北京地区畜禽养殖场周边蔬菜地生食蔬菜抗生素耐药基因(ARGs)的赋存特性

Occurrence of antibiotic resistance genes (ARGs) carried by raw vegetables adjacent to the livestock and poultry feedlots in Beijing

我国畜禽养殖废水灌溉农田广为应用,其中携带的抗生素耐药基因(ARGs)给环境及人类健康带来了潜在的危害,亟需了解畜禽养殖场周边蔬菜地生食蔬菜可食部ARGs的赋存特性.本文选取北京地区畜禽场周边农田中10份蔬菜样品,采用非细菌培养方法直接提取细菌总DNA,通过PCR扩增,考察了5类(磺胺类、四环素类、大环内酯类、氯霉素类、喹诺酮类)ARGs的赋存特性.结果表明,蔬菜样品残留的磺胺类ARGs、四环素类ARGs存在范围最广(蔬菜表面、内部的检出率分别为100%、70%),喹诺酮类ARGs次之(蔬菜表面、内部的检出率分别为100%、60%).无论在种类还是数量,蔬菜样品表面携带的ARGs均比内部丰富;并且蔬菜样品表面及内部均检出已被禁用多年的氯霉素类ARGs(cml A).这说明畜禽养殖场周边蔬菜地生食蔬菜可食部分残留ARGs严重,可能会导致生食蔬菜大量附生及内生细菌的耐药,并通过食物链危害人类健康,应引起高度重视.

Wastewater discharged from livestock and poultry feedlots,with a number of antibiotic resistant genes（ ARGs）,is widely applied in farmland as fertilizer and many pose great potential risk to environment and public health. It is of urgent need to investigate occurrence of ARGs carried by raw vegetables adjacent to the livestock and poultry feedlots. In this study,10 raw vegetable samples were collected from a farmland adjacent to the livestock and poultry feedlots in Beijing. WithDNA extraction and PCR analysis,five ARGs including sulfonamides,tetracyclines,macrolides,chloramphenicols and quinolones were detected. The results showed that the occurrence of sulfonamide and tetracycline resistance genes were the most frequently detected,with detection rates of 100% and 70% on the surface and in the internal of raw vegetables,respectively. The detection rates of the second most frequently detected quinolone resistance genes were 100% and 60% on the surface and in the internal of raw vegetables,respectively. Additionally,ARGs on the surfaces of raw vegetable were more than those in the internals,and cml A was also detected. These results suggested that ARGs carried by raw vegetables had a wide occurrence range,which may produce resistance of epiphytic and endophytic bacteria from raw vegetables,and then threaten human health through food chain. So high attention should be paid.