, no. 4 (2011): 323–27. http://dx.doi.org/10.33073/pjm-2011-046.
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Liquid media containing potato extract and 1% of glucose or sucrose were used to culture root-nodule bacteria (rhizobia) in shaken Erlenmeyer flasks. For comparison, these bacteria were also cultured in yeast extract-mannitol broth (YEMB) as a standard medium. Proliferation of rhizobia was monitored by measuring optical densities (OD550) of the cultures and by plate counting of the viable cells (c.f.u) of the bacteria. In general, multiplication of the rhizobia in potato extract-glucose broth (PEGB) and potato extract-sucrose broth (PESB) was markedly faster, as indicated by higher values of OD550, than in YEMB. The numbers of R. leguminosarum by. vicae GGL and S. meliloti 330 in PEGB and PEGB were high and ranged from 1.2 x 10(10) to 4.9 x 10(10) mL(-1) after 48 h of incubation at 28 degrees C. B. japonicum B3S culture in PEGB contained 6.4 x 10(9) c.f.u. ml(-1) after 72 h of incubation. PEGB and YEMB cultures of the rhizobia were similar with respect to their beneficial effects on nodulation of the host-plants of these bacteria.
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Ulmer, Andreas, Florian Erdemann, Susanne Mueller, Maren Loesch, Sandy Wildt, Maiken Lund Jensen, Paula Gaspar, Ahmad A. Zeidan, and Ralf Takors. "Differential Amino Acid Uptake and Depletion in Mono-Cultures and Co-Cultures of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus in a Novel Semi-Synthetic Medium." Microorganisms 10, no. 9 (September 1, 2022): 1771. http://dx.doi.org/10.3390/microorganisms10091771.
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The mechanistic understanding of the physiology and interactions of microorganisms in starter cultures is critical for the targeted improvement of fermented milk products, such as yogurt, which is produced by Streptococcus thermophilus in co-culture with Lactobacillus delbrueckii subsp. bulgaricus. However, the use of complex growth media or milk is a major challenge for quantifying metabolite production, consumption, and exchange in co-cultures. This study developed a synthetic medium that enables the establishment of defined culturing conditions and the application of flow cytometry for measuring species-specific biomass values. Time courses of amino acid concentrations in mono-cultures and co-cultures of L. bulgaricus ATCC BAA-365 with the proteinase-deficient S. thermophilus LMG 18311 and with a proteinase-positive S. thermophilus strain were determined. The analysis revealed that amino acid release rates in co-culture were not equivalent to the sum of amino acid release rates in mono-cultures. Data-driven and pH-dependent amino acid release models were developed and applied for comparison. Histidine displayed higher concentrations in co-cultures, whereas isoleucine and arginine were depleted. Amino acid measurements in co-cultures also confirmed that some amino acids, such as lysine, are produced and then consumed, thus being suitable candidates to investigate the inter-species interactions in the co-culture and contribute to the required knowledge for targeted shaping of yogurt qualities.
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Altenburger, D., S. Strayer, and S. Carroll. "A Retrospective Analysis of Joint Cultures: Only Time Will Tell (Or Will It?)." American Journal of Clinical Pathology 154, Supplement_1 (October 2020): S138. http://dx.doi.org/10.1093/ajcp/aqaa161.302.
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Abstract Introduction/Objective Multiple textbooks and guidelines, including CLSI, recommend holding joint cultures for 14 days. This prevents false negative results from “slower growers” which include Actinomyces species and Propionibacterium acnes. Holding of these cultures can be a burden for small microbiology labs. Methods A retrospective analysis of three years of joint cultures held for 14 days was reviewed. The length of time for the culture to turn positive and the organism that grew was noted. Results A total of 67 positive joint cultures were evaluated, which covered a period of 3 years at our institution. Of these, only 1 culture turned positive following day 5 (Propionibacterium acnes grew on day 6). The average time to positive for Propionibacterium acnes was 4 days. In comparison, the average growth time for Staphylococcus aureus and Proteus was 1 day, Pseudomonas aeruginosa was 1.2 days, all Streptococcus species was 2.4 days and Staphylococcus epidermidis was 2.7 days. No cultures grew Actinomyces during our study. Conclusion The consequences of missing a positive culture can be grave. In general, culture media has improved and provided increased growth rates. With resources becoming more limited, it may be time to revisit guidelines. This study is too small to be conclusive; a larger study may provide confirmation of the findings.
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Arigony, Ana Lúcia Vargas, Iuri Marques de Oliveira, Miriana Machado, Diana Lilian Bordin, Lothar Bergter, Daniel Prá, and João Antonio Pêgas Henriques. "The Influence of Micronutrients in Cell Culture: A Reflection on Viability and Genomic Stability." BioMed Research International 2013 (2013): 1–22. http://dx.doi.org/10.1155/2013/597282.
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Micronutrients, including minerals and vitamins, are indispensable to DNA metabolic pathways and thus are as important for life as macronutrients. Without the proper nutrients, genomic instability compromises homeostasis, leading to chronic diseases and certain types of cancer. Cell-culture media try to mimic thein vivoenvironment, providingin vitromodels used to infer cells' responses to different stimuli. This review summarizes and discusses studies of cell-culture supplementation with micronutrients that can increase cell viability and genomic stability, with a particular focus on previousin vitroexperiments. In these studies, the cell-culture media include certain vitamins and minerals at concentrations not equal to the physiological levels. In many common culture media, the sole source of micronutrients is fetal bovine serum (FBS), which contributes to only 5–10% of the media composition. Minimal attention has been dedicated to FBS composition, micronutrients in cell cultures as a whole, or the influence of micronutrients on the viability and genetics of cultured cells. Further studies better evaluating micronutrients' roles at a molecular level and influence on the genomic stability of cells are still needed.
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Stone, Nimalie D., Donna R. Lewis, H. K. Lowery, Lyndsey A. Darrow, Catherine M. Kroll, Robert P. Gaynes, John A. Jernigan, John E. McGowan, Fred C. Tenover, and Chesley L. Richards. "Importance of Bacterial Burden Among Methicillin-Resistant Staphylococcus aureus Carriers in a Long-Term Care Facility." Infection Control & Hospital Epidemiology 29, no. 2 (February 2008): 143–48. http://dx.doi.org/10.1086/526437.
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Objective.To evaluate the prevalence and transmission of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization, as well as risk factors associated with MRSA carriage, among residents of a long-term care facility (LTCF).Design.Prospective, longitudinal cohort study.Setting.A 100-bed Veterans Administration LTCFParticipants.All current and newly admitted residents of the LTCF during an 8-week study period.Methods.Nasal swab samples were obtained weekly and cultured on MRSA-selective media, and the cultures were graded for growth on a semiquantitative scale from 0 (no growth) to 6 (heavy growth). Epidemiologic data for the periods before and during the study were collected to assess risk factors for MRSA carriage.Results.Of 83 LTCF residents, 49 (59%) had 1 or more nasal swab cultures that were positive for MRSA; 34 (41%) were consistently culture-negative (designated “noncarriers”). Of the 49 culture-positive residents, 30 (36% of the total of 83 residents) had all cultures positive for MRSA (designated “persistent carriers”), and 19 (23% of the 83 residents) had at least 1 culture, but not all cultures, positive for MRSA (designated “intermittent carriers”). Multivariate analysis showed that participants with at least 1 nasal swab culture positive for MRSA were likely to have had previous hospitalization (odds ratio, 3.9) or wounds (odds ratio, 8.2). Persistent carriers and intermittent carriers did not differ in epidemiologic characteristics but did differ in mean MRSA growth score (3.7 vs 0.7; P < .001).Conclusions.Epidemiologic characteristics differed between noncarriers and subjects with at least 1 nasal swab culture positive for MRSA. However, in this LTCF population, only the degree of bacterial colonization (as reflected by mean MRSA growth score) distinguished persistent carriers from intermittent carriers. Understanding the burden of colonization may be important when determining future surveillance and control strategies.
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Sauvage, Justine, Gary H. Wikfors, Xiaoxu Li, Mark Gluis, Nancy Nevejan, Koen Sabbe, and Alyssa Joyce. "Effect of pluronic block polymers and N-acetylcysteine culture media additives on growth rate and fatty acid composition of six marine microalgae species." Applied Microbiology and Biotechnology 105, no. 5 (February 12, 2021): 2139–56. http://dx.doi.org/10.1007/s00253-021-11147-8.
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Abstract The efficiency of microalgal biomass production is a determining factor for the economic competitiveness of microalgae-based industries. N-acetylcysteine (NAC) and pluronic block polymers are two compounds of interest as novel culture media constituents because of their respective protective properties against oxidative stress and shear-stress-induced cell damage. Here we quantify the effect of NAC and two pluronic (F127 and F68) culture media additives upon the culture productivity of six marine microalgal species of relevance to the aquaculture industry (four diatoms-Chaetoceros calcitrans, Chaetoceros muelleri, Skeletonema costatum, and Thalassiosira pseudonana; two haptophytes-Tisochrysis lutea and Pavlova salina). Algal culture performance in response to the addition of NAC and pluronic, singly or combined, is dosage- and species-dependent. Combined NAC and pluronic F127 algal culture media additives resulted in specific growth rate increases of 38%, 16%, and 24% for C. calcitrans, C. muelleri, and P. salina, respectively. Enhanced culture productivity for strains belonging to the genus Chaetoceros was paired with an ~27% increase in stationary-phase cell density. For some of the species examined, culture media enrichments with NAC and pluronic resulted in increased omega-3-fatty acid content of the algal biomass. Larval development (i.e., growth and survival) of the Pacific oyster (Crassostrea gigas) was not changed when fed a mixture of microalgae grown in NAC- and F127-supplemented culture medium. Based upon these results, we propose that culture media enrichment with NAC and pluronic F127 is an effective and easily adopted approach to increase algal productivity and enhance the nutritional quality of marine microalgal strains commonly cultured for live-feed applications in aquaculture. Key points • Single and combined NAC and pluronic F127 culture media supplementation significantly enhanced the productivity of Chaetoceros calcitrans and Chaetoceros muelleri cultures. • Culture media enrichments with NAC and F127 can increase omega-3-fatty acid content of algal biomass. • Microalgae grown in NAC- and pluronic F127-supplemented culture media are suitable for live-feed applications.
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Kenna, Margaret A. "Microbiology of Chronic Suppurative Otitis Media in Children." Annals of Otology, Rhinology & Laryngology 97, no. 2_suppl (March 1988): 9–15. http://dx.doi.org/10.1177/00034894880970s204.
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The aerobic microorganisms present in 57 MEs of 40 children with C Supp OM without cholesteatoma were evaluated. Specimens were taken directly from the ME through a patent perforation or tympanostomy tube and cultured using standard techniques. Twenty-six organisms were identified, with Pseudomonas aeruginosa being the most prevalent (65% of ears) and the only organism in 30% of ears. The initial treatment of all patients was intravenous administration of an antimicrobial selected on the basis of culture and susceptibility reports. This treatment was successful in all but four children, who subsequently required tympanomastoid surgery. These results indicate that the microbiology of C Supp OM is similar to that in patients with cholesteatoma. However, based on the results of culture and susceptibility studies, medical therapy provides a viable alternative to major mastoid surgery in the management of C Supp OM without cholesteatoma.
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Blane, Beth, Kathy E. Raven, Danielle Leek, Nicholas Brown, Julian Parkhill, and Sharon J. Peacock. "Rapid sequencing of MRSA direct from clinical plates in a routine microbiology laboratory." Journal of Antimicrobial Chemotherapy 74, no. 8 (April 30, 2019): 2153–56. http://dx.doi.org/10.1093/jac/dkz170.
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Abstract Background Routine sequencing of MRSA could bring about significant improvements to outbreak detection and investigation. Sequencing is commonly performed using DNA extracted from a pure culture, but overcoming the delay associated with this step could reduce the time to infection control interventions. Objectives To develop and evaluate rapid sequencing of MRSA using primary clinical cultures. Methods Patients with samples submitted to the clinical laboratory at the Cambridge University Hospitals NHS Foundation Trust from which MRSA was isolated were identified, the routine laboratory culture plates obtained and DNA extraction and sequencing performed. Results An evaluation of routine MRSA cultures from 30 patients demonstrated that direct sequencing from bacterial colonies picked from four different culture media was feasible. The 30 clinical MRSA isolates were sequenced on the day of plate retrieval over five runs and passed quality control metrics for sequencing depth and coverage. The maximum contamination detected using Kraken was 1.09% fragments, which were identified as Prevotella dentalis. The most common contaminants were other staphylococcal species (25 isolate sequences) and Burkholderia dolosa (11 isolate sequences). Core genome pairwise SNP analysis to identify clusters based on isolates that were ≤50 SNPs different was used to triage cases for further investigation. This identified three clusters, but more detailed genomic and epidemiological evaluation excluded an acute outbreak. Conclusions Rapid sequencing of MRSA from clinical culture plates is feasible and reduces the delay associated with purity culture prior to DNA extraction.
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MCCANN, TIM, TRISH EGAN, and GEORGE H. WEBER. "Assay Procedures for Commercial Probiotic Cultures." Journal of Food Protection 59, no. 1 (January 1, 1996): 41–45. http://dx.doi.org/10.4315/0362-028x-59.1.41.
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A number of commercially available cultures, marked for human consumption, were analyzed for viability using a resuspension medium consisting of KH2PO4, Na2HPO4, cysteine, Tween 80, agar, and an antifoam agent together with modifications of multiple-layer diffusion techniques. These methods were compared to the use of MRS plus cysteine, acidified MRS, and M17 culture media and found to be superior in the selection and enumeration of dried cultures of mixed genera.
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Condayan, Chris. "Culture media." Nature Reviews Microbiology 6, no. 9 (September 2008): 646. http://dx.doi.org/10.1038/nrmicro1981.
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Jin, Tianru, and R. G. E. Murray. "Urease activity related to the growth and differentiation of swarmer cells of Proteus mirabilis." Canadian Journal of Microbiology 33, no. 4 (April 1, 1987): 300–303. http://dx.doi.org/10.1139/m87-051.
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Urease activity was measured using whole cells of both long (swarming) and short (nonswarming) populations of Proteus mirabilis from casein hydrolysate agar (CHA) and broth (CHB) cultures, and from brain heart infusion broth (BHIB) cultures. Urease is a constitutive enzyme for both long and short cells, but its activity was tremendously increased when urea was incorporated into the media. Urease production was also affected by culture age and media used. Before exponential phase, urease activity was very low, and it increased to its highest point after about 4 h in BHIB and 8 h in both CHA and CHB cultures at 37 °C. Long cells had higher urease activity than did short cells when grown on CHA, and was also expressed by two different strains cultured in BHIB. Strain PM23, in BHIB, was able to form long cells (swarming cells) to a maximum proportion after about 4 h, but strain IM47 could not differentiate in any of the liquid media. The former had more urease when swarming differentiation was initiated. PM23 grew relatively faster than IM47 when the former began to differentiate, but this fast growth could not be observed when nutrient broth or minimal medium was used. These observations suggest that long or swarming cells are "faster growing" rather than "nongrowing bactera."
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Chen, Annie I., Warren B. Bilker, Keith W. Hamilton, Judith A. O’Donnell, and Irving Nachamkin. "Blood culture utilization at an academic hospital: Addressing a gap in benchmarking." Infection Control & Hospital Epidemiology 39, no. 11 (September 28, 2018): 1353–59. http://dx.doi.org/10.1017/ice.2018.231.
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AbstractObjectiveTo describe the pattern of blood culture utilization in an academic university hospital setting.DesignRetrospective cohort study.SettingA 789-bed tertiary-care university hospital that processes 40,000+blood cultures annually.MethodsWe analyzed blood cultures collected from adult inpatients at the Hospital of the University of Pennsylvania between July 1, 2014, and June 30, 2015. Descriptive statistics and regression models were used to analyze patterns of blood culture utilization: frequency of blood cultures, use of repeat cultures following a true-positive culture, and number of sets drawn per day.ResultsIn total, 38,939 blood culture sets were drawn during 126,537 patient days (incidence rate, 307.7 sets per 1,000 patient days). The median number of blood culture sets drawn per hospital encounter was 2 (range, 1–76 sets). The median interval between blood cultures was 2 days (range, 1–71 days). Oncology services and cultures with gram-positive cocci were significantly associated with greater odds of having repeat blood cultures drawn the following day. Emergency services had the highest rate of drawing single blood-culture sets (16.9%), while oncology services had the highest frequency of drawing ≥5 blood culture sets within 24 hours (0.91%). Approximately 10% of encounters had at least 1 true-positive culture, and 89.2% of those encounters had repeat blood cultures drawn. The relative risk of a patient having repeat blood cultures was lower for those in emergency, surgery, and oncology services than for those in general medicine.ConclusionsOrdering practices differed by service and culture results. Analyzing blood culture utilization can contribute to the development of guidelines and benchmarks for appropriate usage.
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WEI, C. I., T. S. HUANG, J. S. CHEN, M. R. MARSHALL, and K. T. CHUNG. "Production of Kojic Acid by Aspergillus candidus in Three Culture Media." Journal of Food Protection 54, no. 7 (July 1, 1991): 546–48. http://dx.doi.org/10.4315/0362-028x-54.7.546.
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Aspergillus candidus ATCC 44054 grown without agitation produced more kojic acid in the modified Czapek-Dox liquid medium than cultures shaken at 100 rpm. Of the three culture media tested, yeast extract-sucrose medium permitted more kojic acid production by the fungus than modified Czapek-Dox liquid medium or Tadera medium. Maximal kojic acid (57–59 mg/ml) was produced in the yeast extract-sucrose medium on days 9–12. No aflatoxin by the fungus was detected.
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Plain, Karren M., Anna M. Waldron, Douglas J. Begg, Kumudika de Silva, Auriol C. Purdie, and Richard J. Whittington. "Efficient, Validated Method for Detection of Mycobacterial Growth in Liquid Culture Media by Use of Bead Beating, Magnetic-Particle-Based Nucleic Acid Isolation, and Quantitative PCR." Journal of Clinical Microbiology 53, no. 4 (January 21, 2015): 1121–28. http://dx.doi.org/10.1128/jcm.03521-14.
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Pathogenic mycobacteria are difficult to culture, requiring specialized media and a long incubation time, and have complex and exceedingly robust cell walls.Mycobacterium aviumsubsp.paratuberculosis(MAP), the causative agent of Johne's disease, a chronic wasting disease of ruminants, is a typical example. Culture of MAP from the feces and intestinal tissues is a commonly used test for confirmation of infection. Liquid medium offers greater sensitivity than solid medium for detection of MAP; however, support for the BD Bactec 460 system commonly used for this purpose has been discontinued. We previously developed a new liquid culture medium, M7H9C, to replace it, with confirmation of growth reliant on PCR. Here, we report an efficient DNA isolation and quantitative PCR methodology for the specific detection and confirmation of MAP growth in liquid culture media containing egg yolk. The analytical sensitivity was at least 104-fold higher than a commonly used method involving ethanol precipitation of DNA and conventional PCR; this may be partly due to the addition of a bead-beating step to manually disrupt the cell wall of the mycobacteria. The limit of detection, determined using pure cultures of two different MAP strains, was 100 to 1,000 MAP organisms/ml. The diagnostic accuracy was confirmed using a panel of cattle fecal (n= 54) and sheep fecal and tissue (n= 90) culture samples. This technique is directly relevant for diagnostic laboratories that perform MAP cultures but may also be applicable to the detection of other species, includingM. aviumandM. tuberculosis.
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Patel, Parul, Lauren E. Droske, Jignesh Patel, Ruby Barza, Rebecca Lindgren, and Erin McElvania. "2152. Detection of Uropathogens Using BD Kiestra™ Total Laboratory Automation with Urine Culture Application." Open Forum Infectious Diseases 6, Supplement_2 (October 2019): S730. http://dx.doi.org/10.1093/ofid/ofz360.1832.
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Abstract Background Urine is the most frequently cultured specimen type for the majority of clinical microbiology laboratories. Typically, around 30% of cultures are positive for uropathogens with 70% yielding insignificant or mixed growth. BD is developing a software Urine Culture Application (UCA) for the BD Kiestra Total Laboratory Automation (TLA) system to screen images of urine culture plates, sort them based on growth vs. insignificant growth and also allow for presumptive pathogen identification. Methods De-identified urine specimens were inoculated onto BD BBL™ CHROMagar™ Orientation Media (CHROM; BD, Sparks, MD), CHROM/Trypticase™ Soy Agar II with 5% Sheep Blood (TSA) biplate, BD BBL MacConkey II agar, and TSA using the BD Kiestra TLA system. Plates were imaged at 24 hours using the BD Kiestra™ ReadA Compact imaging acquisition software and an algorithm was applied to the images using the UCA (Version 2.0). Semi-quantitative measurements of <100, 100–1,000, 1,000–10,000, 10,000–100,000, and >100,000 cfu/mL growth were determined by UCA for all media types and presumptive ID was determined using CHROM. Manual reading of the images by two technologists was the gold standard for comparison. For discrepant results, a third manual reader was used as an arbitrator. Results Testing between 877 and 934 urine specimens on each of five media types using UCA resulted in an exact semi-quantitative agreement with manual reading for 85.5–95.0% of specimens (Table 1). If semi-quantitative values ± one category of agreement are included, the number rises to 98.2–99.4% agreement. Using CHROM for presumptive identification of pure or predominant organisms, UCA was in agreement with manual identification in 251 of 272 cultures (92.3%). Of the 21 discrepant organisms, 19 were classified as “other” by manual reading but were identified as specific organisms by UCA. Definitive organism identification was not performed. Conclusion UCA was able to accurately categorize bacterial growth into five semi-quantitative categories using five media types. Pure and predominant uropathogens were accurately identified from CHROM using UCA. The use of UCA software application may enable laboratories to save time screening urine cultures by allowing more efficient use of technologist time. Disclosures All authors: No reported disclosures.
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McMullen, Allison R., Caline Mattar, Nigar Kirmani, and Carey-Ann D. Burnham. "Brown-Pigmented Mycobacterium mageritense as a Cause of Prosthetic Valve Endocarditis and Bloodstream Infection." Journal of Clinical Microbiology 53, no. 8 (June 10, 2015): 2777–80. http://dx.doi.org/10.1128/jcm.01041-15.
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Mycobacterium spp. are a rare cause of endocarditis. Herein, we describe a case of Mycobacterium mageritense prosthetic valve endocarditis. This organism produced an unusual brown pigment on solid media. Cultures of valve tissue for acid-fast bacilli might be considered in some cases of apparently culture-negative prosthetic valve endocarditis.
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HUHTANEN, C. N., R. K. JENKINS, and D. W. THAYER. "Gamma Radiation Sensitivity of Listeria monocytogenes." Journal of Food Protection 52, no. 9 (September 1, 1989): 610–13. http://dx.doi.org/10.4315/0362-028x-52.9.610.
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Seven strains of Listeria monocytogenes were irradiated in culture media or in mechanically deboned chicken meat. The survivor plots were quadratic curves when cultures were in the log phase of growth or when they were irradiated in chicken meat; cultures in the senescent phase of growth showed linear responses to irradiation. Cultures from cells surviving an irradiation dose of 1.5 kGy were no more radiation resistant that those which had had no previous exposure to irradiation. Cultures centrifuged and resuspended in water were more sensitive to radiation than those resuspended in solutions containing organic materials. These studies indicated that a dose of 2 kGy was sufficient to destroy 1 × 104 cells of L. monocytogenes.
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Doern, Gary V., Ann Barton, and Sudah Rao. "Controlled Comparative Evaluation of BacT/Alert FAN and ESP 80A Aerobic Media as Means for Detecting Bacteremia and Fungemia." Journal of Clinical Microbiology 36, no. 9 (1998): 2686–89. http://dx.doi.org/10.1128/jcm.36.9.2686-2689.1998.
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During a one-year period, a total of 6,305 blood cultures were processed in a tertiary-care teaching hospital; 6 to 12 ml of blood was inoculated into both a BacT/Alert Fan aerobic bottle and an ESP 80A aerobic bottle. The FAN aerobic bottle contains an antimicrobial-absorbing material; the 80A aerobic bottle does not. Bottles were processed on their respective continuous-monitoring blood culture instruments for up to five days of incubation. Four hundred thirty-three cultures (6.9%) representing 301 septic episodes in 235 different patients yielded 490 bacteria or yeasts thought to be clinically significant. Two hundred seventy-five of the 433 presumed clinically significant positive cultures (63.5%) representing 195 septic episodes and yielding 301 isolates were positive in both FAN and 80A bottles. One hundred nine significant positive cultures (25.2%) (i.e., cultures positive with an organism judged to be of probable clinical significance) from 70 septic episodes yielded 126 isolates only in FAN bottles. Conversely, the 80A bottle was exclusively positive in 49 instances (11.3%), representing 36 septic episodes and yielding 63 isolates. The higher rates of significant positive blood cultures, numbers of septic episodes documented, and numbers of isolates recovered in FAN bottles versus 80A bottles were all statistically significant (P < 0.05). Enhanced rates of detection of presumed clinically significant isolates in FAN bottles were largely accounted for by Staphylococcus aureus, members of the Enterobacteriaceae, and non-Pseudomonas aeruginosa miscellaneous gram-negative bacilli from patients receiving antimicrobial therapy at the time blood cultures were obtained. Enhanced recovery of one organism group, the β-hemolytic streptococci, occurred in 80A. With one exception, detection times were essentially equivalent in the two systems. The single exception pertained to streptococci and enterococci, which were recovered significantly faster in 80A bottles. Three hundred thirty-eight of the 6,305 blood cultures evaluated in this study (5.4%) were judged likely to be contaminated. The percentages of probable contaminated cultures were as follows: 26.6% FAN and 80A; 42.3% FAN only; 31.1% 80A only (P < 0.05). Finally, the instrument false-positive rates for the two systems were 0.7% with FAN and 3.0% with 80A (P < 0.05). We conclude that while contamination rates were slightly higher with FAN than with 80A, use of FAN aerobic bottles in conjunction with the BacT/Alert system will yield significantly higher numbers of clinically significant blood culture isolates than 80A bottles and the ESP system. Furthermore, this enhanced detection is most conspicuous in patients receiving antimicrobial therapy at the time blood cultures are performed, probably due to the presence of an antimicrobial-absorbing material in FAN aerobic bottles.
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Pasqua, Salvatore, Francesco Monaco, Francesca Cardinale, Simone Bonelli, Pier Giulio Conaldi, and Danilo D’Apolito. "Growth Performance and Recovery of Nosocomial Aspergillus spp. in Blood Culture Bottles." Microorganisms 10, no. 10 (October 13, 2022): 2026. http://dx.doi.org/10.3390/microorganisms10102026.
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Theoretically, Aspergillus spp. grow in culture media, but frequently, blood cultures of patients with invasive Aspergillosis are negative, even if until now, the reasons are not clear. This aspect underlines the lack of a good strategy for the cultivation and isolation of Aspergillus spp. In order to develop a complete analytical method to detect Aspergillus in clinical and pharmaceutical samples, we investigated the growth performance of two blood culture systems versus the pharmacopeia standard method. At <72 h, all test systems showed comparable sensitivity, about 1–2 conidia. However, the subculture analysis showed a suboptimal recovery for the methods, despite the positive growth and the visualization of the “Aspergillus balls” in the culture media. To investigate this issue, we studied three different subculture approaches: (i) the use of a sterile subculture unit, (ii) the use of a sterile subculture unit and the collection of a larger aliquot (100 µL), following vigorous agitation of the vials, and (iii) to decapsulate the bottle, withdrawing and centrifuging the sample, and aliquot the pellet onto SDA plates. Our results showed that only the third procedure recovered Aspergillus from all positive culture bottles. This work confirmed that our strategy is a valid and faster method to culture and isolate Aspergillus spp. from blood culture bottles.
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Trzesicka-Mlynarz, D., and O. P. Ward. "Degradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture and its component pure cultures, obtained from PAH-contaminated soil." Canadian Journal of Microbiology 41, no. 6 (June 1, 1995): 470–76. http://dx.doi.org/10.1139/m95-063.
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A mixed culture, isolated from soil contaminated with polycyclic aromatic hydrocarbons (PAHs), grew on and degraded fluoranthene in aqueous media supplemented with glucose, yeast extract, and peptone. Increased complex nitrogen levels in the medium promoted bacterial growth and a greater extent of fluoranthene degradation. Amendment of the media with high glucose levels also diminished specific fluoranthene degradation. The mixed culture was capable of degrading a range of other PAHs, including benzo[a]pyrene, anthracene, phenanthrene, acenaphthene, and fluorene. The mixed culture contained four predominant isolates, all of which were Gram-negative rods, three of which were identified as Pseudomonas putida, Flavobacterium sp., and Pseudomonas aeruginosa. Better degradation of a defined PAH mixture was observed with the mixed culture than with individual isolates. A reconstituted culture, prepared by combining the four individual isolates, manifested a similar PAH biodegradation performance to the original mixed culture. When compared with the mixed culture, individual isolates exhibited a relatively good capacity to remove more water-soluble PAHs (acenaphthene, fluorene, phenanthrene, fluoranthene). In contrast, removal of less water-soluble PAHs (anthracene and pyrene) was low or negligible with isolated cultures compared with the mixed culture.Key words: polycyclic aromatic hydrocarbons, mixed culture, fluoranthene, Pseudomonas, Flavobacterium.
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Saunders, G. A., and J. G. Hancock. "Chloride requirement for reproduction by Pythium ultimum." Canadian Journal of Microbiology 42, no. 2 (February 1, 1996): 115–19. http://dx.doi.org/10.1139/m96-018.
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Chloride (≥ 0.1 mM) was essential for asexual and sexual reproduction, but not mycelial growth, by Pythium ultimum in synthetic culture media. Bromide partially substituted for chloride in support of oogonia formation. The production of gemmae (sporangia or hyphal swellings) increased in proportion to concentrations of KCl in culture media between 0.2 and about 0.5 mM but leveled off between 0.5 and 4 mM. Chloride contents of mycelia after 3 days incubation were proportional to the number of gemmae produced when the fungus was grown in low concentrations of KCl. Under the culture conditions of this study, production of oogonia and gemmae commenced in about 70 and 95 h, respectively, in complete media. When 0.2 mM KCl was added to cultures 95 h or older that were grown in chloride deficient media, oogonium or gemma production was initiated in 20–25 or 10–17 h, respectively. Germination of gemmae, mycelial growth (gain in dry matter), and culture pH were not influenced significantly by the chloride deficiences that prevented sexual and asexual reproduction.Key words: chloride requirement, soilborne plant pathogen, reproduction of fungi, sporangia, hyphal swellings.
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Miller, N. S., D. Rogan, B. L. Orr, and D. Whitney. "Comparison of BD Bactec Plus Blood Culture Media to VersaTREK Redox Blood Culture Media for Detection of Bacterial Pathogens in Simulated Adult Blood Cultures Containing Therapeutic Concentrations of Antibiotics." Journal of Clinical Microbiology 49, no. 4 (February 9, 2011): 1624–27. http://dx.doi.org/10.1128/jcm.01958-10.
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SINHA, R. P. "Evaluation of Inorganic Phosphate on Growth and Lactose Metabolism of Lactic Streptococci in Batch and Continuous Culture1." Journal of Food Protection 49, no. 4 (April 1, 1986): 260–64. http://dx.doi.org/10.4315/0362-028x-49.4.260.
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Addition of 1.9% inorganic phosphates (K2HPO4, 1.33% + KH2PO4, 0.57% wt/vol) in place of 1.9% disodium (β-glycerophosphate (GP) in M17 medium (M17P) resulted in increased buffering capacity. Even at equimolar concentration (88 mM), Na2HPO4 (M17P1) or K2HPO4 (M17P2) showed higher buffering than GP(M17). Cultures consistently showed lower cell density in M17P2 than in other buffered media after 7 h of growth at 32°C, suggesting that buffering media with Na2HPO4 is better than buffering with K2HPO4 for cultivation of lactic streptococci. The effect of buffering media with Na2HPO4 on culture growth and appearance of lactose-negative (Lac−) variants was also tested under continuous culture growth conditions in a chemostat. Growth of Streptococcus lactis C2 continuously at pH 6.8 for 168 h in M17P1, and M17 broths at 32°C failed to yield any lac− strains. Results showed that successful propagation of lactic streptococci in continuous culture growth can be achieved without enriching for cells with undesirable metabolic characteristics.
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Evangelopoulos, Dimitrios, Carolyn M. Shoen, Isobella Honeyborne, Simon Clark, Ann Williams, Galina V. Mukamolova, Michael H. Cynamon, and Timothy D. McHugh. "Culture-Free Enumeration of Mycobacterium tuberculosis in Mouse Tissues Using the Molecular Bacterial Load Assay for Preclinical Drug Development." Microorganisms 10, no. 2 (February 17, 2022): 460. http://dx.doi.org/10.3390/microorganisms10020460.
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Background: The turnaround times for phenotypic tests used to monitor the bacterial load of Mycobacterium tuberculosis, in both clinical and preclinical studies, are delayed by the organism’s slow growth in culture media. The existence of differentially culturable populations of M.tuberculosis may result in an underestimate of the true number. Moreover, culture methods are susceptible to contamination resulting in loss of critical data points. Objectives: We report the adaptation of our robust, culture-free assay utilising 16S ribosomal RNA, developed for sputum, to enumerate the number of bacteria present in animal tissues as a tool to improve the read-outs in preclinical drug efficacy studies. Methods: Initial assay adaptation was performed using naïve mouse lungs spiked with known quantities of M. tuberculosis and an internal RNA control. Tissues were homogenised, total RNA extracted, and enumeration performed using RT-qPCR. We then evaluated the utility of the assay, in comparison to bacterial counts estimated using growth assays on solid and liquid media, to accurately inform bacterial load in tissues from M. tuberculosis-infected mice before and during treatment with a panel of drug combinations. Results: When tested on lung tissues derived from infected mice, the MBL assay produced comparable results to the bacterial counts in solid culture (colony forming units: CFU). Notably, under specific drug treatments, the MBL assay was able to detect a significantly higher number of M. tuberculosis compared to CFU, likely indicating the presence of bacteria that were unable to produce colonies in solid-based culture. Additionally, growth recovery in liquid media using the most probable number (MPN) assay was able to account for the discrepancy between the MBL assay and CFU number, suggesting that the MBL assay detects differentially culturable sub-populations of M. tuberculosis. Conclusions: The MBL assay can enumerate the bacterial load in animal tissues in real time without the need to wait for extended periods for cultures to grow. The readout correlates well with CFUs. Importantly, we have shown that the MBL is able to measure specific populations of bacteria not cultured on solid agar. The adaptation of this assay for preclinical studies has the potential to decrease the readout time of data acquisition from animal experiments and could represent a valuable tool for tuberculosis drug discovery and development.
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Walke, Jenifer B., Matthew H. Becker, Myra C. Hughey, Meredith C. Swartwout, Roderick V. Jensen, and Lisa K. Belden. "Most of the Dominant Members of Amphibian Skin Bacterial Communities Can Be Readily Cultured." Applied and Environmental Microbiology 81, no. 19 (July 10, 2015): 6589–600. http://dx.doi.org/10.1128/aem.01486-15.
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ABSTRACTCurrently, it is estimated that only 0.001% to 15% of bacteria in any given system can be cultured by use of commonly used techniques and media, yet culturing is critically important for investigations of bacterial function. Despite this situation, few studies have attempted to link culture-dependent and culture-independent data for a single system to better understand which members of the microbial community are readily cultured. In amphibians, some cutaneous bacterial symbionts can inhibit establishment and growth of the fungal pathogenBatrachochytrium dendrobatidis, and thus there is great interest in using these symbionts as probiotics for the conservation of amphibians threatened byB. dendrobatidis. The present study examined the portion of the culture-independent bacterial community (based on Illumina amplicon sequencing of the 16S rRNA gene) that was cultured with R2A low-nutrient agar and whether the cultured bacteria represented rare or dominant members of the community in the following four amphibian species: bullfrogs (Lithobates catesbeianus), eastern newts (Notophthalmus viridescens), spring peepers (Pseudacris crucifer), and American toads (Anaxyrus americanus). To determine which percentage of the community was cultured, we clustered Illumina sequences at 97% similarity, using the culture sequences as a reference database. For each amphibian species, we cultured, on average, 0.59% to 1.12% of each individual's bacterial community. However, the average percentage of bacteria that were culturable for each amphibian species was higher, with averages ranging from 2.81% to 7.47%. Furthermore, most of the dominant operational taxonomic units (OTUs), families, and phyla were represented in our cultures. These results open up new research avenues for understanding the functional roles of these dominant bacteria in host health.
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Ledeboer, Nathan A., Bert K. Lopansri, Neelam Dhiman, Robert Cavagnolo, Karen C. Carroll, Paul Granato, Richard Thomson, et al. "Identification of Gram-Negative Bacteria and Genetic Resistance Determinants from Positive Blood Culture Broths by Use of the Verigene Gram-Negative Blood Culture Multiplex Microarray-Based Molecular Assay." Journal of Clinical Microbiology 53, no. 8 (May 20, 2015): 2460–72. http://dx.doi.org/10.1128/jcm.00581-15.
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Bloodstream infection is a serious condition associated with significant morbidity and mortality. The outcome of these infections can be positively affected by the early implementation of effective antibiotic therapy based on the identification of the infecting organism and genetic markers associated with antibiotic resistance. In this study, we evaluated the microarray-based Verigene Gram-negative blood culture (BC-GN) assay in the identification of 8 genus or species targets and 6 genetic resistance determinants in positive blood culture broths. A total of 1,847 blood cultures containing Gram-negative organisms were tested using the BC-GN assay. This comprised 729 prospective fresh, 781 prospective or retrospective frozen, and 337 simulated cultures representing 7 types of aerobic culture media. The results were compared to those with standard bacterial culture and biochemical identification with nucleic acid sequence confirmation of the resistance determinants. Among monomicrobial cultures, the positive percent agreement (PPA) of the BC-GN assay with the reference method was as follows; Escherichia coli , 100%; Klebsiella pneumoniae , 92.9%; Klebsiella oxytoca , 95.5%; Enterobacter spp., 99.3%; Pseudomonas aeruginosa , 98.9%; Proteus spp., 100%; Acinetobacter spp., 98.4%; and Citrobacter spp., 100%. All organism identification targets demonstrated >99.5% negative percent agreement (NPA) with the reference method. Of note, 25/26 cultures containing K. pneumoniae that were reported as not detected by the BC-GN assay were subsequently identified as Klebsiella variicola . The PPA for identification of resistance determinants was as follows; bla CTX-M , 98.9%; bla KPC , 100%; bla NDM , 96.2%; bla OXA , 94.3%; bla VIM , 100%; and bla IMP , 100%. All resistance determinant targets demonstrated >99.9% NPA. Among polymicrobial specimens, the BC-GN assay correctly identified at least one organism in 95.4% of the broths and correctly identified all organisms present in 54.5% of the broths. The sample-to-result processing and automated reading of the detection microarray results enables results within 2 h of culture positivity.
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Abe, Chiyoji, Kazue Hirano, and Tetsuo Tomiyama. "Simple and Rapid Identification of theMycobacterium tuberculosis Complex by Immunochromatographic Assay Using Anti-MPB64 Monoclonal Antibodies." Journal of Clinical Microbiology 37, no. 11 (1999): 3693–97. http://dx.doi.org/10.1128/jcm.37.11.3693-3697.1999.
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A newly developed immunochromatographic assay (MPB64-ICA) for identification of the Mycobacterium tuberculosis complex was evaluated with 20 reference strains of mycobacterial species and 111 clinical isolates. MPB64-ICA displayed a very strong reaction band with organisms belonging to the M. tuberculosis complex but not with mycobacteria other than M. tuberculosis (MOTT bacilli), except for one of four M. marinum strains tested and one M. flavescens strain, both of which gave very weak signals. The effectiveness of MPB64-ICA in combination with two liquid culture systems (MB-REDOX and MGIT) was tested. A total of 108 of 362 sputum specimens processed were positive for acid-fast bacilli. Samples taken from the cultures on the same days when either of the two culture systems became positive for mycobacteria were assayed with MPB64-ICA. Of 108 cultures with mycobacteria, 51 showed a positive signal with the test, in which the presence of the M. tuberculosis complex was demonstrated later by the Accuprobe for M. tuberculosiscomplex. In addition, MPB64-ICA could correctly detect the M. tuberculosis complex in mixed cultures of the M. tuberculosis complex and MOTT bacilli. These results indicate that MPB64-ICA can be easily used for rapid identification of theM. tuberculosis complex in combination with culture systems based on liquid media without any technical complexity in clinical laboratories.
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Lee, Ju-Hoon, Xiulan Li, and Daniel J. O'Sullivan. "Transcription Analysis of a Lantibiotic Gene Cluster from Bifidobacterium longum DJO10A." Applied and Environmental Microbiology 77, no. 17 (July 8, 2011): 5879–87. http://dx.doi.org/10.1128/aem.00571-11.
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ABSTRACTBifidobacterium longumDJO10A was previously demonstrated to produce a lantibiotic, but only during growth on agar media. To evaluate the feasibility of production of this lantibiotic in broth media, a transcription analysis of thelanAgene was undertaken. Comparative microarray analysis of broth and agar cultures ofB. longumDJO10A revealed that the lantibiotic production, modification, transport/peptidase, and immunity genes were significantly upregulated in agar cultures, while the two-component regulatory genes were expressed equally under both conditions. This suggested that the signal transduction regulatory system should function in broth cultures. Real-time PCR and Northern hybridization confirmed thatlanAgene expression was significantly repressed in broth cultures. A crude lantibiotic preparation from an agar-grown culture was obtained, and its antimicrobial spectrum analysis revealed a broad inhibition range. Addition of this extract to broth cultures ofB. longumDJO10A inducedlanAgene expression in a dose-dependent fashion. Subinoculation using >10% of an induced broth culture maintainedlanAexpression. The expression oflanAwas log-phase specific, being significantly downregulated in stationary phase. Transcription start analysis oflanArevealed a 284-bp 5′ untranslated region, which was proposed to be involved in repression of transcription, while an inverted repeat structure located at bp −75 relative to the transcription start was strategically located to likely function as a binding site for the two-component response regulator. Understanding the transcription regulation of thislanAgene is the first step toward enabling production of this novel and potentially interesting lantibiotic in broth cultures.
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Gutierrez, Noemi A., and Ian S. Maddox. "The effect of some culture maintenance and inoculum development techniques on solvent production by Clostridium acetobutylicum." Canadian Journal of Microbiology 33, no. 1 (January 1, 1987): 82–84. http://dx.doi.org/10.1139/m87-014.
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An investigation was made into some methods of culture maintenance and inoculum development procedures by which the production of solvents by Clostridium acetobutylicum could be maximized. Storage of the organism as spores in nonnutrient media at either 4 or −20 °C proved to be the most effective method of culture maintenance. On revival of stock cultures, neither heat shocking nor treatment with aqueous ethanol or butanol gave improvements in solvent production during the subsequent fermentation. However, significantly improved production was obtained when culture transfers during the inoculum development procedure were made at the time of maximum cell motility.
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Kim, H. W., A. Matin, and M. S. Rhee. "Microgravity Alters the Physiological Characteristics of Escherichia coli O157:H7 ATCC 35150, ATCC 43889, and ATCC 43895 under Different Nutrient Conditions." Applied and Environmental Microbiology 80, no. 7 (January 31, 2014): 2270–78. http://dx.doi.org/10.1128/aem.04037-13.
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ABSTRACTThe aim of this study is to provide understanding of microgravity effects on important food-borne bacteria,Escherichia coliO157:H7 ATCC 35150, ATCC 43889, and ATCC 43895, cultured in nutrient-rich or minimal medium. Physiological characteristics, such as growth (measured by optical density and plating), cell morphology, and pH, were monitored under low-shear modeled microgravity (LSMMG; space conditions) and normal gravity (NG; Earth conditions). In nutrient-rich medium, all strains except ATCC 35150 showed significantly higher optical density after 6 h of culture under LSMMG conditions than under NG conditions (P< 0.05). LSMMG-cultured cells were approximately 1.8 times larger than NG-cultured cells at 24 h; therefore, it was assumed that the increase in optical density was due to the size of individual cells rather than an increase in the cell population. The higher pH of the NG cultures relative to that of the LSMMG cultures suggests that nitrogen metabolism was slower in the latter. After 24 h of culturing in minimal media, LSMMG-cultured cells had an optical density 1.3 times higher than that of NG-cultured cells; thus, the higher optical density in the LSMMG cultures may be due to an increase in both cell size and number. Since bacteria actively grew under LSMMG conditions in minimal medium despite the lower pH, it is of some concern that LSMMG-culturedE. coliO157:H7 may be able to adapt well to acidic environments. These changes may be caused by changes in nutrient metabolism under LSMMG conditions, although this needs to be demonstrated in future studies.
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McAlpin, Cesaria E., and Donald T. Wicklow. "Culture media and sources of nitrogen promoting the formation of stromata and ascocarps in Petromyces alliaceus (Aspergillus section Flavi)." Canadian Journal of Microbiology 51, no. 9 (September 1, 2005): 765–71. http://dx.doi.org/10.1139/w05-057.
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Petromyces alliaceus Malloch and Cain is the only known sexually reproducing fungus classified in Asper gillus section Flavi. The goal of this research was to identify culture media and sources of nitrogen that best support the formation of stromata with ascocarps. Three cultures of P. alliaceus isolated from crop field soils were grown on selected agar media in Petri dishes for 7 months at 30 °C in darkness. The largest numbers of stromata were recorded for cultures grown on Czapek's agar (CZA) and a mixed cereal agar (MCA), while the percentage of stromata containing ascocarps was greatest (P ≤ 0.05) for cultures grown on MCA (25%–28%). When P. alliaceus was grown on standard CZA containing 0.3% NaNO3, only 5% of the stromata contained ascocarps. A greater percentage of the stromata (15%–22%) formed ascocarps when the NaNO3 in CZA was replaced with an equivalent amount of available nitrogen supplied by ammonium tartrate, glutamic acid, or serine.Key words: ascospores, homothallic, sclerotia, essential amino acids.
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Oz, Yasemin, Sukran Onder, Ekin Alpaslan, and Gul Durmaz. "Does concomitant bacteraemia hide the fungi in blood cultures? An in vitro study." Journal of Medical Microbiology 69, no. 7 (July 1, 2020): 944–48. http://dx.doi.org/10.1099/jmm.0.001210.
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Introduction. Polymicrobial infections including yeasts and bacteria are not rare and patients with polymicrobial bloodstream infection have higher early and overall case fatality rates. The diagnosis of invasive fungal and bacterial infections is mainly based on blood culture. Aim. The aim was to reveal the effect of concomitant bacteraemia on the detection of fungi from blood cultures in the presence of polymicrobial bloodstream infections involving Candida and non-Candida fungi and to show the superiority of blood culture bottles including selective fungal media in such situations. Methodology. Twenty-four polymicrobial bloodstream infection models – involving one fungus and one bacterium – were constituted by using clinical blood culture isolates ( Escherichia coli , Staphylococcus aureus , Pseudomonas aeruginosa , Candida albicans, Candida glabrata, Fusarium solani and Trichosporon asahii). The Plus Aerobic/F (PAF) and Mycosis IC/F (MICF) culture bottles were used with the BACTEC 9240 device. After a bottle signalled positive, direct microscopic examination and subcultures on agar plates were performed. Results. All of fungi that were inoculated alone and in combination were detected by both direct microscopic examination and subcultures on agar plates from MICF bottles, whereas direct microscopic examination only revealed the bacterial agents from PAF bottles including combinations. Furthermore, fungal growth was hidden by bacterial growth on blood agar subcultures from PAF bottles including combinations of F. solani, C. glabrata or T. asahii with bacteria. Conclusion. Blood culture bottles including selective fungal media that can allow selective growth of fungi and earlier detection of some species should be preferred in addition to non-selective blood culture bottles, especially in specific patient populations. Further, the use of selective agar plates such as inhibitory mould agar may contribute to the solution of this problem in clinical laboratories.
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Ajao, A. O., G. Robinson, M. S. Lee, T. D. Ranke, R. A. Venezia, J. P. Furuno, A. D. Harris, and J. K. Johnson. "Comparison of culture media for detection of Acinetobacter baumannii in surveillance cultures of critically-ill patients." European Journal of Clinical Microbiology & Infectious Diseases 30, no. 11 (April 12, 2011): 1425–30. http://dx.doi.org/10.1007/s10096-011-1237-7.
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Stokely, D. "Isolation of organisms in CAPD peritonitis: use of nutrient broth cultures and Bactec blood culture media." Journal of Hospital Infection 11, no. 1 (January 1988): 77–81. http://dx.doi.org/10.1016/0195-6701(88)90042-4.
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Clark, John, Deborah White, Esther Daubney, Martin Curran, Rachel Bousfield, Theodore Gouliouris, Elizabeth Powell, et al. "Low diagnostic yield and time to diagnostic confirmation results in prolonged use of antimicrobials in critically ill children." Wellcome Open Research 6 (May 18, 2021): 119. http://dx.doi.org/10.12688/wellcomeopenres.16848.1.
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Background: Broad-spectrum antimicrobial therapy is a key driver of antimicrobial resistance. Here, we aimed to review indications for antimicrobial therapy, determine the proportion of suspected bacterial infections that are confirmed by culture, and assess the time taken for microbiology test results to become available in the paediatric intensive care unit (PICU). Methods: A single-centre prospective observational cohort study of 100 consecutive general PICU admissions from 30 October 2019 to 19 February 2020. Data were collected from the hospital medical record and entered into a study database prior to statistical analysis using standard methods. Results: Of all episodes of suspected infection, 22% of lower respiratory tract infection, 43% of bloodstream and 0% of central nervous system infection were associated with growth on microbiology culture. 90% of children received antimicrobial therapy. Hospital-acquired infection occurred less commonly than primary infection, but an organism was grown in a greater proportion (64%) of cultures. Final laboratory reports for negative cultures were issued at a median of 120.3 hours for blood cultures and 55.5 hours for endotracheal tube aspirate cultures. Conclusions: Despite most critically children receiving antimicrobial therapy, infection was often not microbiologically confirmed. Novel molecular diagnostics may improve rationalisation of treatment in this population.
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Clark, John, Deborah White, Esther Daubney, Martin Curran, Rachel Bousfield, Theodore Gouliouris, Elizabeth Powell, et al. "Low diagnostic yield and time to diagnostic confirmation results in prolonged use of antimicrobials in critically ill children." Wellcome Open Research 6 (March 3, 2022): 119. http://dx.doi.org/10.12688/wellcomeopenres.16848.2.
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Background: Broad-spectrum antimicrobial therapy is a key driver of antimicrobial resistance. Here, we aimed to review indications for antimicrobial therapy, determine the proportion of suspected bacterial infections that are confirmed by culture, and assess the time taken for microbiology test results to become available in the paediatric intensive care unit (PICU). Methods: A single-centre prospective observational cohort study of 100 consecutive general PICU admissions from 30 October 2019 to 19 February 2020. Data were collected from the hospital medical record and entered into a study database prior to statistical analysis using standard methods. Results: Of all episodes of suspected infection, 22% of lower respiratory tract infection, 43% of bloodstream and 0% of central nervous system infection were associated with growth on microbiology culture. 90% of children received antimicrobial therapy. Hospital-acquired infection occurred less commonly than primary infection, but an organism was grown in a greater proportion (64%) of cultures. Final laboratory reports for negative cultures were issued at a median of 120.3 hours for blood cultures and 55.5 hours for endotracheal tube aspirate cultures. Conclusions: Despite most critically children receiving antimicrobial therapy, infection was often not microbiologically confirmed. Novel molecular diagnostics may improve rationalisation of treatment in this population.
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Parikh, Harshal R., Anuradha S. De, and Sujata M. Baveja. "Comparison of the Lysis Centrifugation Method with the Conventional Blood Culture Method in Cases of Sepsis in a Tertiary Care Hospital." Journal of Laboratory Physicians 4, no. 02 (July 2012): 089–93. http://dx.doi.org/10.4103/0974-2727.105588.
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ABSTRACT Introduction: Physicians and microbiologists have long recognized that the presence of living microorganisms in the blood of a patient carries with it considerable morbidity and mortality. Hence, blood cultures have become critically important and frequently performed test in clinical microbiology laboratories for diagnosis of sepsis Objectives: To compare the conventional blood culture method with the lysis centrifugation method in cases of sepsis. Materials and Methods: Two hundred nonduplicate blood cultures from cases of sepsis were analyzed using two blood culture methods concurrently for recovery of bacteria from patients diagnosed clinically with sepsis – the conventional blood culture method using trypticase soy broth and the lysis centrifugation method using saponin by centrifuging at 3000 g for 30 minutes. Results: Overall bacteria recovered from 200 blood cultures were 17.5%. The conventional blood culture method had a higher yield of organisms, especially Gram positive cocci. The lysis centrifugation method was comparable with the former method with respect to Gram negative bacilli. The sensitivity of lysis centrifugation method in comparison to conventional blood culture method was 49.75% in this study, specificity was 98.21% and diagnostic accuracy was 89.5%. In almost every instance, the time required for detection of the growth was earlier by lysis centrifugation method, which was statistically significant. Contamination by lysis centrifugation was minimal, while that by conventional method was high. Time to growth by the lysis centrifugation method was highly significant (P value 0.000) as compared to time to growth by the conventional blood culture method. Conclusion: For the diagnosis of sepsis, combination of the lysis centrifugation method and the conventional blood culture method with trypticase soy broth or biphasic media is advocable, in order to achieve faster recovery and a better yield of microorganisms.
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Basu, S., A. Pal, and PK Desai. "Quality control of culture media in a microbiology laboratory." Indian Journal of Medical Microbiology 23, no. 3 (2005): 159. http://dx.doi.org/10.4103/0255-0857.16586.
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Farfour, Eric, Lucie Limousin, Amandine Henry, Emilie Cardot, Pierre Cahen, Didier Lecointe, Emilie Jolly, Marc Vasse, and Damien Mathonnet. "Optimization of incubation duration of culture media in microbiology." Annales de Biologie Clinique 77, no. 5 (October 2019): 525–31. http://dx.doi.org/10.1684/abc.2019.1474.
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