Virulence最新文献

{"title":"In turkeys, unlike chickens, the non-structural NS1 protein does not play a significant role in the replication and tissue tropism of the H7N1 avian influenza virus.","authors":"Maryna Kuryshko, Maria Landmann, Christine Luttermann, Reiner Ulrich, Elsayed M Abdelwhab","doi":"10.1080/21505594.2024.2379371","DOIUrl":"10.1080/21505594.2024.2379371","url":null,"abstract":"<p><p>The economic losses caused by high pathogenicity (HP) avian influenza viruses (AIV) in the poultry industry worldwide are enormous. Although chickens and turkeys are closely related Galliformes, turkeys are thought to be a bridging host for the adaptation of AIV from wild birds to poultry because of their high susceptibility to AIV infections. HPAIV evolve from low pathogenicity (LP) AIV after circulation in poultry through mutations in different viral proteins, including the non-structural protein (NS1), a major interferon (IFN) antagonist of AIV. At present, it is largely unknown whether the virulence determinants of HPAIV are the same in turkeys and chickens. Previously, we showed that mutations in the NS1 of HPAIV H7N1 significantly reduced viral replication in chickens <i>in</i> <i>vitro</i> and <i>in</i> <i>vivo</i>. Here, we investigated the effect of NS1 on the replication and virulence of HPAIV H7N1 in turkeys after inoculation with recombinant H7N1 carrying a naturally truncated wild-type NS1 (with 224 amino-acid \"aa\" in length) or an extended NS1 with 230-aa similar to the LP H7N1 ancestor. There were no significant differences in multiple-cycle viral replication or in the efficiency of NS1 in blocking IFN induction in the cell culture. Similarly, all viruses were highly virulent in turkeys and replicated at similar levels in various organs and swabs collected from the inoculated turkeys. These results suggest that NS1 does not play a role in the virulence or replication of HPAIV H7N1 in turkeys and further indicate that the genetic determinants of HPAIV differ in these two closely related galliform species.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11259080/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141627821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Streptococcus suis</i> subtilisin-like serine proteases SspA-1 and SspA-2 interplay with complement C3a and C5a to facilitate bacterial immune evasion and infection.","authors":"Simin Deng, Junhui Liao, Haojie Li, Jiali Xu, Jingyan Fan, Jing Xia, Jing Wang, Lei Lei, Mianmian Chen, Yue Han, Ruidong Zhai, Chang Zhou, Rui Zhou, Changyong Cheng, Houhui Song","doi":"10.1080/21505594.2023.2301246","DOIUrl":"10.1080/21505594.2023.2301246","url":null,"abstract":"<p><p><i>Streptococcus suis</i> (<i>S. suis</i>), a significant zoonotic bacterial pathogen impacting swine and human, is associated with severe systemic diseases such as streptococcal toxic shock-like syndrome, meningitis, septicaemia, and abrupt fatality. The multifaceted roles of complement components C5a and C3a extend to orchestrating inflammatory cells recruitment, oxidative burst induction, and cytokines release. Despite the pivotal role of subtilisin-like serine proteases in <i>S. suis</i> pathogenicity, their involvement in immune evasion remains underexplored. In the present study, we identify two cell wall-anchored subtilisin-like serine proteases in <i>S. suis</i>, SspA-1 and SspA-2, as binding partners for C3a and C5a. Through Co-Immunoprecipitation, Enzyme-Linked Immunosorbent and Far-Western Blotting Assays, we validate their interactions with the aforementioned components. However, SspA-1 and SspA-2 have no cleavage activity against complement C3a and C5a performed by Cleavage assay. Chemotaxis assays reveal that recombinant SspA-1 and SspA-2 effectively attenuate monocyte chemotaxis towards C3a and C5a. Notably, the <i>ΔsspA-1</i>, <i>ΔsspA-1,</i> and <i>ΔsspA-1/2</i> mutant strains exhibit compromised survival in blood, and resistance of opsonophagocytosis, alongside impaired survival in blood and <i>in vivo</i> colonization compared to the parental strain SC-19. Critical insights from the murine and <i>Galleria mellonella</i> larva infection models further underscore the significance of <i>sspA-1</i> in altering mortality rates. Collectively, our findings indicate that SspA-1 and SspA-2 are novel binding proteins for C3a and C5a, thereby shedding light on their pivotal roles in <i>S. suis</i> immune evasion and the pathogenesis.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10795781/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139088675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The multifaceted interactions between Newcastle disease virus proteins and host proteins: a systematic review.","authors":"Xiaolong Lu, Xiaoquan Wang, Xiufan Liu, Xiaowen Liu","doi":"10.1080/21505594.2023.2299182","DOIUrl":"10.1080/21505594.2023.2299182","url":null,"abstract":"<p><p>Newcastle disease virus (NDV) typically induces severe illness in poultry and results in significant economic losses for the worldwide poultry sector. NDV, an RNA virus with a single-stranded negative-sense genome, is susceptible to mutation and immune evasion during viral transmission, thus imposing enormous challenges to avian health and poultry production. NDV is composed of six structural proteins and two nonstructural proteins that exert pivotal roles in viral infection and antiviral responses by interacting with host proteins. Nowadays, there is a particular focus on the mechanisms of virus-host protein interactions in NDV research, yet a comprehensive overview of such research is still lacking. Herein, we briefly summarize the mechanisms regarding the effects of virus-host protein interaction on viral infection, pathogenesis, and host immune responses. This review can not only enhance the present comprehension of the mechanism underlying NDV and host interplay, but also furnish a point of reference for the advancement of antiviral measures.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10793697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139404600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time to positivity of <i>Klebsiella pneumoniae</i> in blood cultures as prognostic marker in patients with intra-abdominal infection: A retrospective study.","authors":"Yong-Ye Yang, I-Ting Tsai, Chung-Hsu Lai, Chih-Ping Chen, Chia-Chi Chen, Yin-Chou Hsu","doi":"10.1080/21505594.2024.2329397","DOIUrl":"10.1080/21505594.2024.2329397","url":null,"abstract":"<p><p><i>Klebsiella pneumoniae</i> is a common causative pathogen of intra-abdominal infection with concomitant bacteraemia, leading to a significant mortality risk. The time to positivity (TTP) of blood culture is postulated to be a prognostic factor in bacteraemia caused by other species. Therefore, this study aimed to investigate the prognostic value of TTP in these patients. The single-centred, retrospective, observational cohort study was conducted between 1 July 2016 and 30 June 2021. All adult emergency department patients with diagnosis of intra-abdominal infection and underwent blood culture collection which yield <i>K. pneumoniae</i> during this period were enrolled. A total of 196 patients were included in the study. The overall 30-day mortality rate was 12.2% (24/196), and the median TTP of the studied cohort was 12.3 h (10.5-15.8 h). TTP revealed a moderate 30-day mortality discriminative ability (area under the curve 0.73, <i>p</i> < 0.001). Compared with the late TTP group (>12 h, <i>N</i> = 109), patients in the early TTP (≤12 h, <i>N</i> = 87) group had a significantly higher risk of 30-day morality (21.8% vs. 4.6%, <i>p</i> < 0.01) and other adverse outcomes. Furthermore, TTP (odds ratio [OR] = 0.79, <i>p</i> = 0.02), Pitt bacteraemia score (OR = 1.30, <i>p</i> = 0.03), and implementation of source control (OR = 0.06, <i>p</i> < 0.01) were identified as independent factors related to 30-day mortality risk in patients with intra-abdominal infection and <i>K. pneumoniae</i> bacteraemia. Therefore, physicians can use TTP for prognosis stratification in these patients.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10984124/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140319396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coincidence of antibodies against Hwp1 and ASCA, two distinct molecular targets of <i>Candida albicans</i>, reinforces the link between this fungal species and coeliac disease.","authors":"Boualem Sendid, Christopher Cao, Jean-Frederic Colombel, Daniel Poulain","doi":"10.1080/21505594.2024.2334085","DOIUrl":"10.1080/21505594.2024.2334085","url":null,"abstract":"<p><p><i>Candida albicans</i> is an immunogen for anti-<i>Saccharomyces cerevisiae</i> antibodies (ASCA), a serological marker of Crohn's disease. ASCA has also been reported in other autoimmune diseases, including coeliac disease (CeD). A strong antibody response against Hwp1, a protein associated with invasive hyphal form of <i>C. albicans</i> which presents peptide sequence homologies with gliadin, has also been described in CeD. This observation supports the hypothesis that <i>C. albicans</i> hyphal transition in <i>C. albicans</i> may trigger CeD onset through a mechanism of molecular/antigenic mimicry. In this study, we assessed whether the anti-<i>C. albicans</i> oligomannose and anti-Hwp1 protein responses may be linked despite their different pathophysiological significance. The measurement of ASCA levels in a cohort of patients involved in our previous Hwp1 study showed a significant correlation between the two biomarkers. This new observation further reinforces the link between <i>C. albicans</i> and CeD.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10968292/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140289062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analyzing the factors affecting virus invasion by quantitative single-particle analysis.","authors":"Yi-Ning Hou, Li-Juan Zhang, Lei Du, Dan-Dan Fu, Jing Li, Liu Liu, Peng-Fei Xu, Ya-Wen Zheng, Dai-Wen Pang, Hong-Wu Tang","doi":"10.1080/21505594.2024.2367671","DOIUrl":"10.1080/21505594.2024.2367671","url":null,"abstract":"<p><p>Viral diseases are among the main threats to public health. Understanding the factors affecting viral invasion is important for antiviral research. Until now, it was known that most viruses have very low plaque-forming unit (PFU)-to-particle ratios. However, further investigation is required to determine the underlying factors. Here, using quantitative single-particle analysis methods, the invasion of Semliki Forest virus (SFV), Japanese encephalitis virus (JEV), and influenza A virus (IAV) containing attachment to the cell surface, entry into the cell, transport towards the cell interior, and fusion with endosomes to release nucleocapsids were quantitatively analysed in parallel. It was found that for SFV with an PFU-to-particle ratio of approximately 1:2, an entry efficiency of approximately 31% limited infection. For JEV, whose PFU-to-particle ratio was approximately 1:310, an attachment efficiency of approximately 27% and an entry efficiency of 10% were the main factors limiting its infection. Meanwhile, for IAV with PFU-to-particle ratios of 1:8100, 5% attachment efficiency, 9% entry efficiency, and 53% fusion efficiency significantly limited its infection. These results suggest that viruses with different infectivities have different limited steps in the invasion process. Moreover, there are significant differences in attachment efficiencies among viruses, emphasizing the pivotal role of attachment in viral invasion. The influence of the virus purification method on virus invasion was also investigated. This study, for the first time, reports the efficiencies of different stages of virus invasion, leading to a better understanding of virus invasion and providing a protocol to quantitatively analyse the virus invasion efficiency.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11197921/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141443402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Screening optimal DC-targeting peptide to enhance the immune efficacy of recombinant <i>Lactobacillus</i> expressing RHDV VP60.","authors":"Tian Xia, Xiao Lu, Deming Kong, Tiantian Guo, Yueyi Gao, Lingxiang Xin, Yanping Jiang, Xiaona Wang, Zhifu Shan, Jiaxuan Li, Han Zhou, Wen Cui, Xinyuan Qiao, Lijie Tang, Yijing Li, Li Wang","doi":"10.1080/21505594.2024.2368080","DOIUrl":"10.1080/21505594.2024.2368080","url":null,"abstract":"<p><p>Dendritic cells (DCs) present an ideal target for delivering immunogenic cargo due to their potent antigen-presenting capabilities. This targeting approach holds promise in vaccine development by enhancing the efficiency of antigen recognition and capture by DCs. To identify a high-affinity targeting peptide binding to rabbit DCs, rabbit monocyte-derived DCs (raMoDCs) were isolated and cultured, and a novel peptide, HS (HSLRHDYGYPGH), was identified using a phage-displayed peptide library. Alongside HS, two other DC-targeting peptides, KC1 and MY, previously validated in our laboratory, were employed to construct recombinant <i>Lactgobacillus reuteri</i> fusion-expressed rabbit hemorrhagic disease virus (RHDV) capsid protein VP60. These recombinant <i>Lactobacillus</i> strains were named HS-VP60/<i>L. reuteri</i>, KC1-VP60/<i>L. reuteri</i>, and MY-VP60/<i>L. reuteri</i>. The ability of these recombinant <i>Lactobacillus</i> to bind rabbit DCs was evaluated both in vivo and in vitro. Results demonstrated that the DC-targeting peptide KC1 significantly enhanced the capture efficiency of recombinant <i>Lactobacillus</i> by raMoDCs, promoted DC maturation, and increased cytokine secretion. Furthermore, oral administration of KC1-VP60/<i>L. reuteri</i> effectively induced SIgA and IgG production in rabbits, prolonged rabbit survival post-challenge, and reduced RHDV copies in organs. In summary, the DC-targeting peptide KC1 exhibited robust binding to raMoDCs, and recombinant <i>Lactobacillus</i> expressing KC1-VP60 protein antigens efficiently induced systemic and mucosal immune responses in rabbits, conferring protective efficacy against RHDV. This study offers valuable insights for the development of novel RHDV vaccines.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11195490/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141427761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GlmS plays a key role in the virulence factor expression and biofilm formation ability of <i>Staphylococcus aureus</i> promoted by advanced glycation end products.","authors":"Lijia Ni, Rui Shen, Hua Luo, Xuexue Li, Xiaofan Zhang, Lisi Huang, Yawen Deng, Xiaoyan Liao, Yonglin Wu, Chaohui Duan, Xiaoying Xie","doi":"10.1080/21505594.2024.2352476","DOIUrl":"10.1080/21505594.2024.2352476","url":null,"abstract":"<p><p><i>Staphylococcus aureus (S. aureus)</i> is well known for its biofilm formation ability and is responsible for serious, chronic refractory infections worldwide. We previously demonstrated that advanced glycation end products (AGEs), a hallmark of chronic hyperglycaemia in diabetic tissues, enhanced biofilm formation by promoting eDNA release via <i>sigB</i> upregulation in <i>S. aureus</i>, contributing to the high morbidity and mortality of patients presenting a diabetic foot ulcer infection. However, the exact regulatory network has not been completely described. Here, we used pull-down assay and LC-MS/MS to identify the GlmS as a candidate regulator of <i>sigB</i> in <i>S. aureus</i> stimulated by AGEs. Dual-luciferase assays and electrophoretic mobility shift assays (EMSAs) revealed that GlmS directly upregulated the transcriptional activity of <i>sigB</i>. We constructed NCTC 8325 ∆<i>glmS</i> for further validation. qRT-PCR analysis revealed that AGEs promoted both <i>glmS</i> and <i>sigB</i> expression in the NCTC 8325 strain but had no effect on NCTC 8325 ∆<i>glmS</i>. NCTC 8325 ∆<i>glmS</i> showed a significant attenuation in biofilm formation and virulence factor expression, accompanied by a decrease in <i>sigB</i> expression, even under AGE stimulation. All of the changes, including pigment deficiency, decreased haemolysis ability, downregulation of <i>hla</i> and <i>hld</i> expression, and less and sparser biofilms, indicated that <i>sigB</i> and biofilm formation ability no longer responded to AGEs in NCTC 8325 ∆<i>glmS</i>. Our data extend the understanding of GlmS in the global regulatory network of <i>S. aureus</i> and demonstrate a new mechanism by which AGEs can upregulate GlmS, which directly regulates <i>sigB</i> and plays a significant role in mediating biofilm formation and virulence factor expression.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11095574/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140916960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Outer membrane vesicles from genetically engineered <i>Salmonella enterica</i> serovar Typhimurium presenting <i>Helicobacter pylori</i> antigens UreB and CagA induce protection against <i>Helicobacter pylori</i> infection in mice.","authors":"Qiong Liu, Yinpan Shang, Lu Shen, Xiaomin Yu, Yanli Cao, Lingbing Zeng, Hanchi Zhang, Zirong Rao, Yi Li, Ziwei Tao, Zhili Liu, Xiaotian Huang","doi":"10.1080/21505594.2024.2367783","DOIUrl":"10.1080/21505594.2024.2367783","url":null,"abstract":"<p><p><i>Helicobacter pylori</i> causes globally prevalent infections that are highly related to chronic gastritis and even development of gastric carcinomas. With the increase of antibiotic resistance, scientists have begun to search for better vaccine design strategies to eradicate <i>H. pylori</i> colonization. However, while current strategies prefer to formulate vaccines with a single <i>H. pylori</i> antigen, their potential has not yet been fully realized. Outer membrane vesicles (OMVs) are a potential platform since they could deliver multiple antigens. In this study, we engineered three crucial <i>H. pylori</i> antigen proteins (UreB, CagA, and VacA) onto the surface of OMVs derived from <i>Salmonella enterica</i> serovar Typhimurium (<i>S</i>. Typhimurium) mutant strains using the hemoglobin protease (Hbp) autotransporter system. In various knockout strategies, we found that OMVs isolated from the Δ<i>rfbP</i> Δ<i>fliC</i> Δ<i>fljB</i> Δ<i>ompA</i> mutants could cause distinct increases in immunoglobulin G (IgG) and A (IgA) levels and effectively trigger T helper 1- and 17-biased cellular immune responses, which perform a vital role in protecting against <i>H. pylori</i>. Next, OMVs derived from Δ<i>rfbP</i> Δ<i>fliC</i> Δ<i>fljB</i> Δ<i>ompA</i> mutants were used as a vector to deliver different combinations of <i>H. pylori</i> antigens. The antibody and cytokine levels and challenge experiments in mice model indicated that co-delivering UreB and CagA could protect against <i>H. pylori</i> and antigen-specific T cell responses. In summary, OMVs derived from the <i>S</i>. Typhimurium Δ<i>rfbP</i> Δ<i>fliC</i> Δ<i>fljB</i> Δ<i>ompA</i> mutant strain as the vector while importing <i>H. pylori</i> UreB and CagA as antigenic proteins using the Hbp autotransporter system would greatly benefit controlling <i>H. pylori</i> infection.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11216100/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141471110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The roles of cell wall inhibition responsive protein CwrA in the pathogenicity of <i>Staphylococcus aureus</i>.","authors":"Weihua Han, Yanghua Xiao, Li Shen, Xinru Yuan, Jingyi Yu, Haojin Gao, Rongrong Hu, Junhong Shi, Bingjie Wang, Jiao Zhang, Peiyao Zhou, Cailing Wan, Yu Huang, JianBo Lv, Fangyou Yu","doi":"10.1080/21505594.2024.2411540","DOIUrl":"10.1080/21505594.2024.2411540","url":null,"abstract":"<p><p>The ability to form robust biofilms and secrete a diverse array of virulence factors are key pathogenic determinants of <i>Staphylococcus aureus</i>, causing a wide range of infectious diseases. Here, we characterized <i>cwrA</i> as a VraR-regulated gene encoding a cell wall inhibition-responsive protein (CwrA) using electrophoretic mobility shift assays. We constructed <i>cwrA</i> deletion mutants in the genetic background of methicillin-resistant <i>S. aureus</i> (MRSA) and methicillin-sensitive <i>S. aureus</i> (MSSA) strains. Phenotypic analyses indicated that deletion of <i>cwrA</i> led to impaired biofilm formation, which was correlated with polysaccharide intercellular adhesin (PIA). Besides, the results of real-time quantitative PCR (RT-qPCR) and β-galactosidase activity assay revealed that CwrA promoted biofilm formation by influence the <i>ica</i> operon activity in <i>S. aureus</i>. Furthermore, <i>cwrA</i> deletion mutants released less extracellular DNA (eDNA) in the biofilm because of their reduced autolytic activity compared to the wild-type (WT) strains. We also found that <i>cwrA</i> deletion mutant more virulence than the parental strain because of its enhanced hemolytic activity. Mechanistically, this phenotypic alteration is related to activation of the SaeRS two-component system, which positively regulates the transcriptional levels of genes encoding membrane-damaging toxins. Overall, our results suggest that CwrA plays an important role in modulating biofilm formation and hemolytic activity in <i>S. aureus</i>.</p>","PeriodicalId":23747,"journal":{"name":"Virulence","volume":null,"pages":null},"PeriodicalIF":5.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11457683/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142366736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}