水产品中6类抗生素抗性基因和Ⅰ类整合子的定量检测

Quantitative Detection of Six Classes of Antibiotic Resistance and Class Ⅰ Integron Genes in Aquatic Products

摘要:

论文选取广州市天河区两家菜市场、一家海鲜市场和三家超市的48份水产品为研究对象，提取了三种不同水产品：虾、鱼和贝类的总DNA，采用实时荧光定量PCR(Quantitative Real-time PCR)法，对市售水产品中6类抗生素抗性基因（Antibiotic Resistance Genes，ARGs）：tetA、tetB、tetM、sulⅡ、floR、aphA-1、aadA、ermB、cmlA和Ⅰ类整合子5’端整合酶基因intI1、3’端磺胺耐药基因sulⅠ、季铵盐化合物及溴化乙锭的耐药基因qacEΔ1进行定量。研究显示：6类ARGs及Ⅰ类整合子基因在水产品中均有检出，基因拷贝数大小从102~108跨越七个数量级，最小值为1.86×102 copies/g，最大值为8.98×108 copies/g。三种水产品虾、鱼、贝类中，虾类的ARGs含量最高，贝类最低；三类采样地点中，菜市场来源的水产品中ARGs含量最高，海鲜市场来源的次之，超市来源的最低。本研究为进一步探索ARGs和可移动耐药元件整合子介导的细菌耐药性传播而引起的食源性疾病机理奠定了基础。

Abstract:

Forty-eight aquatic products from two farmers’ markets, one seafood market, and three supermarkets in the Tianhe district of Guangzhou were used in this study, and the total DNA from three aquatic products-shrimps, fish, and shellfish-was extracted. Quantitative real-time polymerase chain reaction (PCR) was used to quantify six classes of antibiotic resistance genes (ARGs; tetA, tetB, tetM, sulII, floR, aphA-1, aadA, ermB, and cmlA), the intl1 gene on the 5′ end of class 1 integron, and the sulfanilamide resistance gene sul1 and quaternary ammonium salt compound and ethidium bromide resistance gene qaceΔ 1 on the 3′ end of class Ⅰ integron. The results revealed that all six classes of ARGs were detected in all aquatic products, and the abundance varied over seven orders of magnitude (102~108); the minimum and the maximum values were 1.86×102 copies/g and 8.98×108 copies/g, respectively. Among the three kinds of aquatic products, ARGs were present at the highest concentration in shrimps and the lowest concentration in shellfish. Among the three sampling sites, farmers’ markets had the highest concentration of ARGs, followed by the seafood market and the supermarkets. This study lays the foundation for further research on foodborne diseases caused by antibiotic resistant bacteria with ARGs and mobile integron resistance components.