The Molecular Epidemiology And Risk Factors Of Tigecycline-carbapenem-resistant Enterobacter Cloacae

Objectives: To investigate the molecular characteristics and risk factors of tigecycline-carbapenem-resistant Enterobacter cloacae(TCREC)isolates in our hospital.Methods: Thirty-six TCREC isolates were collected from 2012 to2016 in our hospital.The antimicrobial susceptibilities of 11 antibiotics were performed by using VITEK 2 system and standard microdilution broth method.The pulsed-field gel electrophoresis(PFGE)and multilocus sequence typing(MLST)were performed to determine the molecular epidemiology of TCREC isolates.A retrospective case-control study was conducted to identify the risk factors.Results: All of the 36 isolates were resistant to tigecycline,and the resistant rate to ertapenem was 100%,while 67% remained susceptible to imipenem and meropenem.ST88(10/36)was predominant and strains were scattered and distributed.10 isolates carried carbapenemase genes,6isolates carried blaNDM-1 and 3 isolates carried blaIMP-8 among them.Coexistence of blaNDM-1 and blaIMP-8 was firstly found in one isolate.Extensive spectrum ?-lactamases(ESBLs)genes were prevalent in 27(75%)isolates,blaTEM was the most common carbapenemase gene detected in 16 isolates.Coexistence of extensive spectrum ?-lactamases(ESBLs)genes and outer membrane proteins loss were found in 27 isolates.Admission to intensive care unit(ICU),central venous catheterization,urinary catheterization,bladder irrigation,nasal catheter,expose to penicillin,fluoroquinolones,minocycline were the potential risk factors for TCREC infections,above all,nasal catheter,penicillin,fluoroquinolones were independent risk factors for the acquisition of TCREC.Conclusions: All 36 isolates were multidrug-resistant organism,and showed a scattered distribution.We should strengthen the supervision of antibiotics and reduce aggressive procedures to decrease the prevalence of TCREC infections.