酸奶中保加利亚乳杆菌药物敏感性分析

摘要

Lactobacillus bulgaricus strains were isolated from different yoghurt brands produced in different regions in China and analyzed for genetic diversity and antibiotic susceptibility.Further,antibiotic-resistant isolates were subjected to genetic analysis.A total of 18 Lactobacillus bulgaricus strains were obtained using modified MRS medium.They were subjected to RAPD typing and analyzed for susceptibility to 11 different antibiotics.Besides,their potential antibiotic-resistance genes were detected by PCR.The results showed that 18 Lactobacillus bulgaricus isolates had considerable genetic diversity and diverse antibiotic-resistance phenotypes.All of them were susceptible to roxithromycin and resistant to kanamycin.Meanwhile,they also could resist ampicillin,penicillin G,chlortetracycline,chloramphenicol,tetracycline,lincomycin,streptomycin,neomycin and gentamycin to different extents.tet(M) gene was detected in isolate B-8,and ant(6) gene in both B-8 and B-41,and aph(3')-Ⅲa gene in B-43,B-47,B-49 and B-51.These findings suggested that 18 Lactobacillus bulgaricus isolates had serious multiple antibiotic resistance.%从酸奶中分离保加利亚乳杆菌,对其遗传多样性和药物敏感性进行分析,并进一步对耐药菌株的抗性基因进行检测。利用改良MRS培养基,从国内不同品牌酸奶中分离获得18株保加利亚乳杆菌。18株分离菌先经RAPD分型后采用琼脂稀释法测定其对11种抗生素的药敏性,并通过PCR对耐药菌株中可能存在的抗性基因进行检测。结果显示,18株受试菌具有明显的遗传多样性和耐药表型多样性。18株菌全部对罗红霉素敏感,而全部对卡那霉素耐药;对氨苄青霉素、青霉素G、金霉素、氯霉素、四环素、林克霉素、链霉素、新霉素及庆大霉素等9种抗生素均表现出不同程度的耐药性。通过检测耐药菌株的抗性基因,从1株菌（B-8）中检出四环素抗性基因tet（M）,从2株菌（B-8和B-41）中检出链霉素抗性基因ant（6）,从4株菌（B-43、B-47、B-49和B-51）中检出卡那霉素抗性基因aph（3’）-Ⅲa。结果表明,供试18株保加利亚乳杆菌多重耐药现象比较严重。