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Research article - Peer-reviewed, 2020

Streptococcus suisin Swedish grower pigs: occurrence, serotypes, and antimicrobial susceptibility

Werinder, Anna; Aspan, Anna; Backhans, Annette; Sjolund, Marie; Guss, Bengt; Jacobson, Magdalena

Abstract

Background Streptococcus suisis a major cause of meningitis, arthritis, and pneumonia in pigs worldwide, and an emerging pathogen in humans. In Sweden,S. suishas previously received little attention but has in recent years become increasingly recognized as affecting the pig production. The aim of the present study was to investigate the occurrence, serotypes and antimicrobial susceptibility ofS. suisin Swedish grower pigs from herds with and without reportedS. suisassociated disease, as well as possible associations betweenS. suisassociated disease and selected environmental and production factors. Swab samples were taken from the tonsils of clinically healthy 8-13-week-old grower pigs from ten case herds and ten control herds. Isolates were cultured, identified using MALDI-TOF MS, and serotyped using latex agglutination. The antimicrobial susceptibility of 188 isolates was tested using broth microdilution. Production data was gathered and environmental parameters were measured on the farms. Results Streptococcus suiswas isolated from 95% of the sampled pigs in both the case and the control herds. Serotypes 3, 4, 5, 7, 9, 10, 11, 15, 16, and 17-34 were detected, although a majority of the isolates (81.5%) were non-typeable. There was less diversity among the serotypes isolated from the case herds than among those from the control herds; four and nine different serotypes, respectively. Isolates resistant to penicillin (3.8%) were reported for the first time in Sweden. Tetracycline resistance was common (88.4%). No association was noted between the production and the environmental factors investigated, and the carriership ofS. suis. Conclusions The carriership ofS. suiswas found to be higher in clinically healthy Swedish pigs than previously estimated, and for the first time, the presence of Swedish isolates resistant to penicillin was reported. Many of the most commonly disease-associated serotypes, e.g. serotypes 2, 9, 3, and 7, were detected in healthy grower pigs although further studies are needed to investigate the virulence of these isolates.

Keywords

Antibiotic resistance; Bacteria; Environmental factors; Infectious diseases; Meningitis; Microbiology; Porcine; Streptococci; Swine; Zoonosis

Published in

Acta Veterinaria Scandinavica
2020, volume: 62, number: 1, article number: 36
Publisher: BMC

Authors' information

Swedish University of Agricultural Sciences, Department of Clinical Sciences
Aspan, Anna
Natl Vet Inst SVA
Backhans, Annette
Natl Vet Inst SVA
Sjolund, Marie
Natl Vet Inst SVA
Swedish University of Agricultural Sciences, Department of Biomedical Science and Veterinary Public Health
Swedish University of Agricultural Sciences, Department of Clinical Sciences

Sustainable Development Goals

SDG3 Good health and wellbeing

UKÄ Subject classification

Clinical Science

Publication Identifiers

DOI: https://doi.org/10.1186/s13028-020-00533-3

URI (permanent link to this page)

https://res.slu.se/id/publ/106981