Microbiology-Sgm最新文献

{"title":"Structure and ligand binding in the putative anti-microbial peptide transporter protein, YejA.","authors":"Bryony K Ackroyd, Eleanor J Dodson, Javeria Mehboob, Adam A Dowle, Gavin H Thomas, Anthony J Wilkinson","doi":"10.1099/mic.0.001430","DOIUrl":"10.1099/mic.0.001430","url":null,"abstract":"<p><p>YejABEF is an ATP-binding cassette transporter that is implicated in the sensitivity of <i>Escherichia coli</i> to anti-microbial peptides, the best-characterized example being microcin C, a peptide-nucleotide antibiotic that targets aspartyl-tRNA synthetase. Here the structure of the extracellular solute binding protein, YejA, has been determined, revealing an oligopeptide-binding protein fold enclosing a ligand-binding pocket larger than those of other peptide-binding proteins of known structure. Prominent electron density in this cavity defines an undecapeptide sequence LGEPRYAFNFN, an observation that is confirmed by mass spectrometry. In the structure, the peptide interactions with the protein are mediated by main chain hydrogen bonds with the exception of Arg5 whose guanidinium side chain makes a set of defining polar interactions with four YejA residues. More detailed characterization of purified recombinant YejA, by a combination of ESI and MALDI-mass spectrometry as well as thermal shift assays, reveals a set of YejA complexes containing overlapping peptides 10-19 residues in length. All contain the sequence LGEPRYAFN. Curiously, these peptides correspond to residues 8-26 of the mature YejA protein, which belong to a unique N-terminal extension that distinguishes YejA from other cluster C oligopeptide binding proteins of known structure. This 35-residue extension is well-ordered and packs across the surface of the protein. The undecapeptide ligand occupies only a fraction of the enclosed pocket volume suggesting the possibility that much larger peptides or peptide conjugates could be accommodated, though thermal shift assays of YejA binding to antimicrobial peptides and peptides unrelated to LGEPRYAFNFN have not provided evidence of binding. While the physiological significance of this 'auto-binding' is not clear, the experimental data suggest that it is not an artefact of the crystallization process and that it may have a function in the sensing of periplasmic or membrane stress.</p>","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/PMC10924461/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139708383","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}

{"title":"Time-lapse mesoscopy of <i>Candida albicans</i> and <i>Staphylococcus aureus</i> dual-species biofilms reveals a structural role for the hyphae of <i>C. albicans</i> in biofilm formation.","authors":"Katherine J Baxter, Fiona A Sargison, J Ross Fitzgerald, Gail McConnell, Paul A Hoskisson","doi":"10.1099/mic.0.001426","DOIUrl":"10.1099/mic.0.001426","url":null,"abstract":"<p><p>Polymicrobial infection with <i>Candida albicans</i> and <i>Staphylococcus aureus</i> may result in a concomitant increase in virulence and resistance to antimicrobial drugs. This enhanced pathogenicity phenotype is mediated by numerous factors, including metabolic processes and direct interaction of <i>S. aureus</i> with <i>C. albicans</i> hyphae. The overall structure of biofilms is known to contribute to their recalcitrance to treatment, although the dynamics of direct interaction between species and how it contributes to pathogenicity is poorly understood. To address this, a novel time-lapse mesoscopic optical imaging method was developed to enable the formation of <i>C. albicans</i>/<i>S. aureus</i> whole dual-species biofilms to be followed. It was found that yeast-form or hyphal-form <i>C. albicans</i> in the biofilm founder population profoundly affects the structure of the biofilm as it matures. Different sub-populations of <i>C. albicans</i> and <i>S. aureus</i> arise within each biofilm as a result of the different <i>C. albicans</i> morphotypes, resulting in distinct sub-regions. These data reveal that <i>C. albicans</i> cell morphology is pivotal in the development of global biofilm architecture and the emergence of colony macrostructures and may temporally influence synergy in infection.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10866020/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139543325","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}

{"title":"Identification of a system for hydroxamate xenosiderophore-mediated iron transport in <i>Burkholderia cenocepacia</i>.","authors":"Syakira Mohammed Hussein, Aderonke Sofoluwe, Ameya Paleja, Anne Duhme-Klair, Mark S Thomas","doi":"10.1099/mic.0.001425","DOIUrl":"10.1099/mic.0.001425","url":null,"abstract":"<p><p>One of the mechanisms employed by the opportunistic pathogen <i>Burkholderia cenocepacia</i> to acquire the essential element iron is the production and release of two ferric iron chelating compounds (siderophores), ornibactin and pyochelin. Here we show that <i>B. cenocepacia</i> is also able to take advantage of a range of siderophores produced by other bacteria and fungi ('xenosiderophores') that chelate iron exclusively by means of hydroxamate groups. These include the tris-hydroxamate siderophores ferrioxamine B, ferrichrome, ferricrocin and triacetylfusarinine C, the bis-hydroxamates alcaligin and rhodotorulic acid, and the monohydroxamate siderophore cepabactin. We also show that of the 24 TonB-dependent transporters encoded by the <i>B. cenocepacia</i> genome, two (FhuA and FeuA) are involved in the uptake of hydroxamate xenosiderophores, with FhuA serving as the exclusive transporter of iron-loaded ferrioxamine B, triacetylfusarinine C, alcaligin and rhodotorulic acid, while both FhuA and FeuA are able to translocate ferrichrome-type siderophores across the outer membrane. Finally, we identified FhuB, a putative cytoplasmic membrane-anchored ferric-siderophore reductase, as being obligatory for utilization of all of the tested bis- and tris-hydroxamate xenosiderophores apart from alcaligin.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10866019/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139378666","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}

{"title":"Microbial Primer: The bacterial flagellum - how bacteria swim.","authors":"Judith P Armitage","doi":"10.1099/mic.0.001406","DOIUrl":"10.1099/mic.0.001406","url":null,"abstract":"<p><p>Bacteria swim using membrane-spanning, electrochemical gradient-powered motors that rotate semi-rigid helical filaments. This primer provides a brief overview of the basic synthesis, structure and operation of these nanomachines. Details and variations on the basic system can be found in suggested further reading.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10866024/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139472502","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}

{"title":"An assessment of the airborne longevity of group A Streptococcus.","authors":"Henry P Oswin, Evie Blake, Allen E Haddrell, Adam Finn, Shiranee Sriskandan, Jonathan P Reid, Alice Halliday, Anu Goenka","doi":"10.1099/mic.0.001421","DOIUrl":"10.1099/mic.0.001421","url":null,"abstract":"<p><p>Group A streptococcus (GAS) infections result in more than 500 000 deaths annually. Despite mounting evidence for airborne transmission of GAS, little is known about its stability in aerosol. Measurements of GAS airborne stability were carried out using the Controlled Electrodynamic Levitation and Extraction of Bioaerosols onto a Substrate (CELEBS) instrument. CELEBS measurements with two different isolates of GAS suggest that it is aerostable, with approximately 70 % of bacteria remaining viable after 20 min of levitation at 50 % relative humidity (RH), with lower survival as RH was reduced. GAS airborne viability loss was driven primarily by desiccation and efflorescence (i.e. salt crystallization), with high pH also potentially playing a role, given reduced survival in bicarbonate containing droplet compositions. At low enough RH for efflorescence to occur, a greater proportion of organic components in the droplet appeared to protect the bacteria from efflorescence. These first insights into the aerosol stability of GAS indicate that airborne transmission of these respiratory tract bacteria may occur, and that both the composition of the droplet containing the bacteria, and the RH of the air affect the duration of bacterial survival in this environment. Future studies will explore a broader range of droplet and air compositions and include a larger selection of GAS strains.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10866022/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139099081","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}

{"title":"Construction and characterisation of a structured, tuneable, and transparent 3D culture platform for soil bacteria.","authors":"Liam M Rooney, Lionel X Dupuy, Paul A Hoskisson, Gail McConnell","doi":"10.1099/mic.0.001429","DOIUrl":"10.1099/mic.0.001429","url":null,"abstract":"<p><p>We have developed a tuneable workflow for the study of soil microbes in an imitative 3D soil environment that is compatible with routine and advanced optical imaging, is chemically customisable, and is reliably refractive index matched based on the carbon catabolism of the study organism. We demonstrate our transparent soil pipeline with two representative soil organisms, <i>Bacillus subtilis</i> and <i>Streptomyces coelicolor</i>, and visualise their colonisation behaviours using fluorescence microscopy and mesoscopy. This spatially structured, 3D approach to microbial culture has the potential to further study the behaviour of bacteria in conditions matching their native environment and could be expanded to study microbial interactions, such as competition and warfare.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10866023/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139576397","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}

{"title":"Genomic and functional insights into antibiotic resistance genes <i>floR</i> and <i>strA</i> linked with the SXT element of <i>Vibrio cholerae</i> non-O1/non-O139.","authors":"Mousumi Saha, Agila Kumari Pragasam, Shashi Kumari, Jyoti Verma, Bhabatosh Das, Rupak K Bhadra","doi":"10.1099/mic.0.001424","DOIUrl":"10.1099/mic.0.001424","url":null,"abstract":"<p><p>The emergence and spread of antibiotic-resistant bacterial pathogens are a critical public health concern across the globe. Mobile genetic elements (MGEs) play an important role in the horizontal acquisition of antimicrobial resistance genes (ARGs) in bacteria. In this study, we have decoded the whole genome sequences of multidrug-resistant <i>Vibrio cholerae</i> clinical isolates carrying the ARG-linked SXT, an integrative and conjugative element, in their large chromosomes. As in others, the SXT element has been found integrated into the 5'-end of the <i>prfC</i> gene (which encodes peptide chain release factor 3 involved in translational regulation) on the large chromosome of <i>V. cholerae</i> non-O1/non-O139 strains. Further, we demonstrate the functionality of SXT-linked <i>floR</i> and <i>strAB</i> genes, which confer resistance to chloramphenicol and streptomycin, respectively. The <i>floR</i> gene-encoded protein FloR belongs to the major facilitator superfamily efflux transporter containing 12 transmembrane domains (TMDs). Deletion analysis confirmed that even a single TMD of FloR is critical for the export function of chloramphenicol. The <i>floR</i> gene has two putative promoters, P1 and P2. Sequential deletions reveal that P2 is responsible for the expression of the <i>floR</i>. Deletion analysis of the N- and/or C-terminal coding regions of <i>strA</i> established their importance for conferring resistance against streptomycin. Interestingly, qPCR analysis of the <i>floR</i> and <i>strA</i> genes indicated that both of the genes are constitutively expressed in <i>V. cholerae</i> cells. Further, whole genome-based global phylogeography confirmed the presence of the integrative and conjugative element SXT in non-O1/non-O139 strains despite being non-multidrug resistant by lacking antimicrobial resistance (AMR) gene cassettes, which needs monitoring.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10866021/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139099082","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}

{"title":"Meningeal Metastasis Causing Chronic Subdural Hematoma in a Cancer Patient with Bilateral Papilledema and Suspected Cerebral Venous Thrombosis: A Case Report.","authors":"Cornelia Pangratz-Daller, Jochen Grimm, Johannes A R Pfaff, Theo F J Kraus, Karl Sotlar, Abdul Rahman Al-Schameri, Michael Kral, Christoph J Griessenauer, Christoph Schwartz","doi":"10.1055/a-1832-3598","DOIUrl":"10.1055/a-1832-3598","url":null,"abstract":"<p><p>Meningeal metastasis has been reported as a very rare cause of chronic subdural hematoma (CSH). Here, we report a female patient who had undergone initial burr hole drainage of a CSH at an outside hospital. Postoperatively, the patient additionally suffered from visual impairment due to bilateral papilledema and the patient was eventually transferred to our neurosurgical department for additional treatment. A craniotomy was performed and due to intraoperative suspicious findings, histopathologic samples were obtained that revealed a metastasis of thus far undiagnosed triple negative breast cancer. Furthermore, the patient was suspected to have a partial cerebral venous thrombosis (CVT). Our case report addresses this extremely rare clinical constellation. We provide a detailed overview on our patient's clinical and radiologic course, and discuss the potential association of CSH with meningeal metastasis and bilateral papilledema.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"84 1","pages":"105-111"},"PeriodicalIF":1.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85972755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A toolbox for manipulating the genome of the major goat pathogen, <i>Mycoplasma capricolum</i> subsp. <i>capripneumoniae</i>.","authors":"Géraldine Gourgues, Lucía Manso-Silván, Catherine Chamberland, Pascal Sirand-Pugnet, François Thiaucourt, Alain Blanchard, Vincent Baby, Carole Lartigue","doi":"10.1099/mic.0.001423","DOIUrl":"10.1099/mic.0.001423","url":null,"abstract":"<p><p><i>Mycoplasma capricolum</i> subspecies <i>capripneumoniae</i> (<i>Mccp</i>) is the causative agent of contagious caprine pleuropneumonia (CCPP), a devastating disease listed by the World Organisation for Animal Health (WOAH) as a notifiable disease and threatening goat production in Africa and Asia. Although a few commercial inactivated vaccines are available, they do not comply with WOAH standards and there are serious doubts regarding their efficacy. One of the limiting factors to comprehend the molecular pathogenesis of CCPP and develop improved vaccines has been the lack of tools for <i>Mccp</i> genome engineering. In this work, key synthetic biology techniques recently developed for closely related mycoplasmas were adapted to <i>Mccp</i>. CReasPy-Cloning was used to simultaneously clone and engineer the <i>Mccp</i> genome in yeast, prior to whole-genome transplantation into <i>M. capricolum</i> subsp. <i>capricolum</i> recipient cells. This approach was used to knock out an S41 serine protease gene recently identified as a potential virulence factor, leading to the generation of the first site-specific <i>Mccp</i> mutants. The Cre-lox recombination system was then applied to remove all DNA sequences added during genome engineering. Finally, the resulting unmarked S41 serine protease mutants were validated by whole-genome sequencing and their non-caseinolytic phenotype was confirmed by casein digestion assay on milk agar. The synthetic biology tools that have been successfully implemented in <i>Mccp</i> allow the addition and removal of genes and other genetic features for the construction of seamless targeted mutants at ease, which will pave the way for both the identification of key pathogenicity determinants of <i>Mccp</i> and the rational design of novel, improved vaccines for the control of CCPP.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"170 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10866025/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139404998","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}

{"title":"Microbial Primer: <i>In vivo</i> biofilm.","authors":"Kendra P Rumbaugh, Thomas Bjarnsholt","doi":"10.1099/mic.0.001407","DOIUrl":"10.1099/mic.0.001407","url":null,"abstract":"<p><p>In this primer on biofilms and their role in infections, we trace the historical roots of microbial understanding from Van Leeuwenhoek's observations to Bill Costerton's groundbreaking work, which solidified biofilms' significance in infections. <i>In vivo</i> biofilm research, investigating patient samples and utilizing diverse host models, has yielded invaluable insights into these complex microbial communities. However, it comes with several challenges, particularly regarding replicating biofilm infections accurately in the laboratory. <i>In vivo</i> biofilm analyses involve various techniques, revealing biofilm architecture, composition, and behaviour, while gaps in knowledge persist regarding infection initiation and source, diversity, and the Infectious Microenvironment (IME). Ultimately, the study of biofilms in infections remains a dynamic and evolving field poised to transform our approach to combat biofilm-associated diseases.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"169 12","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10765038/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138488918","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}