D-galactonate, a widely prevalent sugar acid, was first reported as a nutrient source for enteric bacteria in the 1970s. Since then, decades of research enabled a description of the modified Entner-Doudoroff pathway involved in its degradation and reported the structural and biochemical features of its metabolic enzymes, primarily in Escherichia coli K-12. However, only in the last few years, the D-galactonate transporter has been characterized, and the regulation of the dgo operon, encoding the structural genes for the transporter and enzymes of D-galactonate metabolism, has been detailed. Notably, in recent years, multiple evolutionary studies have identified the dgo operon as a dominant target for adaptation of E. coli in the mammalian gut. Despite considerable research on dgo operon, numerous fundamental questions remain to be addressed. The emerging relevance of the dgo operon in host–bacterial interactions further necessitates the study of D-galactonate metabolism in other enterobacterial strains.
{"title":"D-galactonate metabolism in enteric bacteria: a molecular and physiological perspective","authors":"Swati Singh , Chetna Gola , Bhupinder Singh , Vishal Agrawal , Rachna Chaba","doi":"10.1016/j.mib.2024.102524","DOIUrl":"10.1016/j.mib.2024.102524","url":null,"abstract":"<div><p><span>D</span>-galactonate, a widely prevalent sugar acid, was first reported as a nutrient source for enteric bacteria in the 1970s. Since then, decades of research enabled a description of the modified Entner-Doudoroff pathway involved in its degradation and reported the structural and biochemical features of its metabolic enzymes, primarily in <em>Escherichia coli</em> K-12. However, only in the last few years, the <span>D</span>-galactonate transporter has been characterized, and the regulation of the <em>dgo</em> operon, encoding the structural genes for the transporter and enzymes of <span>D</span>-galactonate metabolism, has been detailed. Notably, in recent years, multiple evolutionary studies have identified the <em>dgo</em> operon as a dominant target for adaptation of <em>E. coli</em> in the mammalian gut. Despite considerable research on <em>dgo</em> operon, numerous fundamental questions remain to be addressed. The emerging relevance of the <em>dgo</em> operon in host–bacterial interactions further necessitates the study of <span>D</span>-galactonate metabolism in other enterobacterial strains.</p></div>","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"81 ","pages":"Article 102524"},"PeriodicalIF":5.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141975334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fungal biofilms are a multilayered community of cells attached to mucosal or abiotic surfaces enclosed in a coating of self-produced extracellular polymeric matrix. The sheer density of cells protected by a polymeric shield not only makes the biofilm impermeable to antimicrobials or immune cells but also hidden from host recognition. Biofilms also serve as a reservoir of drug-resistant persister cells and dispersal cells armored with virulence factors adept at evading the immune system. Here, we summarize the latest knowledge on the immunomodulatory properties of biofilms formed by Candida species and by other biofilm-forming fungal pathogens such as Aspergillus and Cryptococcus. Finally, we deliberate on promising strategies to help activate the immune system for combating fungal biofilms.
{"title":"Host immune response against fungal biofilms","authors":"Mohammad Mannan , Sunna Nabeela , Reetakshi Mishra , Priya Uppuluri","doi":"10.1016/j.mib.2024.102520","DOIUrl":"10.1016/j.mib.2024.102520","url":null,"abstract":"<div><p>Fungal biofilms are a multilayered community of cells attached to mucosal or abiotic surfaces enclosed in a coating of self-produced extracellular polymeric matrix. The sheer density of cells protected by a polymeric shield not only makes the biofilm impermeable to antimicrobials or immune cells but also hidden from host recognition. Biofilms also serve as a reservoir of drug-resistant persister cells and dispersal cells armored with virulence factors adept at evading the immune system. Here, we summarize the latest knowledge on the immunomodulatory properties of biofilms formed by <em>Candida</em> species and by other biofilm-forming fungal pathogens such as <em>Aspergillus</em> and <em>Cryptococcus</em>. Finally, we deliberate on promising strategies to help activate the immune system for combating fungal biofilms.</p></div>","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"81 ","pages":"Article 102520"},"PeriodicalIF":5.9,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1369527424000961/pdfft?md5=d1b3631d18ad1cf50b233ae1db6be79e&pid=1-s2.0-S1369527424000961-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141912107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-07DOI: 10.1016/j.mib.2024.102522
Toni Gabaldón , Luiz Pedro Sório de Carvalho
{"title":"Editorial overview: emerging avenues in antimicrobial research","authors":"Toni Gabaldón , Luiz Pedro Sório de Carvalho","doi":"10.1016/j.mib.2024.102522","DOIUrl":"10.1016/j.mib.2024.102522","url":null,"abstract":"","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"81 ","pages":"Article 102522"},"PeriodicalIF":5.9,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141906175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1016/j.mib.2024.102521
Matthew R James, Katherine E Doss, Robert A Cramer
Aspergillus fumigatus is a filamentous fungus abundant in the environment and the most common causative agent of a spectrum of human diseases collectively termed aspergillosis. Invasive pulmonary aspergillosis is caused by deficiencies in innate immune function that result in the inability of the host to clear inhaled Aspergillus conidia that then germinate and form invasive hyphae. Myeloid cells, and their ability to generate reactive oxygen species (ROS), are essential for conidia clearance from the host. To combat ROS, A. fumigatus employs an expansive antioxidant system, though how these canonical antioxidant mechanisms contribute to infection initiation and disease progression remain to be fully defined. Recent research has identified noncanonical pathways in the A. fumigatus ROS response and new host populations with ROS deficiencies that are at-risk for invasive aspergillosis. Here, we highlight recent developments in the understanding of ROS at the interface of the dynamic A. fumigatus–host interaction.
{"title":"New developments in Aspergillus fumigatus and host reactive oxygen species responses","authors":"Matthew R James, Katherine E Doss, Robert A Cramer","doi":"10.1016/j.mib.2024.102521","DOIUrl":"10.1016/j.mib.2024.102521","url":null,"abstract":"<div><p><em>Aspergillus fumigatus</em> is a filamentous fungus abundant in the environment and the most common causative agent of a spectrum of human diseases collectively termed aspergillosis. Invasive pulmonary aspergillosis is caused by deficiencies in innate immune function that result in the inability of the host to clear inhaled <em>Aspergillus</em> conidia that then germinate and form invasive hyphae. Myeloid cells, and their ability to generate reactive oxygen species (ROS), are essential for conidia clearance from the host. To combat ROS, <em>A. fumigatus</em> employs an expansive antioxidant system, though how these canonical antioxidant mechanisms contribute to infection initiation and disease progression remain to be fully defined. Recent research has identified noncanonical pathways in the <em>A. fumigatus</em> ROS response and new host populations with ROS deficiencies that are at-risk for invasive aspergillosis. Here, we highlight recent developments in the understanding of ROS at the interface of the dynamic <em>A. fumigatus</em>–host interaction.</p></div>","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"80 ","pages":"Article 102521"},"PeriodicalIF":5.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141855107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1016/j.mib.2024.102519
Grace A Beggs , Bonnie L Bassler
Phages have wide influence on bacterial physiology, and likewise, bacterial processes impinge on phage biology. Key to these interactions are phage small proteins (<100 aa). Long underappreciated, recent work has revealed millions of phage small proteins, and increasingly, mechanisms by which they function to dictate phage and/or bacterial behavior and evolution. Here, we describe select phage small proteins that mediate phage–bacterial interactions by modulating phage lifestyle decision-making components or by altering host gene expression.
{"title":"Phage small proteins play large roles in phage–bacterial interactions","authors":"Grace A Beggs , Bonnie L Bassler","doi":"10.1016/j.mib.2024.102519","DOIUrl":"10.1016/j.mib.2024.102519","url":null,"abstract":"<div><p>Phages have wide influence on bacterial physiology, and likewise, bacterial processes impinge on phage biology. Key to these interactions are phage small proteins (<100 aa). Long underappreciated, recent work has revealed millions of phage small proteins, and increasingly, mechanisms by which they function to dictate phage and/or bacterial behavior and evolution. Here, we describe select phage small proteins that mediate phage–bacterial interactions by modulating phage lifestyle decision-making components or by altering host gene expression.</p></div>","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"80 ","pages":"Article 102519"},"PeriodicalIF":5.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S136952742400095X/pdfft?md5=6d844c860d56b858dad4083fd7e235f3&pid=1-s2.0-S136952742400095X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141757628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1016/j.mib.2024.102518
Julia Frunzke , Rob Lavigne
{"title":"Editorial overview: There and back again: a phage’s tale","authors":"Julia Frunzke , Rob Lavigne","doi":"10.1016/j.mib.2024.102518","DOIUrl":"10.1016/j.mib.2024.102518","url":null,"abstract":"","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"80 ","pages":"Article 102518"},"PeriodicalIF":5.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141757627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1016/j.mib.2024.102516
Kelley A Gallagher , Natalia Tschowri , Richard G Brennan , Maria A Schumacher , Mark J Buttner
Members of the antibiotic-producing bacterial genus Streptomyces undergo a complex developmental life cycle that culminates in the production of spores. Central to control of this cell differentiation process is signaling through the second messenger 3′, 5′-cyclic diguanylic acid (c-di-GMP). So far, three proteins that are directly controlled by c-di-GMP in Streptomyces have been functionally and structurally characterized: the key developmental regulators BldD and σWhiG, and the glycogen-degrading enzyme GlgX. c-di-GMP signals through BldD and σWhiG, respectively, to control the two most dramatic transitions of the Streptomyces life cycle, the formation of the reproductive aerial hyphae and their differentiation into spore chains. Later in development, c-di-GMP activates GlgX-mediated degradation of glycogen, releasing stored carbon for spore maturation.
{"title":"How c-di-GMP controls progression through the Streptomyces life cycle","authors":"Kelley A Gallagher , Natalia Tschowri , Richard G Brennan , Maria A Schumacher , Mark J Buttner","doi":"10.1016/j.mib.2024.102516","DOIUrl":"10.1016/j.mib.2024.102516","url":null,"abstract":"<div><p>Members of the antibiotic-producing bacterial genus <em>Streptomyces</em> undergo a complex developmental life cycle that culminates in the production of spores. Central to control of this cell differentiation process is signaling through the second messenger 3′, 5′-cyclic diguanylic acid (c-di-GMP). So far<em>,</em> three proteins that are directly controlled by c-di-GMP in <em>Streptomyces</em> have been functionally and structurally characterized: the key developmental regulators BldD and σ<sup>WhiG</sup>, and the glycogen-degrading enzyme GlgX. c-di-GMP signals through BldD and σ<sup>WhiG</sup>, respectively, to control the two most dramatic transitions of the <em>Streptomyces</em> life cycle, the formation of the reproductive aerial hyphae and their differentiation into spore chains. Later in development, c-di-GMP activates GlgX-mediated degradation of glycogen, releasing stored carbon for spore maturation.</p></div>","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"80 ","pages":"Article 102516"},"PeriodicalIF":5.9,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1369527424000924/pdfft?md5=442a6b014b52e3deb82bc7b7cec49506&pid=1-s2.0-S1369527424000924-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141765712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-18DOI: 10.1016/j.mib.2024.102514
Kwang-Woo Jung , Seung-Heon Lee , Kyung-Tae Lee , Yong-Sun Bahn
The sophisticated ability of living organisms to sense and respond to external stimuli is critical for survival. This is particularly true for fungal pathogens, where the capacity to adapt and proliferate within a host is essential. To this end, signaling pathways, whether evolutionarily conserved or unique, have been refined through interactions with the host. Cryptococcus neoformans, an opportunistic fungal pathogen, is responsible for over 190,000 cases and an estimated 147,000 annual deaths globally. Extensive research over the past decades has shed light on the signaling pathways underpinning the pathogenicity of C. neoformans, as well as the host’s responses during infection. In this context, we delineate the regulatory mechanisms employed by C. neoformans to detect and react to stresses derived from the host.
{"title":"Sensing and responding to host-derived stress signals: lessons from fungal meningitis pathogen","authors":"Kwang-Woo Jung , Seung-Heon Lee , Kyung-Tae Lee , Yong-Sun Bahn","doi":"10.1016/j.mib.2024.102514","DOIUrl":"10.1016/j.mib.2024.102514","url":null,"abstract":"<div><p>The sophisticated ability of living organisms to sense and respond to external stimuli is critical for survival. This is particularly true for fungal pathogens, where the capacity to adapt and proliferate within a host is essential. To this end, signaling pathways, whether evolutionarily conserved or unique, have been refined through interactions with the host. <em>Cryptococcus neoformans</em>, an opportunistic fungal pathogen, is responsible for over 190,000 cases and an estimated 147,000 annual deaths globally. Extensive research over the past decades has shed light on the signaling pathways underpinning the pathogenicity of <em>C. neoformans</em>, as well as the host’s responses during infection. In this context, we delineate the regulatory mechanisms employed by <em>C. neoformans</em> to detect and react to stresses derived from the host.</p></div>","PeriodicalId":10921,"journal":{"name":"Current opinion in microbiology","volume":"80 ","pages":"Article 102514"},"PeriodicalIF":5.9,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141636471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}