1
|
Guo G, Du D, Yu Y, Zhang Y, Qian Y, Zhang W. Pan-genome analysis of Streptococcus suis serotype 2 revealed genomic diversity among strains of different virulence. Transbound Emerg Dis 2020; 68:637-647. [PMID: 32654396 DOI: 10.1111/tbed.13725] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 06/26/2020] [Accepted: 07/06/2020] [Indexed: 12/13/2022]
Abstract
Streptococcus suis (SS) is an emerging zoonotic pathogen that causes severe infections in swine and humans. Among the 33 known serotypes, serotype 2 is most frequently associated with infections in pigs and humans. To better understand the virulence characterization of S. suis serotype 2 (SS2) and discriminate the difference between virulent and avirulent strains in SS2, characterization of the genomic features of strains with different virulence is required. The result showed that Streptococcus suis have an open pan-genome. The pan-genome shared by the 19 S. suis serotype 2 strains was composed of 1,239 core genes and 2,436 accessory genes. COG analysis indicated that core genes are involved in the basic physiological function, but accessory genes related to tachytely evolution. Comparative analysis between core genomes of virulent strains and 9 avirulent strains suggested that srtBCD pilus cluster was a significant discrepancy between virulent and avirulent strains. Analysis between high virulent and group B low virulent strains showed 53 and 58 genes specific to each other. Moreover, genomes of avirulent strains tend to be larger than virulent strains; avirulent strains tend to possess more prophages sequences than virulent strains. Our findings could be contributed to a better understanding of the genomics of S. suis serotype 2.
Collapse
Affiliation(s)
- Genglin Guo
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Dechao Du
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Yanfei Yu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China.,Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture, Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yuhang Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Yunyun Qian
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Wei Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| |
Collapse
|
2
|
Fang L, Zhou J, Fan P, Yang Y, Shen H, Fang W. A serine/threonine phosphatase 1 of Streptococcus suis type 2 is an important virulence factor. J Vet Sci 2018; 18:439-447. [PMID: 28057904 PMCID: PMC5746436 DOI: 10.4142/jvs.2017.18.4.439] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 09/30/2016] [Accepted: 11/23/2016] [Indexed: 11/20/2022] Open
Abstract
Streptococcus suis is regarded as one of the major pathogens of pigs, and Streptococcus suis type 2 (SS2) is considered a zoonotic bacterium based on its ability to cause meningitis and streptococcal toxic shock-like syndrome in humans. Many bacterial species contain genes encoding serine/threonine protein phosphatases (STPs) responsible for dephosphorylation of their substrates in a single reaction step. This study investigated the role of stp1 in the pathogenesis of SS2. An isogenic stp1 mutant (Δstp1) was constructed from SS2 strain ZJ081101. The Δstp1 mutant exhibited a significant increase in adhesion to HEp-2 and bEnd.3 cells as well as increased survival in RAW264.7 cells, as compared to the parent strain. Increased survival in macrophage cells might be related to resistance to reactive oxygen species since the Δstp1 mutant was more resistant than its parent strain to paraquat-induced oxidative stress. However, compared to parent strain virulence, deletion of stp1 significantly attenuated virulence of SS2 in mice, as shown by the nearly double lethal dose 50 value and the lower bacterial load in organs and blood in the murine model. We conclude that Stp1 has an essential role in SS2 virulence.
Collapse
Affiliation(s)
- Lihua Fang
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China.,Center for Synthetic Biology Engineering Research, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jingjing Zhou
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| | - Pengcheng Fan
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| | - Yunkai Yang
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| | - Hongxia Shen
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| | - Weihuan Fang
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China
| |
Collapse
|
3
|
Jiang X, Yang Y, Zhu L, Gu Y, Shen H, Shan Y, Li X, Wu J, Fang W. Live Streptococcus suis type 5 strain XS045 provides cross-protection against infection by strains of types 2 and 9. Vaccine 2016; 34:6529-6538. [PMID: 27349838 DOI: 10.1016/j.vaccine.2016.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/26/2016] [Accepted: 05/02/2016] [Indexed: 11/27/2022]
Abstract
Streptococcus suis is one of the common pathogens causing diseases in pigs and covers 35 serotypes with the type 2 strains being more pathogenic and zoonotic. Existing inactivated or subunit vaccines, in clinical use or under trial, could not provide cross protection against other serotypes. We identified a natural low-virulence S. suis type 5 strain XS045 as a live vaccine candidate because it is highly adhesive to the cultured HEp-2 cells, but with no apparent pathogenicity in mice and piglets. We further demonstrate that subcutaneous administration of the live XS045 strain to mice induced high antibody responses and was able to provide cross protection against challenges by a type 2 strain HA9801 (100% protection) and a type 9 strain JX13 (85% protection). Induction of high-titer antibodies with opsonizing activity as well as their cross-reactivity to surface proteins of the types 2 and 9 strains and anti-adhesion effect could be the mechanisms of cross protection. This is the first report that a live vaccine candidate S. suis type 5 strain could induce cross-protection against strains of types 2 and 9. This candidate strain is to be further examined for safety in pigs of different ages and breeds as well as for its protection against other serotypes or other strains of the type 2, a serotype of particular importance from public health concern.
Collapse
Affiliation(s)
- Xiaowu Jiang
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Yunkai Yang
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Lexin Zhu
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Yuanxing Gu
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Hongxia Shen
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Ying Shan
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Xiaoliang Li
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Jiusheng Wu
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China
| | - Weihuan Fang
- Zhejiang University, Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.
| |
Collapse
|
4
|
Sánchez del Rey V, Fernández-Garayzábal JF, Domínguez L, Gottschalk M, Vela AI. Screening of virulence-associated genes as a molecular typing method for characterization of Streptococcus suis isolates recovered from wild boars and pigs. Vet J 2015; 209:108-12. [PMID: 26831161 DOI: 10.1016/j.tvjl.2015.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 11/24/2022]
Abstract
Streptococcus suis is an important zoonotic pathogen associated with a wide range of diseases in pigs, but has also been isolated from wild animals such as rabbits and wild boars. In the current study, 126 S. suis isolates recovered from pigs (n = 85) and wild boars (n = 41) were tested by polymerase chain reaction (PCR) for the presence of nine virulence-associated genes. S. suis isolates from wild boars were differentiated by the lower detection rates of the epf, sly, mrp, sao and dltA genes (0%, 2.4%, 2.4%, 4.8% and 21.9%, respectively) compared with the isolates from pigs (56.5%, 75.3%, 56.5%, 88.2.0% and 88.2%, respectively). The differences in the content of these virulence-associated genes were statistically significant (P < 0.05). There was a correlation between the variants saoM and saoL and serotypes 2 and 9, respectively (P < 0.05). Isolates were classified into 31 virulence-associated gene profiles (VPs). Ten VPs were detected among wild boar isolates and 22 VPs among pig isolates, with only two VPs common to wild boars and pigs. The predominant VPs among isolates from wild boars (VP1, VP7) were different from those observed in pig isolates (VP16 and VP26). VP16 was detected exclusively in clinical pig isolates of serotype 9 and VP26 was detected in 71.4% of the serotype 2 clinical pig isolates. Further multilocus sequence typing (MLST) analysis showed a significant correlation association between certain VPs and STs (VP16 and VP17 with ST123 and ST125 and VP26 with ST1). In conclusion, the current study showed that combination of virulence-associated gene profiling and MLST analysis may provide more information of the relatedness of the S. suis strains from different animal species that could be useful for epidemiological purposes.
Collapse
Affiliation(s)
- Verónica Sánchez del Rey
- Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, 28040 Madrid, Spain
| | - José F Fernández-Garayzábal
- Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, 28040 Madrid, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain
| | - Lucas Domínguez
- Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, 28040 Madrid, Spain
| | - Marcelo Gottschalk
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine, Vétérinaire, Université de Montréal, 3200 Sicotte, St.-Hyacinthe, Québec, J2S 2M2, Canada
| | - Ana I Vela
- Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, 28040 Madrid, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain.
| |
Collapse
|
5
|
Complex Population Structure and Virulence Differences among Serotype 2 Streptococcus suis Strains Belonging to Sequence Type 28. PLoS One 2015; 10:e0137760. [PMID: 26375680 PMCID: PMC4574206 DOI: 10.1371/journal.pone.0137760] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 08/21/2015] [Indexed: 11/19/2022] Open
Abstract
Streptococcus suis is a major swine pathogen and a zoonotic agent. Serotype 2 strains are the most frequently associated with disease. However, not all serotype 2 lineages are considered virulent. Indeed, sequence type (ST) 28 serotype 2 S. suis strains have been described as a homogeneous group of low virulence. However, ST28 strains are often isolated from diseased swine in some countries, and at least four human ST28 cases have been reported. Here, we used whole-genome sequencing and animal infection models to test the hypothesis that the ST28 lineage comprises strains of different genetic backgrounds and different virulence. We used 50 S. suis ST28 strains isolated in Canada, the United States and Japan from diseased pigs, and one ST28 strain from a human case isolated in Thailand. We report a complex population structure among the 51 ST28 strains. Diversity resulted from variable gene content, recombination events and numerous genome-wide polymorphisms not attributable to recombination. Phylogenetic analysis using core genome single-nucleotide polymorphisms revealed four discrete clades with strong geographic structure, and a fifth clade formed by US, Thai and Japanese strains. When tested in experimental animal models, strains from this latter clade were significantly more virulent than a Canadian ST28 reference strain, and a closely related Canadian strain. Our results highlight the limitations of MLST for both phylogenetic analysis and virulence prediction and raise concerns about the possible emergence of ST28 strains in human clinical cases.
Collapse
|
6
|
Fang L, Shen H, Tang Y, Fang W. Superoxide dismutase of Streptococcus suis serotype 2 plays a role in anti-autophagic response by scavenging reactive oxygen species in infected macrophages. Vet Microbiol 2015; 176:328-36. [PMID: 25726301 DOI: 10.1016/j.vetmic.2015.02.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/04/2015] [Accepted: 02/05/2015] [Indexed: 01/08/2023]
Abstract
Streptococcus suis serotype 2 (SS2) causes septic shock and meningitis. However, its pathogenesis is still not well-understood. We have recently shown that superoxide dismutase sodA of SS2 is a virulence factor probably by increasing resistance to oxidative stresses. Reactive oxygen species (ROS) are products of the respiratory burst of phagocytic cells and have been shown to activate autophagy. We wanted to know if and how SS2 explores its sodA to interfere with cell autophagic responses. A sodA deletion mutant (Δsod) was compared with its parent and complemented strain in autophagic response in the murine macrophage cell line RAW264.7. We found that the Δsod mutant induced significant autophagic responses in infected cells, shown as increased LC3 lipidation (LC3-II) and EGFP-LC3 punctae, than those infected by its parent or complemented strain at 1 or 2h post-infection. Co-localization of the autophagosomal EGFP-LC3 vesicles with lysosomes was seen in cells infected with Δsod mutant and its parent strain, indicating that SS2 infection induced complete autophagic responses. Reduced autophagic responses of cells infected with the wild-type strain might be related to decreased ROS by the scavenging effect of its sodA, as shown by increased superoxide anion or ROS level in cells infected with the Δsod mutant and in the cell free xanthine oxidase-hypoxanthine ROS-generating system, as compared with its parent or complemented strain. Taken together, SS2 makes use of its sodA for survival not only by scavenging ROS but also by alleviating the host autophagic responses due to ROS stimulation.
Collapse
Affiliation(s)
- Lihua Fang
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Hongxia Shen
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yulong Tang
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China
| | - Weihuan Fang
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China.
| |
Collapse
|
7
|
Streptococcus suis, an important pig pathogen and emerging zoonotic agent-an update on the worldwide distribution based on serotyping and sequence typing. Emerg Microbes Infect 2014; 3:e45. [PMID: 26038745 PMCID: PMC4078792 DOI: 10.1038/emi.2014.45] [Citation(s) in RCA: 447] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 12/18/2022]
Abstract
Streptococcus suis is an important pathogen causing economic problems in the pig
industry. Moreover, it is a zoonotic agent causing severe infections to people in close
contact with infected pigs or pork-derived products. Although considered sporadic in the
past, human S. suis infections have been reported during the last 45 years, with
two large outbreaks recorded in China. In fact, the number of reported human cases has
significantly increased in recent years. In this review, we present the worldwide
distribution of serotypes and sequence types (STs), as determined by multilocus sequence
typing, for pigs (between 2002 and 2013) and humans (between 1968 and 2013). The methods
employed for S. suis identification and typing, the current epidemiological
knowledge regarding serotypes and STs and the zoonotic potential of S. suis are
discussed. Increased awareness of S. suis in both human and veterinary diagnostic
laboratories and further establishment of typing methods will contribute to our knowledge
of this pathogen, especially in regions where complete and/or recent data is lacking. More
research is required to understand differences in virulence that occur among S.
suis strains and if these differences can be associated with specific serotypes or
STs.
Collapse
|
8
|
Tang Y, Zhang X, Yin Y, Hardwidge PR, Fang W. Streptococcus suis type 2 SSU0587 protein is a beta-galactosidase that contributes to bacterial adhesion but not to virulence in mice. J Vet Med Sci 2014; 76:1055-9. [PMID: 24670993 PMCID: PMC4143649 DOI: 10.1292/jvms.13-0625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Bacterial surface proteins play key roles in virulence and often contribute to bacterial adhesion and invasion. We discovered that the Streptococcus suis type 2 (SS2) gene SSU0587 encodes a protein of 1,491 amino acids that possesses β-galactosidase activity. The surface association of the protein was dependent upon sortase activity. Deleting SSU0587 from clinical SS2 isolate JX081101 caused a loss of both β-galactosidase activity and adherence to microvascular endothelial cells. Deleting SSU0587 had no measurable impact on either invasion of microvascular endothelial cells or on virulence in a murine infection model, although the concentration of JX081101ΔSSU0587 was reduced in the brains of infected mice, as compared with the pathogen loads of the wild-type strain.
Collapse
Affiliation(s)
- Yulong Tang
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Research Center of Healthy Breeding Livestock & Poultry, Hunan Engineering & Research Center of Animal & Poultry Science, Key Lab Agro-ecology Processing Subtropical Region, Scientific Observational and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Changsha, Hunan, People's Republic of China
| | | | | | | | | |
Collapse
|
9
|
Tang Y, Wu W, Zhang X, Lu Z, Chen J, Fang W. Catabolite control protein A of Streptococcus suis type 2 contributes to sugar metabolism and virulence. J Microbiol 2012; 50:994-1002. [PMID: 23274986 DOI: 10.1007/s12275-012-2035-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
Abstract
Catabolite control protein A (CcpA) is the major transcriptional regulator in carbon catabolite repression in several Gram-positive bacteria. We attempted to characterize the role of a CcpA homologue of Streptococcus suis type 2 in sugar metabolism and virulence. Addition of glucose or sucrose to the defined medium significantly reduced the activity of raffinose-inducible α-galactosidase, cellobiose-inducible β-glucosidase, and maltose-inducible α-glucosidase of the wild-type strain by about 9, 4, and 2-3 fold, respectively. Deletion of ccpA substantially derepressed the effects of repressing sugars on α-galactosidase or β-glucosidase activity. The ccpA deletion mutant showed reduced expression of virulence genes sly and eno (P<0.05), decreased adhesion to and invasion into endothelial cells (P<0.05), and attenuated virulence to mice with significant reduction of death rate and bacterial burden in organs, as compared to the wild-type strain. Both the in vitro and in vivo defect phenotypes were reversible by ccpA complementation. Thus, this study shows that CcpA of S. suis type 2 plays an important role in carbon catabolite repression and virulence.
Collapse
Affiliation(s)
- Yulong Tang
- Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | | | | | | | | | | |
Collapse
|
10
|
Chen L, Song Y, Wei Z, He H, Zhang A, Jin M. Antimicrobial susceptibility, tetracycline and erythromycin resistance genes, and multilocus sequence typing of Streptococcus suis isolates from diseased pigs in China. J Vet Med Sci 2012; 75:583-7. [PMID: 23292102 DOI: 10.1292/jvms.12-0279] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Streptococcus suis (S. suis) is an emerging zoonotic pathogen causing significant economic losses in the swine industry. Here, we investigated the antimicrobial susceptibility, associated antibiotic-resistant determinants and sequence type (ST) of S. suis isolates from diseased pigs in China from 2008 to 2010. Serotype 2 was the most frequently observed strain (n=95) among the 106 S. suis strains collected, followed by serotypes 3 (n=3), 5 (n=3), 4 (n=2), 7 (n=1), 11 (n=1) and 28 (n=1). Multilocus sequence typing analysis revealed that ST1 (n=21) and ST7 (n=74) were the predominant STs, and serotype 2 was found to be significantly correlated with ST7 (P=0.017, Fisher's exact test) and CC1 (P=0.024, Fisher's exact test). The antimicrobial susceptibility results indicated that the antibiotic resistance rate was highest for tetracycline (99.1%), followed by azithromycin (68.9%), erythromycin (67.9%), clindamycin (67.9%), trimethoprim/sulfamethoxazole (16%), levofloxacin (2.8%), chloramphenicol (1.9%), cefaclor (0.9%) and ceftriaxone (0.9%). Antibiotic-resistant genes tet(M), tet(O), tet(O/W/32/O), tet(O/32/O), tet(S), tet(W), tet(L), tet(40), erm(B), mef(A/E) and msr(D) could be detected, and several tandem organizations of antibiotic resistance genes were also found in this study. In conclusion, S. suis strains isolated from diseased pigs in China were less diverse and multi-drug resistant.
Collapse
Affiliation(s)
- Lei Chen
- Unit of Animal Infectious Diseases, National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430000, China
| | | | | | | | | | | |
Collapse
|
11
|
Wang K, Zhang W, Li X, Lu C, Chen J, Fan W, Huang B. Characterization of Streptococcus suis Isolates from Slaughter Swine. Curr Microbiol 2012; 66:344-9. [DOI: 10.1007/s00284-012-0275-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 11/13/2012] [Indexed: 12/01/2022]
|
12
|
Onishi H, Sugawara M, Okura M, Osaki M, Takamatsu D. Prevalence of Streptococcus suis genotypes in isolates from porcine endocarditis in East Japan. J Vet Med Sci 2012; 74:1681-4. [PMID: 22878504 DOI: 10.1292/jvms.12-0301] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Streptococcus suis is an important pathogen for both swine and humans. In this study, we genotyped 105 S. suis isolates from porcine endocarditis in East Japan on the basis of profiles of capsular serotype-specific, virulence-associated and pilus-associated genes. The most common genotype was cps2J/mrp+/epf-/sly-/sbp2-/sep1-/sgp1+ (76.19%), followed by nt(non-typeable)/mrp+/epf-/sly-/sbp2-/sep1-/sgp1+ (7.62%) and cps2J/mrp+/epf+/sly+/sbp2+/sep1-/sgp1- (7.62%). The representative isolates of mrp+/epf-/sly-/sbp2-/sep1-/sgp1+ were classified into ST28 complex, a clonal complex previously referred to as ST27 complex, whereas those of mrp+/epf+/sly+/sbp2+/sep1-/sgp1- were classified into ST1 complex by multilocus sequence typing. Because the majority of human clinical isolates were assigned to ST1 and ST28 complexes, most isolates from porcine endocarditis investigated in this study may have the potential to cause S. suis infection in humans.
Collapse
Affiliation(s)
- Hidetaka Onishi
- Fukushima Prefectural Kenchu Livestock Hygiene Service Center, 2 Mansuida, Koriyama, Fukushima 963-8041, Japan
| | | | | | | | | |
Collapse
|
13
|
Inactivation of the sodA gene of Streptococcus suis type 2 encoding superoxide dismutase leads to reduced virulence to mice. Vet Microbiol 2012; 158:360-6. [DOI: 10.1016/j.vetmic.2012.02.028] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 02/19/2012] [Accepted: 02/20/2012] [Indexed: 12/23/2022]
|