中文摘要：

本文从养殖场空气中分离出360株E.coli（大肠杆菌,Escherichia coli）,应用肉汤微量稀释法和PCR方法,分离磺胺甲唑敏感菌株,检测抗生素抗性和抗性基因.在分离的E.coli中,对磺胺甲唑敏感菌株为95株（26.4%）,有48株含有青霉素、氯霉素、四环素、环丙沙星、庆大霉素和利福平的抗性,而47株未含有抗性.其中,7株菌株含有1种抗生素抗性、11株菌株含有2种抗生素抗性、17株菌株含有3种抗生素抗性、6株菌株含有4种抗生素抗性、4株菌株含有5种抗生素抗性、3株菌株含有6种抗生素抗性.对抗生素的耐受能力依次为：氯霉素、青霉素、四环素、环丙沙星、庆大霉素、利福平.磺胺甲唑敏感菌株共检出163个抗性基因,sul1、int1、sul2、Int2、sul3检出数量依次为49、44、29、20和19;含一种、二种、三种、四种、五种抗性基因菌株分别为45、22、10、7、2;但有6株未检测出抗性基因.结果表明养殖场建场时间、抗生素使用、养殖规模等与抗生素抗性菌的抗性呈正相关;养殖场空气中分离的E.coli抗生素抗性较高,且具有多重抗性;抗生素抗性的表现型与其基因型之间出现不完全吻合现象.

英文摘要：

360 Escherichia coli（E. coli） samples were isolated from the air of eight poultry farms.Microdilution and polymerase chain reaction（PCR） were used to evaluate the sulfonamides susceptibility and detect the sulphonamides resistance gene respectively. The results showed that 95 samples were found to be susceptible to sulfamethoxazole, and of which 48 samples showed resistance to at least one of six different kinds of antibiotics. Briefly,7 samples were shown to be resistant to one antibiotics,11 strains were resistant to two kinds of antibiotics,17 sampleswere resistant to three kinds of antibiotics, 6sampleswere resistant to four kinds of antibiotics,4sampleswere resistant to five kinds of antibiotics,and notably 3 strains were resistant to all six kindsof antibiotics. The resistance abilities of the samples from highest to lowest were against to chloramphenicol,penicillin,tetracycline,ciprofloxacin,and rifampicin. Moreover,163 resistance genes were detected from isolated sulfonamide resistance samples. There were 49 resistance genes ofsul1,44 resistance genesofsul2,20 resistance genes of sul3,20 resistance genes of int1 and 19 resistance genes of int2.In addition,there were 45 stains contained one kind of resistance genes,22 contained two kinds of resistance genes,10 contained three kinds of resistance genes,7 contained four kinds of resistance genes,and 2 contained five kinds of resistance genes. But 6 samples had no resistance genes mentioned above. Our study showed that the antibiotic resistance of bacteria was positively correlated with many factors,such as built time,antibiotic use,and breeding scale etc.The E.coli isolated from the air in the poultry farm was more resistant to antibiotics,and displayed multiple antibiotic resistances. Obviously,the sulfonamides resistance did not correlate with the presence of such genes.