Resistance Profile and Molecular Characterization of Toxigenic Vibrio cholerae Strains Responsible for the 2016 to 2018 Epidemic in Republic of Benin (West Africa)

Aims: This study aims to characterize of toxigenic Vibrio cholerae strains for improved cholera surveillance in Benin.

Methodology: 304 diarrheal stool samples were collected from people with watery diarrhea of unknown etiology and vomiting during epidemics from 2016 to 2018 in Benin. Toxigenic Vibrio cholerae strains were isolated and then biochemical tests, serogrouping and serotyping were performed. Antibiotic susceptibility tests were performed using the disc diffusion method and E-tests. Multiplex and real-time PCR were used to identify and detect virulence genes (CtxA, OmpW and TcpA).

Results: The results showed a 21.71% prevalence of toxigenic Vibrio cholera in Benin. All strains were Vibrio cholerae O1 serotype Inaba (100%) and showed a high sensitivity to doxycycline (96.97 %), chloramphenicol (95.45 %) and ciprofloxacin (90.91 %). However, antibiotic resistance was observed, especially for erythromycin (74.24 %), Trimethoprim-sulfamethoxazole (71.21 %) and ampicillin (43.94 %). The CtxA and TcpA virulence genes were respectively detected in 100% and 96.97% of the toxigenic strains of V. cholerae isolated. While the OmpW gene was identified on all the toxigenic strains of Vibrio cholerae isolated.

Conclusion: Vibrio cholerae strains isolated from patients suspected of cholera were highly virulent and resistant to antimicrobials.