重金属对畜禽养殖土壤中抗生素耐药菌影响的研究

Study on the Effects of Heavy Metals on Antibiotic-Resistant Bacteriain in Livestock and Poultry Breeding Soils

从成都市某废弃畜禽养殖场土壤中筛选出一株具有抗生素抗性的菌株C32,研究不同重金属对其抗生素抗性的影响.结果表明,16S rDNA分子鉴定C32属于Citrobacter freundii菌株,对重金属离子的抗性强弱顺序为:Cu^(2+)>Cd^(2+)>Cr^(6+),对抗生素抗性强弱顺序为:阿莫西林>头孢拉定>四环素>庆大霉素.重金属和抗生素交叉抗性研究表明重金属的浓度及种类均会对C32的抗生素抗性影响显著(P<0.05).重金属的加入对阿莫西林抗性的影响最为明显,而对庆大霉素的影响最不明显.研究表明环境中重金属离子会改变抗生素污染物的生态危害和环境行为,为微生物法防治抗生素污染提供科学支撑.

An antibiotic-resistant strain C32 was selected from the soil of an abandoned livestock and poultry farm in Chengdu to study the effects of different heavy metals on its antibiotic resistance.The results showed that the C32 was identified as Citrobacter freundii by 16S rDNA.The orders of resistance to heavy metal ions was:Cu^(2+)>Cd^(2+)>Cr^(6+),and the orders of resistance to antibiotics was:amoxicillin>cefradine>tetracycline>gentamicin.Studies on the cross-resistance of heavy metals and antibiotics showed that the concentration and types of heavy metals significantly affected the antibiotic resistance of C32(P<0.05).The addition of heavy metals had the most obvious effect on amoxicillin resistance and the least significant effect on gentamicin.This study showed that heavy metal ions in the environment can change the ecological hazards and environmental behaviors of antibiotic pollutants,and provided scientific support for microbiological methods to prevent and control antibiotic pollution.