Virulence-associated characteristics and phage lysogenicity of two morphologically distinct colonies ofVibrio choleraeO139 serogroup

Abstract

The presence of a temperate phage was demonstrated in a strain of Vibrio cholerae O139 isolated from a patient. Spontaneous variants with translucent colonies had lost this phage. The loss of the phage was associated with increased hydrophobicity, indicating the loss of the capsule. These clones were sensitive to serum bactericidal activity, showed decreased expression of such presumed virulence factors as proteases, motility and mannose-sensitive pili. Furthermore, excision of the phage made the strain dependent on purines for growth.

Genetic, physiological, and cellular heterogeneities of bacterial pathogens in food matrices: Consequences for food safety

“…A potential link with RsbU, a positive σ B regulator, was suggested but requires further investigation to be demonstrated. In V. cholerae, the induction and excision of a prophage in the proximity of genes involved in purine (pur) and capsule (cap) biosynthesis lead to phase variation of the capsule biosynthesis and a switch from opaque to translucent colonies (Smirnova et al, 1996).…”