多重PCR检测临床产ESBLs阴沟肠杆菌的耐药基因型研究

目的了解产超广谱β-内酰胺酶(ESBLs)阴沟肠杆菌的耐药性、阳性率及基因分布特点。方法改良双纸片法检测80株临床分离阴沟肠杆菌对14种抗生素的耐药性及ESBLs表型,多重PCR检测鉴定ESBLs基因型,DNA测序确认DNA序列。结果 80株阴沟肠杆菌中,29株检出ESBLs,阳性率36.3%。80株阴沟肠杆菌对亚胺培南全部敏感,产ESBLs的阴沟肠杆菌对头孢唑啉、头孢噻肟、头孢曲松、头孢哌酮、头孢他啶等头孢菌素类抗生素的耐药率高达96.1%。29株细菌所产ESBLs中,12株为TEM型,6株为SHV型,24株为CTX-M型。其中CTX-M-1组9株,CTX-M-9组15株,未检出CTX-M-2组及CTX-M-8/CTX-M-25组。结论阴沟肠杆菌ESBLs检出率较高,耐药显著。产ESBLs阴沟肠杆菌的主要基因型为CTX-M型。

Multiplex PCR assay for genotype of ESBLs-producing Enterobacter cloacae in clinical isolates

Objective To investigate the resistence,productivity of extended-spectrum β-lactamases(ESBLs) and ESBLs genotype in Enterobacter cloacae.Methods The modification of the double-disk test is used for antibiotic susceptibility testing to 14 kinds of antibiotics in 80 clinical isolates of Enterobacter cloacae.The genotype of ESBLs are detected by multiplex PCR and DNA sequence analysis is performed as confirmation the DNA sequence of ESBLs.Results 29 of 80 isolated Enterobacter cloacae were detected ESBLs positive with a productivity of 36.3%.All of 80 isolates were sensitive to imipenem.96.1% isolates performed antibiotic resistant to cefazolin, cefotaxime, ceftriaxone, cefoperazone, ceftazidime and other cephalosporins.TEM genotype were acquired in 12 isolates.In 6 isolates,SHV genotype ESBLs are found.In 24 CTX-M genotype ESBLs producing isolates,9 ones are CTX-M-1 class,the others are CTX-M-9 class while CTX-M-2 group and CTX-M-8/CTX-M-25 class are detected negative.Conclusion There is a high productivity of ESBLs among Enterobacter cloacae,which caused significant resistance to most of cephalosporins.Carbapenem may be more efficient as the treatment to Enterobacter cloacae producing ESBLs.CTX-M is the major genotype of ESBLs in our research.