Pub Date : 2024-07-27eCollection Date: 2024-01-01DOI: 10.1093/femsmc/xtae023
Misshelle Bustamante, Floor Koopman, Jesper Martens, Jolanda K Brons, Javier DelaFuente, Thomas Hackl, Oscar P Kuipers, G Sander van Doorn, Marjon G J de Vos
In urinary tract infections (UTIs), different bacteria can live in a polymicrobial community consisting of different species. It is unknown how community members affect the conjugation efficiency of uropathogenic Escherichia coli. We investigated the influence of individual species often coisolated from urinary infections (UTI) on the conjugation efficiency of E. coli isolates in artificial urine medium. Pairwise conjugation rate experiments were conducted between a donor E. coli strain containing the pOXA-48 plasmid and six uropathogenic E. coli isolates, in the presence and absence of five different species commonly coisolated in polymicrobial UTIs to elucidate their effect on the conjugation efficiency of E. coli. We found that the basal conjugation rates of pOXA-48, in the absence of other species, are dependent on the bacterial host genetic background. Additionally, we found that bacterial interactions have an overall positive effect on the conjugation rate of pOXA-48. Particularly, Gram-positive enterococcal species were found to enhance the conjugation rates towards uropathogenic E. coli isolates. We hypothesize that the nature of the coculture and physical interactions are important for these increased conjugation rates in an artificial urine medium environment.
{"title":"Community context influences the conjugation efficiency of <i>Escherichia coli</i>.","authors":"Misshelle Bustamante, Floor Koopman, Jesper Martens, Jolanda K Brons, Javier DelaFuente, Thomas Hackl, Oscar P Kuipers, G Sander van Doorn, Marjon G J de Vos","doi":"10.1093/femsmc/xtae023","DOIUrl":"10.1093/femsmc/xtae023","url":null,"abstract":"<p><p>In urinary tract infections (UTIs), different bacteria can live in a polymicrobial community consisting of different species. It is unknown how community members affect the conjugation efficiency of uropathogenic <i>Escherichia coli</i>. We investigated the influence of individual species often coisolated from urinary infections (UTI) on the conjugation efficiency of <i>E. coli</i> isolates in artificial urine medium. Pairwise conjugation rate experiments were conducted between a donor <i>E. coli</i> strain containing the pOXA-48 plasmid and six uropathogenic <i>E. coli</i> isolates, in the presence and absence of five different species commonly coisolated in polymicrobial UTIs to elucidate their effect on the conjugation efficiency of <i>E. coli</i>. We found that the basal conjugation rates of pOXA-48, in the absence of other species, are dependent on the bacterial host genetic background. Additionally, we found that bacterial interactions have an overall positive effect on the conjugation rate of pOXA-48. Particularly, Gram-positive enterococcal species were found to enhance the conjugation rates towards uropathogenic <i>E. coli</i> isolates. We hypothesize that the nature of the coculture and physical interactions are important for these increased conjugation rates in an artificial urine medium environment.</p>","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"5 ","pages":"xtae023"},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11338288/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142019772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-26eCollection Date: 2024-01-01DOI: 10.1093/femsmc/xtae022
Emma K Sheriff, Fernanda Salvato, Shelby E Andersen, Anushila Chatterjee, Manuel Kleiner, Breck A Duerkop
Increased prevalence of multidrug-resistant bacterial infections has sparked interest in alternative antimicrobials, including bacteriophages (phages). Limited understanding of the phage infection process hampers our ability to utilize phages to their full therapeutic potential. To understand phage infection dynamics, we performed proteomics on Enterococcus faecalis infected with the phage VPE25. We discovered that numerous uncharacterized phage proteins are produced during phage infection of E. faecalis. Additionally, we identified hundreds of changes in bacterial protein abundances during infection. One such protein, enterococcal gelatinase (GelE), an fsr quorum-sensing-regulated protease involved in biofilm formation and virulence, was reduced during VPE25 infection. Plaque assays showed that mutation of either the quorum-sensing regulator fsrA or gelE resulted in plaques with a "halo" morphology and significantly larger diameters, suggesting decreased protection from phage infection. GelE-associated protection during phage infection is dependent on the putative murein hydrolase regulator LrgA and antiholin-like protein LrgB, whose expression have been shown to be regulated by GelE. Our work may be leveraged in the development of phage therapies that can modulate the production of GelE thereby altering biofilm formation and decreasing E. faecalis virulence.
{"title":"Enterococcal quorum-controlled protease alters phage infection.","authors":"Emma K Sheriff, Fernanda Salvato, Shelby E Andersen, Anushila Chatterjee, Manuel Kleiner, Breck A Duerkop","doi":"10.1093/femsmc/xtae022","DOIUrl":"10.1093/femsmc/xtae022","url":null,"abstract":"<p><p>Increased prevalence of multidrug-resistant bacterial infections has sparked interest in alternative antimicrobials, including bacteriophages (phages). Limited understanding of the phage infection process hampers our ability to utilize phages to their full therapeutic potential. To understand phage infection dynamics, we performed proteomics on <i>Enterococcus faecalis</i> infected with the phage VPE25. We discovered that numerous uncharacterized phage proteins are produced during phage infection of <i>E. faecalis</i>. Additionally, we identified hundreds of changes in bacterial protein abundances during infection. One such protein, enterococcal gelatinase (GelE), an <i>fsr</i> quorum-sensing-regulated protease involved in biofilm formation and virulence, was reduced during VPE25 infection. Plaque assays showed that mutation of either the quorum-sensing regulator <i>fsrA</i> or <i>gelE</i> resulted in plaques with a \"halo\" morphology and significantly larger diameters, suggesting decreased protection from phage infection. GelE-associated protection during phage infection is dependent on the putative murein hydrolase regulator LrgA and antiholin-like protein LrgB, whose expression have been shown to be regulated by GelE. Our work may be leveraged in the development of phage therapies that can modulate the production of GelE thereby altering biofilm formation and decreasing <i>E. faecalis</i> virulence.</p>","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"5 ","pages":"xtae022"},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11328733/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142001475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michelle Hallenbeck, Michelle J. Chua, James Collins
Vancomycin-resistant enterococci (VRE) pose a serious threat to public health because of their limited treatment options. Therefore, there is an increasing need to identify novel targets to develop new drugs. Here, we examined the roles of the universal PTS components, PtsI and PtsH, in Enterococcus faecium to determine their roles in carbon metabolism, biofilm formation, stress response, and the ability to compete in the gastrointestinal tract. Clean deletion of ptsHI resulted in a significant reduction in the ability to import and metabolize simple sugars, attenuated growth rate, reduced biofilm formation, and decreased competitive fitness both in vitro and in vivo. However, no significant difference in stress survival was observed when compared with the wild type. These results suggest that targeting universal or specific PTS may provide a novel treatment strategy by reducing the fitness of E. faecium.
{"title":"The role of the universal sugar transport system components PtsI (EI) and PtsH (HPr) in Enterococcus faecium","authors":"Michelle Hallenbeck, Michelle J. Chua, James Collins","doi":"10.1093/femsmc/xtae018","DOIUrl":"https://doi.org/10.1093/femsmc/xtae018","url":null,"abstract":"\u0000 Vancomycin-resistant enterococci (VRE) pose a serious threat to public health because of their limited treatment options. Therefore, there is an increasing need to identify novel targets to develop new drugs. Here, we examined the roles of the universal PTS components, PtsI and PtsH, in Enterococcus faecium to determine their roles in carbon metabolism, biofilm formation, stress response, and the ability to compete in the gastrointestinal tract. Clean deletion of ptsHI resulted in a significant reduction in the ability to import and metabolize simple sugars, attenuated growth rate, reduced biofilm formation, and decreased competitive fitness both in vitro and in vivo. However, no significant difference in stress survival was observed when compared with the wild type. These results suggest that targeting universal or specific PTS may provide a novel treatment strategy by reducing the fitness of E. faecium.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"86 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141272597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Enterococcus faecium is a gut commensal bacterium that is gaining increasing relevance as an opportunistic, nosocomial pathogen. Its high level of intrinsic and acquired antimicrobial resistance is causing a lack of treatment options, particularly for infections with vancomycin-resistant strains, and prioritizes the identification and functional validation of novel druggable targets. Here, we use activity-based protein profiling (ABPP), a chemoproteomics approach using functionalized covalent inhibitors, to detect active serine hydrolases across 11 E. faecium and Enterococcus lactis strains. Serine hydrolases are a big and diverse enzyme family, that includes known drug targets such as penicillin-binding proteins (PBPs), whereas other subfamilies are underexplored. Comparative gel-based ABPP using Bocillin-FL revealed strain- and growth condition dependent variations in PBP activities. Profiling with the broadly serine hydrolase-reactive fluorescent probe fluorophosphonate-TMR showed a high similarity across E. faecium clade A1 strains, but higher variation across A2 and E. lactis strains. To identify these serine hydrolases, we used a biotinylated probe analog allowing for enrichment and identification via liquid chromatography-mass spectrometry. We identified 11 largely uncharacterized targets (α,β-hydrolases, SGNH-hydrolases, phospholipases, amidases, peptidases) that are druggable and accessible in live vancomycin-resistant E. faecium E745 and may possess vital functions that are to be characterized in future studies.
{"title":"Activity-based protein profiling of serine hydrolases and penicillin-binding proteins in Enterococcus faecium","authors":"J. S. Grunnvåg, K. Hegstad, Christian S. Lentz","doi":"10.1093/femsmc/xtae015","DOIUrl":"https://doi.org/10.1093/femsmc/xtae015","url":null,"abstract":"\u0000 Enterococcus faecium is a gut commensal bacterium that is gaining increasing relevance as an opportunistic, nosocomial pathogen. Its high level of intrinsic and acquired antimicrobial resistance is causing a lack of treatment options, particularly for infections with vancomycin-resistant strains, and prioritizes the identification and functional validation of novel druggable targets. Here, we use activity-based protein profiling (ABPP), a chemoproteomics approach using functionalized covalent inhibitors, to detect active serine hydrolases across 11 E. faecium and Enterococcus lactis strains. Serine hydrolases are a big and diverse enzyme family, that includes known drug targets such as penicillin-binding proteins (PBPs), whereas other subfamilies are underexplored. Comparative gel-based ABPP using Bocillin-FL revealed strain- and growth condition dependent variations in PBP activities. Profiling with the broadly serine hydrolase-reactive fluorescent probe fluorophosphonate-TMR showed a high similarity across E. faecium clade A1 strains, but higher variation across A2 and E. lactis strains. To identify these serine hydrolases, we used a biotinylated probe analog allowing for enrichment and identification via liquid chromatography-mass spectrometry. We identified 11 largely uncharacterized targets (α,β-hydrolases, SGNH-hydrolases, phospholipases, amidases, peptidases) that are druggable and accessible in live vancomycin-resistant E. faecium E745 and may possess vital functions that are to be characterized in future studies.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"60 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Stege, J. Beekman, Antoni P. A. Hendrickx, Laura van Eijk, Malbert R. C. Rogers, S. Suen, A. Vonk, Rob J. L. Willems, F. Paganelli
Enterococcus faecium is an opportunistic pathogen able to colonize the intestines of hospitalized patients. This initial colonization is an important step in the downstream pathogenesis, which includes outgrowth of the intestinal microbiota and potential infection of the host. The impact of intestinal overgrowth on host-enterococcal interactions is not well understood. We therefore applied a RNAseq approach in order to unravel the transcriptional dynamics of E. faecium upon co-culturing with human derived colonic epithelium. Co-cultures of colonic epithelium with a hospital-associated vancomycin resistant (vanA-type) E. faecium (VRE) showed that VRE resided on top of the colonic epithelium when analyzed by microscopy. RNAseq revealed that exposure to the colonic epithelium resulted in upregulation of 238 VRE genes compared to the control condition, including genes implicated in pili expression, conjugation (plasmid_2), genes related to sugar uptake and biofilm formation (chromossome). In total, 260 were downregulated including the vanA operon located on plasmid_3. Pathway analysis revealed an overall switch in metabolism to amino acid scavenging and reduction. In summary, our study demonstrates that co-culturing of VRE with human colonic epithelium promotes an elaborate gene response in VRE, enhancing our insight in host-E. faecium interactions, which might facilitate the design of novel anti-infectivity strategies.
{"title":"Colonization of vancomycin-resistant Enterococcus faecium in human-derived colonic epithelium: Unraveling the transcriptional dynamics of host-enterococcal interactions","authors":"P. Stege, J. Beekman, Antoni P. A. Hendrickx, Laura van Eijk, Malbert R. C. Rogers, S. Suen, A. Vonk, Rob J. L. Willems, F. Paganelli","doi":"10.1093/femsmc/xtae014","DOIUrl":"https://doi.org/10.1093/femsmc/xtae014","url":null,"abstract":"\u0000 Enterococcus faecium is an opportunistic pathogen able to colonize the intestines of hospitalized patients. This initial colonization is an important step in the downstream pathogenesis, which includes outgrowth of the intestinal microbiota and potential infection of the host. The impact of intestinal overgrowth on host-enterococcal interactions is not well understood. We therefore applied a RNAseq approach in order to unravel the transcriptional dynamics of E. faecium upon co-culturing with human derived colonic epithelium. Co-cultures of colonic epithelium with a hospital-associated vancomycin resistant (vanA-type) E. faecium (VRE) showed that VRE resided on top of the colonic epithelium when analyzed by microscopy. RNAseq revealed that exposure to the colonic epithelium resulted in upregulation of 238 VRE genes compared to the control condition, including genes implicated in pili expression, conjugation (plasmid_2), genes related to sugar uptake and biofilm formation (chromossome). In total, 260 were downregulated including the vanA operon located on plasmid_3. Pathway analysis revealed an overall switch in metabolism to amino acid scavenging and reduction. In summary, our study demonstrates that co-culturing of VRE with human colonic epithelium promotes an elaborate gene response in VRE, enhancing our insight in host-E. faecium interactions, which might facilitate the design of novel anti-infectivity strategies.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141003830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rebecca A. Keogh, Savannah Huyvaert, Garrett D Moore, Alexander R. Horswill, K. Doran
Diabetic wound infections including diabetic foot ulcers (DFUs) are a major global health concern and a leading cause of non-traumatic amputations. Numerous bacterial species establish infection in DFUs, and treatment with antibiotics often fails due to widespread antibiotic resistance and biofilm formation. Determination of bacterial species that reside in DFU and their virulence potential is critical to inform treatment options. Here, we isolate bacteria from debridement tissues from patients with diabetes at the University of Colorado Anschutz Medical Center. The most frequent species were Gram-positive including Enterococcus faecalis, Staphylococcus aureus, and Streptococcus agalactiae, also known as Group B Streptococcus (GBS). Most tissues had more than one species isolated with E. faecalis and GBS frequently occurring in polymicrobial infection with S. aureus. S. aureus was the best biofilm producing species with E. faecalis and GBS isolates exhibiting little to no biofilm formation. Antibiotic susceptibility varied amongst strains with high levels of penicillin resistance amongst S. aureus, clindamycin resistance amongst GBS and intermediate vancomycin resistance amongst E. faecalis. Finally, we utilized a murine model of diabetic wound infection and found that the presence of S. aureus led to significantly higher recovery of GBS and E. faecalis compared to mice challenged in mono-infection.
{"title":"Virulence Characteristics of Gram-positive Bacteria Isolated from Diabetic Foot Ulcers","authors":"Rebecca A. Keogh, Savannah Huyvaert, Garrett D Moore, Alexander R. Horswill, K. Doran","doi":"10.1093/femsmc/xtae013","DOIUrl":"https://doi.org/10.1093/femsmc/xtae013","url":null,"abstract":"\u0000 Diabetic wound infections including diabetic foot ulcers (DFUs) are a major global health concern and a leading cause of non-traumatic amputations. Numerous bacterial species establish infection in DFUs, and treatment with antibiotics often fails due to widespread antibiotic resistance and biofilm formation. Determination of bacterial species that reside in DFU and their virulence potential is critical to inform treatment options. Here, we isolate bacteria from debridement tissues from patients with diabetes at the University of Colorado Anschutz Medical Center. The most frequent species were Gram-positive including Enterococcus faecalis, Staphylococcus aureus, and Streptococcus agalactiae, also known as Group B Streptococcus (GBS). Most tissues had more than one species isolated with E. faecalis and GBS frequently occurring in polymicrobial infection with S. aureus. S. aureus was the best biofilm producing species with E. faecalis and GBS isolates exhibiting little to no biofilm formation. Antibiotic susceptibility varied amongst strains with high levels of penicillin resistance amongst S. aureus, clindamycin resistance amongst GBS and intermediate vancomycin resistance amongst E. faecalis. Finally, we utilized a murine model of diabetic wound infection and found that the presence of S. aureus led to significantly higher recovery of GBS and E. faecalis compared to mice challenged in mono-infection.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"96 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141007424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-29eCollection Date: 2024-01-01DOI: 10.1093/femsmc/xtae012
Priscillar Mumo Mutungi, Vitalis Wafula Wekesa, Justus Onguso, Erustus Kanga, Steve B S Baleba, Hamadi Iddi Boga
To meet the food and feed demands of the growing population, global food production needs to double by 2050. Climate change-induced challenges to food crops, especially soil salinization, remain a major threat to food production. We hypothesize that endophytic fungi isolated from salt-adapted host plants can confer salinity stress tolerance to salt-sensitive crops. Therefore, we isolated fungal endophytes from shrubs along the shores of saline alkaline Lake Magadi and evaluated their ability to induce salinity stress tolerance in tomato seeds and seedlings. Of 60 endophytic fungal isolates, 95% and 5% were from Ascomycetes and Basidiomycetes phyla, respectively. The highest number of isolates (48.3%) were from the roots. Amylase, protease and cellulase were produced by 25, 30 and 27 isolates, respectively; and 32 isolates solubilized phosphate. Only eight isolates grew at 1.5 M NaCl. Four fungal endophytes (Cephalotrichum cylindricum, Fusarium equiseti, Fusarium falciforme and Aspergilus puniceus) were tested under greenhouse conditions for their ability to induce salinity tolerance in tomato seedlings. All four endophytes successfully colonized tomato seedlings and grew in 1.5 M NaCl. The germination of endophyte-inoculated seeds was enhanced by 23%, whereas seedlings showed increased chlorophyll and biomass content and decreased hydrogen peroxide content under salinity stress, compared with controls. The results suggest that the the four isolates can potentially be used to mitigate salinity stress in tomato plants in salt-affected soils.
{"title":"Fungal endophytes from saline-adapted shrubs induce salinity stress tolerance in tomato seedlings.","authors":"Priscillar Mumo Mutungi, Vitalis Wafula Wekesa, Justus Onguso, Erustus Kanga, Steve B S Baleba, Hamadi Iddi Boga","doi":"10.1093/femsmc/xtae012","DOIUrl":"10.1093/femsmc/xtae012","url":null,"abstract":"<p><p>To meet the food and feed demands of the growing population, global food production needs to double by 2050. Climate change-induced challenges to food crops, especially soil salinization, remain a major threat to food production. We hypothesize that endophytic fungi isolated from salt-adapted host plants can confer salinity stress tolerance to salt-sensitive crops. Therefore, we isolated fungal endophytes from shrubs along the shores of saline alkaline Lake Magadi and evaluated their ability to induce salinity stress tolerance in tomato seeds and seedlings. Of 60 endophytic fungal isolates, 95% and 5% were from <i>Ascomycetes</i> and <i>Basidiomycetes</i> phyla, respectively. The highest number of isolates (48.3%) were from the roots. Amylase, protease and cellulase were produced by 25, 30 and 27 isolates, respectively; and 32 isolates solubilized phosphate. Only eight isolates grew at 1.5 M NaCl. Four fungal endophytes (<i>Cephalotrichum cylindricum, Fusarium equiseti, Fusarium falciforme</i> and <i>Aspergilus puniceus</i>) were tested under greenhouse conditions for their ability to induce salinity tolerance in tomato seedlings. All four endophytes successfully colonized tomato seedlings and grew in 1.5 M NaCl. The germination of endophyte-inoculated seeds was enhanced by 23%, whereas seedlings showed increased chlorophyll and biomass content and decreased hydrogen peroxide content under salinity stress, compared with controls. The results suggest that the the four isolates can potentially be used to mitigate salinity stress in tomato plants in salt-affected soils.</p>","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"5 ","pages":"xtae012"},"PeriodicalIF":0.0,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11104533/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141072458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-23eCollection Date: 2024-01-01DOI: 10.1093/femsmc/xtae011
Stephen Knobloch, Sigurlaug Skirnisdóttir, Marianne Dubois, Lucie Mayolle, Laetitia Kolypczuk, Françoise Leroi, Alexandra Leeper, Delphine Passerini, Viggó Þ Marteinsson
The gut microbiome plays an important role in maintaining health and productivity of farmed fish. However, the functional role of most gut microorganisms remains unknown. Identifying the stable members of the gut microbiota and understanding their functional roles could aid in the selection of positive traits or act as a proxy for fish health in aquaculture. Here, we analyse the gut microbial community of farmed juvenile Arctic char (Salvelinus alpinus) and reconstruct the metabolic potential of its main symbionts. The gut microbiota of Arctic char undergoes a succession in community composition during the first weeks post-hatch, with a decrease in Shannon diversity and the establishment of three dominant bacterial taxa. The genome of the most abundant bacterium, a Mycoplasma sp., shows adaptation to rapid growth in the nutrient-rich gut environment. The second most abundant taxon, a Brevinema sp., has versatile metabolic potential, including genes involved in host mucin degradation and utilization. However, during periods of absent gut content, a Ruminococcaceae bacterium becomes dominant, possibly outgrowing all other bacteria through the production of secondary metabolites involved in quorum sensing and cross-inhibition while benefiting the host through short-chain fatty acid production. Whereas Mycoplasma is often present as a symbiont in farmed salmonids, we show that the Ruminococcaceae species is also detected in wild Arctic char, suggesting a close evolutionary relationship between the host and this symbiotic bacterium.
{"title":"The gut microbiome of farmed Arctic char (<i>Salvelinus alpinus</i>) is shaped by feeding stage and nutrient presence.","authors":"Stephen Knobloch, Sigurlaug Skirnisdóttir, Marianne Dubois, Lucie Mayolle, Laetitia Kolypczuk, Françoise Leroi, Alexandra Leeper, Delphine Passerini, Viggó Þ Marteinsson","doi":"10.1093/femsmc/xtae011","DOIUrl":"10.1093/femsmc/xtae011","url":null,"abstract":"<p><p>The gut microbiome plays an important role in maintaining health and productivity of farmed fish. However, the functional role of most gut microorganisms remains unknown. Identifying the stable members of the gut microbiota and understanding their functional roles could aid in the selection of positive traits or act as a proxy for fish health in aquaculture. Here, we analyse the gut microbial community of farmed juvenile Arctic char (<i>Salvelinus alpinus</i>) and reconstruct the metabolic potential of its main symbionts. The gut microbiota of Arctic char undergoes a succession in community composition during the first weeks post-hatch, with a decrease in Shannon diversity and the establishment of three dominant bacterial taxa. The genome of the most abundant bacterium, a <i>Mycoplasma</i> sp., shows adaptation to rapid growth in the nutrient-rich gut environment. The second most abundant taxon, a <i>Brevinema</i> sp., has versatile metabolic potential, including genes involved in host mucin degradation and utilization. However, during periods of absent gut content, a <i>Ruminococcaceae</i> bacterium becomes dominant, possibly outgrowing all other bacteria through the production of secondary metabolites involved in quorum sensing and cross-inhibition while benefiting the host through short-chain fatty acid production. Whereas <i>Mycoplasma</i> is often present as a symbiont in farmed salmonids, we show that the <i>Ruminococcaceae</i> species is also detected in wild Arctic char, suggesting a close evolutionary relationship between the host and this symbiotic bacterium.</p>","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"5 ","pages":"xtae011"},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11092275/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140923575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Wagner, A. K. Pöntinen, Carolin Kornelia Fenzel, Daniel Engi, J. Janice, Ana C. Almeida-Santos, A. Tedim, Ana R. Freitas, Luísa Peixe, W. van Schaik, Mona Johannessen, K. Hegstad
Enterococcus faecium (Efm) is a versatile pathogen, responsible for multidrug-resistant infections, especially in hospitalized immunocompromised patients. Its population structure has been characterized by diverse clades (A1, A2 and B (reclassified as Enterococcus lactis (Ela)), adapted to different environments, and distinguished by their resistomes and virulomes. These features only partially explain the predominance of clade A1 strains in nosocomial infections. We investigated in vitro interaction of 50 clinical isolates (clade A1 Efm) against 75 commensal faecal isolates from healthy humans (25 clade A2 Efm and 50 Ela). Only 36% of the commensal isolates inhibited clinical isolates, while 76% of the clinical isolates inhibited commensal isolates. The most apparent overall differences in inhibition patterns were presented between clades. The inhibitory activity was mainly mediated by secreted, proteinaceous, heat-stable compounds, likely indicating an involvement of bacteriocins. A custom-made database targeting 76 Bacillota bacteriocins was used to reveal bacteriocins in the genomes. Our systematic screening of the interactions between nosocomial and commensal Efm and Ela on a large scale suggests that, in a clinical setting, nosocomial strains not only have an advantage over commensal strains due to their possession of AMR genes, virulence factors, and resilience but also inhibit the growth of commensal strains.
{"title":"Interactions between commensal Enterococcus faecium and Enterococcus lactis and clinical isolates of E. faecium","authors":"T. Wagner, A. K. Pöntinen, Carolin Kornelia Fenzel, Daniel Engi, J. Janice, Ana C. Almeida-Santos, A. Tedim, Ana R. Freitas, Luísa Peixe, W. van Schaik, Mona Johannessen, K. Hegstad","doi":"10.1093/femsmc/xtae009","DOIUrl":"https://doi.org/10.1093/femsmc/xtae009","url":null,"abstract":"\u0000 Enterococcus faecium (Efm) is a versatile pathogen, responsible for multidrug-resistant infections, especially in hospitalized immunocompromised patients. Its population structure has been characterized by diverse clades (A1, A2 and B (reclassified as Enterococcus lactis (Ela)), adapted to different environments, and distinguished by their resistomes and virulomes. These features only partially explain the predominance of clade A1 strains in nosocomial infections. We investigated in vitro interaction of 50 clinical isolates (clade A1 Efm) against 75 commensal faecal isolates from healthy humans (25 clade A2 Efm and 50 Ela). Only 36% of the commensal isolates inhibited clinical isolates, while 76% of the clinical isolates inhibited commensal isolates. The most apparent overall differences in inhibition patterns were presented between clades. The inhibitory activity was mainly mediated by secreted, proteinaceous, heat-stable compounds, likely indicating an involvement of bacteriocins. A custom-made database targeting 76 Bacillota bacteriocins was used to reveal bacteriocins in the genomes. Our systematic screening of the interactions between nosocomial and commensal Efm and Ela on a large scale suggests that, in a clinical setting, nosocomial strains not only have an advantage over commensal strains due to their possession of AMR genes, virulence factors, and resilience but also inhibit the growth of commensal strains.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"170 S366","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140256764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Balcha, M. Macey, M. T. Gemeda, Barbara Cavalazzi, A. A. Woldesemayat
Microorganisms inhabiting hypersaline environments have received significant attention due to their ability to thrive under poly-extreme conditions, including high salinity, elevated temperatures and heavy metal stress. They are believed to possess biosynthetic gene clusters (BGCs) that encode secondary metabolites as survival strategy and offer potential biotechnological applications. In this study, we mined BGCs in shotgun metagenomic sequences generated from Lake Afdera, a hypersaline lake in the Afar Depression, Ethiopia. The microbiome of Lake Afdera is predominantly bacterial, with Acinetobacter (18.6%) and Pseudomonas (11.8%) being ubiquitously detected. A total of 94 distinct BGCs were identified in the metagenomic data. These BGCs are found to encode secondary metabolites with two main categories of functions: (i) potential pharmaceutical applications (nonribosomal peptide synthase NRPs, polyketide synthase, others) and (ii) miscellaneous roles conferring adaptation to extreme environment (bacteriocins, ectoine, others). Notably, NRPs (20.6%) and bacteriocins (10.6%) were the most abundant. Furthermore, our metagenomic analysis predicted gene clusters that enable microbes to defend against a wide range of toxic metals, oxidative stress and osmotic stress. These findings suggest that Lake Afdera is a rich biological reservoir, with the predicted BGCs playing critical role in the survival and adaptation of extremophiles.
{"title":"Mining the Microbiome of Lake Afdera to Gain Insights into Microbial Diversity and Biosynthetic Potential","authors":"E. Balcha, M. Macey, M. T. Gemeda, Barbara Cavalazzi, A. A. Woldesemayat","doi":"10.1093/femsmc/xtae008","DOIUrl":"https://doi.org/10.1093/femsmc/xtae008","url":null,"abstract":"\u0000 Microorganisms inhabiting hypersaline environments have received significant attention due to their ability to thrive under poly-extreme conditions, including high salinity, elevated temperatures and heavy metal stress. They are believed to possess biosynthetic gene clusters (BGCs) that encode secondary metabolites as survival strategy and offer potential biotechnological applications. In this study, we mined BGCs in shotgun metagenomic sequences generated from Lake Afdera, a hypersaline lake in the Afar Depression, Ethiopia. The microbiome of Lake Afdera is predominantly bacterial, with Acinetobacter (18.6%) and Pseudomonas (11.8%) being ubiquitously detected. A total of 94 distinct BGCs were identified in the metagenomic data. These BGCs are found to encode secondary metabolites with two main categories of functions: (i) potential pharmaceutical applications (nonribosomal peptide synthase NRPs, polyketide synthase, others) and (ii) miscellaneous roles conferring adaptation to extreme environment (bacteriocins, ectoine, others). Notably, NRPs (20.6%) and bacteriocins (10.6%) were the most abundant. Furthermore, our metagenomic analysis predicted gene clusters that enable microbes to defend against a wide range of toxic metals, oxidative stress and osmotic stress. These findings suggest that Lake Afdera is a rich biological reservoir, with the predicted BGCs playing critical role in the survival and adaptation of extremophiles.","PeriodicalId":73024,"journal":{"name":"FEMS microbes","volume":"6 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140260763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}