摘要:
为探讨主动外排泵在鸡大肠杆菌对抗菌药耐药中的作用和超广谱β-内酰胺酶与主动外排作用之间的关系,采用琼脂二倍稀释法检测主动外排抑制剂氰氯苯腙(CCCP)和利血平存在时, ESBLs阳性和阴性鸡大肠杆菌对10种抗菌药物的外排表型的变化.结果表明利血平缺乏与存在时,ESBLs阳性菌中,氨苄西林、头孢曲松、头孢噻肟、磷霉素对其MIC值的变化差异显著(PPP>0.05),而在ESBLs阴性菌株差异显著(P<0.05).说明主动外排泵抑制剂CCCP和利血平与抗菌药物合用均可筛选出外排阳性株,但二者之间作用有很大的不同;ESBLs阳性菌的外排表型筛选率高于阴性菌,ESBLs阳性菌的多重耐药性可能是ESBLs与外排系统共同作用的结果,产ESBLs的特异性耐药与主动泵过度表达的非特异性耐药之间有协同关系.
Abstract:
To explore the role of efflux pump in resistance to antibacterial drugs and the relationship between the extended-spectrum β-lactamase and efflux pump in Escherichia coli.Activities of 10 antibacterial drugs were detected by using 2-fold agar dilution method with or without efflux pump inhibitors,carbonylcyanidem chlorophenylh-dra—zone(CCCP) and Reserpine,in E.coli.After treated with efflux pump inhibitor,Reserpine,the MICs of the positive ESBLs strains decreased on Ampicillin,Ceftriaxone,Cefotaxime and Fosfomycin.The decline in the antimicrobial resistance ranged from 7.7% to 30.7%.But the MICs declined on Ceftriaxone,Cefotaxime,Amikacin and Fosfomycin in the positive ESBLs strains with the addition of CCCP.The decline in the antimicrobial resistance ranged from 15.4% to 46.12%.The rate,which associated with the positive efflux pump,had statistically significant differences in the positive ESBLs strains as compared to Reserpine with CCCP.However,it had no statistically significant differences in the negative ESBLs bacteria.CCCP and Reserpine differed greatly on screening the efflux pump.The rate of postive efflux pump in the positive ESBLs strain was significantly higher than that in the negative ones.There appeared a correlation between the ESBLs and efflux pump.
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