Journal of Bacteriology最新文献

{"title":"AnaToc75 (Alr2269) mediates calcium uptake across the outer membrane in <i>Anabaena</i> sp. PCC 7120.","authors":"Xiaoying Jiang, Hong Gao, Yanling Dong, Jianxin Tang, Shuiling Ji, Xudong Xu","doi":"10.1128/jb.00291-25","DOIUrl":"https://doi.org/10.1128/jb.00291-25","url":null,"abstract":"<p><p>It has been a long-standing notion that cyanobacterial Omp85 proteins are essential because of their role in insertion of β-barrel proteins into the outer membrane (OM). Alr2269 from <i>Anabaena</i> sp. PCC 7120 is such an Omp85 protein, structurally related to the Toc75 channel of the translocon at the outer envelope membrane of chloroplasts but is actually non-essential to <i>Anabaena</i> under calcium-replete conditions. In a completely segregated <i>alr2269</i>-null mutant, a predicted S-layer protein, All3983, and many β-barrel proteins in the OM were upregulated compared with the wild type. By removal of each component from the medium, Ca²⁺ deficiency was identified to be the key environmental signal for upregulation of P<i>_all3983-luxAB</i> in the mutant. Assays of ⁴⁵Ca²⁺ uptake in the wild type and the mutant indicated that Alr2269 is a relatively specific channel for transport of Ca²⁺ across the OM in low-Ca²⁺ medium. Accordingly, inactivation of <i>alr2269</i> greatly reduced the growth under Ca²⁺-limiting conditions, while the complemented strain grew as the wild type. In low-Mg²⁺ medium, however, the <i>alr2269</i> mutant showed only a slight difference in growth from the wild type. These results establish Alr2269 (AnaToc75) as the main channel for Ca²⁺ uptake across the OM of <i>Anabaena</i> in low-Ca²⁺ environments.IMPORTANCECa²⁺ is required for photosynthesis and various cellular activities in cyanobacteria, but Ca²⁺ uptake, in particular how Ca²⁺ is transported across the outer membrane, has been barely investigated in cyanobacterial species. In this study, we found that a cyanobacterial Toc75 homolog is not necessarily essential for protein integration into the outer membrane as was thought before but instead is required for Ca²⁺ uptake in low-Ca²⁺ environments. This finding not only establishes a Ca²⁺ channel across the outer membrane of cyanobacteria but also provides an example of additional functions for Omp85 proteins.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0029125"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protein trafficking across the cell envelope of gram-positive bacteria.","authors":"Dipanwita Bhattacharya, Ran Zhang, Wenqi Yu","doi":"10.1128/jb.00100-25","DOIUrl":"10.1128/jb.00100-25","url":null,"abstract":"<p><p>Protein trafficking from the cytosol to specific sites of action is a fundamental process for bacterial survival and growth. In the monoderm gram-positive bacteria, this process involves traversing the cytoplasmic membrane, the membrane-wall interface, and the thick cell wall. With a primary focus on <i>Bacillus subtilis</i> and <i>Staphylococcus aureus</i>, this minireview aims to provide an overview and mechanistic insights into (i) protein translocation across the cytoplasmic membrane via the Sec system, (ii) protein processing by chaperones and proteases in the membrane-wall interface, and (iii) protein attachment to the cell wall and translocation across the cell wall. Furthermore, we emphasize recent advancements in spatial regulation of protein translocation systems. By examining conserved and unique mechanistic features, this review aims to offer a systematic understanding of protein trafficking in gram-positive bacteria.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0010025"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445088/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The SWIB domain-containing DNA topoisomerase I of <i>Chlamydia trachomatis</i> mediates DNA relaxation.","authors":"Li Shen, Abigail R Swoboda, Caitlynn Diggs, Shomita Ferdous, Andrew Terrebonne, Amanda Santos, Noel Wolf, Luis Lorenzo Carvajal, Guangming Zhong, Scot P Ouellette, Yuk-Ching Tse-Dinh","doi":"10.1128/jb.00190-25","DOIUrl":"10.1128/jb.00190-25","url":null,"abstract":"<p><p><i>Chlamydia trachomatis</i> has a DNA topoisomerase I with a unique C-terminal domain (CTD) homologous to eukaryotic SWIB domains. This study focused on determining the function of the SWIB domain-containing TopA from <i>C. trachomatis</i> (CtTopA). We demonstrated that, despite the lack of sequence similarity at the CTDs between CtTopA and TopA from <i>Escherichia coli</i> (EcTopA), full-length CtTopA removed negative DNA supercoils <i>in vitro</i> and complemented the growth defect of a <i>topA</i> mutant of <i>E. coli</i>. CtTopA is less processive in DNA relaxation than EcTopA in dose-response and time course studies. An antibody generated against the SWIB domain of CtTopA specifically recognized CtTopA but not EcTopA or <i>Mycobacterium tuberculosis</i> TopA, consistent with the sequence differences in their CTDs. The endogenous CtTopA protein is expressed at a relatively high level during the middle and late developmental stages of <i>C. trachomatis</i>. Overexpressing a <i>topA</i> mutant allele lacking the SWIB domain in <i>C. trachomatis</i> resulted in slow growth when host protein synthesis was inhibited. These data suggest that productive infection of <i>C. trachomatis</i> requires functional SWIB domain-containing CtTopA and <i>de novo</i> host protein synthesis. Because SWIB domain-containing CtTopAs are not found in prokaryotes beyond <i>Chlamydia</i> spp., our work suggests an important function of the SWIB domain on CtTopA activity during <i>C. trachomatis</i> infection.IMPORTANCE<i>Chlamydia trachomatis</i> is a medically important bacterial pathogen that is responsible for the most prevalent bacterial sexually transmitted infection. Bioinformatics, genetics, and biochemical analyses have established that the presence of a SWIB domain in CtTopA is relevant to chlamydial physiology. Our findings also underline the mechanistic diversity among the family of TopAs that are likely driven by pathogen-specific adaptations.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0019025"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445093/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144821501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Opposing roles for iron transport systems in gallium tolerance in extraintestinal pathogenic <i>Escherichia coli</i>.","authors":"Nagama Parveen, Seth Durrant, Michael A Olson, Emily P Shakespear, Trevor R Jones, Rachael J David Prince, Eric Wilson, David L Erickson","doi":"10.1128/jb.00349-25","DOIUrl":"https://doi.org/10.1128/jb.00349-25","url":null,"abstract":"<p><p>Gallium is a promising antibacterial candidate because it displaces iron atoms inside bacterial cells but does not undergo redox cycling. It inhibits growth by disrupting essential iron-dependent processes. However, <i>Escherichia coli</i> are naturally less sensitive to gallium than many other bacteria, and the mechanisms that control gallium tolerance are not completely understood. We performed a genome-wide transposon sequencing (TnSeq) screen to identify genes important for the survival of an extraintestinal pathogenic <i>E. coli</i> isolate (M12) in gallium nitrate. The TnSeq results indicated that inactivation of enterobactin siderophore-related genes (<i>entS</i>, <i>fepD</i>, <i>fes</i>, and <i>fepB</i>) enhances bacterial survival in gallium, while disrupting the ferric dicitrate transport system increases susceptibility. We validated these findings through targeted gene knockouts and gallium sensitivity experiments. Our findings suggest that enterobactin can complex with gallium for cellular uptake, but that the ferric citrate receptor FecA can discriminate between gallium citrate and iron citrate. Expression of <i>fecA</i> increased with gallium exposure, showing that gallium induces FecA-mediated iron uptake. Gallium also increased intracellular levels of manganese in the Δ<i>fecA</i> strain. Supplementation with iron or manganese restored growth of M12 Δ<i>fecA</i> in gallium, suggesting that gallium sensitivity is linked to both iron starvation and oxidative stress. As the ferric dicitrate transport system is an important virulence factor in several extraintestinal infection sites, our results suggest that targeting FecA may increase <i>E. coli</i> susceptibility to gallium while also suppressing virulence.IMPORTANCE<i>Escherichia coli</i> extraintestinal infections that are resistant to traditional antibiotics are associated with more deaths than any other species. Gallium-based therapies may represent a non-antibiotic approach for treating extraintestinal pathogenic <i>E. coli</i> strains that affect both humans and animals. Our results are significant as they show that the enterobactin siderophore and the ferric dicitrate iron transport systems expressed by these bacteria have opposing roles in <i>E. coli</i> gallium sensitivity. These findings could be leveraged to enhance the efficacy of gallium therapeutics.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0034925"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of flagellar filament length on <i>Campylobacter jejuni</i> for colonization and flagellar-dependent phenotypes.","authors":"Alexis A Waller, Deborah A Ribardo, David R Hendrixson","doi":"10.1128/jb.00199-25","DOIUrl":"10.1128/jb.00199-25","url":null,"abstract":"<p><p>Many bacteria produce flagella to swim and navigate through environments. Depending on the species, flagella are beneficial for other activities such as sensing surfaces to initiate biofilm development, secretion of specific proteins, and interactions with hosts to promote colonization or pathogenesis of disease. The extracellular region of the flagellum consists mostly of the filament, which is required for many flagellar-dependent activities. The length of the filament varies across bacterial flagellates and even stochastically within a clonal population, but it is unknown whether or how altering filament length impacts flagellar function for motility and other activities. We recently discovered a mechanism by which FlaG of <i>Campylobacter jejuni</i> and other polarly flagellated bacteria controls flagellar filament length so that these species produce shorter filaments than their peritrichous counterparts. We exploited a set of isogenic <i>C. jejuni</i> mutants producing significantly longer and shorter flagellar filaments than WT to assess the impact of filament length on activities of <i>C. jejuni</i> necessary for commensal colonization of a natural host. We found that production of shorter flagellar filaments slows swimming velocity and hinders intestinal colonization of chickens. Although production of shorter and longer flagellar filaments differently impacted cellular autoagglutination, only a subtle impact on biofilm formation was observed. We also acquired evidence that FlaG itself may impact biofilm development, suggesting that FlaG may have another function besides controlling flagellar filament length. Overall, our data suggest that shortening flagellar filaments has a greater impact on flagellar-dependent activities of <i>C. jejuni</i> than producing overly elongated filaments.</p><p><strong>Importance: </strong>Flagella and flagellar motility are important to propel many bacteria through environments, biofilm formation, and infection of respective hosts. Most often, the importance of flagella for a species has been assessed with mutants lacking flagella altogether or only the extracellular filament while retaining the basal body. We addressed whether altering filament length impacts flagellar-dependent activities for host colonization. We exploited isogenic <i>Campylobacter jejuni</i> mutants that synthesize longer and shorter filaments on average relative to WT to find that production of shorter filaments had greater negative impacts on motility, autoagglutination, and commensal colonization compared to bacteria that produce elongated filaments. Our findings suggest that polar flagellates may produce a flagellar filament of minimal length to achieve flagellar functions and preserve fitness.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0019925"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445086/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of low intracellular glutathione and CbrA-CbrB-Crc signaling on methylglyoxal sensitivity in <i>Pseudomonas aeruginosa</i> LasR-deficient mutants.","authors":"Ana Altamirano, Marina Ruzic, Anna E Cryan, Deborah A Hogan","doi":"10.1128/jb.00394-24","DOIUrl":"10.1128/jb.00394-24","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i>, which causes many types of infections, often has loss-of-function mutations in the gene encoding LasR, a transcription factor involved in quorum sensing. Here, we report that LasR- strains are more sensitive to the electrophile methylglyoxal (MGO), which is produced by many cells, including those involved in immune defense. MGO, due to its high reactivity, must be rapidly detoxified to prevent the formation of damaging adducts on macromolecules. GloA3 is a GSH-dependent MGO glyoxalase involved in MGO detoxification, and we found that intracellular GSH levels were lower in ∆<i>lasR</i> strains, as measured by multiple methods. Furthermore, we show that exogenous GSH and GloA3 overexpression both enhance GloA3-dependent MGO resistance, particularly in a ∆<i>lasR</i> mutant. Previous reports suggest that one factor that contributes to the selection for LasR- strains is a growth advantage resulting from increased activity of the CbrAB two-component system, which lowers the Crc-mediated translational repression of many RNAs. Genetic data presented here suggest that low Crc activity leads to increased MGO sensitivity in LasR- strains but not through effects on GSH or GloA3. Together, these data suggest that LasR- strains are more sensitive to MGO due to multiple factors, including lower intracellular levels of GSH and decreased Crc activity, and that these factors may represent fitness trade-offs for LasR- strains.IMPORTANCEMethylglyoxal (MGO) is a highly reactive metabolite detected in various disease states, including those involving <i>Pseudomonas aeruginosa</i>. <i>P. aeruginosa</i> requires the glutathione-dependent glyoxalase enzyme GloA3 for MGO resistance. This study reveals that <i>P. aeruginosa</i> strains with mutations in the gene encoding the transcription factor LasR, commonly found in clinical isolates, are more sensitive to MGO due to lower intracellular glutathione levels and high activity of the CbrAB-Crc regulatory pathway. Thus, sensitivity to MGO and other electrophiles may represent a trade-off for <i>P. aeruginosa</i> in infections.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0039424"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The virulence regulator <i>bvgS</i> controls nutrient-induced filamentation in <i>Bordetella avium</i>.","authors":"Niklas G Perslow, Serena J Meadows-Graves, Robert J Luallen","doi":"10.1128/jb.00030-25","DOIUrl":"10.1128/jb.00030-25","url":null,"abstract":"<p><p>Bacteria can change morphology in response to stressors and changes in their environment, including infection of a host. We previously identified the bacterial species, <i>Bordetella atropi</i>, which uses nutrient-induced filamentation as a novel mechanism for cell-to-cell spreading in the intestinal epithelial cells of a nematode host. To further investigate the conservation of nutrient-induced filamentation in Bordetellae, we utilized the turkey-infecting species <i>Bordetella avium,</i> which filaments <i>in vitro</i> when switched from a standard growth media to an enriched media. We conducted a selection-based filamentation screen with <i>B. avium</i> and isolated two independent non-filamentous mutants that failed to filament in highly enriched media. These mutants contained different alleles in <i>bvgS,</i> the sensor in the two-component master virulence regulator (BvgAS) conserved across the <i>Bordetella</i> genus. To investigate the role of <i>bvgS</i> in nutrient-induced filamentation, we conducted transcriptomics and found that our allele of <i>bvgS</i> resulted in loss of responsiveness to highly enriched media, especially in genes related to nutrient uptake and metabolism. The most dysregulated gene in the <i>bvgS</i> mutant encoded for succinyl-CoA:acetate CoA-transferase, and we were able to regulate filamentation with exogenous metabolites up and downstream of this enzyme. These data suggest that <i>bvgS</i> regulates nutrient-induced filamentation by controlling metabolic capacity. Overall, we found that the virulence regulator <i>bvgS</i> can control nutrient-induced filamentation in <i>B. avium,</i> suggesting there may be conservation in Bordetellae for utilizing this morphological change as a virulence phenotype.IMPORTANCE<i>Bordetella avium</i> is the causative agent of bordetellosis, an infectious disease affecting the respiratory system of birds, significantly increasing morbidity in poultry, ultimately leading to economic losses. It is long known that the pathogenesis of <i>B. avium</i> is governed by the two-component master virulence regulator, BvgAS. However, this regulon has never before been associated with nutrient-induced filamentation. In this study, we identify BvgS to be regulating nutrient-induced filamentation. We also report the first transcriptomics analysis of filamentous <i>B. avium</i>, showing the enzyme succinyl-CoA:acetate CoA-transferase may be involved in a metabolic shift in enriched nutrient conditions leading to filamentation. Our results suggest that virulence in <i>B. avium</i> is a dynamic relationship, affected by nutrient availability, rather than a simple binary decision.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0003025"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445083/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144821502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-frequency ultrasound treatment reduces susceptibility to <i>Salmonella</i> infection in aged mice.","authors":"Parisa Zangoui, Ekta Singh, Michael P Sheetz, Linda J Kenney","doi":"10.1128/jb.00176-25","DOIUrl":"10.1128/jb.00176-25","url":null,"abstract":"<p><p>Increased susceptibility of elderly populations to infection is a major concern, as recently experienced by the coronavirus pandemic. Therefore, the treatment of infected elderly individuals is of immediate interest. Here, we report the use of ultrasound treatment to reduce <i>Salmonella</i> infection in elderly individuals. <i>Salmonella enterica</i> serovar Typhimurium enters the human body through the ingestion of contaminated food or water and causes gastroenteritis. The Centers for Disease Control (CDC) reports 420 deaths per year in the United States caused by the <i>Salmonella</i> pathogen, especially in the elderly population. In this study, we investigated the susceptibility to <i>Salmonella</i> infection in young and old mice by enumerating the number of viable bacteria in the liver 3 days post-infection. We then explored the effect of ultrasound treatment (low-frequency ultrasound [LFU]) prior to infecting aged mice with <i>Salmonella</i>. We observed a higher colonization of <i>Salmonella</i> infection in the livers of old mice compared to young mice. Colonization was significantly reduced when old mice were treated with LFU prior to infection, which significantly reduced colonization. Chemokine analysis revealed a significant increase in ICAM-1, SDF-1, and KC/CXCL1 in aged, treated mice. Ultrasound treatment rejuvenated the immune system in old mice, reducing their susceptibility to <i>Salmonella</i> infection.</p><p><strong>Importance: </strong>Our study demonstrates the efficacy of low-frequency ultrasound (LFU) treatment in significantly rejuvenating the immune system in aged mice and reducing their susceptibility to <i>Salmonella</i> infection. These findings underscore the potential of LFU as a therapeutic intervention to boost immune function in elderly populations, reducing the risk of infectious diseases.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0017625"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445081/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144821499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of <i>Ng</i>Ago-mediated genome editing in <i>Mycobacterium smegmatis</i>.","authors":"Li Zhao, Shi-Qi Yang, Yu-Wei Feng, Bang-Ce Ye, Di You","doi":"10.1128/jb.00214-25","DOIUrl":"10.1128/jb.00214-25","url":null,"abstract":"<p><p><i>Mycobacterium smegmatis</i> is nonpathogenic and fast-growing and is usually used as a model species of <i>Mycobacterium</i>. Studying basic metabolic mechanisms is crucial for accelerating mycobacterial research. Although several tools for genome editing in <i>Mycobacterium smegmatis</i> MC ⁽²⁾ 155 (<i>M. smegmatis</i>) can be used, plasmids are difficult to construct, and the knockout efficiency is still low. Here, the <i>Ng</i>Ago system was utilized to edit the genome of the Gram-positive bacterium <i>M. smegmatis</i>, which has a high guanine-cytosine (GC) content. A shuttle plasmid containing the hsp60 promoter to drive <i>Ng</i>Ago expression was designed. PCR-mediated screening and qRT‒PCR confirmed that the <i>glnR</i> gene (KEGG: <i>MSMEG_5784</i>) and <i>ltmA</i> gene (KEGG: <i>MSMEG_6479</i>) were successfully knocked out by the <i>Ng</i>Ago-F system. The editing efficiency reached 80%, and the time requirement was reduced to 8 days. The optimized <i>Ng</i>Ago system establishes an efficient genome-editing platform for high-GC mycobacteria, advancing functional genomics research on <i>M. smegmatis</i> and potentially enabling precise interrogation of virulence mechanisms in pathogens, such as <i>Mycobacterium tuberculosis</i>.IMPORTANCEIn this work, we demonstrated that the <i>Ng</i>Ago system could be used to edit the genome of <i>Mycobacterium smegmatis</i> and has several advantages: easy plasmid construction, high editing efficiency, and short time requirements. These findings provide a powerful tool for elucidating the basic metabolic mechanisms of <i>M. smegmatis</i> and potentially those of other mycobacterial species.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0021425"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445092/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144955214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of a heparin-binding protein encoded by <i>Mbov_0510</i> gene in <i>Mycoplasma bovis</i>.","authors":"Zhixin Ma, Qi Wu, Hui Yu, Qiao Pan, Tong Liu, Jiuqing Xin, Qingyuan Xu","doi":"10.1128/jb.00160-25","DOIUrl":"10.1128/jb.00160-25","url":null,"abstract":"<p><p><i>Mycoplasma bovis</i> is a highly infectious pathogenic microorganism that causes various clinical signs in cattle, including pneumonia, arthritis, and mastitis, often resulting in significant economic losses. The adhesion of <i>M. bovis</i> to host cells is a pivotal step in the infection process, which is a complex process involving multiple pathogenic and host proteins. Molecules involved in <i>M. bovis</i> adhesion and colonization are widely recognized as important virulence factors and often implicated in the infection and pathogenesis. In this study, the <i>Mbov_0510</i> gene of <i>M. bovis</i> was cloned, and the protein encoded by this gene was expressed and purified. The rabbit polyclonal antibody against this protein was also produced. This protein was shown to be a surface protein and to react with the <i>M. bovis</i>-positive serum. The ability of this protein to adhere to host cells was verified using embryonic bovine lung (EBL) and Madin-Darby bovine kidney (MDBK) cells. Furthermore, the adhesion function of this protein was found to be achieved through interaction with heparin on the host cell surface, and the key region of the protein involved in heparin binding was identified. The conservation of the protein encoded by the <i>Mbov_0510</i> gene was also analyzed. The results of this study suggest that the protein encoded by the <i>Mbov_0510</i> gene is a heparin-binding surface membrane protein of <i>M. bovis</i> associated with infection.IMPORTANCEMycoplasmas lack a cell wall, and the membrane proteins interacting with host cells play essential roles in their infection and proliferation processes. In this study, we identified a membrane protein encoded by <i>Mycoplasma bovis</i> that interacts with heparin on the surface of host cells. Heparin is widely distributed in various cells and tissues of the host and serves as a receptor for the infection and invasion of many pathogenic microorganisms. The ability of <i>M. bovis</i> to invade multiple tissues may be related to its heparin-binding capacity. The heparin-binding protein identified in this study is valuable for further research on the infection and invasion mechanisms of <i>M. bovis</i>.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0016025"},"PeriodicalIF":3.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12445077/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}