Microbiology-Sgm最新文献_第9页

Shigella sonnei utilises colicins during inter-bacterial competition. 子内志贺菌在细菌间竞争中利用了大肠杆菌素。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001434

P B Leung, X M Matanza, B Roche, K P Ha, H C Cheung, S Appleyard, T Collins, O Flanagan, B S Marteyn, A Clements

{"title":"Shigella sonnei utilises colicins during inter-bacterial competition.","authors":"P B Leung, X M Matanza, B Roche, K P Ha, H C Cheung, S Appleyard, T Collins, O Flanagan, B S Marteyn, A Clements","doi":"10.1099/mic.0.001434","DOIUrl":"10.1099/mic.0.001434","url":null,"abstract":"The mammalian colon is one of the most densely populated habitats currently recognised, with 1011-1013 commensal bacteria per gram of colonic contents. Enteric pathogens must compete with the resident intestinal microbiota to cause infection. Among these enteric pathogens are Shigella species which cause approximately 125 million infections annually, of which over 90 % are caused by Shigella flexneri and Shigella sonnei. Shigella sonnei was previously reported to use a Type VI Secretion System (T6SS) to outcompete E. coli and S. flexneri in in vitro and in vivo experiments. S. sonnei strains have also been reported to harbour colicinogenic plasmids, which are an alternative anti-bacterial mechanism that could provide a competitive advantage against the intestinal microbiota. We sought to determine the contribution of both T6SS and colicins to the anti-bacterial killing activity of S. sonnei. We reveal that whilst the T6SS operon is present in S. sonnei, there is evidence of functional degradation of the system through SNPs, indels and IS within key components of the system. We created strains with synthetically inducible T6SS operons but were still unable to demonstrate anti-bacterial activity of the T6SS. We demonstrate that the anti-bacterial activity observed in our in vitro assays was due to colicin activity. We show that S. sonnei no longer displayed anti-bacterial activity against bacteria that were resistant to colicins, and removal of the colicin plasmid from S. sonnei abrogated anti-bacterial activity of S. sonnei. We propose that the anti-bacterial activity demonstrated by colicins may be sufficient for niche competition by S. sonnei within the gastrointestinal environment.","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924462/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139906758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Molecular insights into the determinants of substrate specificity and efflux inhibition of the RND efflux pumps AcrB and AdeB. 关于 RND 外排泵 AcrB 和 AdeB 底物特异性和外排抑制决定因素的分子见解。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001438

Julia Wilhelm, Klaas Martinus Pos

{"title":"Molecular insights into the determinants of substrate specificity and efflux inhibition of the RND efflux pumps AcrB and AdeB.","authors":"Julia Wilhelm, Klaas Martinus Pos","doi":"10.1099/mic.0.001438","DOIUrl":"10.1099/mic.0.001438","url":null,"abstract":"Gram-negative bacterial members of the Resistance Nodulation and cell Division (RND) superfamily form tripartite efflux pump systems that span the cell envelope. One of the intriguing features of the multiple drug efflux members of this superfamily is their ability to recognize different classes of antibiotics, dyes, solvents, bile salts, and detergents. This review provides an overview of the molecular mechanisms of multiple drug efflux catalysed by the tripartite RND efflux system AcrAB-TolC from Eschericha coli. The determinants for sequential or simultaneous multiple substrate binding and efflux pump inhibitor binding are discussed. A comparison is made with the determinants for substrate binding of AdeB from Acinetobacter baumannii, which acts within the AdeABC multidrug efflux system. There is an apparent general similarity between the structures of AcrB and AdeB and their substrate specificity. However, the presence of distinct conformational states and different drug efflux capacities as revealed by single-particle cryo-EM and mutational analysis suggest that the drug binding and transport features exhibited by AcrB may not be directly extrapolated to the homolog AdeB efflux pump.","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924465/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139736555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

P-type ATPase zinc transporter Rv3270 of Mycobacterium tuberculosis enhances multi-drug efflux activity. 结核分枝杆菌的 P 型 ATP 酶锌转运体 Rv3270 可增强多种药物的外流活性。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001441

Debasmita Chatterjee, Aditya Prasad Panda, A R Daya Manasi, Anindya S Ghosh

{"title":"P-type ATPase zinc transporter Rv3270 of Mycobacterium tuberculosis enhances multi-drug efflux activity.","authors":"Debasmita Chatterjee, Aditya Prasad Panda, A R Daya Manasi, Anindya S Ghosh","doi":"10.1099/mic.0.001441","DOIUrl":"10.1099/mic.0.001441","url":null,"abstract":"Metal homeostasis is maintained by the uptake, storage and efflux of metal ions that are necessary for the survival of the bacterium. Homeostasis is mostly regulated by a group of transporters categorized as ABC transporters and P-type ATPases. On the other hand, efflux pumps often play a role in drug-metal cross-resistance. Here, with the help of antibiotic sensitivity, antibiotic/dye accumulation and semi-quantitative biofilm formation assessments we report the ability of Rv3270, a P-type ATPase known for its role in combating Mn2+ and Zn2+ metal ion toxicity in Mycobacterium tuberculosis, in influencing the extrusion of multiple structurally unrelated drugs and enhancing the biofilm formation of Escherichia coli and Mycobacterium smegmatis. Overexpression of Rv3270 increased the tolerance of host cells to norfloxacin, ofloxacin, sparfloxacin, ampicillin, oxacillin, amikacin and isoniazid. A significantly lower accumulation of norfloxacin, ethidium bromide, bocillin FL and levofloxacin in cells harbouring Rv3270 as compared to host cells indicated its role in enhancing efflux activity. Although over-expression of Rv3270 did not alter the susceptibility levels of levofloxacin, rifampicin and apramycin, the presence of a sub-inhibitory concentration of Zn2+ resulted in low-level tolerance towards these drugs. Of note, the expression of Rv3270 enhanced the biofilm-forming ability of the host cells strengthening its role in antimicrobial resistance. Therefore, the study indicated that the over-expression of Rv3270 enhances the drug efflux activity of the micro-organism where zinc might facilitate drug-metal cross-resistance for some antibiotics.","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924464/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139900763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mutation of wbtJ, a N-formyltransferase involved in O-antigen synthesis, results in biofilm formation, phase variation and attenuation in Francisella tularensis. wbtJ 是一种参与 O 抗原合成的 N-甲酰转移酶，它的突变会导致土拉弗氏菌生物膜的形成、阶段性变化和衰减。

IF 2.6 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001437

Kevin D Mlynek, Ronald G Toothman, Elsie E Martinez, Ju Qiu, Joshua B Richardson, Joel A Bozue

{"title":"Mutation of wbtJ, a N-formyltransferase involved in O-antigen synthesis, results in biofilm formation, phase variation and attenuation in Francisella tularensis.","authors":"Kevin D Mlynek, Ronald G Toothman, Elsie E Martinez, Ju Qiu, Joshua B Richardson, Joel A Bozue","doi":"10.1099/mic.0.001437","DOIUrl":"10.1099/mic.0.001437","url":null,"abstract":"Two clinically important subspecies, Francisella tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B) are responsible for most tularaemia cases, but these isolates typically form a weak biofilm under in vitro conditions. Phase variation of the F. tularensis lipopolysaccharide (LPS) has been reported in these subspecies, but the role of variation is unclear as LPS is crucial for virulence. We previously demonstrated that a subpopulation of LPS variants can constitutively form a robust biofilm in vitro, but it is unclear whether virulence was affected. In this study, we show that biofilm-forming variants of both fully virulent F. tularensis subspecies were highly attenuated in the murine tularaemia model by multiple challenge routes. Genomic sequencing was performed on these strains, which revealed that all biofilm-forming variants contained a lesion within the wbtJ gene, a formyltransferase involved in O-antigen synthesis. A ΔwbtJ deletion mutant recapitulated the biofilm, O-antigen and virulence phenotypes observed in natural variants and could be rescued through complementation with a functional wbtJ gene. Since the spontaneously derived biofilm-forming isolates in this study were a subpopulation of natural variants, reversion events to the wbtJ gene were detected that eliminated the phenotypes associated with biofilm variants and restored virulence. These results demonstrate a role for WbtJ in biofilm formation, LPS variation and virulence of F. tularensis.","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924466/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139991597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identification of novel tail-anchored membrane proteins integrated by the bacterial twin-arginine translocase. 鉴定由细菌孪生精氨酸转运酶整合的新型尾锚膜蛋白。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001431

José Jesús Gallego-Parrilla, Emmanuele Severi, Govind Chandra, Tracy Palmer

{"title":"Identification of novel tail-anchored membrane proteins integrated by the bacterial twin-arginine translocase.","authors":"José Jesús Gallego-Parrilla, Emmanuele Severi, Govind Chandra, Tracy Palmer","doi":"10.1099/mic.0.001431","DOIUrl":"10.1099/mic.0.001431","url":null,"abstract":"The twin-arginine protein transport (Tat) system exports folded proteins across the cytoplasmic membranes of prokaryotes and the energy transducing-membranes of plant thylakoids and mitochondria. Proteins are targeted to the Tat machinery by N-terminal signal peptides with a conserved twin-arginine motif, and some substrates are exported as heterodimers where the signal peptide is present on one of the partner proteins. A subset of Tat substrates is found in the membrane. Tat-dependent membrane proteins usually have large globular domains and a single transmembrane helix present at the N- or C-terminus. Five Tat substrates that have C-terminal transmembrane helices have previously been characterized in the model bacterium Escherichia coli. Each of these is an iron-sulfur cluster-containing protein involved in electron transfer from hydrogen or formate. Here we have undertaken a bioinformatic search to identify further tail-anchored Tat substrates encoded in bacterial genomes. Our analysis has revealed additional tail-anchored iron-sulfur proteins associated in modules with either a b-type cytochrome or a quinol oxidase. We also identified further candidate tail-anchored Tat substrates, particularly among members of the actinobacterial phylum, that are not predicted to contain cofactors. Using reporter assays, we show experimentally that six of these have both N-terminal Tat signal peptides and C-terminal transmembrane helices. The newly identified proteins include a carboxypeptidase and a predicted protease, and four sortase substrates for which membrane integration is a prerequisite for covalent attachment to the cell wall.","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924467/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139747586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Current understandings of colibactin regulation. 目前对肠杆菌素调控的理解。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001427

Emily Addington, Sofia Sandalli, Andrew J Roe

引用次数: 0

Ecological dependencies and the illusion of cooperation in microbial communities. 微生物群落的生态依赖性与合作假象。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001442

Elze Hesse, Siobhán O'Brien

{"title":"Ecological dependencies and the illusion of cooperation in microbial communities.","authors":"Elze Hesse, Siobhán O'Brien","doi":"10.1099/mic.0.001442","DOIUrl":"10.1099/mic.0.001442","url":null,"abstract":"Ecological dependencies - where organisms rely on other organisms for survival - are a ubiquitous feature of life on earth. Multicellular hosts rely on symbionts to provide essential vitamins and amino acids. Legume plants similarly rely on nitrogen-fixing rhizobia to convert atmospheric nitrogen to ammonia. In some cases, dependencies can arise via loss-of-function mutations that allow one partner to benefit from the actions of another. It is common in microbiology to label ecological dependencies between species as cooperation - making it necessary to invoke cooperation-specific frameworks to explain the phenomenon. However, in many cases, such traits are not (at least initially) cooperative, because they are not selected for because of the benefits they confer on a partner species. In contrast, dependencies in microbial communities may originate from fitness benefits gained from genomic-streamlining (i.e. Black Queen Dynamics). Here, we outline how the Black Queen Hypothesis predicts the formation of metabolic dependencies via loss-of-function mutations in microbial communities, without needing to invoke any cooperation-specific explanations. Furthermore we outline how the Black Queen Hypothesis can act as a blueprint for true cooperation as well as discuss key outstanding questions in the field. The nature of interactions in microbial communities can predict the ability of natural communities to withstand and recover from disturbances. Hence, it is vital to gain a deeper understanding of the factors driving these dynamic interactions over evolutionary time.","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924460/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139933821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Twists and turns: 40 years of investigating how and why bacteria swim. 一波三折：研究细菌如何以及为何游泳的 40 年历程。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001432

Judith P Armitage

引用次数: 0

Microbial Primer: Bacterial growth kinetics. 微生物入门：细菌生长动力学。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001428

Lorena T Fernández-Martínez, Arnaud Javelle, Paul A Hoskisson

引用次数: 0

Predatory bacteria prevent the proliferation of intraocular Serratia marcescens and fluoroquinolone-resistant Pseudomonas aeruginosa. 捕食性细菌能阻止眼内肉豆蔻沙雷氏菌和耐氟喹诺酮铜绿假单胞菌的增殖。

IF 2.8 4区生物学

Microbiology-Sgm Pub Date : 2024-02-01 DOI: 10.1099/mic.0.001433

Eric G Romanowski, Kimberly M Brothers, Rachel C Calvario, Nicholas A Stella, Tami Kim, Mennat Elsayed, Daniel E Kadouri, Robert M Q Shanks

{"title":"Predatory bacteria prevent the proliferation of intraocular Serratia marcescens and fluoroquinolone-resistant Pseudomonas aeruginosa.","authors":"Eric G Romanowski, Kimberly M Brothers, Rachel C Calvario, Nicholas A Stella, Tami Kim, Mennat Elsayed, Daniel E Kadouri, Robert M Q Shanks","doi":"10.1099/mic.0.001433","DOIUrl":"10.1099/mic.0.001433","url":null,"abstract":"Endogenous endophthalmitis caused by Gram-negative bacteria is an intra-ocular infection that can rapidly progress to irreversible loss of vision. While most endophthalmitis isolates are susceptible to antibiotic therapy, the emergence of resistant bacteria necessitates alternative approaches to combat intraocular bacterial proliferation. In this study the ability of predatory bacteria to limit intraocular growth of Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus aureus was evaluated in a New Zealand white rabbit endophthalmitis prevention model. Predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus were able to reduce proliferation of keratitis isolates of P. aeruginosa and to a lesser extent S. marcescens. However, it was not able to significantly reduce the number of intraocular S. aureus, which is not a productive prey for these predatory bacteria, suggesting that the inhibitory effect on P. aeruginosa and S. marcescens requires active predation rather than an antimicrobial immune response. Similarly, UV-inactivated B. bacteriovorus were unable to prevent proliferation of P. aeruginosa. Together, these data indicate in vivo inhibition of Gram-negative bacteria proliferation within the intra-ocular environment by predatory bacteria.","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 2","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924457/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139736556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0