Tetracyclines-Resistant bacteria in Shrimps sold in major Supermarkets in Da Nang City, Vietnam

The spread of tetracycline-resistant genes has posed a threat to the therapeutic effectiveness of tetracyclines. Misusing tetracyclines in seafood and shrimp farming has only accelerated this resistance process. Our study aimed to evaluate the status of tetracycline-resistant bacteria in shrimps and to evaluate the probability of spreading these antibiotic-resistant genes. The shrimp purchased from three major supermarkets in Da Nang city were analyzed and the results revealed that the ratio of bacteria resistant to tetracycline and oxytetracycline had a relatively high resistance rate of 4-11%. This study found that all tested supermarkets exhibited resistance with the rate of resistance to oxytetracycline being higher than that of tetracycline. In situations where bacteria with oxytetracycline-resistant genes and Lactobacillus acidophilus, were co-cultured, the transmission of the resistant genes to Lactobacillus acidophilus occurred. Moreover, the tetracycline resistance of bacteria isolated from shrimp intestines did not decrease even after being cultured in an antibiotic-free medium. The findings of our study strongly indicate the need for immediate action to control the overuse of tetracyclines in shrimp farming and to prevent the further spread of antibiotic-resistant genes.