Streptococcus suis

Streptococcus suis
Phylum	Firmicutes
Class	Bacilli
Order	Lactobacillales
Family	Streptococcaceae
Genus	Streptococcus
Species	S. suis

Introduction

Streptococcus suis is best known for causing multisystemic disease and mortality in pigs and septicaemia in poultry. It is one of the Streptococcus genus of gram positive cocci.

There are many serotypes of S. suis, most clinical infections generate isolates of capsule types 1-8. Capsule type 2 is responsible for most human infections

Lifecycle

The bacterium is a commensal of healthy pigs and is carried in the tonsils of asymptomatic carrier pigs. It is transmitted via respiratory secretions, ingestion of faeces or exudates or vertically from sows. Disease usually presents after a stressful incident allows opportunistic infection by resident microflora from the respiratory or gastrointestinal tracts.

Pathogenesis

Virulence factors for S. suis include fimbriae, haemagglutinins, capsular antigens, cell wall proteins, IgG binding proteins and haemolysins. The capsule protects the bacteria from phagocytosis.

Diseases

Disease is often multisystemic and includes meningitis, arthritis, pericarditis, pneumonia, endocarditis, rhinitis and septicaemia most notably in pigs and poultry but also in cattle, horses, dogs, cats and people. S. suis is a zoonosis of utmost importance.

See infections in pigs and infections in poultry for details.

Streptococcus suis Learning Resources
Flashcards Test your knowledge using flashcard type questions	S. suis Flashcards

References

This article was originally sourced from The Animal Health & Production Compendium (AHPC) published online by CABI during the OVAL Project. The datasheet was accessed on 6 July 2011.