Katherine J Baxter, Fiona A Sargison, J Ross Fitzgerald, Gail McConnell, Paul A Hoskisson
Polymicrobial infection with Candida albicans and Staphylococcus aureus 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 S. aureus with C. albicans 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 C. albicans/S. aureus whole dual-species biofilms to be followed. It was found that yeast-form or hyphal-form C. albicans in the biofilm founder population profoundly affects the structure of the biofilm as it matures. Different sub-populations of C. albicans and S. aureus arise within each biofilm as a result of the different C. albicans morphotypes, resulting in distinct sub-regions. These data reveal that C. albicans cell morphology is pivotal in the development of global biofilm architecture and the emergence of colony macrostructures and may temporally influence synergy in infection.
{"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":null,"pages":null},"PeriodicalIF":2.8,"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}
Syakira Mohammed Hussein, Aderonke Sofoluwe, Ameya Paleja, Anne Duhme-Klair, Mark S Thomas
One of the mechanisms employed by the opportunistic pathogen Burkholderia cenocepacia 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 B. cenocepacia 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 B. cenocepacia 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.
{"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":null,"pages":null},"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}
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.
{"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":null,"pages":null},"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}
Liam M Rooney, Lionel X Dupuy, Paul A Hoskisson, Gail McConnell
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, Bacillus subtilis and Streptomyces coelicolor, 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.
{"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":null,"pages":null},"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}
Henry P Oswin, Evie Blake, Allen E Haddrell, Adam Finn, Shiranee Sriskandan, Jonathan P Reid, Alice Halliday, Anu Goenka
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.
A 组链球菌(GAS)感染每年导致 50 多万人死亡。尽管有越来越多的证据表明 GAS 通过空气传播,但人们对其在气溶胶中的稳定性却知之甚少。我们使用受控电动悬浮和提取生物气溶胶到基质(CELEBS)仪器对 GAS 在空气中的稳定性进行了测量。通过对两种不同的 GAS 分离物进行 CELEBS 测量,结果表明 GAS 具有空气稳定性,在相对湿度(RH)为 50% 的条件下悬浮 20 分钟后,仍有约 70% 的细菌存活,随着相对湿度的降低,存活率也会降低。GAS 在空气中的存活率下降主要是由于干燥和风化(即盐结晶)造成的,高 pH 值也可能起到一定作用,因为在含有碳酸氢盐的液滴成分中存活率会降低。在相对湿度足够低的情况下,液滴中有机成分的比例越高,细菌就越能免受侵蚀。这些对 GAS 气溶胶稳定性的初步认识表明,这些呼吸道细菌可能会通过空气传播,而含有细菌的液滴成分和空气相对湿度都会影响细菌在这种环境中的存活时间。未来的研究将探索更广泛的液滴和空气成分,并选择更多的 GAS 菌株。
{"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":null,"pages":null},"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}
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 Vibrio cholerae 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 prfC gene (which encodes peptide chain release factor 3 involved in translational regulation) on the large chromosome of V. cholerae non-O1/non-O139 strains. Further, we demonstrate the functionality of SXT-linked floR and strAB genes, which confer resistance to chloramphenicol and streptomycin, respectively. The floR 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 floR gene has two putative promoters, P1 and P2. Sequential deletions reveal that P2 is responsible for the expression of the floR. Deletion analysis of the N- and/or C-terminal coding regions of strA established their importance for conferring resistance against streptomycin. Interestingly, qPCR analysis of the floR and strA genes indicated that both of the genes are constitutively expressed in V. cholerae 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.
{"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":null,"pages":null},"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}
Géraldine Gourgues, Lucía Manso-Silván, Catherine Chamberland, Pascal Sirand-Pugnet, François Thiaucourt, Alain Blanchard, Vincent Baby, Carole Lartigue
Mycoplasma capricolum subspecies capripneumoniae (Mccp) 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 Mccp genome engineering. In this work, key synthetic biology techniques recently developed for closely related mycoplasmas were adapted to Mccp. CReasPy-Cloning was used to simultaneously clone and engineer the Mccp genome in yeast, prior to whole-genome transplantation into M. capricolum subsp. capricolum 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 Mccp 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 Mccp 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 Mccp and the rational design of novel, improved vaccines for the control of CCPP.
{"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":null,"pages":null},"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":"Microbe Profile: The <i>Lactobacillaceae</i>.","authors":"Jens Walter, Paul W O'Toole","doi":"10.1099/mic.0.001414","DOIUrl":"10.1099/mic.0.001414","url":null,"abstract":"","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10765037/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138806852","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}
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. In vivo 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. In vivo 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.
{"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":null,"pages":null},"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}
Oliver J Hills, Isaac O K Noble, Alex Heyam, Andrew J Scott, James Smith, Helen F Chappell
Intravenous gallium nitrate therapy is a novel therapeutic strategy deployed to combat chronic Pseudomonas aeruginosa biofilm infections in the lungs of cystic fibrosis (CF) patients by interfering with iron (Fe3+) uptake. The therapy is a source of Ga3+, which competes with Fe3+ for siderophore binding, subsequently disrupting iron metabolism and inhibiting biofilm proliferation in vivo. It was recently demonstrated that the Pseudomonas quinolone signal (PQS) can chelate Fe3+ to assist in bacterial iron uptake. However, it is unknown whether exogenous gallium also targets [Fe(PQS)3] uptake, which, in turn, would extend the mechanism of gallium therapy beyond siderophore competition, potentially supporting use of the therapy against P. aeruginosa mutants deficient in siderophore uptake proteins. To that end, the thermodynamic feasibility of iron-for-gallium cation exchange into [Fe(PQS)3] was evaluated using quantum chemical density functional theory (DFT) modelling and verified experimentally using 1H nuclear magnetic resonance (NMR). We demonstrate here that Ga3+ can strongly bind to three PQS molecules and, furthermore, displace and substitute Fe3+ from the native chelate pocket within PQS complexes, through a Trojan horse mechanism, retaining the key structural features present within the native ferric complex. As such, [Fe(PQS)3] complexes, in addition to ferric-siderophore complexes, represent another target for gallium therapy.
{"title":"Atomistic modelling and NMR studies reveal that gallium can target the ferric PQS uptake system in <i>P. aeruginosa</i> biofilms.","authors":"Oliver J Hills, Isaac O K Noble, Alex Heyam, Andrew J Scott, James Smith, Helen F Chappell","doi":"10.1099/mic.0.001422","DOIUrl":"10.1099/mic.0.001422","url":null,"abstract":"<p><p>Intravenous gallium nitrate therapy is a novel therapeutic strategy deployed to combat chronic <i>Pseudomonas aeruginosa</i> biofilm infections in the lungs of cystic fibrosis (CF) patients by interfering with iron (Fe<sup>3+</sup>) uptake. The therapy is a source of Ga<sup>3+</sup>, which competes with Fe<sup>3+</sup> for siderophore binding, subsequently disrupting iron metabolism and inhibiting biofilm proliferation <i>in vivo</i>. It was recently demonstrated that the <i>Pseudomonas</i> quinolone signal (PQS) can chelate Fe<sup>3+</sup> to assist in bacterial iron uptake. However, it is unknown whether exogenous gallium also targets [Fe(PQS)<sub>3</sub>] uptake, which, in turn, would extend the mechanism of gallium therapy beyond siderophore competition, potentially supporting use of the therapy against <i>P. aeruginosa</i> mutants deficient in siderophore uptake proteins. To that end, the thermodynamic feasibility of iron-for-gallium cation exchange into [Fe(PQS)<sub>3</sub>] was evaluated using quantum chemical density functional theory (DFT) modelling and verified experimentally using <sup>1</sup>H nuclear magnetic resonance (NMR). We demonstrate here that Ga<sup>3+</sup> can strongly bind to three PQS molecules and, furthermore, displace and substitute Fe<sup>3+</sup> from the native chelate pocket within PQS complexes, through a Trojan horse mechanism, retaining the key structural features present within the native ferric complex. As such, [Fe(PQS)<sub>3</sub>] complexes, in addition to ferric-siderophore complexes, represent another target for gallium therapy.</p>","PeriodicalId":49819,"journal":{"name":"Microbiology-Sgm","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10765035/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138806790","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}