Phage-induced changes in Vibrio cholerae: serotype and biotype conversions

Area of Science:

• Microbiology
• Virology
• Genetics

Background:

• Vibrio cholerae, the causative agent of cholera, exhibits diverse serotypes and characteristics.
• Bacteriophages (phages) are viruses that infect bacteria and can influence bacterial genetics and phenotypes.
• Understanding phage-host interactions is crucial for comprehending bacterial evolution and pathogenicity.

Purpose of the Study:

• To investigate the effects of bacteriophage infection on the antigenic properties and other characteristics of Vibrio cholerae.
• To determine if phage infection can induce stable genetic changes in Vibrio cholerae strains.
• To explore the potential for phage-mediated genetic recombination in Vibrio cholerae.

Main Methods:

• Infection of Vibrio cholerae strains with specific bacteriophages.
• Analysis of antigenic changes using serological methods.
• Assessment of phage resistance and lysogeny in converted strains.
• Evaluation of acquired traits such as polymyxin resistance.

Main Results:

• Phage infection converted Vibrio cholerae Ogawa to Hikojima serotype, acquiring antigenic factor C.
• Some phage-converted strains exhibited stable lysogeny and resistance to superinfection.
• Reinfection of unstable strains restored the ability to synthesize antigen C.
• Polymyxin resistance, a characteristic of El Tor vibrios, was induced in some strains.

Conclusions:

• Bacteriophage infection is a potent driver of genetic and antigenic variation in Vibrio cholerae.
• Phage-induced changes can lead to the emergence of novel Vibrio cholerae strains with altered characteristics.
• These alterations contribute to the genetic diversity and adaptability of Vibrio cholerae populations.