广东省规模化猪场猪粪中典型耐药基因污染分析

Analysis of typical antibiotic resistance genes in the manure of large scale swine farms in Guangdong province

选择广东省6家规模化猪场，采集后备期、空怀期、妊娠期、保育期和育成育肥期猪粪，利用实时荧光定量PCR技术检测四环素类耐药基因驯A、tetG、tetM、tetX，喹诺酮类耐药基因qnrS，磺胺类耐药基因sull，链霉素耐药基因strA，β-内酰胺类耐药基因blaTEM和大环内酯类耐药基因erzrtB的含量，并利用单克隆测序技术比对分析了不同猪场猪粪中tetG基因的多样性。结果表明：（1）117份猪粪样品中，除strA的检出率为97．44％外，其余耐药基因的检出率均为100．00％；（2）猪粪中tetM的绝对含量最高，其拷贝数的对数值达到（10．27±0．68），显著高于其他耐药基因（P〈0．05），其他耐药基因绝对含量由高到低依次为errrtB、tetG、blaTzM、tetX、strA、sull、qnrS和tetA，并且tetA、tetG、qnrS和bla7EM的绝对含量之间呈极显著正相关（P〈0．01），tetM、sulI、strA和tetX的绝对含量之间呈极显著正相关（P〈0．01）；（3）妊娠前期母猪粪中耐药基因tetA、qnrS和blaⅡM的相对含量显著高于其他阶段猪粪（P〈0．05），其余各阶段猪粪耐药基因的相对含量无显著性差异，而且不同猪场猪粪中耐药基因相对舍量也无显著性差异；（4）不同猪场猪粪中tetG耐药基因具有较高的多样性。由此表明，广东省规模化猪场猪粪中广泛存在耐药基因残留，应采取有效措施降低猪粪中耐药基因残留，减少其对环境的污染。

Resistance gene has been considered as a new type of environmental pollutants. And one of the hot spots of concern is the content of resistance gene in livestock and poultry manure. In this study,pig manure of different breeding stages in six different pig farms were collec;ed. The content of total bacterial and resistance genes tetA , tetG, tetM, tetX , qnrS, sulI , strA , blaTEM and erm B were measured and the diversity of tetG was analyzed using clone sequencing. The results were as follows.（1） The detection rate was 97.44% for strA and 100.00% for the other resistant genes in pig manure. （2） The average value of the highest resistance gene terM was 10. 574-0.68. The order of the other resistant genes from high to low were ermB, tetG, bla TEM , tetX, strA, sulI, qnrS, and tetA. There was a significant positive correlation between the content of tetA, tetG, qnrS, and blaTEM （P〈0. 01）. And there was a significant positive correlation between the content of tetM,sulI,strA and tetX （P〈0. 01）. （3） The content of tetA,qnrS and blaTEM in pregnancy pig manurewas significantly higher than that in other stages （P〈0.05）. There was no significant difference in the relative content of resistance genes between the other stages （P〈0.05）. And there was no significant difference in the content of resistant genes among different pig farms （P〈0.05）. （4） The tetG resistance genes were diversity among different pig farms. The results showed that the presence of resistant gene residues in swine manure of Guangdong province should be controlled. To reduce the resistant genes in the pig manure, the veterinary antibiotics should be used properly, thus reducing the pollution of the environment.