摘要
目的研究泛耐药弗劳地柠檬酸杆菌产β内酰胺酶情况及同源性。方法采用改良Hodge试验和乙二胺四乙酸(EDTA)协同试验筛选金属酶,等电聚焦电泳(IEF)测定产β内酰胺酶的等电点,bla_(TEM)、bla_(SHV)、bla_(CTX M-G_1G_3)、bla_(MBL)和bla_(MBL)等引物的聚合酶链反应(PCR)进行β内酰胺酶的基因分型,并对PCR产物进行克隆测序；脉冲场电泳对8株菌的同源性进行研究。结果8株泛耐药弗劳地柠檬酸杆菌均产TEM-1型β内酰胺酶,CTX-M-14型超广谱β内酰胺酶(ESBLs)及IMP-8型金属酶新亚型,其中4株同时产CTX-M-3型ESBLs。未发现质粒介导的头孢菌素酶。所有菌株脉冲场电泳(PFGE)谱型相似。结论泛耐药弗劳地柠檬酸杆菌产多种β内酰胺酶。8株泛耐药菌源自同一克隆。
Objective Study the production of the β-lactamascs in eight pan resistant citrobact- er freundi and their epidemic characteristics. Methods Modified Hodge test and EDTA disk syncrgy test were used to screen Metallo-β-lactamascs, and isoelectric focusing to estimate the production of ESBLs and AmpC enzymes. ESBLs,AmpC, MBL genes were amplified and analyzed by PCR and DNA sequencing. Molecular epidemics were investigated by PFGE. Results All the 8 strains produced TEM-1, CTX M-14, 4 of them at the same time producing CTX-M-3. No Plasmid mediated AmpC was found. Furthermore, a new subtype of MBL with one amino acid different from IMP-8 was detected. All the 8 strains belong to the same PFGE type. Conclusions Pan drug resistant citrobacter freundi produced more than one kind of β-lactamases. All these isolates were clonally related.
出处
《中华传染病杂志》
CAS
CSCD
北大核心
2006年第5期291-295,共5页
Chinese Journal of Infectious Diseases
基金
国家973资助项目(2005CB523101)
