Vibrio parahaemolyticus is a halophilic gram-negative bacterium causing seafood-associated gastroenteritis. The Kanagawa phenomenon, used to distinguish pathogenic from non-pathogenic strains, refers to beta-hemolysis on high-salt Wagatsuma agar mediated by which toxin?
- A Cholera toxin (CT)
- B Thermolabile hemolysin (TLH)
- C Thermostable direct hemolysin (TDH) ✓
- D Shiga toxin (Stx)
Correct answer: C. Thermostable direct hemolysin (TDH)
Explanation
Thermostable direct hemolysin (TDH) is responsible for the Kanagawa phenomenon, beta-hemolysis on Wagatsuma agar containing human or rabbit blood. TDH-positive strains are almost exclusively clinical isolates. Cholera toxin is produced by V. cholerae O1/O139. TLH is a phospholipase common to all V. parahaemolyticus strains. Shiga toxin is produced by Shigella and EHEC, not Vibrio species.
Reference: Jawetz, Melnick, & Adelberg's Medical Microbiology, 28th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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