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Disayathanoowat, Terd, HuanYuan Li, Natapon Supapimon, Nakarin Suwannarach, Saisamorn Lumyong, Panuwan Chantawannakul, and Jun Guo. "Different Dynamics of Bacterial and Fungal Communities in Hive-Stored Bee Bread and Their Possible Roles: A Case Study from Two Commercial Honey Bees in China." Microorganisms 8, no. 2 (February 15, 2020): 264. http://dx.doi.org/10.3390/microorganisms8020264.
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This study investigated both bacterial and fungal communities in corbicular pollen and hive-stored bee bread of two commercial honey bees, Apis mellifera and Apis cerana, in China. Although both honey bees favor different main floral sources, the dynamics of each microbial community is similar. During pH reduction in hive-stored bee bread, results from conventional culturable methods and next-generation sequencing showed a declining bacterial population but a stable fungal population. Different honey bee species and floral sources might not affect the core microbial community structure but could change the number of bacteria. Corbicular pollen was colonized by the Enterobacteriaceae bacterium (Escherichia-Shiga, Panteoa, Pseudomonas) group; however, the number of bacteria significantly decreased in hive-stored bee bread in less than 72 h. In contrast, Acinetobacter was highly abundant and could utilize protein sources. In terms of the fungal community, the genus Cladosporium remained abundant in both corbicular pollen and hive-stored bee bread. This filamentous fungus might encourage honey bees to reserve pollen by releasing organic acids. Furthermore, several filamentous fungi had the potential to inhibit both commensal/contaminant bacteria and the growth of pathogens. Filamentous fungi, in particular, the genus Cladosporium, could support pollen preservation of both honey bee species.
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Alimkulov, Zheksenkul, Saule Zhiyenbayeva, Gulgaisha Baygazieva, Ainash Rustemova, Nurgul Batyrbayeva, and Meruert Bayisbayeva. "Creation of multicomponent mix based on lactic bacteria consortium for flour enrichment." International Journal of Engineering & Technology 7, no. 2.13 (April 15, 2018): 136. http://dx.doi.org/10.14419/ijet.v7i2.13.11627.
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This article presents the results on creating the probiotic preparation with inclusion of microorganisms of highly productive lactic bacteria cultures with high biosynthetic and bactericidal properties. Conditions for production of bacterial preparation and multicomponent mix for flour enrichment and bread making were developed. Composition of the produced improving agent and premix for flour enrichment was studied and conditions for flour enrichment using the produced biological improving agent based on lactic bacteria were developed. Technological parameters of flour semi-products where determined on addition of the enriched flour. It was determined that produced improving agent plays a key role in transformation of protein-proteinase and carbohydrate-amylase flour complex, thereby improving the structural-mechanical properties of dough and further resulting in production of elastic crumb with thin-walled and even texture.
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Lynch, Kieran M., Aidan Coffey, and Elke K. Arendt. "Exopolysaccharide producing lactic acid bacteria: Their techno-functional role and potential application in gluten-free bread products." Food Research International 110 (August 2018): 52–61. http://dx.doi.org/10.1016/j.foodres.2017.03.012.
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Rokop, Z. P., M. A. Horton, and I. L. G. Newton. "Interactions between Cooccurring Lactic Acid Bacteria in Honey Bee Hives." Applied and Environmental Microbiology 81, no. 20 (August 7, 2015): 7261–70. http://dx.doi.org/10.1128/aem.01259-15.
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ABSTRACTIn contrast to the honey bee gut, which is colonized by a few characteristic bacterial clades, the hive of the honey bee is home to a diverse array of microbes, including many lactic acid bacteria (LAB). In this study, we used culture, combined with sequencing, to sample the LAB communities found across hive environments. Specifically, we sought to use network analysis to identify microbial hubs sharing nearly identical operational taxonomic units, evidence which may indicate cooccurrence of bacteria between environments. In the process, we identified interactions between noncore bacterial members (FructobacillusandLactobacillaceae) and honey bee-specific “core” members. BothFructobacillusandLactobacillaceaecolonize brood cells, bee bread, and nectar and may serve the role of pioneering species, establishing an environment conducive to the inoculation by honey bee core bacteria. Coculture assays showed that these noncore bacterial members promote the growth of honey bee-specific bacterial species. Specifically,Fructobacillusby-products in spent medium supported the growth of the Firm-5 honey bee-specific cladein vitro. Metabolic characterization ofFructobacillususing carbohydrate utilization assays revealed that this strain is capable of utilizing the simple sugars fructose and glucose, as well as the complex plant carbohydrate lignin. We testedFructobacillusfor antibiotic sensitivity and found that this bacterium, which may be important for establishment of the microbiome, is sensitive to the commonly used antibiotic tetracycline. Our results point to the possible significance of “noncore” and environmental microbial community members in the modulation of honey bee microbiome dynamics and suggest that tetracycline use by beekeepers should be limited.
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Haro, Carmen, Myriam Villatoro, Luis Vaquero, Jorge Pastor, María Giménez, Carmen Ozuna, Susana Sánchez-León, et al. "The Dietary Intervention of Transgenic Low-Gliadin Wheat Bread in Patients with Non-Celiac Gluten Sensitivity (NCGS) Showed No Differences with Gluten Free Diet (GFD) but Provides Better Gut Microbiota Profile." Nutrients 10, no. 12 (December 12, 2018): 1964. http://dx.doi.org/10.3390/nu10121964.
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The study evaluated the symptoms, acceptance, and digestibility of bread made from transgenic low-gliadin wheat, in comparison with gluten free bread, in Non-coeliac gluten sensitivity (NCGS) patients, considering clinical/sensory parameters and gut microbiota composition. This study was performed in two phases of seven days each, comprising a basal phase with gluten free bread and an E82 phase with low-gliadin bread. Gastrointestinal clinical symptoms were evaluated using the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire, and stool samples were collected for gluten immunogenic peptides (GIP) determination and the extraction of gut microbial DNA. For the basal and E82 phases, seven and five patients, respectively, showed undetectable GIPs content. The bacterial 16S rRNA gene V1-V2 hypervariable regions were sequenced using the Illumina MiSeq platform and downstream analysis was done using a Quantitative Insights into Microbial Ecology (QIIME) pipeline. No significant differences in the GSRS questionnaires were observed between the two phases. However, we observed a significantly lower abundance of some gut genera Oscillospira, Dorea, Blautia, Bacteroides, Coprococcus, and Collinsella, and a significantly higher abundance of Roseburia and Faecalibacterium genera during the E82 phase compared with the basal phase. The consumption of low-gliadin bread E82 by NCGS subjects induced potentially positive changes in the gut microbiota composition, increasing the butyrate-producing bacteria and favoring a microbial profile that is suggested to have a key role in the maintenance or improvement of gut permeability.
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Muñoz-Colmenero, Marta, Igor Baroja-Careaga, Marin Kovačić, Janja Filipi, Zlatko Puškadija, Nikola Kezić, Andone Estonba, Ralph Büchler, and Iratxe Zarraonaindia. "Differences in honey bee bacterial diversity and composition in agricultural and pristine environments – a field study." Apidologie 51, no. 6 (July 29, 2020): 1018–37. http://dx.doi.org/10.1007/s13592-020-00779-w.
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AbstractAgrochemicals and biocides are suspected to cause a dysbiosis of honey bee microbiota, decreasing colonies ability to respond to the environment. As a first step to investigate agriculture and beekeeping impact, hives bacteriomes from an anthropized environment (Agri-env) were compared to that of pristine’s (Prist-env). 16S rRNA sequencing evidenced differences in richness and composition between sample types (Gut (G), Brood (B), Bee-bread (BB)) and environments. Higher opportunist loads and shifts toward taxa capable of metabolizing insecticides were observed in G and B at Agri-env, while beneficial bacteria were enriched in Prist-env. Bacteria in BB did not differ, the acidity of the niche outweighing the influence of external factors. Results showed the environment plays a major role in shaping honey bee microbiota, the agricultural realm inducing a bacterial disruption that would let to colonies vulnerability. In contrast, a less susceptible bee will be promoted in less anthropized locations.
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Mason, Katie L., John R. Erb Downward, Kelly D. Mason, Nicole R. Falkowski, Kathryn A. Eaton, John Y. Kao, Vincent B. Young, and Gary B. Huffnagle. "Candida albicans and Bacterial Microbiota Interactions in the Cecum during Recolonization following Broad-Spectrum Antibiotic Therapy." Infection and Immunity 80, no. 10 (July 9, 2012): 3371–80. http://dx.doi.org/10.1128/iai.00449-12.
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ABSTRACTCandida albicansis a normal member of the gastrointestinal (GI) tract microbiota of healthy humans, but during host immunosuppression or alterations in the bacterial microbiota,C. albicanscan disseminate and cause life-threatening illness. The bacterial microbiome of the GI tract, including lactic acid bacteria (LAB), plays a vital role in preventing fungal invasion. However, little is known about the role ofC. albicansin shaping the bacterial microbiota during antibiotic recovery. We investigated the fungal burdens in the GI tracts of germfree mice and mice with a disturbed microbiome to demonstrate the role of the microbiota in preventingC. albicanscolonization. Histological analysis demonstrated that colonization withC. albicansduring antibiotic treatment does not trigger overt inflammation in the murine cecum. Bacterial diversity is reduced long term following cefoperazone treatment, but the presence ofC. albicansduring antibiotic recovery promoted the recovery of bacterial diversity. Cefoperazone diminishesBacteroidetespopulations long term in the ceca of mice, but the presence ofC. albicansduring cefoperazone recovery promotedBacteroidetespopulation recovery. However, the presence ofC. albicansresulted in a long-term reduction inLactobacillusspp. and promotedEnterococcus faecalispopulations. Previous studies have focused on the ability of bacteria to alterC. albicans; this study addresses the ability ofC. albicansto alter the bacterial microbiota during nonpathogenic colonization.
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Sijabat, Octanina Sari, Marheni Marheni, and Darma Bakti. "THE IDENTIFICATION OF BACTERIAL SYMBIONT’S OF THE LARVAE ORYCTES RHINOCEROS L. AND THE ROLE OF THE BACTERIA IN COMPOSTING PROCESS." Journal of Community Research and Service 1, no. 2 (March 28, 2018): 43. http://dx.doi.org/10.24114/jcrs.v1i2.9334.
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AbstractOryctes rhinoceros L. has symbioses with micro organisms in their hind guts which further break down plant material consumed by beetle. The aim of this research is to determine the identification of the existence of the bacterial species in the hind gut larvae of the symbiotic bacteria using biochemical test and analysis based on 16S rRNA. The result of this research indicate that there were two different bacterials: Bacillus siamensis and Bacillus stratosphericus found. The bacteria was used for starting the composting and more specifically, the Bacillus siamensis can speed up composting with the end result at C/N 13.16.Keywords: Larvae O. rhinoceros L, Bacterial Symbionts, 16S rDNA, Composting
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Petnicki-Ocwieja, Tanja, Tomas Hrncir, Yuen-Joyce Liu, Amlan Biswas, Tomas Hudcovic, Helena Tlaskalova-Hogenova, and Koichi S. Kobayashi. "Nod2 is required for the regulation of commensal microbiota in the intestine." Proceedings of the National Academy of Sciences 106, no. 37 (September 1, 2009): 15813–18. http://dx.doi.org/10.1073/pnas.0907722106.
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Mutations in the Nod2 gene are among the strongest genetic risk factors in the pathogenesis of ileal Crohn's disease, but the exact contributions of Nod2 to intestinal mucosal homeostasis are not understood. Here we show that Nod2 plays an essential role in controlling commensal bacterial flora in the intestine. Analysis of intestinal bacteria from the terminal ilea of Nod2-deficient mice showed that they harbor an increased load of commensal resident bacteria. Furthermore, Nod2-deficient mice had a diminished ability to prevent intestinal colonization of pathogenic bacteria. In vitro, intestinal crypts isolated from terminal ilea of Nod2-deficient mice were unable to kill bacteria effectively, suggesting an important role of Nod2 signaling in crypt function. Interestingly, the expression of Nod2 is dependent on the presence of commensal bacteria, because mice re-derived into germ-free conditions expressed significantly less Nod2 in their terminal ilea, and complementation of commensal bacteria into germ-free mice induced Nod2 expression. Therefore, Nod2 and intestinal commensal bacterial flora maintain a balance by regulating each other through a feedback mechanism. Dysfunction of Nod2 results in a break-down of this homeostasis.
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Liu, Yuan, Jingru Shi, Ziwen Tong, Yuqian Jia, Kangni Yang, and Zhiqiang Wang. "Potent Broad-Spectrum Antibacterial Activity of Amphiphilic Peptides against Multidrug-Resistant Bacteria." Microorganisms 8, no. 9 (September 11, 2020): 1398. http://dx.doi.org/10.3390/microorganisms8091398.
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The emergence and prevalence of multidrug-resistant (MDR) bacteria particularly Gram-negative bacteria presents a global crisis for human health. Colistin and tigecycline were recognized as the last resort of defenses against MDR Gram-negative pathogens. However, the emergence and prevalence of MCR or Tet(X)-mediated acquired drug resistance drastically impaired their clinical efficacy. It has been suggested that antimicrobial peptides might act a crucial role in combating antibiotic resistant bacteria owing to their multiple modes of action and characteristics that are not prone to developing drug resistance. Herein, we report a safe and stable tryptophan-rich amphiphilic peptide termed WRK-12 with broad-spectrum antibacterial activity against various MDR bacteria, including MRSA, colistin and tigecycline-resistant Escherichia coli. Mechanistical studies showed that WRK-12 killed resistant E. coli through permeabilizing the bacterial membrane, dissipating membrane potential and triggering the production of reactive oxygen species (ROS). Meanwhile, WRK-12 significantly inhibited the formation of an E. coli biofilm in a dose-dependent manner. These findings revealed that amphiphilic peptide WRK-12 is a promising drug candidate in the fight against MDR bacteria.
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Oluwagbemigun, Kolade, Jana Foerster, Claire Watkins, Fiona Fouhy, Catherine Stanton, Manuela M. Bergmann, Heiner Boeing, and Ute Nöthlings. "Dietary Patterns Are Associated with Serum Metabolite Patterns and Their Association Is Influenced by Gut Bacteria among Older German Adults." Journal of Nutrition 150, no. 1 (September 2, 2019): 149–58. http://dx.doi.org/10.1093/jn/nxz194.
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ABSTRACT Background Although dietary intakes and dietary intake patterns (DPs) have been associated with single metabolites, it is unclear whether DPs are also reflected in specific metabolite patterns (MPs). Moreover, the influence of groups of gut bacteria on the relationship between DPs and MPs is underexplored. Objectives We aimed to investigate the association of DPs and serum MPs and also the modifying effect of the gut bacteria compositional patterns (BCPs). Methods This is a cross-sectional investigation among 225 individuals (median age: 63 y; 53% women) from the European Prospective Investigation into Cancer and Nutrition study. Dietary intakes were assessed by three 24-h dietary recalls, gut bacteria composition was quantified by 16S rRNA gene sequencing, and the serum metabolome was profiled by an untargeted approach. We identified DPs and BCPs by the treelet transform analysis. We modeled associations between DPs and 8 previously published MPs and the modifying effect of BCPs by fitting generalized linear models using DataSHIELD R. Results We identified 5 DPs and 7 BCPs. The “bread, margarine, and processed meat” and “fruiting vegetables and vegetable oils” DPs were positively associated with the “amino acids” (β = 0.35; 95% CI: 0.02, 0.69; P = 0.03) and “fatty acids” MPs (β = 0.45; 95% CI: 0.16, 0.74; P = 0.01), respectively. The “tea and miscellaneous” was inversely associated with the “amino acids” (β = −0.28; 95% CI: −0.52, −0.05; P = 0.02) and “amino acid derivatives” MPs (β = −0.21; 95% CI: −0.39, −0.02; P = 0.03). One BCP negatively modified the association between the “bread, margarine, and processed meat” DP and the “amino acids” MP (P-interaction = 0.01). Conclusions In older German adults, DPs are reflected in MPs, and the gut bacteria attenuate 1 DP–MP association. These MPs should be explored as biomarkers of these jointly consumed foods while taking into account a potentially modifying role of the gut bacteria.
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Mawardi, H., G. Giro, M. Kajiya, K. Ohta, S. Almazrooa, E. Alshwaimi, S. B. Woo, I. Nishimura, and T. Kawai. "A Role of Oral Bacteria in Bisphosphonate-induced Osteonecrosis of the Jaw." Journal of Dental Research 90, no. 11 (September 15, 2011): 1339–45. http://dx.doi.org/10.1177/0022034511420430.
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No consensus has yet been reached to associate oral bacteria conclusively with the etio-pathogenesis of bisphosphonate-induced osteonecrosis of the jaw (BONJ). Therefore, the present study examined the effects of oral bacteria on the development of BONJ-like lesions in a mouse model. In the pamidronate (Pam)-treated mice, but not control non-drug-treated mice, tooth extraction followed by oral infection with Fusobacterium nucleatum caused BONJ-like lesions and delayed epithelial healing, both of which were completely suppressed by a broad-spectrum antibiotic cocktail. Furthermore, in both in vitro and in vivo experiments, the combination of Pam and Fusobacterium nucleatum caused the death of gingival fibroblasts (GFs) and down-regulated their production of keratinocyte growth factor (KGF), which induces epithelial cell growth and migration. Therefore, in periodontal tissues pre-exposed to bisphosphonate, bacterial infection at tooth extraction sites caused diminished KGF expression in GFs, leading to a delay in the epithelial wound-healing process that was mitigated by antibiotics.
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Ginting, Elvy L., Veibe Warouw, and Rizal W. Suleman. "AKTIVITAS ANTIBAKTERI DARI EKSTRAK KASAR BAKTERI YANG BERASOSIASI DENGAN SPONGE Acanthostrongylophora sp." JURNAL PERIKANAN DAN KELAUTAN TROPIS 6, no. 3 (December 30, 2010): 160. http://dx.doi.org/10.35800/jpkt.6.3.2010.162.
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Sponges have a potential to produce bioactive compounds. Their ability to do it since there is a symbiotic relationship with microorganisms in these bacteria. Because of this critical role, the bacteria symbiotic with sponge allegedly have great potential in terms of producing bioactive compounds that have been isolated from sponges (Lee, et al, 2001). In this study, using bacterial culture preparations isolated from the sponge, Acanthostrongylophora sp., the bacterial isolates were tested for their antibacterial activities using a well diffusion test. Based on the antibacterial activity test, the bacterial isolates known as BPO (shaped wavy white dots) and BPB (white threadlike have a certain type of thread) had antibacterial activity. ODS had a broad spectrum as potent against all three types of tested bacteria (Vibrio cholerae, Staphyloccocus aureus, Bacillus subtillis).
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Yan, Bowen, Huayu Yang, Yejun Wu, Huizhang Lian, Hao Zhang, Wei Chen, Daming Fan, and Jianxin Zhao. "Quality Enhancement Mechanism of Alkali-Free Chinese Northern Steamed Bread by Sourdough Acidification." Molecules 25, no. 3 (February 7, 2020): 726. http://dx.doi.org/10.3390/molecules25030726.
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Alkali was used to adjust the pH and neutralize the excess acids of dough in the processing of Chinese northern steamed bread (CNSB). However, extra alkali addition generally resulted in alkalic flavor and poor appearance. The aim of this work was to investigate the role of proofed dough pH on the texture of CNSB. Correlation analysis demonstrated that the pH value of proofed dough has a significant effect on the textural properties of CNSB. The mechanism studies found that gradual acidification of dough by lactic acid bacteria is a critical factor affecting the process. Conversely, chemical acidification weakened the texture property of products and reduced the dough rheology. Scanning electron microscope (SEM) analysis showed that fermentation with starter for 12 h produced a continuous and extensional protein network in the proofed dough. Furthermore, the decreasing pH of proofed dough increased the extractability of protein in a sodium dodecyl sulfate (SDS)-containing medium and the content of free sulfhydryl (SH). The structure and content of gluten, especially influenced by gradual acidification level, change the quality of the final product. It is a novel approach to obtain an alkali-free CNSB with excellent quality by moderate gluten adjustment.
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Burnham, Carey-Ann, and Marin Kollef. "Ventilator-Associated Pneumonia: The Role of Emerging Diagnostic Technologies." Seminars in Respiratory and Critical Care Medicine 38, no. 03 (June 2017): 253–63. http://dx.doi.org/10.1055/s-0037-1599224.
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AbstractAntibiotic resistance has emerged as a key determinant of outcome in patients with serious infections along with the virulence of the underlying pathogen. Within the intensive care unit (ICU) setting, ventilator-associated pneumonia (VAP) is a common nosocomial infection that is frequently caused by multidrug-resistant bacteria. Antimicrobial resistance is a growing challenge in the care of critically ill patients. Escalating rates of antibiotic resistance add substantially to the morbidity, mortality, and cost related to infection in the ICU. Both gram-positive organisms, such as methicillin-resistant Staphylococcus aureus and vancomycin-intermediate S. aureus, and gram-negative bacteria, including Pseudomonas aeruginosa, Acinetobacter species, carbapenem-resistant Enterobacteriaceae, such as the Klebsiella pneumoniae carbapenemase–producing bacteria, and extended spectrum β-lactamase organisms, have contributed to the escalating rates of resistance seen in VAP and other nosocomial infections. The rising rates of antimicrobial resistance have led to the routine empiric administration of broad-spectrum antibiotics even when bacterial infection is not documented. Moreover, there are several new broader-spectrum antibiotics that have recently become available and others scheduled for approval in the near future. The challenge to ICU clinicians is how to most effectively utilize these agents to maximize patient benefits while minimizing further emergence of resistance. Use of rapid diagnostics may hold the key for achieving this important balance. There is an urgent need for integrating the administration of new and existing antibiotics with the emerging rapid diagnostic technologies in a way that is both cost-effective and sustainable for the long run.
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Bonilla, Carla Y. "Generally Stressed Out Bacteria: Environmental Stress Response Mechanisms in Gram-Positive Bacteria." Integrative and Comparative Biology 60, no. 1 (February 11, 2020): 126–33. http://dx.doi.org/10.1093/icb/icaa002.
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Abstract The ability to monitor the environment for toxic chemical and physical disturbances is essential for bacteria that live in dynamic environments. The fundamental sensing mechanisms and physiological responses that allow bacteria to thrive are conserved even if the molecular components of these pathways are not. The bacterial general stress response (GSR) represents a conceptual model for how one pathway integrates a wide range of environmental signals, and how a generalized system with broad molecular responses is coordinated to promote survival likely through complementary pathways. Environmental stress signals such as heat, osmotic stress, and pH changes are received by sensor proteins that through a signaling cascade activate the sigma factor, SigB, to regulate over 200 genes. Additionally, the GSR plays an important role in stress priming that increases bacterial fitness to unrelated subsequent stressors such as oxidative compounds. While the GSR response is implicated during oxidative stress, the reason for its activation remains unknown and suggests crosstalk between environmental and oxidative stress sensors and responses to coordinate antioxidant functions. Systems levels studies of cellular responses such as transcriptomes, proteomes, and metabolomes of stressed bacteria and single-cell analysis could shed light into the regulated functions that protect, remediate, and minimize damage during dynamic environments. This perspective will focus on fundamental stress sensing mechanisms and responses in Gram-positive bacterial species to illustrate their commonalities at the molecular and physiological levels; summarize exciting directions; and highlight how system-level approaches can help us understand bacterial physiology.
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Kabbara, Samar, Baptiste Bidon, Jaafar Kilani, Marwan Osman, Monzer Hamze, Ann M. Stock, and Nicolas Papon. "Cytokinin Sensing in Bacteria." Biomolecules 10, no. 2 (January 25, 2020): 186. http://dx.doi.org/10.3390/biom10020186.
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Although it has long been known that bacteria detect and react to plant chemicals to establish an interaction, the cellular signaling mechanisms involved in these perception processes have hitherto remained obscure. Some exciting recent advances in the field have described, for the first time, how some phytopathogenic bacteria sense the host plant hormones, cytokinins. These discoveries not only advance the understanding of cell signaling circuitries engaged in cytokinin sensing in non-plant organisms, but also increase our knowledge of the broad role of these ancient molecules in regulating intra- and interspecific communications.
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Binsker, Ulrike, Thomas P. Kohler, and Sven Hammerschmidt. "Contribution of Human Thrombospondin-1 to the Pathogenesis of Gram-Positive Bacteria." Journal of Innate Immunity 11, no. 4 (2019): 303–15. http://dx.doi.org/10.1159/000496033.
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A successful colonization of different compartments of the human host requires multifactorial contacts between bacterial surface proteins and host factors. Extracellular matrix proteins and matricellular proteins such as thrombospondin-1 play a pivotal role as adhesive substrates to ensure a strong interaction with pathobionts like the Gram-positive Streptococcus pneumoniae and Staphylococcus aureus. The human glycoprotein thrombospondin-1 is a component of the extracellular matrix and is highly abundant in the bloodstream during bacteremia. Human platelets secrete thrombospondin-1, which is then acquired by invading pathogens to facilitate colonization and immune evasion. Gram-positive bacteria express a broad spectrum of surface-exposed proteins, some of which also recognize thrombospondin-1. This review highlights the importance of thrombospondin-1 as an adhesion substrate to facilitate colonization, and we summarize the variety of thrombospondin-1-binding proteins of S. pneumoniae and S. aureus.
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Lokachuk, M. N., V. K. Khlestkin, O. A. Savkina, L. I. Kuznetzova, and E. N. Pavlovskaya. "Change in the microbiota of dense rye starter during long-term maintenance." Khleboproducty 29, no. 11 (2020): 33–37. http://dx.doi.org/10.32462/0235-2508-2020-29-11-33-37.
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The article is devoted to the study of the microbial starter cultures preservation during the process of long-term maintenance of the sourdough in the laboratory, as well as the study of the influence of microbiota changes on the physicochemical indicators of the sourdough. The leading role in sourdough is played by lactic acid bacteria and yeast, the quality of the starter culture and bread itself largely depends on the ratio and species diversity of this microorganisms. The strains of L. paracasei / L. casei 5, L. paracasei / L. casei 63, L. plantarum 78 and the yeast C. milleri Chernorechensky are used to prepare sourdough. It was shown that the use of starter cultures of lactic acid bacteria and yeast in the technology of dense rye sourdough leads to the dominance of starter microorganisms and the sourdough production having good biotechnological characteristics already in the first phase of preparinf. However, with long-term maintenance of the sourdough, new species of lactic acid bacteria begin to dominate, which differ from those introduced in first phase. It was found that changes in the starter culture microbiota had a significant effect on the physicochemical indicators of the starter culture quality.
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Dougas, Georgios, Athanassios Tsakris, Stavroula Beleri, Eleni Patsoula, Maria Linou, Charalambos Billinis, and Joseph Papaparaskevas. "Molecular Evidence of a Broad Range of Pathogenic Bacteria in Ctenocephalides spp.: Should We Re-Examine the Role of Fleas in the Transmission of Pathogens?" Tropical Medicine and Infectious Disease 6, no. 1 (March 17, 2021): 37. http://dx.doi.org/10.3390/tropicalmed6010037.
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The internal microbiome of common cat and dog fleas was studied for DNA evidence of pathogenic bacteria. Fleas were grouped in pools by parasitized animal. DNA was extracted and investigated with 16S metagenomics for medically relevant (MR) bacteria, based on the definitions of the International Statistical Classification of Diseases and Related Health Problems (WHO). The MR bacterial species totaled 40, were found in 60% of flea-pools (N = 100), and included Acinetobacterbaumannii, Bacteroidesfragilis, Clostridiumperfringens, Enterococcusfaecalis, E. mundtii, Fusobacteriumnucleatum, Haemophilusaegyptius, Kingellakingae, Klebsiellapneumoniae, Leptotrichiabuccalis, L. hofstadii, Moraxellalacunata, Pasteurellamultocida, Propionibacteriumacnes, P. propionicum, Proteusmirabilis, Pseudomonasaeruginosa, Rickettsiaaustralis, R. hoogstraalii, Salmonellaenterica, and various Bartonella, Staphylococcus, and Streptococcus species. B. henselae (p = 0.004) and B. clarridgeiae (p = 0.006) occurred more frequently in fleas from cats, whereas Rickettsiahoogstraalii (p = 0.031) and Propionibacteriumacnes (p = 0.029) had a preference in fleas from stray animals. Most of the discovered MR species can form biofilm, and human exposure may theoretically occur through the flea-host interface. The fitness of these pathogenic bacteria to cause infection and the potential role of fleas in the transmission of a broad range of diseases should be further investigated.
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Zhong, Lipeng, Jiye Liu, Shiyu Teng, and Zhixiong Xie. "Identification of a Novel Cathelicidin from the Deinagkistrodon acutus Genome with Antibacterial Activity by Multiple Mechanisms." Toxins 12, no. 12 (December 4, 2020): 771. http://dx.doi.org/10.3390/toxins12120771.
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The abuse of antibiotics and the consequent increase of drug-resistant bacteria constitute a serious threat to human health, and new antibiotics are urgently needed. Research shows that antimicrobial peptides produced by natural organisms are potential substitutes for antibiotics. Based on Deinagkistrodonacutus (known as five-pacer viper) genome bioinformatics analysis, we discovered a new cathelicidin antibacterial peptide which was called FP-CATH. Circular dichromatic analysis showed a typical helical structure. FP-CATH showed broad-spectrum antibacterial activity. It has antibacterial activity to Gram-negative bacteria and Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). The results of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that FP-CATH could cause the change of bacterial cell integrity, having a destructive effect on Gram-negative bacteria and inducing Gram-positive bacterial surface formation of vesicular structure. FP-CATH could bind to LPS and showed strong binding ability to bacterial DNA. In vivo, FP-CATH can improve the survival rate of nematodes in bacterial invasion experiments, and has a certain protective effect on nematodes. To sum up, FP-CATH is likely to play a role in multiple mechanisms of antibacterial action by impacting bacterial cell integrity and binding to bacterial biomolecules. It is hoped that the study of FP-CATH antibacterial mechanisms will prove useful for development of novel antibiotics.
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Andersson, Jourdan A., Eric C. Fitts, Michelle L. Kirtley, Duraisamy Ponnusamy, Alex G. Peniche, Sara M. Dann, Vladimir L. Motin, et al. "New Role for FDA-Approved Drugs in Combating Antibiotic-Resistant Bacteria." Antimicrobial Agents and Chemotherapy 60, no. 6 (April 11, 2016): 3717–29. http://dx.doi.org/10.1128/aac.00326-16.
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Antibiotic resistance in medically relevant bacterial pathogens, coupled with a paucity of novel antimicrobial discoveries, represents a pressing global crisis. Traditional drug discovery is an inefficient and costly process; however, systematic screening of Food and Drug Administration (FDA)-approved therapeutics for other indications in humans offers a rapid alternative approach. In this study, we screened a library of 780 FDA-approved drugs to identify molecules that rendered RAW 264.7 murine macrophages resistant to cytotoxicity induced by the highly virulentYersinia pestisCO92 strain. Of these compounds, we identified 94 not classified as antibiotics as being effective at preventingY. pestis-induced cytotoxicity. A total of 17 prioritized drugs, based on efficacy inin vitroscreens, were chosen for further evaluation in a murine model of pneumonic plague to delineate ifin vitroefficacy could be translatedin vivo. Three drugs, doxapram (DXP), amoxapine (AXPN), and trifluoperazine (TFP), increased animal survivability despite not exhibiting any direct bacteriostatic or bactericidal effect onY. pestisand having no modulating effect on crucialY. pestisvirulence factors. These findings suggested that DXP, AXPN, and TFP may modulate host cell pathways necessary for disease pathogenesis. Finally, to further assess the broad applicability of drugs identified fromin vitroscreens, the therapeutic potential of TFP, the most efficacious drugin vivo, was evaluated in murine models ofSalmonella entericaserovar Typhimurium andClostridium difficileinfections. In both models, TFP treatment resulted in increased survivability of infected animals. Taken together, these results demonstrate the broad applicability and potential use of nonantibiotic FDA-approved drugs to combat respiratory and gastrointestinal bacterial pathogens.
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Gerna, Davide, Thomas Roach, Birgit Mitter, Wolfgang Stöggl, and Ilse Kranner. "Hydrogen Peroxide Metabolism in Interkingdom Interaction Between Bacteria and Wheat Seeds and Seedlings." Molecular Plant-Microbe Interactions® 33, no. 2 (February 2020): 336–48. http://dx.doi.org/10.1094/mpmi-09-19-0248-r.
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In endophytes, the abundance of genes coding for enzymes processing reactive oxygen species (ROS), including hydrogen peroxide (H2O2), argues for a crucial role of ROS metabolism in plant-microbe interaction for plant colonization. Here, we studied H2O2 metabolism of bread wheat (Triticum aestivum L.) seeds and their microbiota during germination and early seedling growth, the most vulnerable stages in the plant life cycle. Treatment with hot steam diminished the seed microbiota, and these seeds produced less extracellular H2O2 than untreated seeds. Using a culture-dependent approach, Pantoea and Pseudomonas genera were the most abundant epiphytes of dry untreated seeds. Incubating intact seedlings from hot steam–treated seeds with Pantoea strains triggered H2O2 production, whereas Pseudomonas strains dampened H2O2 levels, attributable to higher catalase activities. The genus Pantoea was much less represented among seedling endophytes than genus Pseudomonas, with other endophytic genera, including Bacillus and Paenibacillus, also possessing high catalase activities. Overall, our results show that certain bacteria of the seed microbiota are able to modulate the extracellular redox environment during germination and early seedling growth, and high catalase activity is proposed as a key trait of seed endophytes.
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Porrini, Constance, Nalini Ramarao, and Seav-Ly Tran. "Dr. NO and Mr. Toxic – the versatile role of nitric oxide." Biological Chemistry 401, no. 5 (April 28, 2020): 547–72. http://dx.doi.org/10.1515/hsz-2019-0368.
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AbstractNitric oxide (NO) is present in various organisms from humans, to plants, fungus and bacteria. NO is a fundamental signaling molecule implicated in major cellular functions. The role of NO ranges from an essential molecule to a potent mediator of cellular damages. The ability of NO to react with a broad range of biomolecules allows on one hand its regulation and a gradient concentration and on the other hand to exert physiological as well as pathological functions. In humans, NO is implicated in cardiovascular homeostasis, neurotransmission and immunity. However, NO can also contribute to cardiovascular diseases (CVDs) or septic shock. For certain denitrifying bacteria, NO is part of their metabolism as a required intermediate of the nitrogen cycle. However, for other bacteria, NO is toxic and harmful. To survive, those bacteria have developed processes to resist this toxic effect and persist inside their host. NO also contributes to maintain the host/microbiota homeostasis. But little is known about the impact of NO produced during prolonged inflammation on microbiota integrity, and some pathogenic bacteria take advantage of the NO response to colonize the gut over the microbiota. Taken together, depending on the environmental context (prolonged production, gradient concentration, presence of partners for interaction, presence of oxygen, etc.), NO will exert its beneficial or detrimental function. In this review, we highlight the dual role of NO for humans, pathogenic bacteria and microbiota, and the mechanisms used by each organism to produce, use or resist NO.
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Hakiki, Dalhar, Latief Mooduto, Ketut Suardita, and Dian Agustin Wahjuningrum. "Effectiveness of flavonoid from mangosteen pericarp (Garcinia mangostana L.) as Enterococcus faecalis antibiofilm." Conservative Dentistry Journal 7, no. 1 (September 27, 2019): 18. http://dx.doi.org/10.20473/cdj.v7i1.2017.18-22.
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Background:Enterococcus faecalis (E. faecalis) is a microorganism that is commonly found in endodontic failure treatment, this due to several characteristics of E.faecalis which has the capabillity to living in environments with high salt levels, high temperature, and pH broad spectrum. Bacteria in biofilms form is one of the adaptive process that allows bacteria to survive in an environment with low nutrients in the root canals. Bacteria in biofilms form have different characteristics from planktonic form, resistance to phagocytic cells and drugs, which can effect to persistent infection. Mangosteen (Garcinia mangostana) has many benefits, especially on the pericarp of the fruit contains alkaloids, tannins, phenolics, flavonoids, and triterpenoids. Flavonoids are the largest group of phenolic compounds that have a nature effectively inhibit the growth of viruses, bacteria, and fungi. Purpose:Purpose of this study wasto find out the role of the antibiofilm of the flavonoid in garcinia mangostana pericarp against E. faecalis bacterial biofilm. Methods:Laboratory experimental in-vitro with post test only group design. The method used is microtitter plate biofilm assay and continued with the readings use Elisa reader at a wavelength of 595 nm. Results:Flavonoids mangosteen pericarp effective as antibiofilm E.faecalis bacteria at a concentration of 12.5%. Conclusion:The study showed that flavonoids from mangosteen pericarp has antibiofilm activity against E. faecalis bacterial biofilm.
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Bhattacharyya, Sudipta, Michael M. Soniat, David Walker, Sooin Jang, Ilya J. Finkelstein, and Rasika M. Harshey. "Phage Mu Gam protein promotes NHEJ in concert withEscherichia coliligase." Proceedings of the National Academy of Sciences 115, no. 50 (November 28, 2018): E11614—E11622. http://dx.doi.org/10.1073/pnas.1816606115.
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The Gam protein of transposable phage Mu is an ortholog of eukaryotic and bacterial Ku proteins, which carry out nonhomologous DNA end joining (NHEJ) with the help of dedicated ATP-dependent ligases. Many bacteria carry Gam homologs associated with either complete or defective Mu-like prophages, but the role of Gam in the life cycle of Mu or in bacteria is unknown. Here, we show that MuGam is part of a two-component bacterial NHEJ DNA repair system. Ensemble and single-molecule experiments reveal that MuGam binds to DNA ends, slows the progress of RecBCD exonuclease, promotes binding of NAD+-dependentEscherichia coliligase A, and stimulates ligation. In vivo, Gam equally promotes both precise and imprecise joining of restriction enzyme-digested linear plasmid DNA, as well as of a double-strand break (DSB) at an engineered I-SceI site in the chromosome. Cell survival after the induced DSB is specific to the stationary phase. In long-term growth competition experiments, particularly upon treatment with a clastogen, the presence ofgamin a Mu lysogen confers a distinct fitness advantage. We also show that the role of Gam in the life of phage Mu is related not to transposition but to protection of genomic Mu copies from RecBCD when viral DNA packaging begins. Taken together, our data show that MuGam provides bacteria with an NHEJ system and suggest that the resulting fitness advantage is a reason that bacteria continue to retain thegamgene in the absence of an intact prophage.
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Pawlowska, Agnieszka, and Zygmunt Sadowski. "Effect of Schwertmannite Surface Modification by Surfactants on Adhesion of Acidophilic Bacteria." Microorganisms 8, no. 11 (November 4, 2020): 1725. http://dx.doi.org/10.3390/microorganisms8111725.
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Bacterial cell adhesion onto mineral surfaces is important in a broad spectrum of processes, including bioweathering, bioleaching, and bacterial cell transport in the soil. Despite many research efforts, a detailed explanation is still lacking. This work investigates the role of surface-active compounds, cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and pure rhamnolipid (RH), in the process of bacteria attachment on the schwertmannite surface. The surface energy was calculated based on the wettability of the tested systems, and for bacteria it was 54.8 mJ/m2, schwertmannite-SDS 54.4 mJ/m2, schwertmannite-CTAB 55.4 mJ/m2, and schwertmannite-RH 39.7 mJ/m2. The total energy of adhesion estimated based on thermodynamic data was found to be negative, suggesting favorable conditions for adhesion for all examined suspensions. However, including electrostatic interactions allowed for a more precise description of bacterial adhesion under the tested conditions. The theoretical analysis using the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) approach showed a negative value of total adsorption energy only in bacteria-mineral suspensions, where SDS and rhamnolipid were added. The calculated data were in good agreement with experimental results indicating the significance of electrostatic forces in adsorption.
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Nikaido, Hiroshi, and Jean-Marie Pagès. "Broad-specificity efflux pumps and their role in multidrug resistance of Gram-negative bacteria." FEMS Microbiology Reviews 36, no. 2 (March 2012): 340–63. http://dx.doi.org/10.1111/j.1574-6976.2011.00290.x.
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Bhattacharya, Sarbani, Victoria A. Ploplis, and Francis J. Castellino. "Bacterial Plasminogen Receptors Utilize Host Plasminogen System for Effective Invasion and Dissemination." Journal of Biomedicine and Biotechnology 2012 (2012): 1–19. http://dx.doi.org/10.1155/2012/482096.
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In order for invasive pathogens to migrate beyond the site of infection, host physiological barriers such as the extracellular matrix, the basement membrane, and encapsulating fibrin network must be degraded. To circumvent these impediments, proteolytic enzymes facilitate the dissemination of the microorganism. Recruitment of host proteases to the bacterial surface represents a particularly effective mechanism for enhancing invasiveness. Plasmin is a broad spectrum serine protease that degrades fibrin, extracellular matrices, and connective tissue. A large number of pathogens express plasminogen receptors which immobilize plasmin(ogen) on the bacterial surface. Surface-bound plasminogen is then activated by plasminogen activators to plasmin through limited proteolysis thus triggering the development of a proteolytic surface on the bacteria and eventually assisting the spread of bacteria. The host hemostatic system plays an important role in systemic infection. The interplay between hemostatic processes such as coagulation and fibrinolysis and the inflammatory response constitutes essential components of host defense and bacterial invasion. The goal of this paper is to highlight mechanisms whereby pathogenic bacteria, by engaging surface receptors, utilize and exploit the host plasminogen and fibrinolytic system for the successful dissemination within the host.
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Dmytriiev, D. V., O. A. Nazarchuk, and Yu M. Babina. "Role and place of levofloxacin in the treatment of community-acquired pneumonia." Perioperaciina Medicina 3, no. 2 (March 11, 2021): 41–48. http://dx.doi.org/10.31636/prmd.v3i2.6.
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Lower respiratory tract infections are the third mortality cause in the world and the first mortality cause in low-income countries. Community-acquired pneumonia (CAP) is a dangerous infectious pathology, especially in children younger than 5 years, elderly people and patients with compromised immunity. Antibiotic therapy is a standard treatment method for CAP. But an increase in antibiotics use caused a development of resistance in bacteria and onset of adverse events in humans. A new class of fluorchinolones is widely used nowadays in clinical practice. They have good activity against Gram-negative bacteria, as early chinolones, as well as against Gram-positive bacteria, such as pneumococci and atypical bacteria. An increasing amount of penicillin-resistant streptococcal pneumonia leads to more intensive studies of the use of new chinolones. In this review the data of 750 mg levofloxacin is presented. It is used in short courses for the treatment of severe and moderate CAP. Taking into account the broad spectrum of activity of levofloxacin ad bactericidal activity of this antibiotic, it can be a potential alternative therapy for the treatment of children and adults with CAP, especially with a tendency of an increase in antibiotic resistance of pneumococcus.
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Daud, Noshin, Valerie Currie, Gary Duncan, Freda Farquharson, Tomoya Yoshinari, Petra Louis, and Silvia W. Gratz. "Prevalent Human Gut Bacteria Hydrolyse and Metabolise Important Food-Derived Mycotoxins and Masked Mycotoxins." Toxins 12, no. 10 (October 13, 2020): 654. http://dx.doi.org/10.3390/toxins12100654.
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Mycotoxins are important food contaminants that commonly co-occur with modified mycotoxins such as mycotoxin-glucosides in contaminated cereal grains. These masked mycotoxins are less toxic, but their breakdown and release of unconjugated mycotoxins has been shown by mixed gut microbiota of humans and animals. The role of different bacteria in hydrolysing mycotoxin-glucosides is unknown, and this study therefore investigated fourteen strains of human gut bacteria for their ability to break down masked mycotoxins. Individual bacterial strains were incubated anaerobically with masked mycotoxins (deoxynivalenol-3-β-glucoside, DON-Glc; nivalenol-3-β-glucoside, NIV-Glc; HT-2-β-glucoside, HT-2-Glc; diacetoxyscirpenol-α-glucoside, DAS-Glc), or unconjugated mycotoxins (DON, NIV, HT-2, T-2, and DAS) for up to 48 h. Bacterial growth, hydrolysis of mycotoxin-glucosides and further metabolism of mycotoxins were assessed. We found no impact of any mycotoxin on bacterial growth. We have demonstrated that Butyrivibrio fibrisolvens, Roseburia intestinalis and Eubacterium rectale hydrolyse DON-Glc, HT-2 Glc, and NIV-Glc efficiently and have confirmed this activity in Bifidobacterium adolescentis and Lactiplantibacillus plantarum (DON-Glc only). Prevotella copri and B. fibrisolvens efficiently de-acetylated T-2 and DAS, but none of the bacteria were capable of de-epoxydation or hydrolysis of α-glucosides. In summary we have identified key bacteria involved in hydrolysing mycotoxin-glucosides and de-acetylating type A trichothecenes in the human gut.
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Martinson, Vincent G., Jamie Moy, and Nancy A. Moran. "Establishment of Characteristic Gut Bacteria during Development of the Honeybee Worker." Applied and Environmental Microbiology 78, no. 8 (February 3, 2012): 2830–40. http://dx.doi.org/10.1128/aem.07810-11.
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ABSTRACTPrevious surveys have shown that adult honeybee (Apis mellifera) workers harbor a characteristic gut microbiota that may play a significant role in bee health. For three major phylotypes within this microbiota, we have characterized distributions and abundances across the life cycle and among gut organs. These distinctive phylotypes, called Beta, Firm-5, and Gamma-1 (BFG), were assayed using quantitative PCR, fluorescentin situhybridization (FISH) microscopy, and the experimental manipulation of inoculation routes within developing bees. Adult workers (9 to 30 days posteclosion) contained a large BFG microbiota with a characteristic distribution among gut organs. The crop and midgut were nearly devoid of these phylotypes, while the ileum and rectum together contained more than 95% of the total BFG microbiota. The ileum contained a stratified community in which the Beta and Gamma-1 phylotypes dominated, filling the longitudinal folds of this organ. Deep sequencing of 16S rRNA genes showed clear differences among communities in midgut, ileum, and rectum. In contrast with older workers, larvae and newly emerged workers contain few or no bacteria, and their major food source, bee bread, lacks most characteristic phylotypes. In experiments aimed at determining the route of inoculation, newly emerged workers (NEWs) sometimes acquired the typical phylotypes through contact with older workers, contact with the hive, and emergence from the brood cell; however, transmission was patchy in these assays. Our results outline a colonization pattern for the characteristic phylotypes throughA. melliferaontogeny. We propose the names “CandidatusSnodgrassella alvi” and “CandidatusGilliamella apicola” for the Beta and Gamma-1 phylotypes, respectively.
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Smelov, Vitaly, Kurt Naber, and Truls E. Bjerklund Johansen. "Letter to the Editor: Diagnostic Criteria in Urological Diseases do not Always Match with Findings by Extended Culture Techniques and Metagenomic Sequencing of 16S rDNA." Open Microbiology Journal 10, no. 1 (February 29, 2016): 23–26. http://dx.doi.org/10.2174/1874285801610010023.
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Some diseases of the urinary tract are defined by the presence of microorganisms while others are defined by their absence. The underlying idea has always been that urine from healthy subjects is sterile and a negative urine culture has usually been taken as discriminative for an infection to be absent. Several disorders with symptoms that resemble infections are regarded as separate entities based on the exclusion of bacterial growth such as overactive neurogenic bladder and pelvic pain syndromes. During the recent years two paradigmata related to the role of bacteria in urological disease classification have changed completely. Firstly, bacteriuria does not necessarily mean an infection, and secondly, if extended sets of culture media for identification of fastidious and anaerobic bacteria or culture-independent metagenomic sequencing (MGS) is applied, a broad range of even non-culturable bacteria has been detected in the ”sterile” bladder urine in healthy individuals. The aim of this editorial is to initiate a discussion to redefine the criteria for urinary tract infections and non-infectious urological disorders with similar symptoms. Clinical studies, in which extended sets of culture media and MGS are integrated, are needed to clarify the pathogenesis of urological disorders where bacteria may play a role. The pure detection of bacteria in the urine does not by itself prove an infectious etiology of a specific disorder. It is important to avoid that results of new technologies lead to unnecessary antibiotic consumption with unwanted collateral damage and adverse events.
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Mendling, Werner, Ana Palmeira‑de‑Oliveira, Stephan Biber, and Valdas Prasauskas. "An update on the role of Atopobium vaginae in bacterial vaginosis: what to consider when choosing a treatment?" Voprosy ginekologii, akušerstva i perinatologii 19, no. 4 (2020): 138–44. http://dx.doi.org/10.20953/1726-1678-2020-4-138-144.
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Introduction. Bacterial vaginosis (BV) is the most common vaginal disorder in reproductive-age women. The condition is characterised by the replacement of a healthy, lactobacilli-dominated vaginal microbiota by anaerobic and facultative anaerobic bacteria. BV increases the risk of acquisition of STIs and is associated with pregnancy complications. Although the composition of the bacteria in BV varies between individuals, there are some species such as Gardnerella, Atopobium, Mycoplasma, Snethia, Megasphera, Dialister, etc., that are found most frequently. Material and methods. Literature research to the importance of Atopobium vaginae in BV and treatment options. Results. Atopobium (A.) vaginae is an important component of the complex abnormal vaginal flora in BV; even though A. vaginae, like Gardnerella vaginalis, has also been detected in the normal flora, it is much more common in BV patients. A. vaginae has been shown to play an important role in the pathophysiology of BV and is thought to be at least a partial cause of the known negative sequelae. The presence of A. vaginae in the BV-associated biofilms and its resistance to some antimicrobial substances has been described – this seems to have a major impact on treatment outcome. Conclusion. Current scientific data demonstrate that dequalinium chloride (Fluomycin®) is one of the valid therapeutic options for BV treatment, since it displays a broad antimicrobial spectrum against relevant vaginal pathogens, especially against G. vaginalis and A. vaginae, without having safety concerns. Key words: Bacterial vaginosis, Bacterial biofilm, Atopobium vaginae, Metronidazole, Clindamycin, Dequalinium chloride, Microbial resistance
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Yang, Jing, Kai Qiao, Junping Lv, Qi Liu, Fangru Nan, Shulian Xie, and Jia Feng. "Isolation and Identification of Two Algae-Lysing Bacteria against Microcystis aeruginosa." Water 12, no. 9 (September 5, 2020): 2485. http://dx.doi.org/10.3390/w12092485.
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Algae blooms present an environmental problem worldwide. In response to the outbreak of harmful algal blooms in cyanobacteria, the role of biological control has drawn wide attention, particularly for algicidal bacteria. The mechanism underlying algicidal activity was determined in our study. Algae-lysing bacteria used were separated from water and sediment collected from the Fenhe scenic spot of Taiyuan. Genetic and molecular identification was conducted by polymerase chain reaction amplification based on 16S rDNA gene. These bacterial strains were identified as Raoultella planticola and Aeromonas sp. The algae-lysing characteristics were evaluated on Microcystis aeruginosa. For the two algicidal bacteria, the high inoculation ratio (>8%) of bacteria strains contributed to the lytic effect. M. aeruginosa could be completely removed by these strains at different cell ages. However, the time used decreased with an increase in cell age. The removal rate was increased while M. aeruginosa was in the lag and logarithmic phases. The earlier bacteria strains could be inoculated, the sooner all algae could be removed. Both algicidal substances were protein, which could destroy the photosynthetic systems and break the cell of M. aeruginosa. The algicidal bacteria strain has important theoretical and practical significance for economic and feasible algae removal and provides good germplasm resources and technical support for the control of cyanobacterial bloom.
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Whelan, Fiona, Aleix Lafita, James Gilburt, Clément Dégut, Samuel C. Griffiths, Huw T. Jenkins, Alexander N. St John, et al. "Periscope Proteins are variable-length regulators of bacterial cell surface interactions." Proceedings of the National Academy of Sciences 118, no. 23 (June 1, 2021): e2101349118. http://dx.doi.org/10.1073/pnas.2101349118.
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Changes at the cell surface enable bacteria to survive in dynamic environments, such as diverse niches of the human host. Here, we reveal “Periscope Proteins” as a widespread mechanism of bacterial surface alteration mediated through protein length variation. Tandem arrays of highly similar folded domains can form an elongated rod-like structure; thus, variation in the number of domains determines how far an N-terminal host ligand binding domain projects from the cell surface. Supported by newly available long-read genome sequencing data, we propose that this class could contain over 50 distinct proteins, including those implicated in host colonization and biofilm formation by human pathogens. In large multidomain proteins, sequence divergence between adjacent domains appears to reduce interdomain misfolding. Periscope Proteins break this “rule,” suggesting that their length variability plays an important role in regulating bacterial interactions with host surfaces, other bacteria, and the immune system.
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Teleky, Bernadette-Emőke, Gheorghe Adrian Martău, and Dan Cristian Vodnar. "Physicochemical Effects of Lactobacillus plantarum and Lactobacillus casei Cocultures on Soy–Wheat Flour Dough Fermentation." Foods 9, no. 12 (December 18, 2020): 1894. http://dx.doi.org/10.3390/foods9121894.
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In contemporary food production, an important role is given to the increase in the nutritional quality of foodstuff. In the bakery industry, one of the main cereals used is wheat flour (WF), which creates bread with proper sensory evaluation but is nutritionally poor. Soy-flour (SF) has increased nutrient content, and its consumption is recommended due to several health benefits. Dough fermentation with lactic acid bacteria (LAB) increases bread shelf life, improves flavor, and its nutritional quality, mostly due to its high organic acid production capability. In the present study, the addition of SF to WF, through fermentation with the cocultures of Lactobacillus plantarum and Lactobacillus casei was analyzed. Three different batches were performed by using WF supplemented with SF, as follows: batch A consisting of 90% WF and 10% SF; batch B—95% WF and 5% SF; batch C—100% WF. The fermentation with these two LABs presented several positive effects, which, together with increased SF content, improved the dough’s rheological and physicochemical characteristics. The dynamic rheological analysis exhibited a more stable elastic-like behavior in doughs supplemented with SF (G′ 4936.2 ± 12.7, and G″ 2338.4 ± 9.1). Organic acid production changes were the most significant, especially for the lactic, citric, and tartaric content.
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Tapia-Torres, Yunuen, Maria Dolores Rodríguez-Torres, James J. Elser, Africa Islas, Valeria Souza, Felipe García-Oliva, and Gabriela Olmedo-Álvarez. "How To Live with Phosphorus Scarcity in Soil and Sediment: Lessons from Bacteria." Applied and Environmental Microbiology 82, no. 15 (May 27, 2016): 4652–62. http://dx.doi.org/10.1128/aem.00160-16.
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ABSTRACTPhosphorus (P) plays a fundamental role in the physiology and biochemistry of all living things. Recent evidence indicates that organisms in the oceans can break down and use P forms in different oxidation states (e.g., +5, +3, +1, and −3); however, information is lacking for organisms from soil and sediment. The Cuatro Ciénegas Basin (CCB), Mexico, is an oligotrophic ecosystem with acute P limitation, providing a great opportunity to assess the various strategies that bacteria from soil and sediment use to obtain P. We measured the activities in sediment and soil of different exoenzymes involved in P recycling and evaluated 1,163 bacterial isolates (mainlyBacillusspp.) for their ability to use six different P substrates. DNA turned out to be a preferred substrate, comparable to a more bioavailable P source, potassium phosphate. Phosphodiesterase activity, required for DNA degradation, was observed consistently in the sampled-soil and sediment communities. A capability to use phosphite (PO33−) and calcium phosphate was observed mainly in sediment isolates. Phosphonates were used at a lower frequency by both soil and sediment isolates, and phosphonatase activity was detected only in soil communities. Our results revealed that soil and sediment bacteria are able to break down and use P forms in different oxidation states and contribute to ecosystem P cycling. Different strategies for P utilization were distributed between and within the different taxonomic lineages analyzed, suggesting a dynamic movement of P utilization traits among bacteria in microbial communities.IMPORTANCEPhosphorus (P) is an essential element for life found in molecules, such as DNA, cell walls, and in molecules for energy transfer, such as ATP. The Valley of Cuatro Ciénegas, Coahuila (Mexico), is a unique desert characterized by an extreme limitation of P and a great diversity of microbial life. How do bacteria in this valley manage to obtain P? We measured the availability of P and the enzymatic activity associated with P release in soil and sediment. Our results revealed that soil and sediment bacteria can break down and use P forms in different oxidation states and contribute to ecosystem P cycling. Even genetically related bacterial isolates exhibited different preferences for molecules, such as DNA, calcium phosphate, phosphite, and phosphonates, as substrates to obtain P, evidencing a distribution of roles for P utilization and suggesting a dynamic movement of P utilization traits among bacteria in microbial communities.
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Mahdi, Ali A., Tuqa S. Al-Salmani, and Mustafa M. Al-Qaisi. "The Novel Role of Healing from Bacterial Infections of Lower Limb Open Fractures by X-Ray Exposure." International Journal of Microbiology 2020 (March 19, 2020): 1–7. http://dx.doi.org/10.1155/2020/3129356.
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Introduction. An open fracture refers to a break in the skin, which is exposed to microbial contamination and eventually leads to most complicated infections. X-rays can kill bacteria by causing irreversible DNA damage. Objective. To confirm the role of X-ray exposure in treating infected wound fractures at the lower limb and determine X-ray exposure times. Methods. Fifty-one wound swabs were collected from patients with infected open fractures at the lower limb with grade II, IIIA, B, and C according to the Gustilo and Anderson classification system and then cultured. The bacterial isolates were identified by biochemical tests and the VITEK-2 System and tested against several antibiotics. The X-ray exposure was done for open fractures by radiography (at kV133 and 5 milliambers). Results. The higher isolation rate was recorded for Staphylococcus aureus with 21 (41.2%) isolates, and most of them (20, 95.2%) were isolated from grade II fractures. The isolation rate of Gram-negative bacteria was 25.5% for Escherichia coli with 13 isolates, 19.6% for Pseudomonas aeruginosa with 10 isolates, and 13.7% for Klebsiella pneumoniae with 7 isolates, most of which were isolated from grade III fractures. The isolation rate of P. aeruginosa was 60% (6 isolates) from grade IIIA and 71.4% (5 isolates) from grade IIIB for K. pneumoniae, while for E. coli it was 69.2% (9 isolates) from grade IIIC. All the bacterial isolates recorded high levels of antibiotic resistance against most tested antibiotics. Wound cultures of grade II fractures appeared sterile after the first X-ray exposure, and these wounds were infected with S. aureus or P. aeruginosa. However, cultures of grade IIIA and IIIB fractures appeared sterile after the second X-ray exposure for all isolated bacteria, except for S. aureus (grade IIIA fractures) (after the third X-ray exposure). Grade IIIC fractures showed sterile culture after the third X-ray exposure for wounds infected with P. aeruginosa and E. coli. Conclusions. The study concluded that X-ray exposure showed high effectiveness in treating infected open fractures.
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Santamarta, Sara, A. Cristina Aldavero, and M. Ángeles Rojo. "Antibacterial Properties of Cymbopogon martinii Essential Oil against Bacillus subtillis Food Industry Pathogen." Proceedings 66, no. 1 (December 18, 2020): 1. http://dx.doi.org/10.3390/proceedings2020066001.
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Essential oils have great potential in the field of the food industry as they can effectively prevent the presence of several bacterial and fungal pathogens. Essential oils are complex volatile compounds, synthesized naturally in different plant parts during the process of the secondary metabolism. The main goal of this work is to perform a qualitative evaluation of the antibacterial properties of 24 chemotyped essential oils against the growth of Bacillus subtillis. These Gram-positive bacteria are responsible for “rope” disease in bread preservation processes. The study was carried out using the method of disk-diffusion in agar. Biological activity was observed in five essential oils: Cymbopogon martinii var. motia, Thymus vulgaris QT Linanol, Thymus satureioides, Mentha piperita and Eugenia caryophyllus. The first three have in common the presence of some mono terpenic derivatives—Geraniol, Linalool and Carvacrol, respectively—with strong antimicrobial effects. The Cymbopogon martinii essential oil is one of the botanicals with the highest geraniol content (up to 80.53%) and showed more activity antimicrobial than the others. A contributing role of this knowledge could be the design of Cymbopogon martinii essential oil formula, which can be used in bakery industry as a preservative, such as nano-encapsulation for bakery doughs, active packaging of baked products or surface disinfectants.
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Hu, Yazhen, Tomofumi Kurobe, Xiaoling Liu, Yong-An Zhang, Jianguo Su, and Gailing Yuan. "Hamp Type-1 Promotes Antimicrobial Defense via Direct Microbial Killing and Regulating Iron Metabolism in Grass Carp (Ctenopharyngodon idella)." Biomolecules 10, no. 6 (May 28, 2020): 825. http://dx.doi.org/10.3390/biom10060825.
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Hepcidin is an antimicrobial peptide and regulator of iron homeostasis which has two isoforms in most fishes and some mammals. Previous studies have reported that the two hepcidin isoforms have different roles. Hamp type-1 plays a regulatory role in iron metabolism and hamp type-2 mostly performs an antimicrobial role. In this study, we found that Ctenopharyngodon idella (C. idella) have only one hepcidin isoform (hamp type-1), which showed both broad-spectrum antibacterial and iron regulatory functions. C. idella hepcidin mature peptide (hepcidin-25) and truncated peptide (hepcidin-20) exhibited bactericidal activities against both Gram-positive and Gram-negative bacteria in a dose-dependent manner in part through membrane rupture and binding to bacterial genomic DNA. The data from challenge tests demonstrated that the administration of hepcidin-25 significantly reduced mortality rates of C. idella by A. hydrophila infection, probably due to direct bactericidal activities of the peptide and a reduction of iron content in the fish serum. In addition, a comparison between hepcidin-20 and -25 suggests that the N terminal 5 amino acids play a critical role in reducing iron content in fish serum. Our findings revealed an important role of hamp type-1 in maintaining iron homeostasis and fighting against bacterial infections, suggesting the hepcidin has implications for the prevention and control of bacterial infection in aquaculture.
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Nissen, Lorenzo, Flavia Casciano, Elena Chiarello, Mattia Di Nunzio, Alessandra Bordoni, and Andrea Gianotti. "Colonic In Vitro Model Assessment of the Prebiotic Potential of Bread Fortified with Polyphenols Rich Olive Fiber." Nutrients 13, no. 3 (February 27, 2021): 787. http://dx.doi.org/10.3390/nu13030787.
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The use of olive pomace could represent an innovative and low-cost strategy to formulate healthier and value-added foods, and bakery products are good candidates for enrichment. In this work, we explored the prebiotic potential of bread enriched with Polyphenol Rich Fiber (PRF), a defatted olive pomace byproduct previously studied in the European Project H2020 EcoProlive. To this aim, after in vitro digestion, the PRF-enriched bread, its standard control, and fructo-oligosaccharides (FOS) underwent distal colonic fermentation using the in vitro colon model MICODE (multi-unit colon gut model). Sampling was done prior, over and after 24 h of fermentation, then metabolomic analysis by Solid Phase Micro Extraction Gas Chromatography Mass Spectrometry (SPME GCMS), 16S-rDNA genomic sequencing of colonic microbiota by MiSeq, and absolute quantification of main bacterial species by qPCR were performed. The results indicated that PRF-enriched bread generated positive effects on the host gut model: (i) surge in eubiosis; (ii) increased abundance of beneficial bacterial groups, such as Bifidobacteriaceae and Lactobacillales; (iii) production of certain bioactive metabolites, such as low organic fatty acids; (iv) reduction in detrimental compounds, such as skatole. Our study not only evidenced the prebiotic role of PRF-enriched bread, thereby paving the road for further use of olive by-products, but also highlighted the potential of the in vitro gut model MICODE in the critical evaluation of functionality of food prototypes as modulators of the gut microbiota.
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Senyürek, Ilknur, Maren Paulmann, Tobias Sinnberg, Hubert Kalbacher, Martin Deeg, Thomas Gutsmann, Marina Hermes, et al. "Dermcidin-Derived Peptides Show a Different Mode of Action than the Cathelicidin LL-37 against Staphylococcus aureus." Antimicrobial Agents and Chemotherapy 53, no. 6 (April 3, 2009): 2499–509. http://dx.doi.org/10.1128/aac.01679-08.
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ABSTRACT Dermcidin (DCD) is an antimicrobial peptide which is constitutively expressed in eccrine sweat glands. By postsecretory proteolytic processing in sweat, the DCD protein gives rise to anionic and cationic DCD peptides with a broad spectrum of antimicrobial activity. Many antimicrobial peptides induce membrane permeabilization as part of their killing mechanism, which is accompanied by a loss of the bacterial membrane potential. In this study we show that there is a time-dependent bactericidal activity of anionic and cationic DCD-derived peptides which is followed by bacterial membrane depolarization. However, DCD-derived peptides do not induce pore formation in the membranes of gram-negative and gram-positive bacteria. This is in contrast to the mode of action of the cathelicidin LL-37. Interestingly, LL-37 as well as DCD-derived peptides inhibit bacterial macromolecular synthesis, especially RNA and protein synthesis, without binding to microbial DNA or RNA. Binding studies with components of the cell envelope of gram-positive and gram-negative bacteria and with model membranes indicated that DCD-derived peptides bind to the bacterial envelope but show only a weak binding to lipopolysaccharide (LPS) from gram-negative bacteria or to peptidoglycan, lipoteichoic acid, and wall teichoic acid, isolated from Staphylococcus aureus. In contrast, LL-37 binds strongly in a dose-dependent fashion to these components. Altogether, these data indicate that the mode of action of DCD-derived peptides is different from that of the cathelicidin LL-37 and that components of the bacterial cell envelope play a role in the antimicrobial activity of DCD.
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Kannan, Anerudh, Zhenbin Yang, Minyoung Kevin Kim, Howard A. Stone, and Albert Siryaporn. "Dynamic switching enables efficient bacterial colonization in flow." Proceedings of the National Academy of Sciences 115, no. 21 (May 7, 2018): 5438–43. http://dx.doi.org/10.1073/pnas.1718813115.
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Bacteria colonize environments that contain networks of moving fluids, including digestive pathways, blood vasculature in animals, and the xylem and phloem networks in plants. In these flow networks, bacteria form distinct biofilm structures that have an important role in pathogenesis. The physical mechanisms that determine the spatial organization of bacteria in flow are not understood. Here, we show that the bacteriumP. aeruginosacolonizes flow networks using a cyclical process that consists of surface attachment, upstream movement, detachment, movement with the bulk flow, and surface reattachment. This process, which we have termed dynamic switching, distributes bacterial subpopulations upstream and downstream in flow through two phases: movement on surfaces and cellular movement via the bulk. The model equations that describe dynamic switching are identical to those that describe dynamic instability, a process that enables microtubules in eukaryotic cells to search space efficiently to capture chromosomes. Our results show that dynamic switching enables bacteria to explore flow networks efficiently, which maximizes dispersal and colonization and establishes the organizational structure of biofilms. A number of eukaryotic and mammalian cells also exhibit movement in two phases in flow, which suggests that dynamic switching is a modality that enables efficient dispersal for a broad range of cell types.
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Zgadzaj, Rafal, Ruben Garrido-Oter, Dorthe Bodker Jensen, Anna Koprivova, Paul Schulze-Lefert, and Simona Radutoiu. "Root nodule symbiosis in Lotus japonicus drives the establishment of distinctive rhizosphere, root, and nodule bacterial communities." Proceedings of the National Academy of Sciences 113, no. 49 (November 18, 2016): E7996—E8005. http://dx.doi.org/10.1073/pnas.1616564113.
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Lotus japonicus has been used for decades as a model legume to study the establishment of binary symbiotic relationships with nitrogen-fixing rhizobia that trigger root nodule organogenesis for bacterial accommodation. Using community profiling of 16S rRNA gene amplicons, we reveal that in Lotus, distinctive nodule- and root-inhabiting communities are established by parallel, rather than consecutive, selection of bacteria from the rhizosphere and root compartments. Comparative analyses of wild-type (WT) and symbiotic mutants in Nod factor receptor5 (nfr5), Nodule inception (nin) and Lotus histidine kinase1 (lhk1) genes identified a previously unsuspected role of the nodulation pathway in the establishment of different bacterial assemblages in the root and rhizosphere. We found that the loss of nitrogen-fixing symbiosis dramatically alters community structure in the latter two compartments, affecting at least 14 bacterial orders. The differential plant growth phenotypes seen between WT and the symbiotic mutants in nonsupplemented soil were retained under nitrogen-supplemented conditions that blocked the formation of functional nodules in WT, whereas the symbiosis-impaired mutants maintain an altered community structure in the nitrogen-supplemented soil. This finding provides strong evidence that the root-associated community shift in the symbiotic mutants is a direct consequence of the disabled symbiosis pathway rather than an indirect effect resulting from abolished symbiotic nitrogen fixation. Our findings imply a role of the legume host in selecting a broad taxonomic range of root-associated bacteria that, in addition to rhizobia, likely contribute to plant growth and ecological performance.
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Jorgenson, Margaret R., Daryl D. DePestel, and Peggy L. Carver. "Ceftaroline Fosamil: A Novel Broad-Spectrum Cephalosporin with Activity Against Methicillin-Resistant Staphylococcus aureus." Annals of Pharmacotherapy 45, no. 11 (October 18, 2011): 1384–98. http://dx.doi.org/10.1345/aph.1q225.
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Objective: To review the pharmacology, microbiology, chemistry, in vitro activity, pharmacokinetics, clinical efficacy, safety, dosage, and administration of ceftaroline fosamil (Teflaro, Forest Laboratories, Inc.), a novel parenteral broad-spectrum cephalosporin approved by the Food and Drug Administration (FDA) on October 29, 2010, for the treatment of adults with acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). Data Sources: A search of MEDLINE (1966-July 2011) using the search terms ceftaroline fosamil, ceftaroline, TAK-599, PPI-0903, PPI-0903M, and T-91825 was performed. Supplementary sources included program abstracts from the Interscience Conference on Antimicrobial Agents and Chemotherapy American Society of Microbiology, European Congress on Clinical Microbiology and Infectious Diseases, and the Infectious Diseases Society of America from 2005 to 2010, as well as information available from the manufacturer's Web site. Study Selection Ano Data Extraction: All English-language articles identified from the data sources were evaluated. In vitro, preclinical, and Phase 1,2, and 3 clinical trials were included. Data Synthesis: Clinical trials have been conducted evaluating use of ceftaroline for treatment of ABSSSI and CABP. Safety data from Phase 1,2, and 3 clinical trials suggest that it is well tolerated and has a safety and tolerability profile common to the cephalosporin class. Ceftaroline has excellent in vitro activity against gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), which makes it an attractive monotherapy (or the treatment of ABSSSI. However, it lacks activity against problem gram-negative bacteria (eg, Pseudomonas spp.), which will likely limit its use for serious health care-associated infections. While its role in treating CABP is supported by excellent in vitro activity against Streptococcus pneumoniae and clinical efficacy data, currently available comparators may offer some advantages over ceftaroline. Finally, data are lacking to assess its role in the treatment of serious infections due to MRSA (eg, pneumonia, bacteremia). Conclusions: These considerations should be part of the formulary review process; however, when considering the significant role MRSA plays in ABSSSI in both the community and hospital settings, we believe that ceftaroline will provide clinicians with a welcome option in addition to currently available anti-MRSA therapies for the treatment of ABSSSI.
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Kisand, Veljo, Rocio Cuadros, and Johan Wikner. "Phylogeny of Culturable Estuarine Bacteria Catabolizing Riverine Organic Matter in the Northern Baltic Sea." Applied and Environmental Microbiology 68, no. 1 (January 2002): 379–88. http://dx.doi.org/10.1128/aem.68.1.379-388.2002.
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ABSTRACT The objective of our study was to isolate and determine the phylogenetic affiliation of culturable estuarine bacteria capable of catabolizing riverine dissolved organic matter (RDOM) under laboratory conditions. Additions of RDOM consistently promoted the growth of estuarine bacteria in carbon-limited dilution cultures, with seasonal variation in growth rates and yields. At least 42 different taxa were culturable on solid agar media and, according to quantitative DNA-DNA hybridizations, constituted 32 to 89% of the total bacterial number in the enriched treatments. Five species in the Cytophaga-Flexibacter-Bacteroides group and one in the γ-proteobacteria phylogenetic group (Marinomonas sp.) were numerically dominant during the stationary phase of the RDOM-enriched dilution cultures but not in the control cultures. Four of the isolates in Cytophaga-Flexibacter-Bacteroides group were putatively affiliated with the genus Flavobacterium. All dominating isolates were determined to be new species based on comparison to the current databases. The same group of species dominated independently of the season investigated, suggesting a low diversity of bacteria catabolizing RDOM in the estuary. It also suggested a broad tolerance of the dominating species to seasonal variation in hydrography, chemistry, and competition with other species. Taken together, our results suggest that a limited group of bacteria, mainly in the Flavobacterium genus, played an important role in introducing new energy and carbon to the marine system in the northern Baltic Sea.
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Rathman, M., P. de Lanerolle, H. Ohayon, P. Gounon, and P. Sansonetti. "Myosin light chain kinase plays an essential role in S. flexneri dissemination." Journal of Cell Science 113, no. 19 (October 1, 2000): 3375–86. http://dx.doi.org/10.1242/jcs.113.19.3375.
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Shigella flexneri, the causitive agent of bacillary dysentery, has been shown to disseminate in colonic epithelial cells via protrusions that extend from infected cells and are endocytosed by adjacent cells. This phenomenon occurs in the region of the eukaryotic cell's adherens junctions and is inhibited by pharmacological reagents or host cell mutations that completely disrupt the junctional complex. In this study, inhibitors of the myosin light chain kinase (MLCK) were shown to dramatically decrease intercellular spread of S. flexneri but to have no inhibitory effect on bacterial entry, multiplication or actin-based motility within the host cell. Furthermore, cell-to-cell spread of Listeria monocytogenes, another bacterial pathogen that uses an actin-based mechanism to move within the eukaryotic cytoplasm and to spread from cell to cell, was not affected by the MLCK inhibitors, indicating that (1) the inhibition of S. flexneri cell-to-cell spread in treated cells is not due to a complete break down of cell-cell contacts, which was subsequently confirmed by confocal microscopy, and (2) MLCK plays a role in a S. flexneri-specific mechanism of dissemination. Myosin has been shown to play a role in a variety of membrane-based phenomena. The work presented here suggests that activation of this molecule via phosphorylation by MLCK, at the very least participates in the formation of the bacteria-containing protrusion, and could also contribute to the endocytosis of this structure by neighboring cells.
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Pavić, Ana, Alexandra O. M. Holmes, Vincent L. G. Postis, and Adrian Goldman. "Glutamate transporters: a broad review of the most recent archaeal and human structures." Biochemical Society Transactions 47, no. 4 (August 5, 2019): 1197–207. http://dx.doi.org/10.1042/bst20190316.
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Abstract Glutamate transporters play important roles in bacteria, archaea and eukaryotes. Their function in the mammalian central nervous system is essential for preventing excitotoxicity, and their dysregulation is implicated in many diseases, such as epilepsy and Alzheimer's. Elucidating their transport mechanism would further the understanding of these transporters and promote drug design as they provide compelling targets for understanding the pathophysiology of diseases and may have a direct role in the treatment of conditions involving glutamate excitotoxicity. This review outlines the insights into the transport cycle, uncoupled chloride conductance and modulation, as well as identifying areas that require further investigation.
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Siddall, Mark E., Paul L. Worthen, Matthew Johnson, and Joerg Graf. "Novel Role for Aeromonas jandaei as a Digestive Tract Symbiont of the North American Medicinal Leech." Applied and Environmental Microbiology 73, no. 2 (November 17, 2006): 655–58. http://dx.doi.org/10.1128/aem.01282-06.
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ABSTRACT The gut bacteria of the North American medicinal leech, Macrobdella decora, were characterized. Biochemical tests and DNA sequences indicated that Aeromonas jandaei is the dominant culturable symbiont in leeches from a broad geographic area. In this work we identified a new habitat for A. jandaei, and here we suggest that there is unexpected specificity between leeches and Aeromonas species.