抗生素耐药基因在畜禽粪便-土壤系统中的分布、扩散及检测方法

抗生素耐药基因作为一种新型的环境污染物已引起研究者的高度关注。畜禽养殖业长期将抗生素添加到饲料中,在促进动物生长、预防和治疗动物疾病等方面起了重要作用。这些抗生素大多数不能被动物完全吸收,在动物肠道中诱导出耐抗生素细菌和抗生素耐药基因,并随着粪便排出体外。畜禽粪便作为重要的抗生素、耐抗生素细菌和抗生素耐药基因储存库,通过堆粪、施肥等农业活动进入土壤环境中,可刺激土壤中耐抗生素细菌和抗生素耐药基因的富集。耐药基因借助于基因水平转移等方式在土壤介质中进一步传播扩散,甚至进入植物中随食物链传播,对生态环境和人类健康造成极大的威胁。为了正确评估抗生素耐药基因的生态风险,本文结合国内外相关研究,系统阐述了畜禽粪便-土壤系统中抗生素耐药基因的来源、分布及扩散机制,同时探讨了细菌耐药性的主要研究方法,指出堆肥化处理仍是目前去除抗生素耐药基因的主要手段,并对今后的研究方向进行展望。

Distribution, spread and detection methods of antibiotic resistance genes in livestock manure and soil system

There are increasing concerns about antibiotic resistance genes (ARGs) as emerging environmental contaminants. Antibiotics have been routinely utilized in livestock farming as feed additives to promote animal growth, prevent and treat diseases caused by various bacteria pathogens. Most of them could not be totally absorbed by animals but induce the development of antibiotic resistance bacteria (ARB) and ARGs in animal intestinal tracts. The residual antibiotics, ARB or ARGs are discharged with fecal. Therefore, animal wastes are important reservoirs of antibiotics, ARB, and ARGs. Antibiotic resistance may be transferred to the soil environment through composting and manure fertilization process. Furthermore, ARGs can disseminate in the environment by horizontal gene transfer, and even spread along the food chain, which poses a huge threat to the environment and human health. In this paper, the profiles of the occurrence, distribution and spread of ARGs in animal manure-soil system are reviewed in detail. The main detection methods of antibiotic resistance are discussed. Composting is still an effective way to reduce the spread of antibiotic resistance genes in animal manure and therefore should be an important consideration in the future.