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Kobayashi K, Kubota H, Tohya M, Ushikubo M, Yamamoto M, Ariyoshi T, Uchitani Y, Mitobe M, Okuno R, Nakagawa I, Sekizaki T, Suzuki J, Sadamasu K. Characterization of pig tonsils as niches for the generation of Streptococcus suis diversity. Vet Res 2024; 55:17. [PMID: 38321502 PMCID: PMC10848530 DOI: 10.1186/s13567-024-01270-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/12/2024] [Indexed: 02/08/2024] Open
Abstract
Streptococcus suis is a gram-positive bacterium that causes meningitis, septicemia, endocarditis, and other disorders in pigs and humans. We obtained 42 and 50 S. suis isolates from lesions of porcine endocarditis and palatine tonsils, respectively, of clinically healthy pigs in Japan; we then determined their sequence types (STs) by multilocus sequence typing (MLST), cps genotypes, serotypes, and presence of classical major virulence-associated marker genes (mrp, epf, and sly). The 42 isolates from endocarditis lesions were assigned to a limited number of STs and clonal complexes (CCs). On the other hand, the 50 isolates from tonsils were diverse in these traits and seemingly in the degree of virulence, suggesting that tonsils can accommodate a variety of S. suis isolates. The goeBURST full algorithm using tonsil isolates obtained in this study and those retrieved from the database showed that major CCs as well as many other clusters were composed of isolates originating from different countries, and some of the STs were very similar to each other despite the difference in country of origin. These findings indicate that S. suis with not only different but also similar mutations in the genome have survived in tonsils independently across different geographical locations. Therefore, unlike the lesions of endocarditis, the tonsils of pigs seemingly accommodate various S. suis lineages. The present study suggests that S. suis acquired its diversity by natural mutations during colonization and persistence in the tonsils of pigs.
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Affiliation(s)
- Kai Kobayashi
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan.
| | - Hiroaki Kubota
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan
| | - Mari Tohya
- Division of Biomedical Food Research, National Institute of Health Sciences, Tonomachi 3-25-26, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan
- Department of Microbiology and Department of Microbiome Research, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Megumi Ushikubo
- Shibaura Meat Sanitary Inspection Station, Tokyo Metropolitan Government, Konan 2-7-19, Minato-ku, Tokyo, 108-0075, Japan
| | - Miki Yamamoto
- Shibaura Meat Sanitary Inspection Station, Tokyo Metropolitan Government, Konan 2-7-19, Minato-ku, Tokyo, 108-0075, Japan
| | - Tsukasa Ariyoshi
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan
| | - Yumi Uchitani
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan
| | - Morika Mitobe
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan
| | - Rumi Okuno
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan
| | - Ichiro Nakagawa
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Tsutomu Sekizaki
- Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Jun Suzuki
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan
| | - Kenji Sadamasu
- Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunincho 3-24-1, Shinjuku-ku, Tokyo, 169-0073, Japan
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Wang S, Ma M, Liang Z, Zhu X, Yao H, Wang L, Wu Z. Pathogenic investigations of Streptococcus pasteurianus, an underreported zoonotic pathogen, isolated from a diseased piglet with meningitis. Transbound Emerg Dis 2022; 69:2609-2620. [PMID: 34871467 DOI: 10.1111/tbed.14413] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/28/2021] [Accepted: 11/28/2021] [Indexed: 01/14/2023]
Abstract
Streptococcus pasteurianus, an underreported opportunistic pathogen, is considered an increasingly recognized cause of meningitis and bacteremia in many animals and humans worldwide. However, except for some epidemiological studies, there is no report about the gene-deletion mutagenesis, virulence factors, reservoir niches or animal infection models for this pathogen. In this study, we first isolated an S. pasteurianus strain from a newly weaned piglet's brain with meningitis. The genomic sequence of this swine isolate WUSP067 shared high homology with that of two human strains. The comparative genome analysis showed that strain WUSP067 contained a fucose utilization cluster absent in human strains, and it shared 91% identity with that of an integrative and conjugative element (ICE) ICEssuZJ20091101-2 from Streptococcus suis, another important swine bacterial pathogen. Strain WUSP067 was resistant to erythromycin, tulathromycin, lincomycin, clindamycin, doxycycline and gentamycin, and ICEs are vehicles for harbouring antimicrobial resistance genes. The infection model was established using the 3-week-old newly weaned ICR mice. The 50% lethal dose value of strain WUSP067 was 4.0 × 107 colony-forming units per mouse. The infected mice showed severe signs of meningitis and pathological changes in brains. Furthermore, the capsule-deficient mutant was generated using natural transformation, and we showed that capsule was an essential virulence factor for S. pasteurianus. In addition, we found that tonsils and hilar lymph nodes of healthy pigs may be reservoir niches for this bacterium. Thus, our study provided valuable information about the pathogenetic characteristics and antimicrobial resistance of S. pasteurianus and paved the way for studying its pathogenesis.
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Affiliation(s)
- Shuoyue Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, 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
| | - Miaohang Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, 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
| | - Zijing Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, 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
| | - Xinchi Zhu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, 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
| | - Huochun Yao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, 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
| | - Liping Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, 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
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3
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Henriet SSV, Langereis JD, Lo SW, Bentley S, Mesman RJ, Fejzic Z, van Niftrik L, van Sorge NM, Wertheim HFL, de Jonge MI, Cremers AJH. Endocarditis caused by non-typeable Streptococcus pneumoniae. Clin Infect Dis 2022; 75:719-722. [PMID: 35134152 PMCID: PMC9464071 DOI: 10.1093/cid/ciac079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Indexed: 11/15/2022] Open
Abstract
The Streptococcus pneumoniae capsule is regarded as indispensable in bacteremia. We report an infant with a ventricular septal defect and infective endocarditis caused by nontypeable S. pneumoniae. In-depth investigation confirmed a deficient capsule yet favored pneumococcal fitness for causing infective endocarditis, rather than a host immune disorder, as the cause of infective endocarditis in this case.
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Affiliation(s)
- Stefanie S V Henriet
- Department of Pediatric Infectious Diseases and Immunology, Amalia Children's Hospital, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jeroen D Langereis
- Laboratory of Medical Immunology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Stephanie W Lo
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, UK
| | - Stephen Bentley
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, UK
| | - Rob J Mesman
- Department of Microbiology, Institute for Water and Wetland Research, Faculty of Science, Radboud University, Nijmegen, the Netherlands
| | - Zina Fejzic
- Department of Pediatric Cardiology, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura van Niftrik
- Department of Microbiology, Institute for Water and Wetland Research, Faculty of Science, Radboud University, Nijmegen, the Netherlands
| | - Nina M van Sorge
- Department of Medical Microbiology and Infection Prevention and Netherlands Reference Laboratory for Bacterial Meningitis, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Heiman F L Wertheim
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Marien I de Jonge
- Laboratory of Medical Immunology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Amelieke J H Cremers
- Department of Medical Microbiology, Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
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Aradanas M, Poljak Z, Fittipaldi N, Ricker N, Farzan A. Serotypes, Virulence-Associated Factors, and Antimicrobial Resistance of Streptococcus suis Isolates Recovered From Sick and Healthy Pigs Determined by Whole-Genome Sequencing. Front Vet Sci 2021; 8:742345. [PMID: 34796225 PMCID: PMC8593187 DOI: 10.3389/fvets.2021.742345] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/23/2021] [Indexed: 11/20/2022] Open
Abstract
Streptococcus suis is ubiquitous in swine, and yet, only a small percentage of pigs become clinically ill. The objective of this study was to describe the distribution of serotypes, virulence-associated factor (VAF), and antimicrobial resistance (AMR) genes in S. suis isolates recovered from systemic (blood, meninges, spleen, and lymph node) and non-systemic (tonsil, nasal cavities, ileum, and rectum) sites of sick and healthy pigs using whole-genome sequencing. In total, 273 S. suis isolates recovered from 112 pigs (47 isolates from systemic and 136 from non-systemic sites of 65 sick pigs; 90 isolates from non-systemic sites of 47 healthy pigs) on 17 Ontario farms were subjected to whole-genome sequencing. Using in silico typing, 21 serotypes were identified with serotypes 9 (13.9%) and 2 (8.4%) as the most frequent serotypes, whereas 53 (19.4%) isolates remained untypable. The relative frequency of VAF genes in isolates from systemic (Kruskal–Wallis, p < 0.001) and non-systemic (Kruskal–Wallis, p < 0.001) sites in sick pigs was higher compared with isolates from non-systemic sites in healthy pigs. Although many VAF genes were abundant in all isolates, three genes, including dltA [Fisher's test (FT), p < 0.001], luxS (FT, p = 0.01), and troA (FT, p = 0.02), were more prevalent in isolates recovered from systemic sites compared with non-systemic sites of pigs. Among the isolates, 98% had at least one AMR gene, and 79% had genes associated with at least four drug classes. The most frequently detected AMR genes were tetO conferring resistance to tetracycline and ermB conferring resistance to macrolide, lincosamide, and streptogramin. The wide distribution of VAFs genes in S. suis isolates in this study suggests that other host and environmental factors may contribute to S. suis disease development.
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Affiliation(s)
- Maverick Aradanas
- Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Zvonimir Poljak
- Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Nahuel Fittipaldi
- Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Nicole Ricker
- Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Abdolvahab Farzan
- Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.,Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
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5
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Tohya M, Dozaki S, Ishida-Kuroki K, Watanabe T, Sekizaki T. Basis of the persistence of capsule-negative Streptococcus suis in porcine endocarditis inferred from comparative genomics. FEMS Microbiol Lett 2021; 368:6315327. [PMID: 34223887 DOI: 10.1093/femsle/fnab083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 07/01/2021] [Indexed: 11/14/2022] Open
Abstract
The capsule (cap) of Streptococcus suis is an anti-phagocytic element and is one of the major virulence factors. However, we have found cap-positive and cap-negative isolates in porcine endocarditis. Here, we compared genome sequences of multiple cap-negative isolates with those of a cap-positive isolate from a single endocarditis. Cap-positive and cap-negative isolates from the same pig were phylogenetically closest compared with those from other pigs. Some of cap-negative isolates from the same pig showed different mutations in capsular polysaccharide synthesis (cps) genes, suggesting that these isolates arisen in pigs after infection. Different mutations in whole-genomes were also found among isolates with identical mutations in cps genes, indicating that mutations in cps genes and the whole-genome occurred independently. Since cap-negative isolates are rarely found in lesions of other diseases, these results suggest that endocarditis lesions may simply favored cap-negative mutants to survive the niches, leading to their persistence in the lesions.
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Affiliation(s)
- Mari Tohya
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.,Department of Microbiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Shinichi Dozaki
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kasumi Ishida-Kuroki
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.,Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Aoba-cho 4-2-1, Higashimurayama, Tokyo, 189-0002, Japan
| | - Takayasu Watanabe
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.,Department of Chemistry, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Tsutomu Sekizaki
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.,Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
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6
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Pei X, Liu M, Zhou H, Fan H. Screening for phagocytosis resistance-related genes via a transposon mutant library of Streptococcus suis serotype 2. Virulence 2021; 11:825-838. [PMID: 32614642 PMCID: PMC7567436 DOI: 10.1080/21505594.2020.1782088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Streptococcus suis serotype 2 (SS2) is a serious zoonotic pathogen which causes symptoms of streptococcal toxic shock syndrome (STSS) and septicemia; these symptoms suggest that SS2 may have evade innate immunity. Phagocytosis is an important innate immunity process where phagocytosed pathogens are killed by lysosome enzymes, reactive oxygen, and nitrogen species, and acidic environments in macrophages following engulfment. A previously constructed mutant SS2 library was screened, revealing 13 mutant strains with decreased phagocytic resistance. Through inverse PCR, the transposon insertion sites were determined. Through bioinformatic analysis, the 13 disrupted genes were identified as Cps2F, 3 genes belonging to ABC transporters, WalR, TehB, rpiA, S-transferase encoding gene, prs, HsdM, GNAT family N-acetyltransferase encoding gene, proB, and upstream region of DnaK. Except for the capsular polysaccharide biosynthesis associated Cps2F, the other genes had not been linked to a role in anti-phagocytosis. The survival ability in macrophages and whole blood of randomly picked mutant strains were significantly impaired compared with wild-type ZY05719. The virulence of the mutant strains was also attenuated in a mouse infection model. In the WalR mutant, the transcription of HP1065 decreased significantly compared with wild-type strain, indicating WalR might regulated HP1065 expression and contribute to the anti-phagocytosis of SS2. In conclusion, we identified 13 genes that influenced the phagocytosis resistant ability of SS2, and many of these genes have not been reported to be associated with resistance to phagocytosis. Our work provides novel insight into resistance to phagocytosis, and furthers our understanding of the pathogenesis mechanism of SS2.
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Affiliation(s)
- Xiaomeng Pei
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing, China
| | - Mingxing Liu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing, China
| | - Hong Zhou
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing, China
| | - Hongjie Fan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing, China.,Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University , Yangzhou, China
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7
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Auger JP, Payen S, Roy D, Dumesnil A, Segura M, Gottschalk M. Interactions of Streptococcus suis serotype 9 with host cells and role of the capsular polysaccharide: Comparison with serotypes 2 and 14. PLoS One 2019; 14:e0223864. [PMID: 31600314 PMCID: PMC6786723 DOI: 10.1371/journal.pone.0223864] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/30/2019] [Indexed: 12/21/2022] Open
Abstract
Streptococcus suis is an important porcine bacterial pathogen and a zoonotic agent responsible for sudden death, septic shock and meningitis, of which serotype 2 is the most widespread, with serotype 14 also causing infections in humans in South-East Asia. Knowledge of its pathogenesis and virulence are almost exclusively based on these two serotypes. Though serotype 9 is responsible for the greatest number of porcine cases in Spain, the Netherlands and Germany, very little information is currently available regarding this serotype. Of the different virulence factors, the capsular polysaccharide (CPS) is required for S. suis virulence as it promotes resistance to phagocytosis and killing and masks surface components responsible for host cell activation. However, these roles have been described for serotypes 2 and 14, whose CPSs are structurally and compositionally similar, both containing sialic acid. Consequently, we evaluated herein the interactions of serotype 9 with host cells and the role of its CPS, which greatly differs from those of serotypes 2 and 14. Results demonstrated that serotype 9 adhesion to but not invasion of respiratory epithelial cells was greater than that of serotypes 2 and 14. Furthermore serotype 9 was more internalized by macrophages but equally resistant to whole blood killing. Though recognition of serotypes 2, 9 and 14 by DCs required MyD88-dependent signaling, in vitro pro-inflammatory mediator production induced by serotype 9 was much lower. In vivo, however, serotype 9 causes an exacerbated inflammatory response, which combined with persistent bacterial presence, is probably responsible for host death during the systemic infection. Though presence of the serotype 9 CPS masks surface components less efficiently than those of serotypes 2 and 14, the serotype 9 CPS remains critical for virulence as it is required for survival in blood and development of clinical disease, and this regardless of its unique composition and structure.
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Affiliation(s)
- Jean-Philippe Auger
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - Servane Payen
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - David Roy
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - Audrey Dumesnil
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - Mariela Segura
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - Marcelo Gottschalk
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Center (CRIPA), Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
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8
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Zhou Y, Nie R, Liu X, Kong J, Wang X, Li J. GntR is involved in the expression of virulence in strain Streptococcus suis P1/7. FEMS Microbiol Lett 2018; 365:4964750. [DOI: 10.1093/femsle/fny091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/06/2018] [Indexed: 12/16/2022] Open
Affiliation(s)
- Ying Zhou
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China
| | - Ruonan Nie
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China
| | - Xiaoyue Liu
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China
| | - Jinghui Kong
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China
| | - Xiaohong Wang
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China
| | - Jinquan Li
- Key Laboratory of Environment Correlative Dietology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, People's Republic of China
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9
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Roy D, Takamatsu D, Okura M, Goyette-Desjardins G, Van Calsteren MR, Dumesnil A, Gottschalk M, Segura M. Capsular Sialyltransferase Specificity Mediates Different Phenotypes in Streptococcus suis and Group B Streptococcus. Front Microbiol 2018; 9:545. [PMID: 29666608 PMCID: PMC5891629 DOI: 10.3389/fmicb.2018.00545] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/09/2018] [Indexed: 01/04/2023] Open
Abstract
The capsular polysaccharide (CPS) represents a key virulence factor for most encapsulated streptococci. Streptococcus suis and Group B Streptococcus (GBS) are both well-encapsulated pathogens of clinical importance in veterinary and/or human medicine and responsible for invasive systemic diseases. S. suis and GBS are the only Gram-positive bacteria which express a sialylated CPS at their surface. An important difference between these two sialylated CPSs is the linkage between the side-chain terminal galactose and sialic acid, being α-2,6 for S. suis but α-2,3 for GBS. It is still unclear how sialic acid may affect CPS production and, consequently, the pathogenesis of the disease caused by these two bacterial pathogens. Here, we investigated the role of sialic acid and the putative effect of sialic acid linkage modification in CPS synthesis using inter-species allelic exchange mutagenesis. To this aim, a new molecular biogenetic approach to express CPS with modified sialic acid linkage was developed. We showed that sialic acid (and its α-2,6 linkage) is crucial for S. suis CPS synthesis, whereas for GBS, CPS synthesis may occur in presence of an α-2,6 sialyltransferase or in absence of sialic acid moiety. To evaluate the effect of the CPS composition/structure on sialyltransferase activity, two distinct capsular serotypes within each bacterial species were compared (S. suis serotypes 2 and 14 and GBS serotypes III and V). It was demonstrated that the observed differences in sialyltransferase activity and specificity between S. suis and GBS were serotype unrestricted. This is the first time that a study investigates the interspecies exchange of capsular sialyltransferase genes in Gram-positive bacteria. The obtained mutants represent novel tools that could be used to further investigate the immunomodulatory properties of sialylated CPSs. Finally, in spite of common CPS structural characteristics and similarities in the cps loci, sialic acid exerts differential control of CPS expression by S. suis and GBS.
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Affiliation(s)
- David Roy
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Disease Research Centre, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Daisuke Takamatsu
- Division of Bacterial and Parasitic Diseases, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan.,The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Masatoshi Okura
- Division of Bacterial and Parasitic Diseases, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Guillaume Goyette-Desjardins
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Disease Research Centre, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Marie-Rose Van Calsteren
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Disease Research Centre, University of Montreal, Saint-Hyacinthe, QC, Canada.,Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Hyacinthe, QC, Canada
| | - Audrey Dumesnil
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Disease Research Centre, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Marcelo Gottschalk
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Disease Research Centre, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Mariela Segura
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Disease Research Centre, University of Montreal, Saint-Hyacinthe, QC, Canada
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10
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Auger JP, Meekhanon N, Okura M, Osaki M, Gottschalk M, Sekizaki T, Takamatsu D. Streptococcus suis Serotype 2 Capsule In Vivo. Emerg Infect Dis 2018; 22:1793-6. [PMID: 27648583 PMCID: PMC5038428 DOI: 10.3201/eid2210.151640] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Many Streptococcus suis isolates from porcine endocarditis in slaughterhouses have lost their capsule and are considered avirulent. However, we retrieved capsule- and virulence-recovered S. suis after in vivo passages of a nonencapsulated strain in mice, suggesting that nonencapsulated S. suis are still potentially hazardous for persons in the swine industry.
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11
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Potentially hazardous Streptococcus suis strains latent in asymptomatic pigs in a major swine production area of Thailand. J Med Microbiol 2017; 66:662-669. [DOI: 10.1099/jmm.0.000483] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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12
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Critical Streptococcus suis Virulence Factors: Are They All Really Critical? Trends Microbiol 2017; 25:585-599. [PMID: 28274524 DOI: 10.1016/j.tim.2017.02.005] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/30/2017] [Accepted: 02/09/2017] [Indexed: 01/15/2023]
Abstract
Streptococcus suis is an important swine pathogen that can be transmitted to humans by contact with diseased animals or contaminated raw pork products. This pathogen possesses a coat of capsular polysaccharide (CPS) that confers protection against the immune system. Yet, the CPS is not the only virulence factor enabling this bacterium to successfully colonize, invade, and disseminate in its host leading to severe systemic diseases such as meningitis and toxic shock-like syndrome. Indeed, recent research developments, cautiously inventoried in this review, have revealed over 100 'putative virulence factors or traits' (surface-associated or secreted components, regulatory genes or metabolic pathways), of which at least 37 have been claimed as being 'critical' for virulence. In this review we discuss the current contradictions and controversies raised by this explosion of virulence factors and the future directions that may be conceived to advance and enlighten research on S. suis pathogenesis.
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13
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Zheng H, Qiu X, Roy D, Segura M, Du P, Xu J, Gottschalk M. Genotyping and investigating capsular polysaccharide synthesis gene loci of non-serotypeable Streptococcus suis isolated from diseased pigs in Canada. Vet Res 2017; 48:10. [PMID: 28219415 PMCID: PMC5322794 DOI: 10.1186/s13567-017-0417-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 01/20/2017] [Indexed: 11/13/2022] Open
Abstract
Streptococcus suis (S. suis) is an important swine pathogen and an emerging zoonotic agent. Most clinical S. suis strains express capsular polysaccharides (CPS), which can be typed by antisera using the coagglutination test. In this study, 79 S. suis strains recovered from diseased pigs in Canada and which could not be typed using antisera were further characterized by capsular gene typing and sequencing. Four patterns of cps locus were observed: (1) fifteen strains were grouped into previously reported serotypes but presented several mutations in their cps loci, when compared to available data from reference strains; (2) seven strains presented a complete deletion of the cps locus, which would result in an inability to synthesize capsule; (3) forty-seven strains were classified in recently described novel cps loci (NCLs); and (4) ten strains carried novel NCLs not previously described. Different virulence gene profiles (based on the presence of mrp, epf, and/or sly) were observed in these non-serotypeable strains. This study provides further insight in understanding the genetic characteristics of cps loci in non-serotypeable S. suis strains recovered from diseased animals. When using a combination of the previously described 35 serotypes and the complete NCL system, the number of untypeable strains recovered from diseased animals in Canada would be significantly reduced.
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Affiliation(s)
- Han Zheng
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
| | - Xiaotong Qiu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
| | - David Roy
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Diseases Research Center, University of Montreal, Quebec, Canada
| | - Mariela Segura
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Diseases Research Center, University of Montreal, Quebec, Canada
| | - Pengchen Du
- Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing Key Laboratory of Emerging Infectious Diseases, Beijing, People's Republic of China
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
| | - Marcelo Gottschalk
- Faculty of Veterinary Medicine, Swine and Poultry Infectious Diseases Research Center, University of Montreal, Quebec, Canada.
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14
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Yang YB, Chen JQ, Zhao YL, Bai JW, Ding WY, Zhou YH, Chen XY, Liu D, Li YH. Sub-MICs of Azithromycin Decrease Biofilm Formation of Streptococcus suis and Increase Capsular Polysaccharide Content of S. suis. Front Microbiol 2016; 7:1659. [PMID: 27812354 PMCID: PMC5072222 DOI: 10.3389/fmicb.2016.01659] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/05/2016] [Indexed: 01/13/2023] Open
Abstract
Streptococcus suis (S. suis) caused serious disease symptoms in humans and pigs. S. suis is able to form thick biofilms and this increases the difficulty of treatment. After growth with 1/2 minimal inhibitory concentration (MIC) of azithromycin, 1/4 MIC of azithromycin, or 1/8 MIC of azithromycin, biofilm formation of S. suis dose-dependently decreased in the present study. Furthermore, scanning electron microscopy analysis revealed the obvious effect of azithromycin against biofilm formation of S. suis. Especially, at two different conditions (1/2 MIC of azithromycin non-treated cells and treated cells), we carried out comparative proteomic analyses of cells by using iTRAQ technology. Finally, the results revealed the existence of 19 proteins of varying amounts. Interestingly, several cell surface proteins (such as ATP-binding cassette superfamily ATP-binding cassette transporter (G7SD52), CpsR (K0FG35), Cps1/2H (G8DTL7), CPS16F (E9NQ13), putative uncharacterized protein (G7SER0), NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (G5L259), putative uncharacterized protein (G7S2D6), amino acid permease (B0M0G6), and NsuB (G5L351)) were found to be implicated in biofilm formation. More importantly, we also found that azithromycin affected expression of the genes cps1/2H, cpsR and cps16F. Especially, after growth with 1/2 MIC of azithromycin and 1/4 MIC of azithromycin, the capsular polysaccharide content of S. suis was significantly higher.
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Affiliation(s)
- Yan-Bei Yang
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
| | - Jian-Qing Chen
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
| | - Yu-Lin Zhao
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
| | - Jing-Wen Bai
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
| | - Wen-Ya Ding
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
| | - Yong-Hui Zhou
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
| | - Xue-Ying Chen
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
| | - Di Liu
- Heilongjiang Academy of Agricultural Sciences Harbin, China
| | - Yan-Hua Li
- College of Veterinary Medicine, Northeast Agricultural University Harbin, China
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15
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Chu M, Mallozzi MJG, Roxas BP, Bertolo L, Monteiro MA, Agellon A, Viswanathan VK, Vedantam G. A Clostridium difficile Cell Wall Glycopolymer Locus Influences Bacterial Shape, Polysaccharide Production and Virulence. PLoS Pathog 2016; 12:e1005946. [PMID: 27741317 PMCID: PMC5065235 DOI: 10.1371/journal.ppat.1005946] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 09/21/2016] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile is a diarrheagenic pathogen associated with significant mortality and morbidity. While its glucosylating toxins are primary virulence determinants, there is increasing appreciation of important roles for non-toxin factors in C. difficile pathogenesis. Cell wall glycopolymers (CWGs) influence the virulence of various pathogens. Five C. difficile CWGs, including PSII, have been structurally characterized, but their biosynthesis and significance in C. difficile infection is unknown. We explored the contribution of a conserved CWG locus to C. difficile cell-surface integrity and virulence. Attempts at disrupting multiple genes in the locus, including one encoding a predicted CWG exporter mviN, were unsuccessful, suggesting essentiality of the respective gene products. However, antisense RNA-mediated mviN downregulation resulted in slight morphology defects, retarded growth, and decreased surface PSII deposition. Two other genes, lcpA and lcpB, with putative roles in CWG anchoring, could be disrupted by insertional inactivation. lcpA- and lcpB- mutants had distinct phenotypes, implying non-redundant roles for the respective proteins. The lcpB- mutant was defective in surface PSII deposition and shedding, and exhibited a remodeled cell surface characterized by elongated and helical morphology, aberrantly-localized cell septae, and an altered surface-anchored protein profile. Both lcpA- and lcpB- strains also displayed heightened virulence in a hamster model of C. difficile disease. We propose that gene products of the C. difficile CWG locus are essential, that they direct the production/assembly of key antigenic surface polysaccharides, and thereby have complex roles in virulence. Clostridium difficile infection is a leading healthcare-onset bacterial disease, and its management and prevention imposes significant clinical and financial burdens worldwide. While toxins TcdA and TcdB are the primary virulence factors, there is increasing interest in, and appreciation of, non-toxin virulence factors in C. difficile pathogenesis. Cell wall glycopolymers (CWGs) are important virulence determinants in many pathogens, but their role(s) in C. difficile pathogenesis is unclear. We propose a model for C. difficile CWG biosynthesis, and demonstrate that alterations in cell wall assembly profoundly impact bacterial morphology and virulence.
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Affiliation(s)
- Michele Chu
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Michael J. G. Mallozzi
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Bryan P. Roxas
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Lisa Bertolo
- Department of Chemistry, University of Guelph, Guelph, Ontario, Canada
| | - Mario A. Monteiro
- Department of Chemistry, University of Guelph, Guelph, Ontario, Canada
| | - Al Agellon
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - V. K. Viswanathan
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, Bio5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona, United States of America
| | - Gayatri Vedantam
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, Bio5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona, United States of America
- Southern Arizona VA Healthcare System, Tucson, Arizona, United States of America
- * E-mail:
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16
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Tohya M, Watanabe T, Maruyama F, Arai S, Ota A, Athey TBT, Fittipaldi N, Nakagawa I, Sekizaki T. Comparative Genome Analyses of Streptococcus suis Isolates from Endocarditis Demonstrate Persistence of Dual Phenotypic Clones. PLoS One 2016; 11:e0159558. [PMID: 27433935 PMCID: PMC4951133 DOI: 10.1371/journal.pone.0159558] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/04/2016] [Indexed: 11/19/2022] Open
Abstract
Many bacterial species coexist in the same niche as heterogeneous clones with different phenotypes; however, understanding of infectious diseases by polyphenotypic bacteria is still limited. In the present study, encapsulation in isolates of the porcine pathogen Streptococcus suis from persistent endocarditis lesions was examined. Coexistence of both encapsulated and unencapsulated S. suis isolates was found in 26 out of 59 endocarditis samples. The isolates were serotype 2, and belonged to two different sequence types (STs), ST1 and ST28. The genomes of each of the 26 pairs of encapsulated and unencapsulated isolates from the 26 samples were sequenced. The data showed that each pair of isolates had one or more unique nonsynonymous mutations in the cps gene, and the encapsulated and unencapsulated isolates from the same samples were closest to each other. Pairwise comparisons of the sequences of cps genes in 7 pairs of encapsulated and unencapsulated isolates identified insertion/deletions (indels) ranging from one to 104 bp in different cps genes of unencapsulated isolates. Capsule expression was restored in a subset of unencapsulated isolates by complementation in trans with cps expression vectors. Examination of gene content common to isolates indicated that mutation frequency was higher in ST28 pairs than in ST1 pairs. Genes within mobile genetic elements were mutation hot spots among ST28 isolates. Taken all together, our results demonstrate the coexistence of dual phenotype (encapsulated and unencapsulated) bacterial clones and suggest that the dual phenotypes arose independently in each farm by means of spontaneous mutations in cps genes.
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Affiliation(s)
- Mari Tohya
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takayasu Watanabe
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Fumito Maruyama
- Department of Microbiology, Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan
- * E-mail: (TS); (FM)
| | - Sakura Arai
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Atsushi Ota
- Department of Microbiology, Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan
| | | | - Nahuel Fittipaldi
- Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ichiro Nakagawa
- Department of Microbiology, Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan
| | - Tsutomu Sekizaki
- Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail: (TS); (FM)
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17
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Recruitment of Factor H to the Streptococcus suis Cell Surface is Multifactorial. Pathogens 2016; 5:pathogens5030047. [PMID: 27399785 PMCID: PMC5039427 DOI: 10.3390/pathogens5030047] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 06/22/2016] [Accepted: 07/04/2016] [Indexed: 01/15/2023] Open
Abstract
Streptococcus suis is an important bacterial swine pathogen and a zoonotic agent. Recently, two surface proteins of S. suis, Fhb and Fhbp, have been described for their capacity to bind factor H—a soluble complement regulatory protein that protects host cells from complement-mediated damages. Results obtained in this study showed an important role of host factor H in the adhesion of S. suis to epithelial and endothelial cells. Both Fhb and Fhbp play, to a certain extent, a role in such increased factor H-dependent adhesion. The capsular polysaccharide (CPS) of S. suis, independently of the presence of its sialic acid moiety, was also shown to be involved in the recruitment of factor H. However, a triple mutant lacking Fhb, Fhbp and CPS was still able to recruit factor H resulting in the degradation of C3b in the presence of factor I. In the presence of complement factors, the double mutant lacking Fhb and Fhbp was similarly phagocytosed by human macrophages and killed by pig blood when compared to the wild-type strain. In conclusion, this study suggests that recruitment of factor H to the S. suis cell surface is multifactorial and redundant.
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18
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Haas B, Grenier D. Impact of Sub-Inhibitory Concentrations of Amoxicillin on Streptococcus suis Capsule Gene Expression and Inflammatory Potential. Pathogens 2016; 5:pathogens5020037. [PMID: 27104570 PMCID: PMC4931388 DOI: 10.3390/pathogens5020037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 11/16/2022] Open
Abstract
Streptococcus suis is an important swine pathogen and emerging zoonotic agent worldwide causing meningitis, endocarditis, arthritis and septicemia. Among the 29 serotypes identified to date, serotype 2 is mostly isolated from diseased pigs. Although several virulence mechanisms have been characterized in S. suis, the pathogenesis of S. suis infections remains only partially understood. This study focuses on the response of S. suis P1/7 to sub-inhibitory concentrations of amoxicillin. First, capsule expression was monitored by qRT-PCR when S. suis was cultivated in the presence of amoxicillin. Then, the pro-inflammatory potential of S. suis P1/7 culture supernatants or whole cells conditioned with amoxicillin was evaluated by monitoring the activation of the NF-κB pathway in monocytes and quantifying pro-inflammatory cytokines secreted by macrophages. It was found that amoxicillin decreased capsule expression in S. suis. Moreover, conditioning the bacterium with sub-inhibitory concentrations of amoxicillin caused an increased activation of the NF-κB pathway in monocytes following exposure to bacterial culture supernatants and to a lesser extent to whole bacterial cells. This was associated with an increased secretion of pro-inflammatory cytokines (CXCL8, IL-6, IL-1β) by macrophages. This study identified a new mechanism by which S. suis may increase its inflammatory potential in the presence of sub-inhibitory concentrations of amoxicillin, a cell wall-active antibiotic, thus challenging its use for preventive treatments or as growth factor.
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Affiliation(s)
- Bruno Haas
- Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, QC G1V 0A6, Canada.
| | - Daniel Grenier
- Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, QC G1V 0A6, Canada.
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Fonds de Recherche du Québec-Nature et Technologies (FRQNT), Saint-Hyacinthe, QC J2S 2M2, Canada.
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19
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Fedashchin A, Cernota WH, Gonzalez MC, Leach BI, Kwan N, Wesley RK, Weber JM. Random transposon mutagenesis of the Saccharopolyspora erythraea genome reveals additional genes influencing erythromycin biosynthesis. FEMS Microbiol Lett 2015; 362:fnv180. [PMID: 26468041 DOI: 10.1093/femsle/fnv180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2015] [Indexed: 12/25/2022] Open
Abstract
A single cycle of strain improvement was performed in Saccharopolyspora erythraea mutB and 15 genotypes influencing erythromycin production were found. Genotypes generated by transposon mutagenesis appeared in the screen at a frequency of ~3%. Mutations affecting central metabolism and regulatory genes were found, as well as hydrolases, peptidases, glycosyl transferases and unknown genes. Only one mutant retained high erythromycin production when scaled-up from micro-agar plug fermentations to shake flasks. This mutant had a knockout of the cwh1 gene (SACE_1598), encoding a cell-wall-associated hydrolase. The cwh1 knockout produced visible growth and morphological defects on solid medium. This study demonstrated that random transposon mutagenesis uncovers strain improvement-related genes potentially useful for strain engineering.
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Affiliation(s)
- Andrij Fedashchin
- Fermalogic, Research and Development, 4222 N. Ravenswood Avenue, Chicago, IL 60613, USA
| | - William H Cernota
- Fermalogic, Research and Development, 4222 N. Ravenswood Avenue, Chicago, IL 60613, USA
| | - Melissa C Gonzalez
- Fermalogic, Research and Development, 4222 N. Ravenswood Avenue, Chicago, IL 60613, USA
| | - Benjamin I Leach
- Fermalogic, Research and Development, 4222 N. Ravenswood Avenue, Chicago, IL 60613, USA
| | - Noelle Kwan
- Fermalogic, Research and Development, 4222 N. Ravenswood Avenue, Chicago, IL 60613, USA
| | - Roy K Wesley
- Fermalogic, Research and Development, 4222 N. Ravenswood Avenue, Chicago, IL 60613, USA
| | - J Mark Weber
- Fermalogic, Research and Development, 4222 N. Ravenswood Avenue, Chicago, IL 60613, USA
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20
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Hatrongjit R, Kerdsin A, Gottschalk M, Takeuchi D, Hamada S, Oishi K, Akeda Y. First human case report of sepsis due to infection with Streptococcus suis serotype 31 in Thailand. BMC Infect Dis 2015; 15:392. [PMID: 26420029 PMCID: PMC4588491 DOI: 10.1186/s12879-015-1136-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 09/21/2015] [Indexed: 01/11/2023] Open
Abstract
Background Streptococcus suis is a zoonotic pathogen that causes invasive infections in humans and pigs. It has been reported that S. suis infection in humans is mostly caused by serotype 2. However, human cases caused by other serotypes have rarely been reported. This is the first report of a human case of infection with S. suis serotype 31 in Thailand. Case presentation A 55-year-old male alcohol misuser with liver cirrhosis was admitted with sepsis to a hospital in the Central Region of Thailand. He had consumed a homemade, raw pork product prior to the onset of illness. He was alive after treatment with ceftriaxone and no complication occurred. An isolate from blood culture at the hospital was suspected as viridans group Streptococcus. It was confirmed at a reference laboratory as S. suis serotype 31 by biochemical tests, 16S rDNA sequencing, and multiplex polymerase chain reaction for serotyping, but it was untypable by the co-agglutination test with antisera against recognized S. suis serotypes, suggesting loss of capsular material. The absence of a capsule was confirmed by transmission electron microscopy. The isolate was confirmed to be sequence type 221, with 13 putative virulence genes that are usually found in serotype 2 strains. Conclusion We should be aware of the emergence of S. suis infections caused by uncommon serotypes in patients with predisposing conditions. Laboratory capacity to identify S. suis in the hospital is needed in developing countries, which can contribute to enhanced surveillance, epidemiological control, and prevention strategies in the prevalent area. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-1136-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rujirat Hatrongjit
- Faculty of Science and Engineering, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Muang, Sakon Nakhon Province, 47000, Thailand.
| | - Anusak Kerdsin
- National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Tiwanon Road, Muang, Nonthaburi Province, 11000, Thailand. .,Present address: Faculty of Public Health, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon, Thailand.
| | | | - Dan Takeuchi
- Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Shigeyuki Hamada
- Thailand-Japan Research Collaboration Center on Emerging and Re-emerging Infections, Nonthaburi Province, Thailand.
| | - Kazunori Oishi
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Shinjyuku, Tokyo, Japan.
| | - Yukihiro Akeda
- Laboratory of Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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21
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Delorme C, Abraham AL, Renault P, Guédon E. Genomics of Streptococcus salivarius, a major human commensal. INFECTION GENETICS AND EVOLUTION 2014; 33:381-92. [PMID: 25311532 DOI: 10.1016/j.meegid.2014.10.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/30/2014] [Accepted: 10/02/2014] [Indexed: 10/24/2022]
Abstract
The salivarius group of streptococci is of particular importance for humans. This group consists of three genetically similar species, Streptococcus salivarius, Streptococcus vestibularis and Streptococcus thermophilus. S. salivarius and S. vestibularis are commensal organisms that may occasionally cause opportunistic infections in humans, whereas S. thermophilus is a food bacterium widely used in dairy production. We developed Multilocus sequence typing (MLST) and comparative genomic analysis to confirm the clear separation of these three species. These analyses also identified a subgroup of four strains, with a core genome diverging by about 10%, in terms of its nucleotide sequence, from that of S. salivarius sensu stricto. S. thermophilus species displays a low level of nucleotide variability, due to its recent emergence with the development of agriculture. By contrast, nucleotide variability is high in the other two species of the salivarius group, reflecting their long-standing association with humans. The species of the salivarius group have genome sizes ranging from the smallest (∼ 1.7 Mb for S. thermophilus) to the largest (∼ 2.3 Mb for S. salivarius) among streptococci, reflecting genome reduction linked to a narrow, nutritionally rich environment for S. thermophilus, and natural, more competitive niches for the other two species. Analyses of genomic content have indicated that the core genes of S. salivarius account for about two thirds of the genome, indicating considerable variability of gene content and differences in potential adaptive features. Furthermore, we showed that the genome of this species is exceptionally rich in genes encoding surface factors, glycosyltransferases and response regulators. Evidence of widespread genetic exchanges was obtained, probably involving a natural competence system and the presence of diverse mobile elements. However, although the S. salivarius strains studied were isolated from several human body-related sites (all levels of the digestive tract, skin, breast milk, and body fluids) and included clinical strains, no genetic or genomic niche-specific features could be identified to discriminate specific group.
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Affiliation(s)
- Christine Delorme
- INRA, UMR 1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France; AgroParisTech, UMR MICALIS, Jouy-en-Josas, France
| | - Anne-Laure Abraham
- INRA, UMR 1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France; AgroParisTech, UMR MICALIS, Jouy-en-Josas, France
| | - Pierre Renault
- INRA, UMR 1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France; AgroParisTech, UMR MICALIS, Jouy-en-Josas, France
| | - Eric Guédon
- INRA, UMR 1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France; AgroParisTech, UMR MICALIS, Jouy-en-Josas, France.
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