Microbiology-Sgm最新文献

{"title":"Group B <i>Streptococcus</i> growth in human urine is associated with asymptomatic bacteriuria rather than urinary tract infection and is unaffected by iron sequestration.","authors":"Deepak S Ipe, Kelvin G K Goh, Devika Desai, Nouri Ben-Zakour, Matthew J Sullivan, Scott A Beatson, Glen C Ulett","doi":"10.1099/mic.0.001533","DOIUrl":"10.1099/mic.0.001533","url":null,"abstract":"<p><p>Group B <i>Streptococcus</i> (GBS) causes various infections in adults, including urinary tract infection (UTI) and asymptomatic bacteriuria (ABU). Some bacteria that cause ABU can utilize urine as a substrate for growth, which can promote asymptomatic colonization in the host. An analysis of diverse GBS isolates associated with ABU and UTI for growth in human urine has not been undertaken. Here, we examined a large collection of clinical urinary GBS isolates from individuals with acute UTI (<i>n</i>=62), and ABU with bacteriuria ≥10⁴ c.f.u. ml^-1 (<i>n</i>=206) or <10⁴ c.f.u. ml^-1 (<i>n</i>=90) for their ability to grow in human urine. Among all 358 GBS isolates analysed, 40 exhibited robust growth in urine in contrast to 25 that were unable to grow and non-culturable after incubation in urine. Growth phenotypes were disproportionately represented among the different groups of isolates, whereby robust growth was significantly more likely to be associated with high-grade ABU versus low-grade ABU or acute UTI (38/40 vs. 11/25; odds ratio 4.6, 95% CI, 1.5-14.8). Growth of bacteria in urine can depend on iron bioavailability, and we therefore performed growth assays using urine supplemented with 2,2-dipyridyl to chelate iron. In contrast to a control strain of ABU <i>Escherichia coli,</i> for which iron limitation significantly attenuated growth, iron sequestration had no significant attenuation effect on the growth of ABU GBS strain 834 in urine. Despite this finding, PCR confirmed the presence of several known growth-associated genes in GBS 834, including <i>fhuD</i> for iron uptake. We conclude that GBS adaptation for growth in human urine is more likely to be associated with high-grade ABU than acute UTI, and for GBS 834, this growth trait is not significantly constrained by conditions of iron sequestration.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11842879/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143459998","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":"SOS - save our seaside! The microbiological risks to human health of raw sewage in our coastal waters.","authors":"Jonathan A G Cox","doi":"10.1099/mic.0.001529","DOIUrl":"10.1099/mic.0.001529","url":null,"abstract":"<p><p>Most of us enjoy a day at the beach, but we rarely consider that recreational use of our coastal waters could impact our health. This article explores the microbiological threats of sewage discharge to our fun in the sea and proposes a simple way to make sure it's only sand that you and your family bring home from a visit to the seaside.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11806199/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143366630","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":"Corrigendum: Characterizing a stable five-species microbial community for use in experimental evolution and ecology.","authors":"Meaghan Castledine, Joseph Pennycook, Arthur Newbury, Luke Lear, Zoltan Erdos, Rai Lewis, Suzanne Kay, Dirk Sanders, David Sünderhauf, Angus Buckling, Elze Hesse, Daniel Padfield","doi":"10.1099/mic.0.001528","DOIUrl":"10.1099/mic.0.001528","url":null,"abstract":"","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143081630","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":"The nisin O cluster: species dissemination, candidate leader peptide proteases and the role of regulatory systems.","authors":"Jacob Scadden, Rebecca Ansorge, Stefano Romano, Andrea Telatin, Dave J Baker, Rhiannon Evans, Cristina Gherghisan-Filip, Zhenrun J Zhang, Melinda J Mayer, Arjan Narbad","doi":"10.1099/mic.0.001531","DOIUrl":"10.1099/mic.0.001531","url":null,"abstract":"<p><p>Nisin O is an antimicrobial peptide encoded by the human gut bacterium <i>Blautia obeum</i> A2-162 which has antimicrobial activity against clinically relevant organisms. The nisin O biosynthetic gene cluster (BGC) varies from other nisin BGCs as it lacks a leader-peptide cleaving protease and contains two bacterial two-component response regulator-histidine kinase (RK) systems. The dissemination of the nisin O cluster, the final proteolytic biosynthesis step and the regulation of nisin O are currently unknown and are the foci of this study. We identified six nisin O-like BGCs across <i>Blautia</i>, <i>Dorea</i> and <i>Ruminococcus</i> species using comparative genomics. These BGCs show evidence of genetic transfer between genera, with genes involved in transposition discovered up- and downstream of the BGCs. All nisin O-like BGCs contained two RK systems but no protease. Mining the <i>B. obeum</i> A2-162 genome identified candidate proteases that were cloned and used in pre-nisin O leader peptide cleavage assays. None of the candidate proteases removed the leader; however, cleavage was achieved using trypsin. To maximize the expression of the <i>nsoA1-4</i> peptides, the interactions of the two RK systems with predicted promoters in the nisin O cluster were assessed using a PepI reporter assay. We observed that the P<i>nsoR2K2</i> promoter was constitutively expressed, with NsoR1K1 increasing its activity, and that there was increased <i>nsoA1-4</i> expression when the nisin A RK system and nisin A were present. Long-read cDNA sequencing confirmed <i>nso</i> gene transcription in the heterologous expression system and identified a novel, highly expressed gene. This study provides evidence that the nisin O BGC has been transferred between different gut-associated genera, with all clusters lacking a protease and containing two RK systems. We hypothesize that this BGC has lost its protease due to negative selection as a result of high trypsin concentrations in the gut. Further work is required to maximize nisin O expression for it to be used as a potential antimicrobial therapy.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11811420/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392335","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":"Crosstalk between cyclic-di-guanosine monophosphate and the sensor kinase MtrB regulates MtrA-dependent genes, bacterial growth, biofilm formation and lysosomal trafficking of <i>Mycobacterium tuberculosis</i>.","authors":"Shreya Bagchi, Arun Kumar Sharma, Soumya Mal, Manikuntala Kundu, Joyoti Basu","doi":"10.1099/mic.0.001532","DOIUrl":"10.1099/mic.0.001532","url":null,"abstract":"<p><p>Cyclic-di-guanosine monophosphate (c-di-GMP) plays an important role in bacterial signalling networks. C-di-GMP exerts a regulatory function through binding to diverse molecules that include transcription factors, riboswitches and sensor kinases (SKs), thereby regulating diverse processes. Here, we demonstrate the crosstalk between c-di-GMP and the SK MtrB of <i>Mycobacterium tuberculosis</i>. MtrB phosphorylates and regulates its cognate response regulator MtrA. C-di-GMP binds directly to the cytosolic domain of MtrB to inhibit its autophosphorylation. C-di-GMP levels in <i>M. tuberculosis</i> were manipulated by overexpressing a c-di-GMP synthesizing enzyme <i>ydeH</i> and a degrading enzyme <i>rv1357c</i>. We demonstrate that overexpression of <i>ydeH</i> lowers growth of the bacterium both <i>in vitro</i> and in <i>M. tuberculosis</i> grown in macrophages. This is in conformity with lowered expression of <i>mtrA</i> and selected genes of the <i>mtrA</i> regulon involved in cell wall turnover in the <i>ydeH</i>-overexpressing strain compared to the parent strain. We also demonstrate that overexpression of <i>ydeH</i> in <i>M. tuberculosis</i> hinders biofilm formation, whereas overexpression of <i>rv1357c</i> has the opposite effect. Neither of the two genes could rescue the biofilm defective phenotype of the MtrB knock out mutant (<i>ΔmtrB</i>), suggesting that c-di-GMP exerts its role on biofilm formation through MtrB. Finally, we show by fluorescence microscopy that the trafficking of <i>M. tuberculosis</i> overexpressing <i>ydeH</i> is significantly higher than that of the parent strain and that this is linked to reduced expression of the MtrB-dependent genes <i>esxG</i> and <i>esxH</i>, which play a role in subversion of lysosomal trafficking of <i>M. tuberculosis</i>. These results provide important new insight into the crosstalk between c-di-GMP and MtrB in <i>M. tuberculosis</i>.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143371372","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":"Building an inclusive culture at scientific meetings: foundations for future progress.","authors":"Kevin Maringer, Edward Cunningham-Oakes, Ffion Lane, Kirsty L Jones, Bruno Francesco Rodrigues de Oliveira, Aisha Baba-Dikwa, Arindam Mitra, Blanca Perez-Sepulveda, Callie R Chappell, Guerrino Macori, I'ah Donovan-Banfield, Prerna Vohra, Rowan Casey, Roshan Nepal, C M Anjam Khan","doi":"10.1099/mic.0.001527","DOIUrl":"10.1099/mic.0.001527","url":null,"abstract":"<p><p>Scientific meetings and conferences are crucial in knowledge dissemination, fostering collaborations, professional development and inspiring innovative research. However, their traditional structure and organization have remained largely unchanged, perpetuating barriers that continue to exclude scientists from historically marginalized backgrounds. In response, the Microbiology Society has begun its journey to address these longstanding challenges, redesigning its meetings to create a more inclusive culture and a welcoming environment for all participants.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11803081/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143257178","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":"Linking volatile metabolites from bacterial pathogens to exhaled breath condensate of people with cystic fibrosis.","authors":"P Hansani Karunarathne, Christopher Bridges, Lacy Remisoski, Madisen Crane, Claudia Soria Casanova, Samantha N Kinne, Alicia L Castillo Bahena, Marissa Gil, Lienwil Padillo, Gabriel Querido, Jenna Mielke, Marc McClelland, Doug Conrad, Robert A Quinn","doi":"10.1099/mic.0.001536","DOIUrl":"10.1099/mic.0.001536","url":null,"abstract":"<p><p>Obtaining sputum samples from people with cystic fibrosis (pwCF) for microbiology has become challenging due to the positive clinical effects of the cystic fibrosis transmembrane conductance regulator modulator therapy, elexacaftor-tezacaftor-ivacaftor (ETI). Although ETI improves lung function and reduces sputum production, recent data shows that bacterial pathogens persist, making continued monitoring of infection important. As an alternative to sputum sampling, this study developed a non-invasive technique called 'Cough Breath' (CB) to identify volatile organic compounds (VOCs) in exhaled breath condensate (EBC) and link them to cystic fibrosis (CF) bacterial pathogens using purge and trap GC-MS. The CB culturing approach was able to isolate pathogens from expectorated particulates simultaneously with EBC collection; however, culturing positivity was low, with 6% of samples collected (<i>n</i>=47) positive for either <i>Pseudomonas aeruginosa</i> or <i>Staphylococcus aureus</i>. From EBC, we identified VOCs matching those uniquely produced by <i>P. aeruginosa</i> (7), <i>S. aureus</i> (12), <i>Achromobacter xylosoxidans</i> (8) and <i>Granulicatella adiacens</i> (2); however, the overall detection rate was also low. Expanding to VOCs produced across multiple pathogens identified 30 frequently detected in the EBC of pwCF, including 2,3-pentanedione, propyl pyruvate, oxalic acid diallyl ester, methyl isobutyl ketone, methyl nitrate, 2-propenal, acetonitrile, acetoin and 2,3-butanedione. Comparing isolate volatilomes and EBC samples from the same pwCF enhanced detection rates with key VOCs, such as 2,3-pentanedione (86%) and propyl pyruvate (83%), in <i>P. aeruginosa</i> isolates. Further investigation showed that VOC production differed across strains and at different growth phases, creating variability that may explain the overall low EBC detection rate. Although this study successfully cultured CF pathogens from cough particulates and matched their unique VOCs in EBC samples, our results indicate that microbial volatiles more generally indicative of infection, such as 2,3-pentanedione, may have the most utility in aiding diagnostics in pwCF on ETI who have reduced sputum production in the clinic.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143460228","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":"<i>Reflecting on Fleming's caveat:</i> the impact of stakeholder decision-making on antimicrobial resistance evolution.","authors":"Tom Ashfield, Mineli Cooray, Isabel Jimenez-Acha, Zeshan Riaz, Danna R Gifford, Mato Lagator","doi":"10.1099/mic.0.001534","DOIUrl":"10.1099/mic.0.001534","url":null,"abstract":"<p><p>Antimicrobial resistance poses one of the greatest and most imminent threats to global health, environment and food security, for which an urgent response is mandated. Evolutionary approaches to tackling the crisis tend to focus on proximate issues including the mechanisms and pathways to resistance, with associated calls to action for infection control and antimicrobial stewardship. This is of clear benefit but overlooks the fundamental influence of policy and stakeholder decision-making on resistance evolution. In 1945, Fleming issued a stark warning on the irresponsible use of penicillin and its potential to cause death due to penicillin-resistant infections. Attention to resistance evolution theory and heeding Fleming's advice could have allowed for a vastly different reality. Embedding evolutionary theory within policy, industry and regulatory bodies is not only essential but is now a race against time. Hence, critical appraisal of historical behaviour and attitudes at a global scale can inform a paradigm of anticipatory and adaptive policy. To undertake this exercise, we focused on the largest group of antibiotics with the greatest clinical and economic footprint, the beta-lactams. We examined historical case studies that affected how beta-lactams were developed, produced, approved and utilized, in order to relate stakeholder decision-making to resistance evolution. We derive lessons from these observations and propose sustainable approaches to curb resistance evolution. We set a position that actively incorporates an evolutionary theory of antimicrobial resistance into decision-making within antimicrobial development, production and stewardship.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11865498/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143505753","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":"Determination of protein transporter function using Raman spectroscopy.","authors":"Dominic Gilchrist, Meez Islam, Muhammad Safwan Akram, Paul Dean","doi":"10.1099/mic.0.001526","DOIUrl":"10.1099/mic.0.001526","url":null,"abstract":"<p><p>Transporter proteins are essential across the tree of life as they provide a cell with a means of exchanging vital metabolites with the external milieu. Characterizing the function of transporters is challenging and traditionally uses methods involving radiolabelled substrates, which requires prolonged exposure times and specialist equipment. Here, we provide an alternative method to the classical uptake assay using Raman spectroscopy to detect the uptake of alkyne-labelled substrates and determine transporter function. As a proof of principle, we demonstrate the method using a candidate nucleotide transporter (ThNTT4) expressed in <i>Escherichia coli</i>, which is shown to transport alkyne-labelled ATP molecules (N6pATP), which was readily detected using Raman spectroscopy. We show that ATP transport can be detected in a time-dependent manner using alkyne labels and demonstrate the substrate specificity of the transporter for purine but not pyrimidine substrates. This work establishes that Raman spectroscopy is an excellent alternative to using radioactive substrates in analysing, not only pathogen transporters, but potentially any transporter in which its substrate can be alkyne tagged.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392334","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":"Modelling host-pathogen interactions: <i>Galleria mellonella</i> as a platform to study <i>Pseudomonas aeruginosa</i> response to host-imposed zinc starvation.","authors":"Emma Michetti, Tulasi Abinya Mandava, Valerio Secli, Francesca Pacello, Andrea Battistoni, Serena Ammendola","doi":"10.1099/mic.0.001524","DOIUrl":"10.1099/mic.0.001524","url":null,"abstract":"<p><p>Nutritional immunity, a key component of the vertebrate innate immune response, involves the modulation of zinc availability to limit the growth of pathogens. <i>Pseudomonas aeruginosa</i> counteracts host-imposed zinc starvation through metabolic adaptations, including reprogramming of gene expression and activating efficient metal uptake systems. To unravel how zinc shortage contributes to the complexity of bacterial adaptation to the host environment, it is critical to use model systems that mimic fundamental features of <i>P. aeruginosa</i>-related diseases in humans. Among available animal models, <i>Galleria mellonella</i> has recently emerged as a promising alternative to mammalian hosts. This study aims to evaluate whether <i>G. mellonella</i> can recapitulate the zinc-related nutritional immunity responses observed in mammalian infections. Our results show that, upon <i>P. aeruginosa</i> infection, the larvae upregulate several zinc transporters, suggesting an active redistribution of the metal in response to the pathogen. Additionally, <i>P. aeruginosa</i> colonizing the larvae induces Zn uptake regulator-controlled genes, consistent with bacterial adaptation to zinc starvation. Disruption of bacterial zinc uptake capability significantly reduces <i>P. aeruginosa</i> virulence, underscoring the importance of zinc acquisition in pathogenesis also within this model host. As a proof of concept, we also demonstrate that this <i>in vivo</i> model can serve as a viable preliminary screening tool to unveil novel players involved in <i>P. aeruginosa</i> response to zinc starvation, offering valuable insights into the host-pathogen battle for micronutrients.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":"171 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11753293/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143014983","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}