临床分离产头孢菌素酶阴沟肠杆菌的耐药性研究  

Study on the resistance of cephalosporin β-lactamase-producing Enterobacter cloacae

作　　者：余娴[1] 凌保东[1] 周岐新[2] 雷军[1] 谢勇恩[1] 

机构地区：[1]川北医学院药物研究所,南充637007 [2]重庆医科大学药理教研室,重庆400016

出　　处：《四川生理科学杂志》2005年第4期156-159,共4页Sichuan Journal of Physiological Sciences

基　　金：四川省重点科技攻关项目(编号02SG022-030)

摘　　要：目的:研究我院产头孢菌素酶(AmpC酶)阴沟肠杆菌的检出率、耐药情况及ampC基因型。方法:收集临床分离的耐药阴沟肠杆菌15株;三维试验检测AmpC酶;NCCLS方法检测超广谱β-内酰胺酶(ESBLs);琼脂二倍稀释法测定M IC值;PCR扩增检测ampC基因及序列测定。结果:15株菌中8株菌(53.3%)产AmpC酶,3株菌(20.0%)产ESBLs。产AmpC酶的菌株除对亚胺培南全敏感外,对其它抗菌药不同程度耐药。5株菌的ampC基因与阴沟肠杆菌ECLC074的ampC基因100%同源,3株菌与之99%同源,2株菌的AmpC酶发生了1个氨基酸残基的改变。结论:产AmpC酶是阴沟肠杆菌对β-内酰胺类抗生素耐药的主要机制之一。阴沟肠杆菌ECLC074 ampC基因是我院主要的阴沟肠杆菌ampC基因型。产AmpC酶的阴沟肠杆菌常呈多重耐药,亚胺培南是治疗此类菌所致感染的最有效药物。Objective： To study the detection rate, the resistance phenotypes and the ampC gene of cephalosporin （AmpC） β-lactamase-producing Enterobacter cloacae isolates. Methods： 15 randomly chosen piperaeillin-resistant Enterobacter cloacae were isolated. AmpC β-lactamases were examined by three dimension test. Extended spectrum β-lactamases（ESBLs） were tested according to NCCLS Test. MICs of antibacterials were determined by two-fold agar dilution method, ampC genes were amplified by PCR and PCR products were sequenced. Results： Of 15 Enterobacter cloacae, 8 （53.3%） isolates produced AmpC β-lactamases and 3 （20.0%） produced ESBLs. AmpC β-lactamase-producing isolates were susceptive to imipenem, while they had the different resistant rates to the other antibacterials. Compared with Enterobacter cloacae ECLC074 ampC gene, the ampC genes of 5 strains had 100% homology, and those of the rest 3 strains had 99% homology. AmpC β-lactamases of 2 strains had one amino acid residue mutagenesis. Conclusion ： Production of AmpC β-lactamases is one of the main resistant mechanisms of Enterebacter cloacae to β-lactam antibiotics. Enterobacter cloacae ECLC074 ampC gene is the main gene style of AmpC β-lactamases-producing Enterobacter cloacae. AmpC β-laetamase-producing Enterobacter cloacae isolates are muhidrug resistant frequently. Imipenem is the appropriate antibiotic for the treatment of the infections caused by this kind of strains.

关 键 词：阴沟肠杆菌 头孢菌素酶 AMPC基因 耐药 耐药性研究 临床分离 产AMPC酶 超广谱β-内酰胺酶 琼脂二倍稀释法 C基因型 

分 类 号：R378[医药卫生—病原生物学]