Identification of multi-antibiotic resistant bacteria isolated from Vietnamese climbing perch (Anabas testudineus) on fish farms in Ho Chi Minh City, Vietnam

Abstract

Climbing perch (Anabas testudineus) is considered a cultured species with high economic value and is widely distributed in several Asian countries, including Vietnam. In climbing perch aquaculture, antibiotic and antibacterial agents have been overused, leading to the emergence of antibiotic-resistant bacteria or genes in the aquatic environment as well as in the seafood products. These antibiotic-resistant bacteria and/or genes can then be spread to human through the food chain, generating detrimental consequences for public health and environment. In this study, 14 bacterial strains were isolated from Vietnamese climbing perch collected from various fish farms in Ho Chi Minh City which possess abnormal symptoms on the outside and in their organs. These bacterial strains were then subjected to several biochemical tests to characterize their colony morphologies. Besides, gene sequencing was performed and as compared to the 16S rRNA, 4 bacterial strains were identified with a high percentage in similarity, including Pseudomonas aeruginosa (99.7%), Aeromonas caviae (99.93%), Kosakonia sacchari (100%), and Edwardsiella ictaluri (99.44%). Additionally, these bacteria showed high levels of antibiotic resistance against beta-lactam, tetracycline, and others. Taken together, these results showed that the four identified bacterial strains isolated from Vietnamese climbing perch circulated in fish farms in Ho Chi Minh City. Their current status of multi-antibiotic resistance indicates further alternative sources of antimicrobial agents, for example, natural compounds, to overcome antibiotic resistance. It is then crucial to identify fish diseases, the associated pathogens, and the new alternatives for antibiotics to protect aquatic ecosystems and water resources.