Molecular diversity and antimicrobial susceptibility profile of Vibrio species and distribution of other bacteria isolated from water Hyacinth (Eichornia crassipes) and Lagos lagoon

Aquatic environments, including their flora and fauna, are known reservoirs of pathogenic Vibrio species. This study aimed to determine the diversity and antimicrobial susceptibility of bacteria from water hyacinth (Eichornia crassipes) and surrounding waters in Lagos lagoons. Bacteria isolation, phenotypic, and genotypic analysis were conducted using standard microbiology and molecular methods..Sampled lagoons exhibited physicochemical parameters such as dissolved oxygen (4.76—6.91 mgL⁻¹) and biochemical oxygen demand (80.5 – 242 mgL⁻¹) that exceeded permissible levels, indicating pollution. A total of 41 bacterial isolates were recovered from water hyacinth samples and surrounding lagoon waters. Twelve (29.26%) were Vibrio strains, comprising 4 (9.8%) Vibrio cholerae, 3 (7.3%) V. paracholerae, 2 (4.9%) V. parahaemolyticus, 2 (4.88%) V. injensis and 1 (2.4%) V. mimicus. Of the 4 V. cholerae isolates, 1 belonged to the O1 serotype. Vibrio species were exclusively recovered from water samples. Phylogenetic analysis of the Vibrio strains isolated from different lagoons showed genetic relatedness. All 41(100%) bacteria isolates displayed pan sensitivity to meropenem, while the highest resistance rate 27(65.9%) was recorded for amoxicillin + clavulanic acid. Multiple antibiotic resistance index of 8/12 (66.7%) of multidrug resistant Vibrio isolates was > 0.2 (20%) which could imply a high risk source of contamination in the environment where they were isolated. tdh, trh, and t1 genes were detected in V. parahaemolyticus isolates. Although, water hyacinth in this study did not harbored Vibrio species, the lagoon remains a source of pathogenic drug resistant Vibrio species. Therefore, surveillance should be enhanced.