Vibrio cholerae O139 can cause epidemic cholera whereas most other O serogroups cannot. The unique feature of V. cholerae O139 that allows this is:
- A Production of a novel heat-stable toxin instead of cholera toxin
- B Possession of a polysaccharide capsule that V. cholerae O1 lacks ✓
- C Resistance to all aminoglycoside antibiotics
- D Ability to survive in freshwater unlike O1 biotypes
Correct answer: B. Possession of a polysaccharide capsule that V. cholerae O1 lacks
Explanation
V. cholerae O139 (Bengal) emerged in 1992 and can cause epidemic cholera equivalent to O1; it uniquely possesses a polysaccharide capsule (absent in O1 strains) which confers resistance to complement and phagocytosis, contributing to epidemic potential; O139 also lacks the O1 somatic antigen but still carries the same CT and TCP pathogenicity islands. It produces the same cholera toxin CT as O1, not a novel HST. Both O1 and O139 are intrinsically susceptible to aminoglycosides. O1 El Tor also survives well in aquatic environments.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.