加工环境中单核细胞增生性李斯特菌耐药特征分析

Antimicrobial resistance of Listeria monocytogenes isolated from processing environment

中文关键词:  单核细胞增生性李斯特菌  耐药性  耐药基因

英文关键词:Listeria monocytogenes  drug-resistance  drug-resistant gene

中文摘要:

      目的 分析食源性李斯特菌耐药性及耐药基因携带情况,明确在流通过程中加工环境对该菌的影响。方法 收集2016-2017年分离自加工环境中的71株单核细胞增生性李斯特菌,利用微量肉汤稀释法对8种抗菌药物进行药物敏感性分析,PCR鉴定10种耐药基因(tetA、tetM、tetS、ermA、ermB、ermC、mecA、aac(6’)-Ib、van A、van B、cfr)。结果 71株Lm对庆大霉素(11.27%)、氨苄西林(4.22%)、头孢他啶(98.59%)、环丙沙星(97.18%)、四环素(21.12%)、红霉素(15.49%)、林可霉素(92.96%)均具有不同程度的耐药性,对万古霉素敏感。其中耐受3~6种抗菌药为主,耐药情况较为严重。耐药基因检测表明四环素类tetA,tetM为主要耐药基因,检出率高达50%以上,其次为红霉素类ermA、ermB、ermC,检出率约11%,氨基糖苷类aac(6’)-Ib的检出率为5.63%。结论 加工环境单核细胞增生性李斯特菌的耐药性呈上升趋势,其耐药表型与耐药基因型并不完全一致,从而表明加工环境中存在影响单核细胞增生性李斯特菌耐药性因素,同时为食源性李斯特菌病的防治及预警提供参考依据。

英文摘要:

      Objective To determine the environmental influence against Listeria monocytogenes isolates, antibiotic resistance and associated resistance genes carrying in Listeria monocytogenes were analyzed. Methods Antibiotic susceptibility testing was performed by broth microdilution with 8 antibiotics. 10 resistance genes (tetA, tetM, tetS, ermA, ermB, ermC, mecA, aac(6’)-Ib, van A, van B, cfr) were identified by PCR in 71 Listeria monocytogenes, isolated in processing environment from 2016 to 2017. Results The results showed that 71 isolates presented different degrees of tolerance against 8 antibiotics: gentamicin (11.27%), ampicillin (4.22%), ceftazidime (98.59%), ciprofloxacin (97.18%), tetracycline (21.12%), erythromycin (15.49%), Lincomycin (92.96%), vancomycin (Sensitive). Over 50 % isolates were tolerant 3 to 6 antibiotics, which showed that antibiotic resistance in processing environment was severe. From the results of resistance genes, over 50% isolates carried tetA and tetM. The frequency of the genes ermA, ermB, ermC and aac(6’)-Ib was 11% and 5.63%, respectively. Conclusion Antibiotic resistance of Listeria monocytogenes isolated from processing environment was on the rise. The resistance phenotype and genotypes were not exactly the same. Therefore, resistance of Listeria monocytogenes isolates relates to processing environment. These results are able to provide useful information to prophylaxis and warning of food-borne listeriosis.