STREPTOCOCCUS SUIS, TWO-FACED GAME CHANGER

Abstract

Streptococcus suis infection is one of the major health problems in the swine industry worldwide. During the last decade, the number of reported human cases due to S. suis has dramatically increased, and while most sporadic human cases of infection appear to be due to close occupational contact with pigs/pork products. S. suis infection is considered to be multifactorial, with transition from subclinical to clinical that depends on many factors. These factors can be divided in two groups, host-based and external factors. Pathogenesis of S. suis infection can be divided into 4 phases: adherence to and colonisation of mucosal and epithelial surfaces, invasion into deeper tissues and entering the bloodstream, crossing bloodbrain barrier and inflammation. S. suis virulence-associated factors are divided into the following 4 groups: surface/secreted elements, enzymes (such as including proteases), transcription factors and regulatory systems and other factors (such as transporting and secreting systems). Therefore significant research support is needed to obtain a vaccine as a valuable and universal protection against disease caused by S. suis strains and thus national and international support will be crucial for the aim many researchers hope for.