Abstract:

Objective To investigate the antimicrobial susceptibility and drug resistance of clinical isolates at Tongling People's Hospital. Methods A total of 3 912 nonduplicated clinical isolates were collected in 2014. Kirby-Bauer disc diffusion method was employed to study the antimicrobial susceptibility. The data were analyzed by WHONET 5.6 software according to the Clinical and Laboratory Standards Institute (CLIS) 2013 breakpoints. Results Of the clinical isolates, Gram-negative microorganisms, Gram-positive microorganisms and fungi accounted for 74.5%, 24.6% and 0.9%, respectively. The overall prevalence of methicillin-resistant Staphylococcus aureus (MRSA) was 39.0%, and it was 65.1% for methicillin-resistant coagulase negative Staphylococcus (MRCNS). The resistance rates of methicillin-resistant isolates to beta-lactams and other antimicrobial agents were much higher than those of methicillin-susceptible isolates. No staphylococcal isolate was found being resistant to vancomycin or teicoplanin. Enterococcus faecalis showed relatively low resistance to ampicillin, penicillin and nitrofurantoin. Enterococcus faecium were more resistant than Enterococcus faecalis to most antibiotics tested. Approximately 49.1% of Escherich coli and 50.8% of Klebsiella isolates produced extended-spectrum beta-lactamases(ESBLs). The ESBLs-producing isolates were significantly more resistant to most antibiotics than the corresponding non-ESBLs-producing isolates. The prevalence of carbapenem-resistant isolates was 27.5% in Klebsiella and 2.3% in Escherich coli. The percentage of Acinetobacter baumannii isolates resistant to imipenem and meropenem was 76.7% and 77.0%, respectively. The 28.4% and 27.7% of Pseudomonas aeruginosa isolates were resistant to imipenem and meropenem. Nearly 93.6% Pseudomonas aeruginosa isolates were susceptible to amikacin. Conclusions There appears a trend of increasing durg resistance for the clinical isolates in this hospital, especially carbapenem-resistant Enterobacteriaceae, which is of great concern. It is mandatory to take effective antibiotic policy and infection control measures.

Key words: Bacterial drug resistance surveillance, Antimicrobial agent, Multi-drug resistant bacterium, Carbapenem-resistant Enterobacteriaceae