Prevalence of virulence-associated genes in culture-confirmed Vibrio cholerae isolates: a PCR-based study

Abstract

Vibrio cholerae remains a major cause of cholera outbreaks in Ethiopia, yet information on the distribution of virulence-associated genes among circulating strains is limited. This study aimed to detect major virulence genes in culture-confirmed V. cholerae isolates recovered from cholera outbreak sites in Ethiopia using multiplex polymerase chain reaction. A total of 125 culture-confirmed V. cholerae isolates recovered from fecal samples collected during cholera outbreaks in Ethiopia were analyzed. Following sub-culture and genomic DNA extraction, multiplex PCR assays were performed to detect nine virulence-associated genes ( ompW , tcpA , rfbO1 , zot , toxR , rtxC , ace , hlyA , and ompU ). All nine target genes were identified among the isolates, although their frequencies varied. The most frequently detected gene was hlyA (84.0%, 105/125), followed by ompW (80.8%, 101/125), rfbO1 (76.8%, 96/125), tcpA (75.2%, 94/125), zot (72.8%, 91/125), ompU and toxR (71.2%, 89/125 each), ace (69.6%, 87/125), and rtxC (68.8%, 86/125). All the virulence genes were observed among isolates obtained from outbreak sites in the Amhara, Oromia, and Addis Ababa regions. The detection of multiple virulence-associated genes highlights the pathogenic potential of outbreak-associated V. cholerae strains and provides baseline molecular data for future epidemiological and genomic investigations in Ethiopia.