Antimicrobial resistance of gram-negative bacilli isolated from 14 teaching hospitals across China in 2016

Abstract

Objective To investigate antimicrobial resistance among nosocomial gram-negative bacilli in 2016 across China. Methods About 1 394 consecutive and non-repetitive gram-negative bacilli were isolated from 14 teaching hospitals from March to August in 2016 across China. All of these isolates were sent to the central laboratory for reidentification and susceptibility testing. The minimal inhibitory concentration(MICs)of meropenem and other antibacterial agents were determined by agar dilution method. The data were analyzed by using WHONET-5.6 software. Results The activity of antimicrobial agents against Enterobacteriaceae was as follows in descending order of susceptible rate: meropenem (95.2%, 891/936), amikacin (94.6%, 885/936), ertapenem (92.1%, 862/936), piperacillin/tazobactam (88.1%, 825/936), imipenem (88.0%, 823/936), cefoperazone-sulbactam (83.1%, 778/936), cefepime (72.2%, 676/936), cefiazidime (72.2%, 676/936), levofloxacin(68.8%, 644/936), ciprofloxacin (63.2%, 592/936), minocyline (62.9%, 589/936), cefiriaxone (54.9%, 514/936), cefotaxime (54.0%, 505/936), cefoxitin (44.3%, 415/936). The sensitivities of E. coli to carbapenems, amikacin, piperacillin-tazobactam, polymyxin B and cefoperazone-sulbactam were over 80%. The more sensitive antibiotic to Klebsiella pneumoniae was polymyxin B (99.0%), followed by amikacin (84.9%), meropenem (84.4%) and imipenem (82.0%). The prevalence of extended-spectrum β-lactamase was 62.8%(137/218)in Escherichia coli and 28.3%(58/205)in Klebsiella pneumonia. The activity of antimicrobial agents against E. cloacae, E. aerogenes and Citrobacter freundii was as follows in descending order of susceptible rate: meropenem (97.0%-98.5%), amikacin (95.8%-98.3% ), imipenem (94.5%-97.5% ), polymyxin B (96.4%-100%), cefoperazone-sulbactam (76.5%-90.0%), ertapenem (73.3%-90.1%), piperacillin/tazobactam (82.4%-88.3%). The most active agents against Pseudomonas aeruginosa were polymyxinB (100%), followed by amikacin (89.3%) and ciprofloxacin (82.4%). The most active agents against Acinetobacter baumannii were polymyxinB (100%). The sensitivities of Acinetobacter baumannii to meropenem, imipenem, minocycline and cefoperazone-sulbactam were 20.3%(39/202), 19.3%(41/202), 66.3%(134/202) and 24.8%(50/202), respectively. Conclusions Carbapenems remain high sensitive against Enterobacteriaceae.Controlling carbapenem resistant Klebsiella pneumoniae is urgent. Drug antimicrobial resistance in A. baumanni is a still serious problem.(Chin J Lab Med, 2017, 40: 614-622) Key words: Gram-negative bacteria; Drug resistance, bacterial; Microbial sensitivity tests