Streptococcus suis (S. suis)

Streptococcus suis is a Gram-positive, facultatively anaerobic coccus that serves as a major pathogen in the swine industry and an emerging zoonotic threat to humans (Wikipedia, 2023). It primarily colonizes the upper respiratory tract of pigs but can cause severe systemic infections, including meningitis, septicemia, and endocarditis, in both swine and humans (StatPearls, 2023). Human infection typically occurs through direct contact with infected pigs or raw pork products, with a high prevalence noted in Southeast Asia (NIH, 2021). The bacterium utilizes several virulence factors, most notably the capsular polysaccharide (CPS) for immune evasion and suilysin, a pore-forming toxin that facilitates tissue invasion (PubMed, 2020). While Streptococcus suis is a whole organism rather than a single molecular target, it contains numerous essential proteins and enzymes targeted by traditional antibiotics such as penicillins and cephalosporins. Effective clinical management requires prompt diagnosis and intensive antimicrobial therapy, although the high incidence of permanent sensorineural hearing loss following meningitis remains a significant therapeutic challenge (The Lancet Infectious Diseases, 2009).

Other names

S. suisLancefield group R streptococciLancefield group S streptococciLancefield group T streptococci

Antibacterial agents target Streptococcus suis through various mechanisms: beta-lactams (e.g., Penicillin) inhibit cell wall synthesis by binding to penicillin-binding proteins; aminoglycosides (e.g., Gentamicin) inhibit protein synthesis by binding to the 30S ribosomal subunit; and vancomycin inhibits cell wall synthesis by binding to the D-Ala-D-Ala terminus of nascent peptidoglycan.