Drug resistance and clinical distribution of Gram positive bacteria strains from culturing blood samples

LI Ruiyun; ZHA Gan; WU Xiaojun

doi:10.3969/j.issn.1671-6450.2017.06.008

Abstract：Objective To provide the evidence for treatment of Gram-positive bacteria infection by investigating its distribution and drug resistance.Methods Antimicrobial susceptibility testing were carried out in the strains of Gram-positive bacteria with minimum inhibitory concentration (MIC) and the data were analyzed by WHONET 5.6 software according to CLSI 2015 Standards and calculated bacteria resistant rate (R%) and the sensitive rate (S%).Results A total of 1 051 clinical isolates of Gram-positive bacteria were collected including 754 strains of Staphylococci (71.74%),234 strains of Staphylococcus aureus(22.26%),96 strains of Enterococci (9.18%);The prevalence of Methicillin resistant S.aureus (MRSA) and Methicillin resistant coagulase negative S.aureus (MRCNS) were 47.86% and 65.00%,respectively.The drug resistance of MRSA was above 55% to AMK,CLI,CIP,RIF,GEN,TCY and TOB,above 92% to ERY,but maintained a good sensitivity to SET and QDA.MRSCN maintained a good sensitivity to NIT,TEC,LNZ and VAN about 0~3%;The resistance rate of Enterococcus faecium (EFM) was higher than that of Enterococcus faecalis (EFA).No resistance of Staphylococcus aureus to VAN,TEC,LNZ and CHL was found.No resistance of Enterococci to SET,QDA and CHL was found.Conclusion Gram-positive bacteria isolated from blood culture is highly resistant to drugs.The drug resistance of MRSA,MRSCN and EFM are very serious and its drug resistance monitoring should be strengthened in order to use drug rationally.