As in other countries, in the Czech Republic, Streptococcus suis infection in pigs is considered an economically significant disease for the pig industry, though little is known about its population structure. We collected S. suis isolates from 144 farms in the years 2018-2022. All samples were taken from animals suffering from symptoms indicating possible S. suis infection. Serotyping revealed the presence of 23 different serotypes, and 18.94% were non-typable strains. The most common was S7 (14.96%), while other serotypes had frequencies of less than 10%. Sequence typing identified 56 different sequence types, including 31 newly assigned sequence types together with 41 new alleles in genes in the MLST schema. A large portion of isolates (25.70%) were of unknown sequence type. The most common sequence types were ST29 (14.77%) and ST28 (10.04%); the other sequence types had frequencies of less than 10%. In total, 100 different combinations of serotypes and sequence types were identified. Among them, S7ST29 was found in 72 isolates, representing 13.63% of all isolates, and was significantly associated with the central nervous system. Many other isolates of particular serotype and sequence type combinations were found in a few cases, and a number of isolates were non-typable.

Department of Experimental Biology Faculty of Science Masaryk University 602 00 Brno Czech Republic

State Veterinary Institute Jihlava 586 01 Jihlava Czech Republic

Veterinary Research Institute 621 00 Brno Czech Republic

See more in PubMed

Reams R.Y., Glickman L.T., Harrington D.D., Thacker H.L., Bowersock T.L. Streptococcus suis infection in swine: A retrospective study of 256 cases. Part II. Clinical signs, gross and microscopic lesions, and coexisting microorganisms. J. Vet. Diagn. Investig. 1994;6:326–334. doi: 10.1177/104063879400600308. PubMed DOI

Staats J.J., Feder I., Okwumabua O., Chengappa M.M. Streptococcus suis: Past and present. Vet. Res. Commun. 1997;21:381–407. doi: 10.1023/A:1005870317757. PubMed DOI

Gottschalk M., Segura M., Xu J. Streptococcus suis infections in humans: The Chinese experience and the situation in North America. Anim. Health Res. Rev. 2007;8:29–45. doi: 10.1017/S1466252307001247. PubMed DOI

Galina L., Collins J.E., Pijoan C. Porcine Streptococcus suis in Minnesota. J. Vet. Diagn. Investig. 1992;4:195–196. doi: 10.1177/104063879200400216. PubMed DOI

Weinert L.A., Chaudhuri R.R., Wang J., Peters S.E., Corander J., Jombart T., Baig A., Howell K.J., Vehkala M., Välimäki N., et al. Genomic signatures of human and animal disease in the zoonotic pathogen Streptococcus suis. Nat. Commun. 2015;6:6740–6748. doi: 10.1038/ncomms7740. PubMed DOI PMC

Estrada A.A., Gottschalk M., Rossow S., Rendahl A., Gebhart C., Marthaler D.G. Serotype and Genotype (Multilocus Sequence Type) of Streptococcus suis Isolates from the United States Serve as Predictors of Pathotype. J. Clin. Microbiol. 2019;57:e00377-19. doi: 10.1128/JCM.00377-19. PubMed DOI PMC

Okura M., Osaki M., Nomoto R., Arai S., Osawa R., Sekizaki T., Takamatsu D. Current taxonomical situation of Streptococcus suis. Pathogens. 2016;5:45. doi: 10.3390/pathogens5030045. PubMed DOI PMC

Perch B., Pedersen K.B., Heinrichsen J. Serology of capsulated streptococci pathogenic for pigs: Six new serotypes of Streptococcus suis. J. Clin. Microbiol. 1983;17:993–996. doi: 10.1128/jcm.17.6.993-996.1983. PubMed DOI PMC

El Garch F., de Jong A., Simjee S., Moyaert H., Klein U., Ludwig C., Marion H., Haag-Diergarten S., Richard-Mazet A., Thomas V., et al. Monitoring of antimicrobial susceptibility of respiratory tract pathogens isolated from diseased cattle and pigs across Europe. 2009–2012: VetPath results. Vet. Microbiol. 2016;194:11–22. doi: 10.1016/j.vetmic.2016.04.009. PubMed DOI

Gottschalk M., Higgins R., Boudreau M. Use of polyvalent coagglutination reagents for serotyping of Streptococcus suis. J. Clin. Microbiol. 1993;31:2192–2194. doi: 10.1128/jcm.31.8.2192-2194.1993. PubMed DOI PMC

Gottschalk M., Higgins R., Jacques M., Mittal K.R., Henrichsen J. Description of 14 new capsular types of Streptococcus suis. J.Clin. Microbiol. 1989;27:2633–2635. doi: 10.1128/jcm.27.12.2633-2636.1989. PubMed DOI PMC

Gottschalk M., Higgins R., Jacques M., Beaudoin M., Henrichsen J. Characterization of six new capsular types (23 through 28) of Streptococcus suis. J. Clin. Microbiol. 1991;29:2590–2594. doi: 10.1128/jcm.29.11.2590-2594.1991. PubMed DOI PMC

Liu Z., Zheng H., Gottschalk M., Bai X., Lan R., Ji S., Liu H., Xu J. Development of multiplex PCR assays for the identification of the 33 serotypes of Streptococcus suis. PLoS ONE. 2013;8:e72070. doi: 10.1371/journal.pone.0072070. PubMed DOI PMC

Okura M., Lachance C., Osaki M., Sekizaki T., Maruyama F., Nozawa T., Nakagawa I., Hamada S., Rossignol C., Gottschalk M., et al. Development of a two-step multiplex PCR assay for typing of capsular polysaccharide synthesis gene clusters of Streptococcus suis. J. Clin. Microbiol. 2014;52:1714–1719. doi: 10.1128/JCM.03411-13. PubMed DOI PMC

Scherrer S., Rademacher F., Spoerry Serrano N., Schrenzel J., Gottschalk M., Stephan R., Landolt P. Rapid high resolution melting assay to differentiate Streptococcus suis serotypes 2, 1/2, 1, and 14. Microbiol. Open. 2020;9:e995. doi: 10.1002/mbo3.995. PubMed DOI PMC

Matiasovic J., Zouharova M., Nedbalcova K., Kralova N., Matiaskova K., Simek B., Kucharovicova I., Gottschalk M. Resolution of Streptococcus suis serotypes 1/2 versus 2 and 1 versus 14 by PCR-Restriction Fragment Lenght Polymorphism Method. J. Clin. Microbiol. 2020;58:e00480-20. doi: 10.1128/JCM.00480-20. PubMed DOI PMC

Athey T.B., Teatero S., Lacouture S., Takamatsu D., Gottschalk M., Fittipaldi N. Determining Streptococcus suis serotype from short-read whole-genome sequencing data. BMC Microbiol. 2016;16:162. doi: 10.1186/s12866-016-0782-8. PubMed DOI PMC

Wisselink H.J., Smith H.E., Stockhofe-Zurwieden N., Peperkamp K., Vecht U. Distribution of capsular types and production of muramidase-released protein (MRP) and extracellular factor (EF) of Streptococcus suis strains isolated from diseased pigs in seven European countries. Vet. Microbiol. 2000;74:237–248. doi: 10.1016/S0378-1135(00)00188-7. PubMed DOI

Goyette-Desjardins G., Auger J.P., Xu J., Segura M., Gottschalk M. Streptococcus suis, an important pig pathogen and emerging zoonotic agent-an update on the worldwide distribution based on serotyping and sequence typing. Emerg. Microbes. Infec. 2014;3:e45. doi: 10.1038/emi.2014.45. PubMed DOI PMC

Messier S., Lacouture S., Gottschalk M. Distribution of Streptococcus suis capsular types from 2001 to 2007. Can. Vet. J. 2008;49:461–462. PubMed PMC

Fittipaldi N., Fuller T.E., Teel J.F., Wilson T.L., Wolfram T.J., Lowery D.E., Gottschalk M. Serotype distribution and production of muramidasereleased protein, extracellular factor and suilysin by field strains of Streptococcus suis isolated in the United States. Vet. Microbiol. 2009;139:310–317. doi: 10.1016/j.vetmic.2009.06.024. PubMed DOI

Vela A.I., Goyache J., Tarradas C., Luque I., Mateos A., Moreno M.A., Borge C., Perea J.A., Dominguez L., Fernandez-Garayzabal J.F. Analysis of genetic diversity of Streptococcus suis clinical isolates from pigs in Spain by pulsed-field gel electrophoresis. J. Clin. Microbiol. 2003;41:2498–2502. doi: 10.1128/JCM.41.6.2498-2502.2003. PubMed DOI PMC

King S.J., Leigh J.A., Heath P.J., Luque I., Tarradas C., Dowson C.G., Whatmore A.M. Development of a multilocus sequence typing scheme for the pig pathogen Streptococcus suis: Identification of virulent clones and potential capsular serotype exchange. J. Clin. Microbiol. 2002;40:3671–3680. doi: 10.1128/JCM.40.10.3671-3680.2002. PubMed DOI PMC

Athey T.B., Auger J.P., Teatero S., Dumesnil A., Takamatsu D., Wasserscheid J., Dewar K., Gottschalk M., Fittipaldi N. Complex population structure and virulence differences among serotype 2 Streptococcus suis strains belonging to sequence type 28. PLoS ONE. 2015;10:e0137760. doi: 10.1371/journal.pone.0137760. PubMed DOI PMC

Schultsz C., Jansen E., Keijzers W., Rothkamp A., Duim B., Wagenaar J.A., van der Ende A. Differences in the population structure of invasive Streptococcus suis strains isolated from pigs and from humans in the Netherlands. PLoS ONE. 2012;7:e33854. doi: 10.1371/journal.pone.0033854. PubMed DOI PMC

Kozáková J., Okonji Z., Kubartová H. Molecular diagnosis of Streptococcus suis newly introduced in the National Reference Laboratory for Streptococcal Infections. Zprávy CEM (SZÚ Praha) 2019;28:12–13.

Kerdsin A., Akeda Y., Hatrongjit R., Detchawna U., Sekizaki T., Hamada S., Gottschalk M., Oishi K. Streptococcus suis serotyping by a new multiplex PCR. J. Med. Microbiol. 2014;63:824–830. doi: 10.1099/jmm.0.069757-0. PubMed DOI

Ishida S., Tienle H.T., Osawa R., Tohya M., Nomoto R., Kawamura Y., Takahashi T., Kikuchi N., Kikuchi K., Sekizaki T. Development of an appropriate PCR system for the reclassification of Streptococcus suis. J. Microbiol. Methods. 2014;107:66–70. PubMed

Mittal K.R., Higgins R., Larivière S. Identification and serotyping of Haemophilus pleuropneumoniae by coagglutination test. J. Clin. Microbiol. 1983;18:1351–1354. doi: 10.1128/jcm.18.6.1351-1354.1983. PubMed DOI PMC

Lê S., Josse J., Husson F. FactoMineR: An R Package for Multivariate Analysis. J. Stat. Soft. 2008;25:1–18. doi: 10.18637/jss.v025.i01. DOI

Kassambara A., Mundt F., Factoextra: Extract and Visualize the Results of Multivariate Data Analyses R Package Version 1.0.7. 2020. [(accessed on 9 November 2022)]. Available online: https://cran.r-project.org/package=factoextra.

Prüfer T.L., Rohde J., Verspohl J., Rohde M., de Greeff A., Willenborg J., Valentin-Weigand P. Molecular typing of Streptococcus suis strains isolated from diseased and healthy pigs between 1996-2016. PLoS ONE. 2019;14:e0210801. doi: 10.1371/journal.pone.0210801. PubMed DOI PMC

Scherrer S., Rosato G., Spoerry Serrano N., Stevens M.J.A., Rademacher F., Schrenzel J., Gottschalk M., Stephan R., Peterhans S. Population structure, genetic diversity and pathotypes of Streptococcus suis isolated during the last 13 years from diseased pigs in Switzerland. Vet Res. 2020;51:85. doi: 10.1186/s13567-020-00813-w. PubMed DOI PMC

Yang H., Huang J., Hu X., Hu M., Zhang Q., Jin M. Comparative Genome Analysis of Streptococcus suis Serotype 9 Isolates from China, The Netherland, and the U.K. Life. 2021;11:1324. doi: 10.3390/life11121324. PubMed DOI PMC

Rieckmann K., Seydel A., Szewczyk K., Klimke K., Rungelrath V., Baums C.G. Streptococcus suis cps7: An emerging virulent sequence type (ST29) shows a distinct, IgM-determined pattern of bacterial survival in blood of piglets during the early adaptive immune response after weaning. Vet Res. 2018;49:48. doi: 10.1186/s13567-018-0544-8. PubMed DOI PMC

Matiašovic J., Nedbalcová K., Žižlavský M., Fleischer P., Pokludová L., Kellnerová D., Nechvátalová K., Šimek B., Czanderlová L., Zouharová M., et al. Streptococcus suis Isolates—Serotypes and Susceptibility to Antimicrobials in Terms of Their Use on Selected Repopulated Czech Pig Farms. Pathogens. 2021;10:1314. doi: 10.3390/pathogens10101314. PubMed DOI PMC