Occurrence of multidrug-resistant Enterobacteriaceae and antibiotic-resistant genes in the anthropogenic impacted bay of Nha Trang, Viet Nam

Abstract

Antimicrobial resistance (AMR) has increased significantly due to the widespread transmission of multidrug-resistant (MDR) bacteria and antibiotic-resistance genes (ARGs) within and between animals, environments, and humans. Unfortunately, the AMR situation in the coastal areas is little known. In this study, we investigated the occurrence and distribution of MDR Enterobacteriaceae from water and sediment samples collected in Nha Trang Bay, Viet Nam. Overall, 48/107 (45.8 %) identified and isolated bacteria belong to risk group 2 pathogens. More than 57 % of Enterobacteriaceae isolates exhibited MDR phenotypes, in which Escherichia coli, Klebsiella pneumoniae, and Citrobacter freundii were the most prevalent species. In addition, eight ARGs including sul1, sul2, sul3, tetQ, tetB, mecA, bla_VIM and bla_KPC were detected with high abundance in most of water and sediment samples. Notably, class 1 integron-integrase gene intI1 was widely distributed (95.8 %) in all samples with a total absolute abundance of 2.9 × 10⁵ copies/ml water and 9.7 × 10⁷ copies/g sediment. We also identified significant relationships between sul3, tetB, bla_VIM, bla_KPC and intI1 with bacterial density, chlorophyll A, phosphorus and temperature. These observations suggest that intI1 gene and nutrients could promote the emergence and propagation of antibiotic-resistance bacteria (ARB) and ARGs in the Nha Trang Bay.