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Wang J, Liang P, Sun H, Wu Z, Gottschalk M, Qi K, Zheng H. Comparative transcriptomic analysis reveal genes involved in the pathogenicity increase of Streptococcus suis epidemic strains. Virulence 2022; 13:1455-1470. [PMID: 36031944 PMCID: PMC9423846 DOI: 10.1080/21505594.2022.2116160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Streptococcus suis epidemic strains were responsible for two outbreaks in China and possessed increased pathogenicity which was featured prominently by inducing an excessive inflammatory response at the early phase of infection. To discover the critical genes responsible for the pathogenicity increase of S. suis epidemic strains, the genome-wide transcriptional profiles of epidemic strain SC84 were investigated at the early phase of interaction with BV2 cells. The overall low expression levels of 89K pathogenicity island (PAI) and 129 known virulence genes in the SC84 interaction groups indicated that its pathogenicity increase should be attributed to novel mechanisms. Using highly pathogenic strain P1/7 and intermediately pathogenic strain 89–1591 as controls, 11 pathogenicity increase crucial genes (PICGs) and 38 pathogenicity increase-related genes (PIRGs) were identified in the SC84 incubation groups. The PICGs encoded proteins related to the methionine biosynthesis/uptake pathway and played critical roles in the pathogenicity increase of epidemic strains. A high proportion of PIRGs encoded surface proteins related to host cell adherence and immune escape, which may be conducive to the pathogenicity increase of epidemic strains by rapidly initiating infection. The fact that none of PICGs and PIRGs belonged to epidemic strain-specific gene indicated that the pathogenicity increase of epidemic strain may be determined by the expression level of genes, rather than the presence of them. Our results deepened the understanding on the mechanism of the pathogenicity increase of S. suis epidemic strains and provided novel approaches to control the life-threatening infections of S. suis epidemic strains.
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Affiliation(s)
- Jianping Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
| | - Pujun Liang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
- OIE Reference Lab for Swine Streptococcosis, MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Hui Sun
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
| | - Zongfu Wu
- Swine and Poultry Infectious Diseases Research Center, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Marcelo Gottschalk
- Department of Clinical Laboratory, Nanxishan Hospital of Guangxi Zhuang Autonomous Region, Guilin, Guangxi Zhuang Autonomous Region, China
| | - Kexin Qi
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
| | - Han Zheng
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
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Yang X, Peng W, Wang N, Dou B, Yang F, Chen H, Yuan F, Bei W. Role of the Two-Component System CiaRH in the Regulation of Efflux Pump SatAB and Its Correlation with Fluoroquinolone Susceptibility. Microbiol Spectr 2022; 10:e0041722. [PMID: 35638854 PMCID: PMC9241815 DOI: 10.1128/spectrum.00417-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/04/2022] [Indexed: 11/26/2022] Open
Abstract
Streptococcus suis is an important pathogen in both pigs and humans. Although the diseases associated with S. suis can typically be treated with antibiotics, such use has resulted in a sustained increase in drug resistance. Bacteria can sense and respond to antibiotics via two-component systems (TCSs). In this study, the TCS CiaRH was identified as playing an important role in the susceptibility of S. suis to fluoroquinolones (FQs). We found that a ΔciaRH mutant possessed lower susceptibility to FQs than the wild-type strain, with no observed growth defects at the tested concentrations and lower levels of intracellular drugs and dye. Proteomic data revealed that the levels of SatA and SatB expression were upregulated in the ΔciaRH mutant compared with their levels in the wild-type strain. The satA and satB genes encode a narrow-spectrum FQ efflux pump. The phenomena associated with combined ciaRH-and-satAB deletion mutations almost returned the ΔciaRH ΔsatAB mutant to the phenotype of the wild-type strain compared to the phenotype of the ΔciaRH mutant, suggesting that the resistance of the ΔciaRH strain to FQs could be attributed to satAB overexpression. Moreover, SatAB expression was regulated by CiaR (a response regulator of CiaRH) and SatR (a regulator of the MarR family). The ciaRH genes were consistently downregulated in response to antibiotic stress. The results of electrophoretic mobility shift assays (EMSAs) and affinity assays revealed that both regulator proteins directly controlled the ABC transporter proteins SatAB. Together, the results show that cascade-mediated regulation of antibiotic export by CiaRH is crucial for the ability of S. suis to adapt to conditions of antibiotic pressure. Our study may provide a new target for future antibiotic research and development. IMPORTANCE Streptococcus suis is a zoonotic pathogen with high incidence and mortality rates in both swine and humans. Following antibiotic treatment, the organism has evolved many resistance mechanisms, among which efflux pump overexpression can promote drug extrusion from the cell. This study clarified the role of CiaRH in fluoroquinolone resistance. A mutant with the ciaRH genes deleted showed decreased susceptibility to the antibiotics tested, an invariant growth rate, and reduced intracellular efflux pump substrates. This research also demonstrated that overexpression of the efflux pump SatAB was the main cause of ΔciaRH resistance. In addition, CiaR could combine with the promoter region of satAB to further directly suppress target gene transcription. Simultaneously, satAB was also directly regulated by SatR. Our findings may provide novel insights for the development of drug targets and help to exploit corresponding inhibitors to combat bacterial multidrug resistance.
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Affiliation(s)
- Xia Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Wei Peng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Ningning Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Beibei Dou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Fengming Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Fangyan Yuan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture), Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Weicheng Bei
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- Guangxi Yangxiang Co., Ltd., Guigang, China
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Arenas J, Bossers-de Vries R, Harders-Westerveen J, Buys H, Ruuls-van Stalle LMF, Stockhofe-Zurwieden N, Zaccaria E, Tommassen J, Wells JM, Smith HE, de Greeff A. In vivo transcriptomes of Streptococcus suis reveal genes required for niche-specific adaptation and pathogenesis. Virulence 2020; 10:334-351. [PMID: 30957693 PMCID: PMC6527017 DOI: 10.1080/21505594.2019.1599669] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Streptococcus suis is a Gram-positive bacterium and a zoonotic pathogen residing in the nasopharynx or the gastrointestinal tract of pigs with a potential of causing life-threatening invasive disease. It is endemic in the porcine production industry worldwide, and it is also an emerging human pathogen. After invasion, the pathogen adapts to cause bacteremia and disseminates to different organs including the brain. To gain insights in this process, we infected piglets with a highly virulent strain of S. suis, and bacterial transcriptomes were obtained from blood and different organs (brain, joints, and heart) when animals had severe clinical symptoms of infection. Microarrays were used to determine the genome-wide transcriptional profile at different infection sites and during growth in standard growth medium in vitro. We observed differential expression of around 30% of the Open Reading Frames (ORFs) and infection-site specific patterns of gene expression. Genes with major changes in expression were involved in transcriptional regulation, metabolism, nutrient acquisition, stress defenses, and virulence, amongst others, and results were confirmed for a subset of selected genes using RT-qPCR. Mutants were generated in two selected genes, and the encoded proteins, i.e., NADH oxidase and MetQ, were shown to be important virulence factors in coinfection experiments and in vitro assays. The knowledge derived from this study regarding S. suis gene expression in vivo and identification of virulence factors is important for the development of novel diagnostic and therapeutic strategies to control S. suis disease.
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Affiliation(s)
- Jesús Arenas
- a Department of Infection Biology , Wageningen BioVeterinary Research (WBVR) , Lelystad , The Netherlands
| | - Ruth Bossers-de Vries
- a Department of Infection Biology , Wageningen BioVeterinary Research (WBVR) , Lelystad , The Netherlands
| | - José Harders-Westerveen
- a Department of Infection Biology , Wageningen BioVeterinary Research (WBVR) , Lelystad , The Netherlands
| | - Herma Buys
- a Department of Infection Biology , Wageningen BioVeterinary Research (WBVR) , Lelystad , The Netherlands
| | | | | | - Edoardo Zaccaria
- b Host Microbe Interactions , Wageningen UR , Wageningen , The Netherlands
| | - Jan Tommassen
- c Department of Molecular Microbiology and Institute of Biomembranes , Utrecht University , Utrecht , The Netherlands
| | - Jerry M Wells
- b Host Microbe Interactions , Wageningen UR , Wageningen , The Netherlands
| | - Hilde E Smith
- a Department of Infection Biology , Wageningen BioVeterinary Research (WBVR) , Lelystad , The Netherlands
| | - Astrid de Greeff
- a Department of Infection Biology , Wageningen BioVeterinary Research (WBVR) , Lelystad , The Netherlands
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Huan H, Jiang L, Tang L, Wang Y, Guo S. Isolation and characterization of Streptococcus suis strains from swine in Jiangsu province, China. J Appl Microbiol 2020; 128:1606-1612. [PMID: 31981255 DOI: 10.1111/jam.14591] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 12/25/2019] [Accepted: 01/17/2020] [Indexed: 11/29/2022]
Abstract
AIMS The aim of this study is to investigate Streptococcus suis strains present in Jiangsu province, China. METHODS AND RESULTS In all, 1650 nasal and anal swab samples and 100 tonsils were collected from clinically healthy swine. Culture characteristics, colony morphology and PCR-based analysis of the glutamate dehydrogenase (gdh) gene were performed for S. suis identification, and eight isolates were confirmed to be S. suis. The isolates serogroups were identified by agglutinating test, including 4, 7, 3, 5 and 8. Gene profiling by PCR showed that the manN, purD, orf2, gdh genes were conserved among the isolates and that 50% of the isolates carried dltA, pgdA, srtA and sspA. Antimicrobial susceptibility test showed the isolates displayed resistance to clindamycin, erythromycin, tetracycline, penicillin G, vancomycin and linezolid; while none was resistant to chloramphenicol, multi-drug resistance was seen in most of the isolates. Finally, the LD50 (assessed by zebrafish) of isolates RD105 was 2·6431 × 105 and HA24 was 7·1198 × 106 , which showed RD105 more virulent and was consistent with the results of virulence factor identification. CONCLUSIONS There is a very low proportion of S. suis in the healthy pigs. The virulence factors were related to pathogenicity. Bacteria in Nantong possess greater virulence potential than those in Huaian. SIGNIFICANCE AND IMPACT OF THE STUDY Systematic investigation of S. suis provided the most basic theoretical support for the prevention and control of swine streptococcosis.
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Affiliation(s)
- H Huan
- Huaiyin Normal University, College of Life Sciences, Huaian, Jiangsu, China
| | - L Jiang
- Yangzhou University, College of Veterinary Medicine, Yangzhou, Jiangsu, China
| | - L Tang
- Huaiyin Normal University, College of Life Sciences, Huaian, Jiangsu, China
| | - Y Wang
- Yangzhou University, College of Veterinary Medicine, Yangzhou, Jiangsu, China
| | - S Guo
- Huaiyin Normal University, College of Life Sciences, Huaian, Jiangsu, China
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Ma F, Yi L, Yu N, Wang G, Ma Z, Lin H, Fan H. Streptococcus suis Serotype 2 Biofilms Inhibit the Formation of Neutrophil Extracellular Traps. Front Cell Infect Microbiol 2017; 7:86. [PMID: 28373968 PMCID: PMC5357632 DOI: 10.3389/fcimb.2017.00086] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 03/06/2017] [Indexed: 12/11/2022] Open
Abstract
Invasive infections caused by Streptococcus suis serotype 2 (SS2) has emerged as a clinical problem in recent years. Neutrophil extracellular traps (NETs) are an important mechanism for the trapping and killing of pathogens that are resistant to phagocytosis. Biofilm formation can protect bacteria from being killed by phagocytes. Until now, there have only been a few studies that focused on the interactions between bacterial biofilms and NETs. SS2 in both a biofilm state and a planktonic cell state were incubated with phagocytes and NETs, and bacterial survival was assessed. DNase I and cytochalasin B were used to degrade NET DNA or suppress phagocytosis, respectively. Extracellular DNA was stained with impermeable fluorescent dye to quantify NET formation. Biofilm formation increased up to 6-fold in the presence of neutrophils, and biofilms were identified in murine tissue. Both planktonic and biofilm cells induced neutrophils chemotaxis to the infection site, with neutrophils increasing by 85.1 and 73.8%, respectively. The bacteria in biofilms were not phagocytized. The bactericidal efficacy of NETs on the biofilms and planktonic cells were equal; however, the biofilm extracellular matrix can inhibit NET release. Although biofilms inhibit NETs release, NETs appear to be an important mechanism to eliminate SS2 biofilms. This knowledge advances the understanding of biofilms and may aid in the development of treatments for persistent infections with a biofilm component.
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Affiliation(s)
- Fang Ma
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Li Yi
- College of Veterinary Medicine, Nanjing Agricultural UniversityNanjing, China; College of Life Science, Luoyang Normal UniversityLuoyang, China
| | - Ningwei Yu
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Guangyu Wang
- National Center of Meat Quality and Safety Control, Nanjing Agriculture University Nanjing, China
| | - Zhe Ma
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Huixing Lin
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural UniversityNanjing, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and ZoonosesYangzhou, China
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de Greeff A, Buys H, Wells JM, Smith HE. A naturally occurring nucleotide polymorphism in the orf2/folc promoter is associated with Streptococcus suis virulence. BMC Microbiol 2014; 14:264. [PMID: 25384512 PMCID: PMC4232619 DOI: 10.1186/s12866-014-0264-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 10/09/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Streptococcus suis is a major problem in the swine industry causing meningitis, arthritis and pericarditis in piglets. Pathogenesis of S. suis is poorly understood. We previously showed that introduction of a 3 kb genomic fragment from virulent serotype 2 strain 10 into a weakly virulent serotype 2 strain S735, generated a hypervirulent isolate. The 3 kb genomic fragment contained two complete open reading frames (ORF) in an operon-structure of which one ORF showed similarity to folylpolyglutamate synthetase, whereas the function of the second ORF could not be predicted based on database searches for protein similarity. RESULTS In this study we demonstrate that introduction of orf2 from strain 10 into strain S735 is sufficient to dramatically increase the virulence of S735 in pigs. This increase in virulence could not be associated with changes in pro-inflammatory responses of porcine blood mononucleated cells in response to S. suis in vitro. Sequence analysis of the orf2-folC-operon of S. suis isolates 10 and S735 revealed an SNP in the -35 region of the putative promoter sequence of the operon, as well as several SNPs resulting in amino acid substitutions in the ORF2 protein. Transcript levels of orf2 and folC were significantly higher in the virulent strain 10 than in the weakly virulent strain S735 and in vitro mutagenesis of the orf2 promoter confirmed that this was due to a SNP in the predicted -35 region upstream of the orf2 promoter. In this study, we demonstrated that the stronger promoter was present in all virulent and highly virulent S. suis isolates included in our study. This highlights a correlation between high orf2 expression and virulence. Conversely, the weaker promoter was present in isolates known to be weakly pathogenic or non-pathogenic. CONCLUSION In summary, we demonstrate the importance of orf2 in the virulence of S. suis.
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Affiliation(s)
- Astrid de Greeff
- Central Veterinary Institute of Wageningen UR, Edelhertweg 15, 8219, , PH, Lelystad, The Netherlands.
| | - Herma Buys
- Central Veterinary Institute of Wageningen UR, Edelhertweg 15, 8219, , PH, Lelystad, The Netherlands.
| | - Jerry M Wells
- Wageningen UR, Host Microbe Interactions, De Elst 1, 6708, , WD, Wageningen, The Netherlands.
| | - Hilde E Smith
- Central Veterinary Institute of Wageningen UR, Edelhertweg 15, 8219, , PH, Lelystad, The Netherlands.
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Bi Y, Li J, Yang L, Zhang S, Li Y, Jia X, Sun L, Yin Y, Qin C, Wang B, Gao GF, Liu W. Assessment of the pathogenesis of Streptococcus suis type 2 infection in piglets for understanding streptococcal toxic shock-like syndrome, meningitis, and sequelae. Vet Microbiol 2014; 173:299-309. [PMID: 25200597 DOI: 10.1016/j.vetmic.2014.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 08/03/2014] [Accepted: 08/09/2014] [Indexed: 01/29/2023]
Abstract
Streptococcus suis type 2 (SS2) is an zoonotic pathogen that had caused outbreaks in 1998 and 2005 in China. It is still not very clear how the disease progresses into the streptococcal toxic shock-like syndrome (STSLS) or meningitis, as well as the sequelae from the survivals. The present study used piglets as infection model to systematically investigate the pathogenesis of the infection caused by the SS2 strain 05ZYH33. The infected piglets showed joint swelling, lameness, and crouch at beginning, then developed into septic-like shock syndrome (SLSS) or prostration syndrome, at last the survivals showed physical activity impairment. The morbidity and mortality were 100% (71% for SLSS, 29% for prostration syndrome) and 29%, respectively. The pigs exhibiting SLSS had deep invasive infections in tissues and organs, and displayed more severe bacteremia and cytokine secretion in the bloodstream and organs than pigs with prostration syndrome. Moreover, the polymorphisms in the toll-like receptor 1 (TLR1) and TLR2 genes varied between the pigs affected with SLSS and prostration syndrome. Several lines of evidence indicated that SS2 infection progression into SLSS or relatively lighter prostration syndrome in pigs is closely related to the degrees of bacteremia and cytokine storm, which may be inherently determined by the diversity of innate immunity-associated genes. Furthermore, brain lesions, such as venous thrombosis, may directly contribute to the sequelae in human cases, were identified in the pigs. These results might help us to further understand the pathogenesis of SS2 in humans.
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Affiliation(s)
- Yuhai Bi
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jing Li
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Limin Yang
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shuang Zhang
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun Li
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaojuan Jia
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lei Sun
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanbo Yin
- College of Animal Science and Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, China
| | - Chuan Qin
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS) & Comparative Medicine Center, Peking Union Medical Collage (PUMC), Beijing 100021, China
| | - Beinan Wang
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - George Fu Gao
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Office of Director-General, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Wenjun Liu
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology (CASPMI), Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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Ferrando ML, van Baarlen P, Orrù G, Piga R, Bongers RS, Wels M, De Greeff A, Smith HE, Wells JM. Carbohydrate availability regulates virulence gene expression in Streptococcus suis. PLoS One 2014; 9:e89334. [PMID: 24642967 PMCID: PMC3958366 DOI: 10.1371/journal.pone.0089334] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 01/17/2014] [Indexed: 12/04/2022] Open
Abstract
Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans. Colonization of porcine oropharynx by S. suis is considered to be a high risk factor for invasive disease. In the oropharyngeal cavity, where glucose is rapidly absorbed but dietary α-glucans persist, there is a profound effect of carbohydrate availability on the expression of virulence genes. Nineteen predicted or confirmed S. suis virulence genes that promote adhesion to and invasion of epithelial cells were expressed at higher levels when S. suis was supplied with the α-glucan starch/pullulan compared to glucose as the single carbon source. Additionally the production of suilysin, a toxin that damages epithelial cells, was increased more than ten-fold when glucose levels were low and S. suis was growing on pullulan. Based on biochemical, bioinformatics and in vitro and in vivo gene expression studies, we developed a biological model that postulates the effect of carbon catabolite repression on expression of virulence genes in the mucosa, organs and blood. This research increases our understanding of S. suis virulence mechanisms and has important implications for the design of future control strategies including the development of anti-infective strategies by modulating animal feed composition.
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Affiliation(s)
- M. Laura Ferrando
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Peter van Baarlen
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Germano Orrù
- Oral Biotechnology Laboratory, University of Cagliari, Cagliari, Italy
| | - Rosaria Piga
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | | | | | - Astrid De Greeff
- Central Veterinary Institute, Animal Sciences Group, Wageningen University, Lelystad, The Netherlands
| | - Hilde E. Smith
- Central Veterinary Institute, Animal Sciences Group, Wageningen University, Lelystad, The Netherlands
| | - Jerry M. Wells
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
- * E-mail:
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Zhang J, Yang Y, Teng D, Tian Z, Wang S, Wang J. Expression of plectasin in Pichia pastoris and its characterization as a new antimicrobial peptide against Staphyloccocus and Streptococcus. Protein Expr Purif 2011; 78:189-96. [PMID: 21558006 DOI: 10.1016/j.pep.2011.04.014] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 04/24/2011] [Accepted: 04/25/2011] [Indexed: 01/08/2023]
Abstract
Recombinant plectasin, the first fungus defensin, was expressed in Pichia pastoris and purified, and its physical, chemical and antimicrobial characteristics were studied. Following a 120 h induction of recombinant yeast, the amount of total secreted protein reached 748.63 μg/ml. The percentage of recombinant plectasin was estimated to be 71.79% of the total protein. After purification with a Sephadex G-25 column and RP-HPLC, the identity of plectasin was verified by MALDI-TOF MS. Plectasin exhibited strong antimicrobial activity against the Gram-positive bacteria Staphyloccocusaureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Streptococcus suis. At a concentration of 2560 μg/ml, this peptide showed approximately equal activity against S. aureus, S. epidermidis, S. suis, and S. pneumoniae, when compared to 320 μg/ml vancomycin, 640 μg/ml penicillin, 320 μg/ml vancomycin and 160 μg/ml vancomycin, respectively. In addition, plectasin showed anti-S. aureus activity over a wide pH range of 2.0 and 10.0, a high thermal stability at 100 °C for 1h and remarkable resistance to papain and pepsin. The expression and characterization of recombinant plectasin in P. pastoris has potential to treat Streptococcus and Staphyloccocus infections when most traditional antibiotics show no effect on them. Our results indicate that plectasin can be produced in large quantities, and that it has pharmaceutical importance for the prevention and clinical treatment of Staphyloccocus and Streptococcus infections.
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Papatsiros VG, Vourvidis D, Tzitzis AA, Meichanetsidis PS, Stougiou D, Papaioannou D. Streptococcus suis: an important zoonotic pathogen for human � prevention aspects. Vet World 2011. [DOI: 10.5455/vetworld.2011.216-221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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VirA: A virulence-related gene of Streptococcus suis serotype 2. Microb Pathog 2010; 49:305-10. [DOI: 10.1016/j.micpath.2010.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 06/30/2010] [Accepted: 07/03/2010] [Indexed: 11/21/2022]
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12
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Zhang XH, He KW, Duan ZT, Zhou JM, Yu ZY, Ni YX, Lu CP. Identification and characterization of inosine 5-monophosphate dehydrogenase in Streptococcus suis type 2. Microb Pathog 2009; 47:267-73. [DOI: 10.1016/j.micpath.2009.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 08/31/2009] [Accepted: 09/01/2009] [Indexed: 11/28/2022]
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Jin H, Wan Y, Zhou R, Li L, Luo R, Zhang S, Hu J, Langford PR, Chen H. Identification of genes transcribed byHaemophilus parasuisin necrotic porcine lung through the selective capture of transcribed sequences (SCOTS). Environ Microbiol 2008; 10:3326-36. [DOI: 10.1111/j.1462-2920.2008.01729.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Wu Z, Zhang W, Lu C. Comparative proteome analysis of secreted proteins of Streptococcus suis serotype 9 isolates from diseased and healthy pigs. Microb Pathog 2008; 45:159-66. [PMID: 18554861 DOI: 10.1016/j.micpath.2008.04.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 04/21/2008] [Accepted: 04/29/2008] [Indexed: 11/27/2022]
Abstract
Streptococcus suis is an important swine pathogen responsible for a variety of human diseases. Investigations of virulence factors have focused on S. suis serotype 2 strains (SS2), which are the most invasive isolates worldwide. However, S. suis serotype 9 (SS9) is also a prevalent serotype. Unlike SS2, little is known about virulence factors for SS9. The two strains, GZ0565 and SH040917, were isolated from a diseased pig and a healthy pig, respectively. The virulence of these two SS9 strains was evaluated in zebrafish. The 50% lethal dose value of strain GZ0565 was 3.8x10(5)cfu/fish, while zebrafish injected with strain SH040917 exhibited no mortalities. For revealing proteins probably involved in different pathogenicity, a comparative proteomics approach was used to distinguish between the two-dimensional electrophoresis profiles of secreted proteins in two strains. With the use of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and MALDI-TOF/TOF-MS, protein spots that were unique to strain GZ0565 were identified, and led to the identification of 13 candidate proteins. The largest proportion of these proteins was metabolism-related. Five of the proteins are putative virulence-associated factors: DNA nuclease, o-acetylserine lyase, peptidoglycan-binding LysM, phosphoglycerate mutase, and putative 5'-nucleotidase. These findings contribute to the understanding of SS9 pathogenic mechanisms.
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Affiliation(s)
- Zongfu Wu
- Key Laboratory of Animal Disease Diagnostic and Immunology, Ministry of Agriculture, Nanjing Agricultural University, Weigang 1, Nanjing 210095, Jiangsu, PR China
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Lefébure T, Stanhope MJ. Evolution of the core and pan-genome of Streptococcus: positive selection, recombination, and genome composition. Genome Biol 2007; 8:R71. [PMID: 17475002 PMCID: PMC1929146 DOI: 10.1186/gb-2007-8-5-r71] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 04/24/2007] [Accepted: 05/02/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The genus Streptococcus is one of the most diverse and important human and agricultural pathogens. This study employs comparative evolutionary analyses of 26 Streptococcus genomes to yield an improved understanding of the relative roles of recombination and positive selection in pathogen adaptation to their hosts. RESULTS Streptococcus genomes exhibit extreme levels of evolutionary plasticity, with high levels of gene gain and loss during species and strain evolution. S. agalactiae has a large pan-genome, with little recombination in its core-genome, while S. pyogenes has a smaller pan-genome and much more recombination of its core-genome, perhaps reflecting the greater habitat, and gene pool, diversity for S. agalactiae compared to S. pyogenes. Core-genome recombination was evident in all lineages (18% to 37% of the core-genome judged to be recombinant), while positive selection was mainly observed during species differentiation (from 11% to 34% of the core-genome). Positive selection pressure was unevenly distributed across lineages and biochemical main role categories. S. suis was the lineage with the greatest level of positive selection pressure, the largest number of unique loci selected, and the largest amount of gene gain and loss. CONCLUSION Recombination is an important evolutionary force in shaping Streptococcus genomes, not only in the acquisition of significant portions of the genome as lineage specific loci, but also in facilitating rapid evolution of the core-genome. Positive selection, although undoubtedly a slower process, has nonetheless played an important role in adaptation of the core-genome of different Streptococcus species to different hosts.
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Affiliation(s)
- Tristan Lefébure
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Michael J Stanhope
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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Tang J, Wang C, Feng Y, Yang W, Song H, Chen Z, Yu H, Pan X, Zhou X, Wang H, Wu B, Wang H, Zhao H, Lin Y, Yue J, Wu Z, He X, Gao F, Khan AH, Wang J, Zhao GP, Wang Y, Wang X, Chen Z, Gao GF. Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2. PLoS Med 2006; 3:e151. [PMID: 16584289 PMCID: PMC1434494 DOI: 10.1371/journal.pmed.0030151] [Citation(s) in RCA: 280] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Accepted: 01/10/2006] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Streptococcus suis serotype 2 (S. suis 2, SS2) is a major zoonotic pathogen that causes only sporadic cases of meningitis and sepsis in humans. Most if not all cases of Streptococcal toxic shock syndrome (STSS) that have been well-documented to date were associated with the non-SS2 group A streptococcus (GAS). However, a recent large-scale outbreak of SS2 in Sichuan Province, China, appeared to be caused by more invasive deep-tissue infection with STSS, characterized by acute high fever, vascular collapse, hypotension, shock, and multiple organ failure. METHODS AND FINDINGS We investigated this outbreak of SS2 infections in both human and pigs, which took place from July to August, 2005, through clinical observation and laboratory experiments. Clinical and pathological characterization of the human patients revealed the hallmarks of typical STSS, which to date had only been associated with GAS infection. Retrospectively, we found that this outbreak was very similar to an earlier outbreak in Jiangsu Province, China, in 1998. We isolated and analyzed 37 bacterial strains from human specimens and eight from pig specimens of the recent outbreak, as well as three human isolates and two pig isolates from the 1998 outbreak we had kept in our laboratory. The bacterial isolates were examined using light microscopy observation, pig infection experiments, multiplex-PCR assay, as well as restriction fragment length polymorphisms (RFLP) and multiple sequence alignment analyses. Multiple lines of evidence confirmed that highly virulent strains of SS2 were the causative agents of both outbreaks. CONCLUSIONS We report, to our knowledge for the first time, two outbreaks of STSS caused by SS2, a non-GAS streptococcus. The 2005 outbreak was associated with 38 deaths out of 204 documented human cases; the 1998 outbreak with 14 deaths out of 25 reported human cases. Most of the fatal cases were characterized by STSS; some of them by meningitis or severe septicemia. The molecular mechanisms underlying these human STSS outbreaks in human beings remain unclear and an objective for further study.
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Affiliation(s)
- Jiaqi Tang
- 1Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
- * To whom correspondence should be addressed. E-mail:
(GFG), E-mail:
(JT), E-mail:
(XW), E-mail:
(YW)
| | - Changjun Wang
- 1Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Youjun Feng
- 2Center for Molecular Immunology and State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- 10Graduate School, Chinese Academy of Sciences, Beijing, China
| | - Weizhong Yang
- 3Chinese Center for Disease Control and Prevention (China CDC), Beijing, China
| | - Huaidong Song
- 4State Key Laboratory of Medical Genomics, Ruijin Hospital Affiliated to Medical School of Shanghai Jiao-Tong University, Shanghai, China
- 9Chinese National Human Genome Center, Shanghai, China
| | | | - Hongjie Yu
- 3Chinese Center for Disease Control and Prevention (China CDC), Beijing, China
| | - Xiuzhen Pan
- 1Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Xiaojun Zhou
- 6Department of Pathology, Jinling Hospital of Nanjing, Nanjing, China
| | - Huaru Wang
- 1Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Bo Wu
- 6Department of Pathology, Jinling Hospital of Nanjing, Nanjing, China
| | - Haili Wang
- 1Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Huamei Zhao
- 1Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Ying Lin
- 7School of Biosciences and Bioengineering, South China University of Technology, Guangzhou, China
| | - Jianhua Yue
- 1Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Zhenqiang Wu
- 7School of Biosciences and Bioengineering, South China University of Technology, Guangzhou, China
| | - Xiaowei He
- 7School of Biosciences and Bioengineering, South China University of Technology, Guangzhou, China
| | - Feng Gao
- 2Center for Molecular Immunology and State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Abdul Hamid Khan
- 2Center for Molecular Immunology and State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- 10Graduate School, Chinese Academy of Sciences, Beijing, China
| | - Jian Wang
- 8Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
| | - Guo-Ping Zhao
- 9Chinese National Human Genome Center, Shanghai, China
| | - Yu Wang
- 3Chinese Center for Disease Control and Prevention (China CDC), Beijing, China
- * To whom correspondence should be addressed. E-mail:
(GFG), E-mail:
(JT), E-mail:
(XW), E-mail:
(YW)
| | - Xiaoning Wang
- 7School of Biosciences and Bioengineering, South China University of Technology, Guangzhou, China
- * To whom correspondence should be addressed. E-mail:
(GFG), E-mail:
(JT), E-mail:
(XW), E-mail:
(YW)
| | - Zhu Chen
- 4State Key Laboratory of Medical Genomics, Ruijin Hospital Affiliated to Medical School of Shanghai Jiao-Tong University, Shanghai, China
- 9Chinese National Human Genome Center, Shanghai, China
| | - George F Gao
- 2Center for Molecular Immunology and State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- * To whom correspondence should be addressed. E-mail:
(GFG), E-mail:
(JT), E-mail:
(XW), E-mail:
(YW)
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Rediers H, Rainey PB, Vanderleyden J, De Mot R. Unraveling the secret lives of bacteria: use of in vivo expression technology and differential fluorescence induction promoter traps as tools for exploring niche-specific gene expression. Microbiol Mol Biol Rev 2005; 69:217-61. [PMID: 15944455 PMCID: PMC1197422 DOI: 10.1128/mmbr.69.2.217-261.2005] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A major challenge for microbiologists is to elucidate the strategies deployed by microorganisms to adapt to and thrive in highly complex and dynamic environments. In vitro studies, including those monitoring genomewide changes, have proven their value, but they can, at best, mimic only a subset of the ensemble of abiotic and biotic stimuli that microorganisms experience in their natural habitats. The widely used gene-to-phenotype approach involves the identification of altered niche-related phenotypes on the basis of gene inactivation. However, many traits contributing to ecological performance that, upon inactivation, result in only subtle or difficult to score phenotypic changes are likely to be overlooked by this otherwise powerful approach. Based on the premise that many, if not most, of the corresponding genes will be induced or upregulated in the environment under study, ecologically significant genes can alternatively be traced using the promoter trap techniques differential fluorescence induction and in vivo expression technology (IVET). The potential and limitations are discussed for the different IVET selection strategies and system-specific variants thereof. Based on a compendium of genes that have emerged from these promoter-trapping studies, several functional groups have been distinguished, and their physiological relevance is illustrated with follow-up studies of selected genes. In addition to confirming results from largely complementary approaches such as signature-tagged mutagenesis, some unexpected parallels as well as distinguishing features of microbial phenotypic acclimation in diverse environmental niches have surfaced. On the other hand, by the identification of a large proportion of genes with unknown function, these promoter-trapping studies underscore how little we know about the secret lives of bacteria and other microorganisms.
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Affiliation(s)
- Hans Rediers
- Centre of Microbial and Plant Genetics, Heverlee, Belgium
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Tian Y, Aarestrup FM, Lu CP. Characterization of Streptococcus suis serotype 7 isolates from diseased pigs in Denmark. Vet Microbiol 2004; 103:55-62. [PMID: 15381266 DOI: 10.1016/j.vetmic.2004.07.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2004] [Revised: 06/16/2004] [Accepted: 07/01/2004] [Indexed: 11/19/2022]
Abstract
Isolates of Streptococcus suis serotype 7 from diseased pigs in Denmark were characterized by ribotyping, pulsed field gel electrophoresis (PFGE), MIC-determinations and detection of resistance genes. Forty-one different ribotype profiles were found among the 103 isolates and could be divided into two main clusters. No obvious relationship between ribotypes and the clinical origin of the isolates could be observed. Fifty-four isolates, including all 24 isolates belonging to the main ribotype profile were examined by PFGE and 50 different profiles were found. A high frequency of resistance to erythromycin (41%), tetracycline (24%) and streptomycin (28%) was observed. Furthermore, almost all isolates (101) were resistant to sulphamethoxazol. Most isolates were susceptible to ceftiofur, chloramphenicol, florfenicol, penicillin, ciprofloxacin, trimethoprim and trimethoprim + sulphonamides. The tet(M) gene was found among 11 (44%) and the tet(O) gene in six (24%) of 25 tetracycline resistant isolates. The tet(L) and tet(S) genes were not detected in any isolates. The erm(B) gene was detected in 39 (93%) of 42 erythromycin resistant isolates.
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Affiliation(s)
- Y Tian
- The College of Veterinary Medicine, Nanjing Agricultural University, China
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Harel J, Martinez G, Nassar A, Dezfulian H, Labrie SJ, Brousseau R, Moineau S, Gottschalk M. Identification of an inducible bacteriophage in a virulent strain of Streptococcus suis serotype 2. Infect Immun 2003; 71:6104-8. [PMID: 14500539 PMCID: PMC201037 DOI: 10.1128/iai.71.10.6104-6108.2003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus suis infection is considered to be a major problem in the swine industry worldwide. Most virulent Canadian isolates of S. suis serotype 2 do not produce the known virulence markers for this pathogen. PCR-based subtraction hybridization was adapted to isolate unique DNA sequences which were specific to virulent strains of S. suis isolated in Canada. Analysis of some subtracted DNA clones revealed significant homology with bacteriophages of gram-positive bacteria. An inducible phage (named Ss1) was observed in S. suis following the incubation of the virulent strain 89-999 with mitomycin C. Phage Ss1 has a long noncontractile tail and a small isometric nucleocapsid and is a member of the Siphoviridae family. Ss1 phage DNA appears to be present in most Canadian S. suis strains tested in this study, which were isolated from diseased pigs or had proven virulence in mouse or pig models. To our knowledge, this is the first report of the isolation of a phage in S. suis.
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Affiliation(s)
- J Harel
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal C.P. 5000, St-Hyacinthe, Quebec J2S 7C6, Canada .
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de Greeff A, Buys H, Verhaar R, Dijkstra J, van Alphen L, Smith HE. Contribution of fibronectin-binding protein to pathogenesis of Streptococcus suis serotype 2. Infect Immun 2002; 70:1319-25. [PMID: 11854216 PMCID: PMC127759 DOI: 10.1128/iai.70.3.1319-1325.2002] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the present study we investigated the role of the fibronectin (FN)- and fibrinogen (FGN)-binding protein (FBPS) in the pathogenesis of Streptococcus suis serotype 2 in piglets. The complete gene encoding FBPS from S. suis serotype 2 was cloned in Escherichia coli and sequenced. The occurrence of the gene in various serotypes was analyzed by hybridization studies. The FBPS protein was expressed in E. coli and purified, and binding to human FN and FGN was demonstrated. The induction of antibodies in piglets was studied upon infection. An isogenic mutant unable to produce FBPS was constructed, and the levels of virulence of the wild-type and mutant strains were compared in a competitive infection model in young piglets. Organ cultures showed that FBPS was not required for colonization of the tonsils but that FBPS played a role in the colonization of the specific organs involved in an S. suis infection. Therefore, the FBPS mutant was considered as an attenuated mutant.
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Affiliation(s)
- Astrid de Greeff
- Department of Medical Microbiology, University of Amsterdam, The Netherlands.
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