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Jeffery A, Gilbert M, Corsaut L, Gaudreau A, Obradovic MR, Cloutier S, Frenette MC, Surprenant C, Lacouture S, Arnal JL, Gottschalk M, Segura M. Immune response induced by a Streptococcus suis multi-serotype autogenous vaccine used in sows to protect post-weaned piglets. Vet Res 2024; 55:57. [PMID: 38715138 PMCID: PMC11076212 DOI: 10.1186/s13567-024-01313-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/09/2024] [Indexed: 05/12/2024] Open
Abstract
Streptococcus suis is a bacterial pathogen that causes important economic losses to the swine industry worldwide. Since there are no current commercial vaccines, the use of autogenous vaccines applied to gilts/sows to enhance transfer of passive immunity is an attractive alternative to protect weaned piglets. However, there is no universal standardization in the production of autogenous vaccines and the vaccine formulation may be highly different among licenced manufacturing laboratories. In the present study, an autogenous vaccine that included S. suis serotypes 2, 1/2, 5, 7 and 14 was prepared by a licensed laboratory and administrated to gilts using a three-dose program prior to farrowing. The antibody response in gilts as well as the passive transfer of antibodies to piglets was then evaluated. In divergence with previously published data with an autogenous vaccine produced by a different company, the increased response seen in gilts was sufficient to improve maternal antibody transfer to piglets up to 5 weeks of age. However, piglets would still remain susceptible to S. suis disease which often appears during the second part of the nursery period. Vaccination did not affect the shedding of S. suis (as well as that of the specific S. suis serotypes included in the vaccine) by either gilts or piglets. Although all antibiotic treatments were absent during the trial, the clinical protective effect of the vaccination program with the autogenous vaccine could not be evaluated, since limited S. suis cases were present during the trial, confirming the need for a complete evaluation of the clinical protection that must include laboratory confirmation of the aetiological agent involved in the presence of S. suis-associated clinical signs. Further studies to evaluate the usefulness of gilt/sow vaccination with autogenous vaccines to protect nursery piglets should be done.
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Affiliation(s)
- Alison Jeffery
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Mélina Gilbert
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Lorelei Corsaut
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Annie Gaudreau
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Milan R Obradovic
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada
| | | | | | | | - Sonia Lacouture
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada
| | - Jose Luis Arnal
- Exopol, Veterinary Diagnostic and Autogenous Vaccine Laboratory, Zaragoza, Spain
| | - Marcelo Gottschalk
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada.
| | - Mariela Segura
- Swine and Poultry Infectious Diseases Research Centre, and Research Group On Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, J2S 2M2, Canada.
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de O Costa M, Gamage R, Christensen J. Molecular profile and epidemiological traits of Streptococcus suis isolated from diseased pigs in western Canada reveal multiple-serotype infection: Implications for disease control. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2024; 65:429-436. [PMID: 38694742 PMCID: PMC11017942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2024]
Abstract
Objective Streptococcus suis is a major agent of disease in modern swine operations, linked to increased mortality, treatment costs, and secondary infections. Although it is ubiquitous in swine, only a fraction of pigs develop clinical disease. The goals of this study were to profile isolates obtained from diseased pigs in western Canada and to investigate potential associations with disease severity. Procedure Isolates of S. suis (n = 128) from 75 diagnostic submission and 63 premises were paired with epidemiological surveys completed by submitting practitioners (n = 22). Whole-genome sequencing was used to type isolates. Results The most prevalent serotypes identified were 1/2 (7.8%, 10/128), 2 (9.3%, 12/128), 3 (9.3%, 12/128), and 7 (7.8%, 10/128); and sequence types 28 (17%, 23/128) and 839 (14%, 19/128). There was no association between serotype or sequence type and organ source or barn location. Approximately 74% (14/19) of the premises had diseased animals colonized by > 1 S. suis serotype, but only 1 pig was simultaneously infected with multiple serotypes and sequence types. Serotype distribution from diseased pigs in western Canada differed from that of those in other geographic regions. Conclusion Infection of diseased pigs by multiple serotypes should be considered when disease control strategies are implemented. No association between S. suis type and isolation organ was identified.
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Affiliation(s)
- Matheus de O Costa
- Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Costa, Gamage); Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, Utrecht, The Netherlands (Costa); Canada West Swine Health Intelligence Network (CWSHIN) Inc., Winnipeg, Manitoba (Christensen); Epidemiologic Surveillance and Analysis Consulting (EpiSAC), Charlottetown, Prince Edward Island (Christensen)
| | - Ruwini Gamage
- Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Costa, Gamage); Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, Utrecht, The Netherlands (Costa); Canada West Swine Health Intelligence Network (CWSHIN) Inc., Winnipeg, Manitoba (Christensen); Epidemiologic Surveillance and Analysis Consulting (EpiSAC), Charlottetown, Prince Edward Island (Christensen)
| | - Jette Christensen
- Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Costa, Gamage); Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, Utrecht, The Netherlands (Costa); Canada West Swine Health Intelligence Network (CWSHIN) Inc., Winnipeg, Manitoba (Christensen); Epidemiologic Surveillance and Analysis Consulting (EpiSAC), Charlottetown, Prince Edward Island (Christensen)
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Uruén C, Fernandez A, Arnal JL, Del Pozo M, Amoribieta MC, de Blas I, Jurado P, Calvo JH, Gottschalk M, González-Vázquez LD, Arenas M, Marín CM, Arenas J. Genomic and phenotypic analysis of invasive Streptococcus suis isolated in Spain reveals genetic diversification and associated virulence traits. Vet Res 2024; 55:11. [PMID: 38268053 PMCID: PMC10807230 DOI: 10.1186/s13567-024-01267-0] [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: 10/06/2023] [Accepted: 01/02/2024] [Indexed: 01/26/2024] Open
Abstract
Streptococcus suis is a zoonotic pathogen that causes a major health problem in the pig production industry worldwide. Spain is one of the largest pig producers in the world. This work aimed to investigate the genetic and phenotypic features of invasive S. suis isolates recovered in Spain. A panel of 156 clinical isolates recovered from 13 Autonomous Communities, representing the major pig producers, were analysed. MLST and serotyping analysis revealed that most isolates (61.6%) were assigned to ST1 (26.3%), ST123 (18.6%), ST29 (9.6%), and ST3 (7.1%). Interestingly, 34 new STs were identified, indicating the emergence of novel genetic lineages. Serotypes 9 (27.6%) and 1 (21.8%) prevailed, followed by serotypes 7 (12.8%) and 2 (12.2%). Analysis of 13 virulence-associated genes showed significant associations between ST, serotype, virulence patterns, and clinical features, evidencing particular virulence traits associated with genetic clusters. The pangenome was generated, and the core genome was distributed in 7 Bayesian groups where each group included a variable set of over- and under-represented genes of different categories. The study provides comprehensive data and knowledge to improve the design of new vaccines, antimicrobial treatments, and bacterial typing approaches.
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Affiliation(s)
- Cristina Uruén
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
- Institute Agrofood of Aragón-IA2, University of Zaragoza-Center of Research and Technology of Aragón (CITA), Zaragoza, Spain
| | - Ana Fernandez
- Exopol. Veterinary Diagnostic and Autogenous Vaccine Laboratory, San Mateo de Gállego, Zaragoza, Spain
| | - José Luis Arnal
- Exopol. Veterinary Diagnostic and Autogenous Vaccine Laboratory, San Mateo de Gállego, Zaragoza, Spain
| | | | | | - Ignacio de Blas
- Institute Agrofood of Aragón-IA2, University of Zaragoza-Center of Research and Technology of Aragón (CITA), Zaragoza, Spain
- Unit of Infectious Diseases, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Paula Jurado
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
- Institute Agrofood of Aragón-IA2, University of Zaragoza-Center of Research and Technology of Aragón (CITA), Zaragoza, Spain
| | - Jorge Hugo Calvo
- Department of Animal Science, Center of Research and Technology of Aragón CITA, Zaragoza, Spain
- ARAID, Saragossa, Spain
| | - Marcelo Gottschalk
- Research Group on Infectious Diseases in Production Animals and Swine and Poultry Infectious Diseases Research Centre, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada
| | | | - Miguel Arenas
- Department of Biochemistry, Genetics and Immunology, University of Vigo, Vigo, Spain
- CINBIO, Vigo, Spain
| | - Clara M Marín
- Institute Agrofood of Aragón-IA2, University of Zaragoza-Center of Research and Technology of Aragón (CITA), Zaragoza, Spain
- Department of Animal Science, Center of Research and Technology of Aragón CITA, Zaragoza, Spain
| | - Jesús Arenas
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain.
- Institute Agrofood of Aragón-IA2, University of Zaragoza-Center of Research and Technology of Aragón (CITA), Zaragoza, Spain.
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Uruén C, Gimeno J, Sanz M, Fraile L, Marín CM, Arenas J. Invasive Streptococcus suis isolated in Spain contain a highly promiscuous and dynamic resistome. Front Cell Infect Microbiol 2024; 13:1329632. [PMID: 38317790 PMCID: PMC10839070 DOI: 10.3389/fcimb.2023.1329632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 12/26/2023] [Indexed: 02/07/2024] Open
Abstract
Introduction Streptococcus suis is a major pathogen for swine and human. Here we aimed to know the rates of antimicrobial resistance (AMR) in invasive S. suis isolates recovered along Spain between 2016 - 2021 and elucidate their genetic origin. Methods Antibiotic susceptibility testing was performed for 116 isolates of different genetic backgrounds and geographic origins against 18 antibiotics of 9 families. The association between AMR and genotypes and the origin of the isolates were statistically analyzed using Pearson´s chi-square test and the likelihood ratio. The antimicrobial resistant genes were identified by whole genome sequencing analysis and PCR screenings. Results High AMR rates (>80%) were detected for tetracyclines, spectinomycin, lincosamides, and marbofloxacin, medium (20-40%) for sulphonamides/trimethoprim, tiamulin, penicillin G, and enrofloxacin, and low (< 20%) for florfenicol, and four additional β-lactams. The occurrence of multidrug resistance was observed in 90% of isolates. For certain antibiotics (penicillin G, enrofloxacin, marbofloxacin, tilmicosin, and erythromycin), AMR was significantly associated with particular sequence types (STs), geographic regions, age of pigs, and time course. Whole genome sequencing comparisons and PCR screenings identified 23 AMR genes, of which 19 were previously reported in S. suis (aph(3')-IIIa, sat4, aadE, spw, aac(6')-Ie-aph(2'')-Ia, fexA, optrA, erm(B), mef(A/E), mrs(D), mph(C), lnu(B), lsa(E), vga(F), tet(M), tet(O), tet(O/W/32/O), tet(W)), and 4 were novel (aph(2'')-IIIa, apmA, erm(47), tet(T)). These AMR genes explained the AMR to spectinomycin, macrolides, lincosamides, tiamulin, and tetracyclines. Several genes were located on mobile genetic elements which showed a variable organization and composition. As AMR gene homologs were identified in many human and animal pathogens, the resistome of S. suis has a different phylogenetic origin. Moreover, AMR to penicillin G, fluoroquinolones, and trimethoprim related to mutations in genes coding for target enzymes (pbp1a, pbp2b, pbp2x, mraY, gyrA, parC, and dhfr). Bioinformatic analysis estimated traits of recombination on target genes, also indicative of gene transfer events. Conclusions Our work evidences that S. suis is a major contributor to AMR dissemination across veterinary and human pathogens. Therefore, control of AMR in S. suis should be considered from a One Health approach in regions with high pig production to properly tackle the issue of antimicrobial drug resistance.
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Affiliation(s)
- Cristina Uruén
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
- Institute Agrofood of Aragón-IA2, University of Zaragoza-CITA, Zaragoza, Spain
| | - Jorge Gimeno
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
- Institute Agrofood of Aragón-IA2, University of Zaragoza-CITA, Zaragoza, Spain
| | - Marina Sanz
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
- Institute Agrofood of Aragón-IA2, University of Zaragoza-CITA, Zaragoza, Spain
| | - Lorenzo Fraile
- Department of Animal Science, ETSEA, University of Lleida-Agrotecno, Lleida, Spain
| | - Clara M. Marín
- Institute Agrofood of Aragón-IA2, University of Zaragoza-CITA, Zaragoza, Spain
- Department of Animal Production and Health, CITA, Zaragoza, Spain
| | - Jesús Arenas
- Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
- Institute Agrofood of Aragón-IA2, University of Zaragoza-CITA, Zaragoza, Spain
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Bornemann NN, Mayer L, Lacouture S, Gottschalk M, Baums CG, Strutzberg-Minder K. Invasive Bacterial Infections of the Musculoskeletal and Central Nervous System during Pig Rearing: Detection Frequencies of Different Pathogens and Specific Streptococcus suis Genotypes. Vet Sci 2024; 11:17. [PMID: 38250923 PMCID: PMC10820919 DOI: 10.3390/vetsci11010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024] Open
Abstract
Locomotor and central nervous system disorders occur during pig rearing, but there is no systematic recording of the different causative agents in Germany. Joint and meningeal swabs, kidneys, lungs, and eight different lymph nodes per pig were cultured, and isolated pathogens were identified using polymerase chain reactions (PCRs). The cps and pathotype of Streptococcus suis (S. suis) isolates were determined using multiplex-PCR. S. suis was the most important pathogen in the infected joints (70.8%) and meningeal swabs (85.4%) and was most frequently detected in both sites in suckling and weaning piglets. To elucidate the possible portal of entry of S. suis, eight different lymph nodes from 201 pigs were examined in a prospective study. S. suis was detected in all examined lymph nodes (n = 1569), including the mesenteric lymph nodes (15.8%; n = 121/765), with cps 9 (37.2%; n = 147) and cps 2 (24.3%; n = 96) being the most dominating cps types. In piglets with a systemic S. suis infection, different lymph nodes are frequently infected with the invasive S. suis strain, which does not help clarify the portal of entry for S. suis.
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Affiliation(s)
| | - Leonie Mayer
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany (C.G.B.)
| | - Sonia Lacouture
- Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2, Canada; (S.L.); (M.G.)
| | - Marcelo Gottschalk
- Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC J2S 2M2, Canada; (S.L.); (M.G.)
| | - Christoph Georg Baums
- Institute of Bacteriology and Mycology, Centre for Infectious Diseases, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany (C.G.B.)
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Dolbec D, Lehoux M, Okura M, Takamatsu D, Gottschalk M, Segura M. Streptococcus suis surface-antigen recognition by antibodies and bacterial elimination is influenced by capsular polysaccharide structure. Front Cell Infect Microbiol 2023; 13:1228496. [PMID: 37545852 PMCID: PMC10401424 DOI: 10.3389/fcimb.2023.1228496] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/05/2023] [Indexed: 08/08/2023] Open
Abstract
Streptococcus suis is an encapsulated bacterium causing severe diseases in swine. Here, we compared the protective properties of the capsular polysaccharide (CPS) of different S. suis serotypes by using serotype-switched mutants in a mouse model of infection. CPS structure influenced bacterial survival in mice, antibody binding, and antibody-mediated bacterial killing. The CPS of serotypes 3, 4 and 14 allowed more antibody binding and bacterial elimination than the CPS of serotypes 2, 7 and 9. Results suggest that the different CPS structures of S. suis provide varying levels of protection by influencing antigen availability and elimination by the host immune system.
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Affiliation(s)
- Dominic Dolbec
- 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, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Mélanie Lehoux
- 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, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Masatoshi Okura
- Division of Transboundary Animal Disease Research, National Institute of Animal Health, National Agriculture and Food Research Organization, Kagoshima, Japan
| | - Daisuke Takamatsu
- Division of Infectious Animal Disease Research, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan
- The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - 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, University of Montreal, Saint-Hyacinthe, QC, 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, University of Montreal, Saint-Hyacinthe, QC, Canada
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Pageaut H, Lacouture S, Lehoux M, Marois-Créhan C, Segura M, Gottschalk M. Interactions of Mycoplasma hyopneumoniae and/or Mycoplasma hyorhinis with Streptococcus suis Serotype 2 Using In Vitro Co-Infection Models with Swine Cells. Pathogens 2023; 12:866. [PMID: 37513713 PMCID: PMC10383509 DOI: 10.3390/pathogens12070866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/17/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023] Open
Abstract
Bacterial and/or viral co-infections are very common in swine production and cause severe economic losses. Mycoplasma hyopneumoniae, Mycoplasma hyorhinis and Streptococcus suis are pathogenic bacteria that may be found simultaneously in the respiratory tracts of pigs. In the present study, the interactions of S. suis with epithelial and phagocytic cells in the presence or absence of a pre-infection with M. hyopneumoniae and/or M. hyorhinis were studied. Results showed relatively limited interactions between these pathogens. A previous infection with one or both mycoplasmas did not influence the adhesion or invasion properties of S. suis in epithelial cells or its resistance to phagocytosis (including intracellular survival) by macrophages and dendritic cells. The most important effect observed during the co-infection was a clear increment in toxicity for the cells. An increase in the relative expression of the pro-inflammatory cytokines IL-6 and CXCL8 was also observed; however, this was the consequence of an additive effect due to the presence of different pathogens rather than a synergic effect. It may be hypothesized that if one or both mycoplasmas are present along with S. suis in the lower respiratory tract at the same time, then increased damage to epithelial cells and phagocytes, as well as an increased release of pro-inflammatory cytokines, may eventually enhance the invasive properties of S. suis. However, more studies should be carried out to confirm this hypothesis.
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Affiliation(s)
- Héloïse Pageaut
- Swine and Poultry Infectious Diseases Research Center (CRIPA) and Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Sonia Lacouture
- Swine and Poultry Infectious Diseases Research Center (CRIPA) and Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Mélanie Lehoux
- Swine and Poultry Infectious Diseases Research Center (CRIPA) and Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Corinne Marois-Créhan
- Ploufragan-Plouzané-Niort Laboratory, Mycoplasmology Bacteriology and Antimicrobial Resistance Unit, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 22 440 Ploufragan, France
| | - Mariela Segura
- Swine and Poultry Infectious Diseases Research Center (CRIPA) and Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Marcelo Gottschalk
- Swine and Poultry Infectious Diseases Research Center (CRIPA) and Groupe de Recherche sur les Maladies Infectieuses en Production Animale, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, QC J2S 2M2, Canada
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Fredriksen S, Guan X, Boekhorst J, Molist F, van Baarlen P, Wells JM. Environmental and maternal factors shaping tonsillar microbiota development in piglets. BMC Microbiol 2022; 22:224. [PMID: 36163011 PMCID: PMC9513891 DOI: 10.1186/s12866-022-02625-8] [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: 03/18/2022] [Accepted: 08/25/2022] [Indexed: 11/24/2022] Open
Abstract
Background The palatine tonsils are part of the mucosal immune system and stimulate immune responses through M cell uptake sampling of antigens and bacteria in the tonsillar crypts. Little is known about the development of the tonsillar microbiota and the factors determining the establishment and proliferation of disease-associated bacteria such as Streptococcus suis. In this study, we assessed tonsillar microbiota development in piglets during the first 5 weeks of life and identified the relative importance of maternal and environmental farm parameters influencing the tonsillar microbiota at different ages. Additionally, we studied the effect sow vaccination with a bacterin against S. suis on microbiota development and S. suis colonisation in their offspring. Results Amplicon sequencing of the 16S rRNA gene V3-V4 region revealed that a diverse tonsillar microbiota is established shortly after birth, which then gradually changes during the first 5 weeks of life without a large impact of weaning on composition or diversity. We found a strong litter effect, with siblings sharing a more similar microbiota compared to non-sibling piglets. Co-housing in rooms, within which litters were housed in separate pens, also had a large impact on microbiota composition. Sow parity and prepartum S. suis bacterin vaccination of sows had weaker but significant associations with microbiota composition, impacting on the abundance of Streptococcus species before and after weaning. Sex and birthweight had limited impact on the tonsillar microbiota, and none of the measured factors had consistent associations with microbiota diversity. Conclusions The piglet tonsillar microbiota is established shortly after birth. While microbiota development is associated with both environmental and maternal parameters, weaning has limited impact on microbiota composition. Intramuscular vaccination of sows pre-partum had a significant effect on the tonsillar microbiota composition of their piglets. These findings provide new insights into the mechanisms shaping the tonsillar microbiota.
Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02625-8.
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Affiliation(s)
- Simen Fredriksen
- Host-Microbe Interactomics Group, Animal Sciences Department, Wageningen University, Wageningen, The Netherlands.
| | - Xiaonan Guan
- Host-Microbe Interactomics Group, Animal Sciences Department, Wageningen University, Wageningen, The Netherlands.,Schothorst Feed Research B.V, Lelystad, The Netherlands
| | - Jos Boekhorst
- Host-Microbe Interactomics Group, Animal Sciences Department, Wageningen University, Wageningen, The Netherlands
| | | | - Peter van Baarlen
- Host-Microbe Interactomics Group, Animal Sciences Department, Wageningen University, Wageningen, The Netherlands
| | - Jerry M Wells
- Host-Microbe Interactomics Group, Animal Sciences Department, Wageningen University, Wageningen, The Netherlands. .,Department of Veterinary Medicine, University of Cambridge, Cambridge, U.K..
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Neutrophils in Streptococcus suis Infection: From Host Defense to Pathology. Microorganisms 2021; 9:microorganisms9112392. [PMID: 34835517 PMCID: PMC8624082 DOI: 10.3390/microorganisms9112392] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/11/2021] [Accepted: 11/17/2021] [Indexed: 01/02/2023] Open
Abstract
Streptococcus suis is a swine pathogen and zoonotic agent responsible for economic losses to the porcine industry. Infected animals may develop meningitis, arthritis, endocarditis, sepsis and/or sudden death. The pathogenesis of the infection implies that bacteria breach mucosal host barriers and reach the bloodstream, where they escape immune-surveillance mechanisms and spread throughout the organism. The clinical manifestations are mainly the consequence of an exacerbated inflammation, defined by an exaggerated production of cytokines and recruitment of immune cells. Among them, neutrophils arrive first in contact with the pathogens to combat the infection. Neutrophils initiate and maintain inflammation, by producing cytokines and deploying their arsenal of antimicrobial mechanisms. Furthermore, neutrophilic leukocytosis characterizes S. suis infection, and lesions of infected subjects contain a large number of neutrophils. Therefore, this cell type may play a role in host defense and/or in the exacerbated inflammation. Nevertheless, a limited number of studies addressed the role or functions of neutrophils in the context of S. suis infection. In this review, we will explore the literature about S. suis and neutrophils, from their interaction at a cellular level, to the roles and behaviors of neutrophils in the infected host in vivo.
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Obradovic MR, Corsaut L, Dolbec D, Gottschalk M, Segura M. Experimental evaluation of protection and immunogenicity of Streptococcus suis bacterin-based vaccines formulated with different commercial adjuvants in weaned piglets. Vet Res 2021; 52:133. [PMID: 34666827 PMCID: PMC8527783 DOI: 10.1186/s13567-021-01004-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 10/01/2021] [Indexed: 12/04/2022] Open
Abstract
Streptococcus suis is an important swine pathogen responsible for economic losses to the swine industry worldwide. There is no effective commercial vaccine against S. suis. The use of autogenous (“bacterin”) vaccines to control S. suis outbreaks is a frequent preventive measure in the field, although scientific data on immunogenicity and reduction in mortality and morbidity are scarce. The goal of our study is to experimentally evaluate the immunogenicity and protective efficacy against homologous challenge in weaned piglets of a S. suis serotype 2 bacterin-based vaccine formulated with six different commercial adjuvants (Alhydrogel®, Emulsigen®-D, Quil-A®, Montanide™ ISA 206 VG, Montanide™ ISA 61 VG, and Montanide™ ISA 201 VG). The vaccine formulated with Montanide™ ISA 61 VG induced a significant increase in anti-S. suis antibodies, including both IgG1 and IgG2 subclasses, protected against mortality and significantly reduced morbidity and severity of clinical signs. Vaccines formulated with Montanide ISA 206 VG or Montanide ISA 201 VG also induced a significant increase in anti-S. suis antibodies and showed partial protection and reduction of clinical signs severity. Vaccines formulated with Alhydrogel®, Emulsigen®-D, or Quil-A® induced a low and IgG1-shifted antibody response and failed to protect vaccinated piglets against a homologous challenge. In conclusion, the type of adjuvant used in the vaccine formulation significantly influenced the immune response and efficacy of the vaccine against a homologous challenge.
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Affiliation(s)
- Milan R Obradovic
- Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada
| | - Lorelei Corsaut
- Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada
| | - Dominic Dolbec
- Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada
| | - Marcelo Gottschalk
- Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada.
| | - Mariela Segura
- Research Group On Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada.
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11
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Neila-Ibáñez C, Casal J, Hennig-Pauka I, Stockhofe-Zurwieden N, Gottschalk M, Migura-García L, Pailler-García L, Napp S. Stochastic Assessment of the Economic Impact of Streptococcus suis-Associated Disease in German, Dutch and Spanish Swine Farms. Front Vet Sci 2021; 8:676002. [PMID: 34490389 PMCID: PMC8417327 DOI: 10.3389/fvets.2021.676002] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/27/2021] [Indexed: 01/15/2023] Open
Abstract
The economic assessment of animal diseases is essential for decision-making, including the allocation of resources for disease control. However, that assessment is usually hampered by the lack of reliable data on disease incidence, or treatment and control measures, and that is particularly true for swine production diseases, such as infections caused by Streptococcus suis. Therefore, we deployed a questionnaire survey of clinical swine veterinarians to obtain the input data needed for a stochastic model to calculate the costs caused by S. suis, which was implemented in three of the main swine producing countries in Europe: Germany, the Netherlands and Spain. S. suis-associated disease is endemic in those countries in all production phases, though nursery was the phase most severely impacted. In affected nursery units, between 3.3 and 4.0% of pigs had S. suis-associated disease and the mortalities ranged from 0.5 to 0.9%. In Germany, the average cost of S. suis per pig (summed across all production phases) was 1.30 euros (90% CI: 0.53-2.28), in the Netherlands 0.96 euros (90% CI: 0.27-1.54), and in Spain 0.60 euros (90% CI: 0.29-0.96). In Germany, that cost was essentially influenced by the expenditure in early metaphylaxis in nursery and in autogenous vaccines in sows and nursery pigs; in the Netherlands, by expenditure on autogenous vaccines in sows and nursery pigs; and in Spain, by the expenditures in early metaphylaxis and to a lesser extent by the mortality in nursery pigs. Therefore, the differences in costs between countries can be explained to a great extent by the measures to control S. suis implemented in each country. In Spain and in Germany, use of antimicrobials, predominantly beta-lactams, is still crucial for the control of the disease.
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Affiliation(s)
- Carlos Neila-Ibáñez
- Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.,Office International des Epizooties Collaborating Centre for the Research and Control of Emerging and Re-emerging Diseases in Europe, Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Bellaterra, Spain
| | - Jordi Casal
- Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.,Office International des Epizooties Collaborating Centre for the Research and Control of Emerging and Re-emerging Diseases in Europe, Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Bellaterra, Spain.,Department of Animal Health and Anatomy, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Isabel Hennig-Pauka
- Field Station for Epidemiology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | | | - Marcelo Gottschalk
- Research Group on Infectious Diseases in Production Animals and Swine and Poultry Infectious Diseases Research Centre, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Lourdes Migura-García
- Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.,Office International des Epizooties Collaborating Centre for the Research and Control of Emerging and Re-emerging Diseases in Europe, Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Bellaterra, Spain
| | - Lola Pailler-García
- Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.,Office International des Epizooties Collaborating Centre for the Research and Control of Emerging and Re-emerging Diseases in Europe, Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Bellaterra, Spain
| | - Sebastián Napp
- Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain.,Office International des Epizooties Collaborating Centre for the Research and Control of Emerging and Re-emerging Diseases in Europe, Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Bellaterra, Spain
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12
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Obradovic MR, Segura M, Segalés J, Gottschalk M. Review of the speculative role of co-infections in Streptococcus suis-associated diseases in pigs. Vet Res 2021; 52:49. [PMID: 33743838 PMCID: PMC7980725 DOI: 10.1186/s13567-021-00918-w] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/25/2021] [Indexed: 12/21/2022] Open
Abstract
Streptococcus suis is one of the most important bacterial swine pathogens affecting post-weaned piglets, causing mainly meningitis, arthritis and sudden death. It not only results in severe economic losses but also raises concerns over animal welfare and antimicrobial resistance and remains an important zoonotic agent in some countries. The definition and diagnosis of S. suis-associated diseases can be complex. Should S. suis be considered a primary or secondary pathogen? The situation is further complicated when referring to respiratory disease, since the pathogen has historically been considered as a secondary pathogen within the porcine respiratory disease complex (PRDC). Is S. suis a respiratory or strictly systemic pathogen? S. suis is a normal inhabitant of the upper respiratory tract, and the presence of potentially virulent strains alone does not guarantee the appearance of clinical signs. Within this unclear context, it has been largely proposed that co-infection with some viral and bacterial pathogens can significantly influence the severity of S. suis-associated diseases and may be the key to understanding how the infection behaves in the field. In this review, we critically addressed studies reporting an epidemiological link (mixed infections or presence of more than one pathogen at the same time), as well as in vitro and in vivo studies of co-infection of S. suis with other pathogens and discussed their limitations and possibilities for improvement and proposed recommendations for future studies.
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Affiliation(s)
- Milan R Obradovic
- Groupe de Recherche Sur Les Maladies Infectieuses en Production Animale (GREMIP), Centre de Recherche en Infectiologie Porcine et Aviaire (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada
| | - Mariela Segura
- Groupe de Recherche Sur Les Maladies Infectieuses en Production Animale (GREMIP), Centre de Recherche en Infectiologie Porcine et Aviaire (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada
| | - Joaquim Segalés
- UAB, CReSA (IRTA-UAB), Campus de la UAB, 08193, Bellaterra (Cerdanyola del Vallès), Spain.,Departament de Sanitat I Anatomia Animals, Facultat de Veterinària, UAB, 08193, Bellaterra (Cerdanyola del Vallès), Spain.,OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), 08193, Bellaterra, Barcelona, Spain
| | - Marcelo Gottschalk
- Groupe de Recherche Sur Les Maladies Infectieuses en Production Animale (GREMIP), Centre de Recherche en Infectiologie Porcine et Aviaire (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada.
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13
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Corsaut L, Martelet L, Goyette-Desjardins G, Beauchamp G, Denicourt M, Gottschalk M, Segura M. Immunogenicity study of a Streptococcus suis autogenous vaccine in preparturient sows and evaluation of passive maternal immunity in piglets. BMC Vet Res 2021; 17:72. [PMID: 33546699 PMCID: PMC7866767 DOI: 10.1186/s12917-021-02774-4] [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: 08/26/2020] [Accepted: 01/21/2021] [Indexed: 12/28/2022] Open
Abstract
Background Streptococcus suis is an important pathogen that causes severe diseases mostly in weaned piglets. Only available vaccines in the field are those composed of killed bacteria (bacterins) but data about their effectiveness are missing. We report here a field study on the immunological response induced by an autogenous vaccine applied in pre-parturient sows. Using a farm with recurrent S. suis serotype 7 problems, the study was divided in three experiments: (I) Sows received the vaccine at 7 and 3 weeks pre-farrowing. (II) Replacement gilts introduced to the herd received the vaccine at 4 and 7 weeks after their entry in quarantine and a boost 3 weeks pre-farrowing. (III) Gilts from experiment II received another boost 3 weeks pre-farrowing at their 3rd/4th parity. Levels, isotype profile and opsonophagocytosis capacity of the serum antibodies induced by vaccination were evaluated in sows and maternal immunity in piglets. Results In sows (I), the vaccine induced a slight, albeit significant, increase in anti-S. suis total antibodies after 2 doses when compare to basal levels already present in the animals. These antibodies showed a high opsonic capacity in vitro, highlighting their potential protective capacity. A gilt vaccination program of 3 doses (II) resulted in a significant increase in anti-S. suis total antibodies. Levels of maternal immunity transferred to piglets were high at 7 days of age, but rapidly decreased by 18 days of age. A gilt vaccination program ensued a higher transfer of maternal immunity in piglets compared to control animals; nevertheless duration was not improved at 18 day-old piglets. The vaccine response in both gilts and sows was mainly composed of IgG1 subclass, which was also the main Ig transferred to piglets. IgG2 subclass was also found in piglets, but its level was not increased by vaccination. Finally, a recall IgG1 response was induced by another boost vaccination at 3rd/4th parity (III), indicating that the vaccine induced the establishment of a lasting memory response in the herd. Conclusions Overall, an optimal gilt/sow vaccination program might result in increased antibody responses; nevertheless duration of maternal immunity would not last long enough to protect post-weaned piglets. Supplementary Information The online version contains supplementary material available at 10.1186/s12917-021-02774-4.
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Affiliation(s)
- Lorelei Corsaut
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, Quebec, J2S 2M2, Canada
| | - Léa Martelet
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, Quebec, J2S 2M2, Canada
| | - Guillaume Goyette-Desjardins
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, Quebec, J2S 2M2, Canada
| | - Guy Beauchamp
- Biostatistics Office, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Martine Denicourt
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, Quebec, J2S 2M2, Canada
| | - Marcelo Gottschalk
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, Quebec, J2S 2M2, Canada
| | - Mariela Segura
- Research Group on Infectious Diseases in Production Animals (GREMIP) and Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte St., Saint-Hyacinthe, Quebec, J2S 2M2, Canada.
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14
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Comparative Study of Immunogenic Properties of Purified Capsular Polysaccharides from Streptococcus suis Serotypes 3, 7, 8, and 9: the Serotype 3 Polysaccharide Induces an Opsonizing IgG Response. Infect Immun 2020; 88:IAI.00377-20. [PMID: 32747605 PMCID: PMC7504959 DOI: 10.1128/iai.00377-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 07/30/2020] [Indexed: 12/17/2022] Open
Abstract
Streptococcus suis is an encapsulated bacterium and one of the most important swine pathogens and a zoonotic agent for which no effective vaccine exists. Bacterial capsular polysaccharides (CPSs) are poorly immunogenic, but anti-CPS antibodies are essential to the host defense against encapsulated bacteria. In addition to the previously known serotypes 2 and 14, which are nonimmunogenic, we have recently purified and described the CPS structures for serotypes 1, 1/2, 3, 7, 8, and 9. Streptococcus suis is an encapsulated bacterium and one of the most important swine pathogens and a zoonotic agent for which no effective vaccine exists. Bacterial capsular polysaccharides (CPSs) are poorly immunogenic, but anti-CPS antibodies are essential to the host defense against encapsulated bacteria. In addition to the previously known serotypes 2 and 14, which are nonimmunogenic, we have recently purified and described the CPS structures for serotypes 1, 1/2, 3, 7, 8, and 9. Here, we aimed to elucidate how these new structurally diverse CPSs interact with the immune system to generate anti-CPS antibody responses. CPS-stimulated dendritic cells produced significant levels of C–C motif chemokine ligand 3 (CCL3), partially via Toll-like receptor 2 (TLR2)- and myeloid differentiation factor 88-dependent pathways, and CCL2, via TLR-independent mechanisms. Mice immunized with purified serotype 3 CPS adjuvanted with TiterMax Gold produced an opsonizing IgG response, whereas other CPSs or adjuvants were negative. Mice hyperimmunized with heat-killed S. suis serotypes 3 and 9 both produced anti-CPS type 1 IgGs, whereas serotypes 7 and 8 remained negative. Also, mice infected with sublethal doses of S. suis serotype 3 produced primary anti-CPS IgM and IgG responses, of which only IgM were boosted after a secondary infection. In contrast, mice sublethally infected with S. suis serotype 9 produced weak anti-CPS IgM and IgG responses following a secondary infection. This study provides important information on the divergent evolution of CPS serotypes with highly different structural and/or biochemical properties within S. suis and their interaction with the immune system.
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