Antimicrobial susceptibility of Enterobacteriaceae and Haemophilus: results from China Antimicrobial Resistance Surveillance Trial Program, 2013-2014

Abstract

Objective To investigate the antibacterial resistance of Enterobacteriaceae and Haemophilus in nationwide's tertiary hospitals and understand the trend of antimicrobial resistance. Methods The clinical isolates were collected from 19 tertiary hospitals in 19 cities nationwide over the period from July 2013 to June 2014 according to the same protocol. About 190 strains were collected from each hospital.The minimal inhibitory concentrations (MICs) were tested using agar dilution method recommended by Clinical and Laboratory Standards Institute (CLSI) in the central laboratory (Institute of Clinical Pharmacoloty, Peking University First Hospital). The susceptibilities of isolates to antimicrobial agents were determined using CLSI or European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2015 guideline. SPSS 17.0 was used to caculated MIC50, MIC90, MICrange, susceptible rate and resistance rate. Results A total of 2 762 pathogenic isolates were studied. Based on the MIC results, extended spectrum β-lactamase (ESBLs) phenotype rates of Escherichia coli and Klebsiella pneumoniae were 66.0% (532/806) and 38.7% (226/584), respectively. Carbapenems, tigecycline, moxalactam, β-lactam/β-lactamase inhibitor combinations, amikacin and fosfomycin displayed desirable antibacterial activity against Enterbacteriaceae, but a significant increase in carbapenems resistant K. pneumoniae was noted (from 3.5%-5.9% in last surveillance raise to 9.1%-12.5%). About 70% K. pneumoniae isolated from children (≤14 years) were resistant to penicillins and cephalosporin, which was more than those from old people (≥65 years, t=2.085, P=0.042). Haemohpilus influenzae isolated from children were more resistant to some β-lactam than those from old people (21.9%-43.8% vs 3.3%-19.7%, t=2.229, P=0.031), so bacterial resistance in children is an important problem in China. Conclusions The resistance rates for E. coli to many antimicrobial agents were higher in China than foreign countries, which was one of the main resistance problem in our country. Compared with past surveillance results, growth of carbapenem resistant K. pneumoniae should be payed more attention.Haemohpilus spp.resistance was more serious in children in China.(Chin J Lab Med, 2016, 39: 103-119) Key words: Drug Resistance, Microbial; Enterobacteriaceae; Haemophilus; Microbial Sensitivity Tests; Drug Monitoring