Drug resistance of Escherichia coli causing blood stream infections

OBJECTIVE To investigate the drug resistance of Escherichia coli causing blood stream infections so as to provide the basis for empirical medication in the hospital.METHODS The France Bio-Merieux company VITEK-2Compact automatic bacterial identification instrument was employed to identify the bacteria.According to the CLSI2010standard,the ESBLs confirmation experiment was performed by using K-B agar diffusion method,and WHONET5.6analysis software was used for statistics.RESULTS Of totally 4723strains of pathogens isolated from the blood during 2009-2011,the top three species were the coagulase-negative Staphylococcus,Escherichia coli,and Klebsiela pneumoniae,accounting for 46.8%,11.9%,and 9.5%,respectively.Of totally 562strains of E.coli,there were 314(55.87%)strains of ESBLs-producing E.coli;of totally 453strains of E.coli isolated from the hospitalized patients,there were 245(54.1%)strains of ESBLs-producing E.coli.The ICU,liver transplantation and hepatobiliary and pancreatic center,and hemology department were the most common departments where the ESBLs-producing strains were isolated,accounting for 63.3%,59.3%,and 58.7%,respectively.Of 109strains of E.coli isolated from the emergency outpatient department,there were 45(41.3%)strains of ESBLs-producing E.coli.The in vitro test indicated that the drug resistance of the ESBLsproducing E.coli to imipenem was 0.6%in 2009,0.8%in 2010,and 0.9%in 2011;the drug resistance rate to amikacin was 11.4%in 2009,6.7%in 2010,and 9.7%in 2011;the drug resistance rate to piperacillin/tazobactam was 7.2%in 2009,17.6%in 2010,and 4.3%in 2011;the drug resistance rate to cefoxitin was 16.3%in 2009,17.6%in 2010,and 11.9%in 2011;the drug resistance rate to ceftazidime was 16.3%in 2009,28.7%in 2010,and 19.1%in 2011;the drug resistance rate of the ESBLs-producing E.coli was significantly higher than that of the non-ESBLs-producing strains.CONCLUSIONThe detection rate of the ESBLs-producing E.coli causing blood stream infections is high,and the isolation rate of the ESBLs-producing E.coli isolated from the hospitalized patients is higher than that of the strains isolated from the outpatients.The ESBLs have not yet been effectively controlled;the drug resistance spectrum of the ESBLs-producing E.coli dose not change too much,and the strains resistant to imipenem are increased;amikacin,piperacillin / tazobactam,cefoxitin,and imipenem can achieve good therapeutic effect.