Analysis Of Drug Resistance Characteristics And Risk Factors Of E.Coli And K.Pneumoniae In Bloodstream Infections

Objective:Bloodstream infections has the characteristics of severe clinical symptoms and high mortality.To investigate the clinical epidemiology of E.coli and K.pneumoniae in bloodstream infections and to explore the clinical epidemiology of ESBLs-producing bacteria in bloodstream infections.By analyzing the risk factors of ESBLs-producing E.coli and K.pneumoniae infections,to provide laboratory evidence to the clinical and to improve the safety and efficacy of experical treatment.Methods:A total of 311 strains of Enterobacteriaceae in bloodstream infections were collected from January 2010 to December 2014 in Zhejiang Xiaoshan Hospital.The bacterial identification and drug sensitivity test were carried out.To detect the ESBLs-producing E.coli and K.pneumoniae by K-B diffusion method.And to analyze its drug resistance by collecting clinical medical records;The CTX,TEM and SHV genes of ESBLs positive strains were amplified by PCR in the whole year of 2014,and the genotyping was confirmed.The risk factors of ESBLs-producing E.coli and K.pneumoniae infections were analyzed by SPSS 24.0 software.Results:A total of 311 pathogens were collected,including 236 strains(75.9%)of E.coli,75 strains(24.1%)of K.pneumoniae,47.9%(113/236)of E.coli producing ESBLs,K.pneumoniae were 30.7%(23/75),imipenem and meropenem had the strongest antibacterial activity,but a small amount of carbapenem resistant strains had been found.Fosfomycin,piperacillin/tazobactam,cefoperazone/sulbactam and amikacin were also lower than 10%.The genotype of ESBLs was mainly CTX-M,and the top three genotypes were CTX-M-14,CTX-M-15 and CTX-M-55,respectively 37.8%(17/45),22.2%(10/45),13.3%(6/45).SHV type,TEM type ESBLs were not found in this study.The risk factors of bloodstream infection caused by ESBLs-producing E.coli including basic diseases(OR:0.092,95%CI:0.033-0.261,P=0.000),obstructive urinary tract disease(OR:7.765,95%CI:2.571-23.454,P=0.000),malignant neoplasms(OR:5.591,95%CI:1.659-18.846,P=0.005),hospital history in nearly 3 months(OR:107.667,95%CI:7.352-1576.706,P=0.001)and the antimicrobial use in nearly 3 months(OR:0.021,95%CI:0.002-0.283,P=0.004).The prious surgical history(OR:13.034,95%CI:2.710-62.687,P=0.001)?hospital history in nearly 3 months(OR:9.650,95%CI:2.029-45.901,P=0.004)were independent predictors for ESBLs-induced Klebsiella pneumoniae.Conclusion:ESBLs-producing E.coli and K.pneumoniae were significantly higher than those of non-ESBLs-producing strains,and the genotype was mainly CTX-M.The risk factors of bloodstream infections caused by ESBLs-producing E.coli and K.pneumoniae were significantly different.