THE CHARACTERISTICS, INFECTION MECHANISM AND INDEPENDENT RISK FACTORS IN PATIENTS INFECTED BY CARBAPENEM-RESISTANT ENTEROBACTERIACEAE

FangFang Hu, Xiangrong Luo, ZHisHun Lu, Yongjie Xu, jiaLing Liu, Hua ZHang *

Department of Laboratory Medicine, Guizhou Provincial People’s Hospital, Guiyang 550002, Guizhou, China

 Objective: To analyse the clinical characteristics and understand the resistance mechanism of bacteria and the independent risk factors of carbapenem-resistant Enterobacteriaceae (CRE) infection in our hospital, in order to detect resistance genes of CRE.

Methods: In total, 82 strains of CRE were isolated from our hospital; strains were identified, drug susceptibility tests were con- ducted, and the related drug resistance genes were determined. Another 80 strains of carbapenem-sensitive Enterobacteriaceae (CSE) were used as a control group. Analysis of the clinical characteristics of the two groups of strains, including general information of patients and the use of antibiotics, was performed. The independent risk factors of CRE strain infection were analysed by multivariate logistic regression analysis.

Results: The resistance rates of carbapenem-resistant Enterobacteriaceae to imipenem, levofloxacin, amikacin and polymyxin B were 12.2%, 20.7%, 18.3%, and 14.6%, respectively, to ertapenem, ceftriaxone, ceftazidime, cefoxitin and cefoperazone/sulbactam were 100%, and to aztreonam, cefepime and meropenem were 93.9%, 85.4% and 82.9%, respectively. Seven kinds of resistance genes (KPC, TEM, SHV, CTX, IMP, OXA-1 and OXA-27) were positive, with a positive rate of 26.8%, 35.4%, 28.0%, 100%, 19.5%, 2.4% and 14.6%, respectively. Of these, about 62.2% (51 strains) of the strains carry more than two resistance genes. Clinical analysis showed that the carbapenem-resistant Enterobacteriaceae, hospital days, number of bed changes, nosocomial infections, invasive procedure, and catheters were independent risk factors for carbapenem resistance (P<0.05).

Conclusion: The drug resistance of Enterobacteriaceae is related to the multidrug resistance gene, which is an important cause of carbapenem-resistant Enterobacteriaceae in our hospital. The number of hospital days, number of bed changes, nosocomial infec- tions, invasive procedures, and catheters were independent risk factors for carbapenem resistance. Therefore, relevant departments should take protective measures to reduce unnecessary invasive operations and use antibacterial drugs rationally, thereby reducing the emergence of drug-resistant strains.