Wild waterfowl as potential vectors of Vibrio cholerae and Aeromonas species

Objective: To study the hypothesis that migratory waterfowl are possible disseminators of Vibrio cholerae and Aeromonas. Methods: We monitored the presence of V. cholerae and Aeromonas in three wild waterfowl species. Results: V. cholerae and Aeromonas species were isolated and identified from intestine samples of little egrets and black-crowned night herons. Only Aeromonas species were isolated from black-headed gulls. The majority of Aeromonas isolates were A. veronii. Twenty-three V. cholerae serogroups were identified. V. cholerae serogroup O1 was found in the intestine DNA extractions from four little egrets and black-crowned night herons; six birds carried cholera toxin subunit A gene. Conclusion: Wild waterfowl species may carry pathogenic V. cholerae O1 and non-O1 serogroups and Aeromonas species in their intestine. The migration of waterfowl is a potential mechanism for global distribution of V. cholerae and Aeromonas.