mSphere最新文献

{"title":"Characterization of diet-linked amino acid pool influence on <i>Fusobacterium</i> spp. growth and metabolism.","authors":"Avery V Robinson, Sarah J Vancuren, Massimo Marcone, Emma Allen-Vercoe","doi":"10.1128/msphere.00789-24","DOIUrl":"10.1128/msphere.00789-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The genus &lt;i&gt;Fusobacterium&lt;/i&gt; contains multiple proteolytic opportunistic pathogens that have been increasingly linked to colorectal cancer (CRC). \"Oncomicrobes\" such as these fusobacterial species within the gut microbiota may contribute to CRC onset and/or progression. Protein-rich diets may both directly increase CRC risk and enrich for proteolytic oncomicrobes, including &lt;i&gt;Fusobacterium&lt;/i&gt; spp. Individual food substrates vary in amino acid content, and released amino acid content that is not absorbed in the small intestine may influence the growth of colonic proteolytic fermenters. Fusobacteria such as &lt;i&gt;Fusobacterium&lt;/i&gt; spp. are known to preferentially metabolize certain amino acids. As such, some foods may better support the growth of these species within the colonic environment than others. To explore this, in this study, we created free amino acid pools (FAAPs) to represent proportions of amino acids in major proteins of three common dietary protein sources (soy, beef, and bovine milk). Growth curves were generated for 39 &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains cultured in a dilute medium supplemented with each of the three FAAPs. Thereafter, amino acid use by 31 of the 39 &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains in each FAAP treatment was assessed. FAAP supplementation increased growth metrics of all &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains tested; however, the strains varied greatly in terms of the FAAP(s) generating the greatest increase in growth. Furthermore, the amino acid utilization strategy was highly variable between strains of &lt;i&gt;Fusobacterium&lt;/i&gt; spp. Neither growth metrics nor amino acid utilization could be explained by species classification of &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains. This report expands upon the previous knowledge of fusobacterial amino acid metabolism and indicates that proteolytic oncomicrobial activity should be assessed in the context of available protein sources.IMPORTANCE&lt;i&gt;Fusobacterium&lt;/i&gt; spp. including &lt;i&gt;F. animalis&lt;/i&gt;, &lt;i&gt;F. nucleatum&lt;/i&gt;, &lt;i&gt;F. vincentii&lt;/i&gt;, and &lt;i&gt;F. polymorphum&lt;/i&gt; are common oral commensals with emerging importance in diseases across multiple body sites, including CRC. CRC lesions associated with fusobacteria tend to result in poorer prognosis and increased disease recurrence. While &lt;i&gt;Fusobacterium&lt;/i&gt; spp. are thought to colonize after tumorigenesis, little is known about the factors that facilitate this colonization. Protein-rich diets yielding readily metabolized free amino acids within the colon may promote the growth of proteolytic fermenters such as fusobacteria. Here, we show that variable concentrations of free amino acids within pools that represent different dietary protein sources differentially influence fusobacterial growth, including CRC-relevant strains of &lt;i&gt;Fusobacterium&lt;/i&gt; spp. This work highlights the high degree of variation in fusobacterial amino acid utilization patterns and suggests differing proportions of dietary amino acids that reach the colon could influenc","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0078924"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934328/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409348","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}

{"title":"Understanding the impacts of temperature and precipitation on antimicrobial resistance in wastewater: theory, modeling, observation, and limitations.","authors":"Carly Ching, Indorica Sutradhar, Muhammad H Zaman","doi":"10.1128/msphere.00947-24","DOIUrl":"10.1128/msphere.00947-24","url":null,"abstract":"<p><p>Changing climate may contribute to increased antimicrobial resistance (AMR), particularly in wastewater which acts as a reservoir for resistant bacteria. Here, we determined how applying climate dependencies to our previously published model, rooted in theory, impacts computational simulations of AMR in wastewater. We found AMR levels were reduced at lower temperatures but increased with lower precipitation. The impact of precipitation on AMR was more pronounced at higher temperatures compared to lower temperatures. To validate our model, we investigated associations between total AMR gene abundance in wastewater from the Global Sewage Surveillance project and mean temperature and rainfall values extracted from European Centre for Medium-Range Weather Forcasts Reanalysis v5 (ERA5) reanalysis. We observed similar trends between the simulations and observations. Observations and simulations from our study can inform experiments to determine causal relationships as well as help identify other key drivers. We also discuss study challenges given the complex nature of AMR in the environment.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0094724"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934317/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143557501","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}

{"title":"mSphere of Influence: The ever-expanding universe of parasite cell biology.","authors":"Benjamin Liffner","doi":"10.1128/msphere.00043-25","DOIUrl":"10.1128/msphere.00043-25","url":null,"abstract":"<p><p>Ben Liffner studies the cell biology of apicomplexan parasites. In this mSphere of Influence article, he reflects on two key papers: \"Three-dimensional ultrastructure of <i>Plasmodium falciparum</i> throughout cytokinesis\" by R. M. Rudlaff, S. Kraemer, J. Marshman, J. D. Dvorin, et al. (PLoS Pathog 16:e1008587, 2020, https://doi.org/10.1371/journal.ppat.1008587) and \"Expansion microscopy provides new insights into the cytoskeleton of malaria parasites including the conservation of a conoid\" by E. Bertiaux, A. C. Balestra, L. Bournonville, V. Louvel, et al. (PLoS Biol 19:e3001020, 2021, https://doi.org/10.1371/journal.pbio.3001020). These two studies provided Ben with the conceptual framework to understand how parasites are organized in three dimensions, and the technique of ultrastructure expansion microscopy that he has since used to investigate this intriguing area of biology.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0004325"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934323/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143542623","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}

{"title":"Abundance of clinically relevant antimicrobial resistance genes in the golden jackal (<i>Canis aureus</i>) gut.","authors":"Roi Lapid, Yair Motro, Hillary Craddock, Ikram Salah, Roni King, Katherine Winner, Gila Kahila Bar-Gal, Jacob Moran-Gilad","doi":"10.1128/msphere.00819-24","DOIUrl":"10.1128/msphere.00819-24","url":null,"abstract":"<p><p>The spread of antimicrobial resistance (AMR) is a critical One Health issue. Wildlife could act as reservoirs or vehicles of AMR bacteria (ARBs) and AMR genes (ARGs) but are relatively understudied. We sought to investigate clinically relevant ARGs in golden jackals (<i>Canis aureus</i>) thriving near human settlements in Israel. Fecal samples were collected from 111 jackals across four regions over a 10-month period. Various animal and spatio-temporal metadata were collected. Samples were analyzed by quantitative PCR (qPCR) for beta-lactamases (<i>bla</i>TEM, <i>bla</i>CTX-M15, and <i>bla</i>SHV), <i>qnrS</i> and <i>int1</i>. A subset of samples was subject to shotgun metagenomic sequencing followed by resistome and microbiome analyses. qPCR detected a high prevalence of ARGs, including beta-lactamases (<i>bla</i>TEM-1, 96.4%; <i>bla</i>CTX-M-15, 51.4%, <i>bla</i>SHV, 15.3%), fluoroquinolone resistance (<i>qnrS</i>, 87.4%), and class 1 integrons (<i>Int1</i>, 94.6%). The <i>bla</i>TEM-1 gene was found to be more prevalent in adult jackals compared to younger ones. Metagenomic analysis of a subset of samples revealed a diverse gut microbiome harboring a rich resistome with tetracycline resistance genes being the most prevalent. Metagenome-assembled genome analysis further identified several ARGs associated with clinically relevant bacteria. These findings highlight the potential role of golden jackals as reservoirs for AMR and emphasize the need for ongoing surveillance to better understand AMR transmission dynamics at the wildlife-human interface.</p><p><strong>Importance: </strong>The research highlights the potential role of the golden jackals as reservoirs for antimicrobial resistance (AMR). The high prevalence of clinically relevant AMR genes in these jackals emphasizes the need for ongoing surveillance and monitoring to better understand AMR transmission dynamics at the wildlife-human interface.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0081924"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934335/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409345","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}

{"title":"UV-irradiated rotifers for the maintenance of gnotobiotic zebrafish larvae.","authors":"Susana Márquez Rosales, Peter I Bouchard, Emily M Olmstead, Raghuveer Parthasarathy","doi":"10.1128/msphere.00698-24","DOIUrl":"10.1128/msphere.00698-24","url":null,"abstract":"<p><p>Host-associated microbial communities profoundly impact the health of humans and other animals. Zebrafish have proven to be a useful model for uncovering mechanisms of host-microbe interactions, but the difficulty of maintaining germ-free or gnotobiotic zebrafish beyond 1 week post-fertilization has limited their utility. To address this, we have developed a simple protocol using UV irradiation of rotifers, a common and nutrient-rich prey species for larval zebrafish, to reduce the bacterial load associated with the rotifers by several orders of magnitude while maintaining their motility and viability. We find that though feeding with UV-treated rotifers does not preserve the sterility of germ-free fish, it enables the maintenance of pre-existing bacterial communities. Normal feeding, in striking contrast, leads to the near-total depletion of these prior populations. We measure the abundance of single- and three-species consortia of zebrafish-commensal bacteria inoculated into initially germ-free larvae in a series of experiments extending to 8 days of feeding, or 13 days post-fertilization. We find, in fish-fed UV-treated rotifers, the persistence of bacterial populations on timescales of days, together with strong species-specific variation. In addition, re-inoculation of differently labeled strains of the same zebrafish-commensal species alongside feeding leads to colonization by the new bacteria without displacement of earlier microbes. Our method will facilitate the use of gnotobiotic zebrafish for investigations of phenomena that emerge later in animal development and for studies that probe microbiome composition fluctuations and stability over extended timescales.IMPORTANCEAll animals, including humans, are host to vast microbial communities that contribute to health and disease through mechanisms that remain largely mysterious. These microbiomes are challenging to study, spurring the use of various model organisms, including zebrafish. Zebrafish, however, are difficult to raise beyond 1 week post-fertilization under gnotobiotic conditions, in other words, germ free or with known microbial constituents, a consequence of normally feeding on live prey that brings their own, generally unknown, microbes. Therefore, we developed a simple protocol in which UV irradiation of rotifers, a widely used small-animal food for larval zebrafish, facilitates the maintenance of gnotobiotic larvae. We show that pre-existing bacterial communities in larvae are minimally affected by feeding on UV-treated rotifers, in strong contrast to feeding on untreated rotifers. We demonstrate that this feeding method allows investigations of zebrafish-associated bacterial community stability over several days, allowing investigation of previously intractable questions about microbiome stability.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0069824"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934316/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143483719","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}

{"title":"mSphere of Influence: Rapid evolution of pathogenesis and drug resistance in human pathogenic fungi.","authors":"Pengjie Hu","doi":"10.1128/msphere.00570-24","DOIUrl":"10.1128/msphere.00570-24","url":null,"abstract":"<p><p>Pengjie Hu works in the field of fungal pathogenesis, drug resistance, and evolution. In this mSphere of Influence article, he reflects on how three works, \"Transposon mobilization in the human fungal pathogen <i>Cryptococcus</i> is mutagenic during infection and promotes drug resistance in vitro\" and \"Genome-wide analysis of heat stress-stimulated transposon mobility in the human fungal pathogen <i>Cryptococcus deneoformans</i>\" by Gusa et al. and \"Rapid evolution of an adaptive multicellular morphology of <i>Candida auris</i> during systemic infection\" by Bing et al. have impacted his work on the evolution of virulence, resistance, and adaptation in human fungal pathogens.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0057024"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934322/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492979","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}

{"title":"A call for the United States to continue investing in science.","authors":"Ira Blader, Felicia Goodrum, Michael J Imperiale, Arturo Casadevall, Cesar A Arias, Andreas Baumler, Carey-Ann D Burnham, Christina A Cuomo, Corrella S Detweiler, Graeme N Forrest, Jack A Gilbert, Susan Lovett, Stanley Maloy, Alexander McAdam, Irene Newton, Gemma Reguera, George A O'Toole, Patrick D Schloss, Ashley Shade, Marvin Whiteley","doi":"10.1128/msphere.00128-25","DOIUrl":"10.1128/msphere.00128-25","url":null,"abstract":"","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0012825"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934304/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143516092","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}

{"title":"Prospective comparison of the digestive tract resistome and microbiota in cattle raised in grass-fed versus grain-fed production systems.","authors":"Jiye Kwon, Windy Tanner, Yong Kong, Martina Wade, Chad Bitler, Marilia B Chiavegato, Melinda M Pettigrew","doi":"10.1128/msphere.00738-24","DOIUrl":"10.1128/msphere.00738-24","url":null,"abstract":"<p><p>Most antimicrobials sold in the United States are used in food animals. Farm management practices contribute to antibacterial resistance (AR). Controversially, grass-fed diets have been recommended over grain-fed diets to reduce AR in beef cattle. Ionophore feed additives (non-therapeutic antibiotics that enhance feed efficiency) may contribute to AR development. We used shotgun metagenomic sequencing of fecal swabs to prospectively compare the cattle gastrointestinal resistome and microbiota in two different production systems over five periods from pre-weaning to pre-harvest. Cattle were grass-fed and pasture-raised (system A, <i>n</i> = 33) or grain-fed with ionophore additives in feedlots (system B, <i>n</i> = 34). System A cattle averaged 639 lb and 22.8 months of age, and system B cattle averaged 1,173 lb and 12.4 months of age preharvest. In total, 367 antibiotic resistance genes (ARGs) and 329 bacterial species were identified. The resistome of system A cattle had higher alpha diversity than system B cattle over their lifespan (<i>P</i> = 0.008). Beta-diversity estimates indicated overlap in the pre-weaning resistome and microbiota in both systems, which diverged post-weaning, with increases in several medically important ARGs when system B cattle transitioned to a grain diet. Analysis of compositions of microbiomes with bias correction indicated that levels of tetracycline, macrolide, aminoglycoside, beta-lactam, and bacitracin ARGs were significantly higher in system B cattle pre-harvest. Resistome changes were highly correlated with bacterial community changes (Procrustes, <i>M</i>² = 0.958; <i>P</i> = 0.001). Potentially modifiable farm management strategies, including diet and ionophores, may influence abundance and diversity of ARGs in fecal samples from cattle.IMPORTANCEAntibiotic resistance is a One Health threat. More antibiotics are used in agriculture than in human medicine. We compared the relative abundance of antibiotic resistance genes (ARGs) and bacterial species in cattle raised in two different cattle production systems (grass- and grain-fed). Fecal swab samples were collected at five time points spanning pre-weaning and prior to harvest. The antibiotic resistance gene and bacterial communities were relatively similar in the pre-weaning period when cattle in both systems were milking and on pasture. Resistance genes and bacterial communities diverged post-weaning when system B cattle were given a grain diet with feed additives for growth promotion containing non-medically important antibiotics (i.e., ionophores). The levels of medically important ARGs (e.g., macrolides) increased in system B grain-fed cattle post-weaning and were higher than in system A just prior to slaughter. These data provide additional evidence that farm management strategies impact the level of antibiotic resistance.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0073824"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934311/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414677","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}

{"title":"A novel <i>Erwiniaceae</i> gut symbiont modulates gene expression of the intracellular bacterium <i>Cardinium</i> in the stored product mite <i>Tyrophagus putrescentiae</i>.","authors":"Jan Hubert, Eliza Glowska-Patyniak, Scot E Dowd, Pavel B Klimov","doi":"10.1128/msphere.00879-24","DOIUrl":"https://doi.org/10.1128/msphere.00879-24","url":null,"abstract":"<p><p>We examined host and bacterial gene expression profiles in the stored product mite <i>Tyrophagus putrescentiae</i> co-infected with <i>Wolbachia</i> (wTPut) and <i>Cardinium</i> (cTPut) while varying the presence of the <i>Erwiniaceae</i> symbiont (SLS). SLS, a novel symbiont in the family <i>Erwiniaceae</i>, with a genome size of 1.7 Mb, is found in 16% of mite species in infected cultures. In addition, SLS was detected in mite feces but not in their eggs. Although <i>Wolbachia</i> expression remained unchanged, the presence or absence of SLS significantly affected <i>Cardinium</i> expression. It indicated that the effect of <i>Wolbachia</i> on SLS was neutral. In SLS-positive samples, <i>Cardinium</i> exhibited 29 upregulated and 48 downregulated genes compared to SLS-negative samples. Furthermore, <i>Cardinium</i> gene expression strongly correlated with mite KEGG gene expression in SLS-positive samples. Positive Spearman's correlations between <i>Cardinium</i> gene expression and mite KEGG immune and regulatory pathways were doubled in SLS-positive compared to SLS-negative samples. The diversity of expressed genes in the mite host decreased in the presence of SLS. <i>Cardinium</i> had more interacting genes to mite host in SLS-positive samples than without SLS. Transposases are the most affected <i>Cardinium</i> genes, showing upregulation in the presence of SLS. Correlation analyses revealed interactions between <i>Cardinium</i> and SLS via mite immune and regulatory pathways, including lysosome, ubiquitin-mediated proteolysis, PIK3_Akt, and cGMP-PKG. The results showed that <i>Cardinium</i> indirectly affects the gut symbionts of mites.IMPORTANCEThis study introduces a new model to analyze interactions between intracellular bacterial symbionts, gut bacterial symbionts, and their mite hosts. Using gene expression correlations, we investigated how the intracellular <i>Cardinium</i> responds to the novel <i>Erwiniaceae</i> gut symbiont in the mold mite <i>Tyrophagus putrescentiae</i>. The data showed that both mite and <i>Cardinium</i> gene expression are different in the samples with and without <i>Erwiniaceae</i> symbionts. In the presence of <i>Erwiniaceae</i> symbionts, <i>Cardinium</i> increased the interaction with the mite host in terms of changes in gene expression. The mite immune and regulatory pathway gene expression is differently correlated to <i>Cardinium</i> genes in relation to <i>Erwiniaceae</i> symbionts. As a well-known producer of allergens, <i>T. putrescentiae</i> physiology and thus its allergen production are influenced by both symbionts, potentially affecting the release of allergens into human environments.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0087924"},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143692721","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}

{"title":"The impact of the flagellar protein gene <i>fliK</i> on <i>Helicobacter pylori</i> biofilm formation.","authors":"Hongjin Tao, Wangjingyi Zhang, Jing Liu, Yu Zhou, Gangshi Wang","doi":"10.1128/msphere.00018-25","DOIUrl":"https://doi.org/10.1128/msphere.00018-25","url":null,"abstract":"<p><p>The biofilm structure of <i>Helicobacter pylori</i> is known to enhance its capabilities for antimicrobial resistance. This study aims to investigate the role of the flagellar hook length control protein gene <i>fliK</i> in the biofilm formation of <i>H. pylori</i>. Homologous recombination was employed to knock out the <i>fliK</i> gene in the <i>H. pylori</i> NCTC 11637 strain. The flagella of <i>H. pylori</i> were observed using transmission electron microscopy (TEM), whereas <i>H. pylori</i> motility and growth were examined through semi-solid agar assays and growth curve analyses, respectively. The bacterial biofilm and its constituents were visualized utilizing fluorescence confocal microscopy. Assessments of <i>H. pylori</i> adhesion to gastric mucosal cells, its vacuolar toxicity, and antibiotic resistance were evaluated using co-culture experiments and E-test methods. The <i>fliK</i> gene was successfully knocked out in <i>H. pylori</i> NCTC 11637. The Δ<i>fliK</i> mutant exhibited polyhook structures or lacked typical flagellar morphology, reduced mobility, and a slower bacterial growth rate compared with the wild-type strain. Fluorescence confocal microscopy revealed a decrease in the thickness of the biofilm formed by the Δ<i>fliK</i> strain, along with reductions in polysaccharide and DNA components. The deletion of <i>fliK</i> did not affect vacuolar toxicity or antibiotic resistance but did reduce the adhesive capacity of the bacterium to gastric mucosal cells. The deletion of the <i>fliK</i> gene significantly impairs <i>H. pylori</i> biofilm formation, leading to substantial decreases in biofilm components, bacterial growth, and adhesion capabilities. These findings underscore the importance of <i>fliK</i> in the pathogenicity of <i>H. pylori</i>.IMPORTANCEThe increasing antibiotic resistance of <i>Helicobacter pylori</i> has emerged as a global health concern, with biofilm formation serving as a crucial mechanism underlying this resistance. This study investigates the role of the <i>fliK</i> gene, which encodes the flagellar hook length control protein, in <i>H. pylori</i> biofilm formation. Furthermore, we examined the influence of <i>fliK</i> on <i>H. pylori</i> growth, motility, and cellular adhesion capabilities. Our findings elucidate the molecular mechanisms governing <i>H. pylori</i> biofilm formation and suggest potential therapeutic strategies for addressing <i>H. pylori</i> antibiotic resistance.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0001825"},"PeriodicalIF":3.7,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143674272","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}