How Has Pathogenicity in Pandemic Strains of Vibrio Cholerae Been

Question

How has pathogenicity in pandemic strains of Vibrio cholerae been acquired?
A) By transformation
B) By transduction
C) By conjugation
D) By vertical gene transfer

Accepted Answer

Pathogenicity in V. cholerae is associated with infection of the bacteria with bacteriophages. Incorporation of the CTXφ bacteriophage created the Classical pathogenic strains of V. cholerae responsible for the first six worldwide cholera epidemics. The seventh was caused by a strain that picked up the CTXφ bacteriophage along with an associated bacteriophage RS1φ.