替加环素对不同耐药基因型耐碳青霉烯类肠杆菌科细菌的敏感性研究

Sensitivity of carbapenem-resistant Enterobacteriaceae with different resistant genotypes against tigecycline

目的探讨替加环素对不同耐药基因型耐碳青霉烯类肠杆菌科细菌（CRE）的敏感性。方法采用改良Hodge试验（MHT）筛查厄它培南耐药的肠杆菌科细菌,采用纸片扩散法检测替加环素的抑菌环直径,采用聚合酶链反应（PCR）测定CRE的β-内酰胺酶基因种类。结果 68株CRE中有48株（70.6%）MHT初筛阳性,其中40株（83.3%）携带能水解碳青霉烯类抗菌药物的超广谱β-内酰胺酶基因（KPC、NDM-1、IMP-8、IMP-4,以KPC为最多,占67.5%）。68株菌株中有54株对替加环素敏感,12株中介,2株耐药,总敏感性为97%。MHT筛查试验阳性和阴性菌株对替加环素的敏感性差异无统计学意义（χ^2=3.599,P〉0.05）。结论替加环素对CRE显示出优异的抗菌活性,其抗菌作用不受β-内酰胺酶的影响。

Objective To investigate the sensitivity of carbapenem-resistant Enterobacteriaceae（CRE）with different resistant genotypes against tigecycline. Methods The isolates of Enterobacteriaceae against ertapenem were screened by modified Hodge test（MHT）,the diameters of tigecycline inhibition zones were determined by K-B method, and beta-lactamase gene of CRE was determined by polymerase chain reaction（PCR）. Results A total of 68 isolates of CRE were screened by MHT,and there were 48 positive isolates,accounting for 70.6%. In the 48 positive isolates, there were 40 isolates（83.3%） carrying hydrolyzed carbapenem antibiotics extended-spectrum beta-lactamase gene, including KPC,NDM-1,IMP-8 and IMP-4. KPC was the most,accounting for 67.5%. In the 68 isolates of CRE,54 isolates were sensitive,12 isolates were intermediary,2 isolates were resistant,and the total sensitivity was 97%. There was no statistical signifi cance for the sensitivity of positive and negative isolates in the 68 isolates of CRE by MHT（χ~2=3.599,P〉0.05）. Conclusions Tigecycline for CRE exhibits excellent antibacterial activity. Antibacterial effect of tigecycline is not infl uenced by enzyme activity.