Incidence of antimicrobial-resistance genes and integrons in antibiotic-resistant bacteria isolated from eels and aquaculture ponds

Diseases of Aquatic Organisms

,, Qingpi Yan, Ying Ma, Lixing Huang, Yingxue Qin, Xiaojin Xu¹  ,, Xiaomei Wu¹  Mao Lin¹ 

关键词: Anguilla rostrata;    Antibiotic-resistant bacteria;    Antimicrobial-resistance genes;    Integrons;   

DOI  :  10.3354/dao03013

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The overuse of antimicrobials in aquaculture has promoted the selection of antimicrobial-resistant bacteria. Here we investigated the abundance of antimicrobial-resistance genes and integrons in 108 strains of antibiotic-resistant bacteria isolated from eels and aquaculture ponds in China. Conventional PCR was implemented to examine common antibiotic-resistance genes, integrons, and their gene cassette arrays. The results showed that the antibiotic-resistance genes bla_TEM, tetC, sulI, aadA, floR, and qnrB were detected at high percentages, as were a number of other resistance genes. Class I integrons were present in 79.63% of the strains, and 10 out of 108 isolates carried class II integrons. Class III integrons were not detected. Three strains carried both class I and class II integrons, and 73.26% of the class I integron-positive isolates contained the qacEΔ1/sul1 gene. Fourteen types of integron cassette arrays were found among class I integron-positive isolates. A new array, dfrB4–catB3–bla_OXA-10–aadA1, was discovered in this study. The gene cassette array dfrA12–orfF–aadA2 was the most widely distributed. In summary, 23 different gene cassettes encoding resistance to 8 classes of antibiotics were identified in the class I integrons, and the main cassettes contained genes encoding resistance to aminoglycosides (aad) and trimethoprim (dfr). All class II integron-positive strains had only a single gene cassette array, viz. dfrA1–catB2–sat2–aadA1. High levels of antimicrobial-resistance genes and integrons in eels and auqauculture ponds suggest that the overuse of antimicrobials should be strictly controlled and that the levels of bacterial antimicrobial-resistance genes in aquaculture should be monitored.

【 授权许可】

Unknown