Surveillance of antibiotic resistance in clinical isolates from Peking Union Medical College Hospital during 2010

Objective To investigate the antimicrobial resistance of clinical isolates in Peking Union Medical College Hospital during 2010.Methods Antibiotic susceptibility testing was conducted by using disc diffusion method.The antimicrobial susceptibility of staphylococcal strains was tested by using Phoenix 100.All the data were analyzed by WHONET 5.4 software according to CLSI 2011 breakpoints.Results A total of 5 383 clinical isolates were collected during 2010,of which gram negative rods and gram positive cocci accounted for 61.2% and 38.8%,respectively.The most common specimen source was respiratory tract(37.0%),followed by urine(12.8%) and blood(12.4%).Escherichia coli was the most frequently isolated bacteria,followed by Acinetobacter baumannii,Pseudomonas aeruginosa,Klebsiella pneumoniae,coagulase-negative Staphylococcus,and Staphylococcus aureus,accounting for 18.8%,12.1%,11.8%,9.1%,7.5% and 7.1%,respectively.The prevalence of ESBLs in the strains of E.coli,Klebsiella pneumoniae,Klebsiella oxytoca and Proteus mirabilis was 56.2%,30.4%,24.0% and 17.4%,respectively.The resistance rates of ESBLs-positive strains to most antibiotics were higher than ESBLs-negative strains.Some strains of Enterobacteriaceae were resistant to imipenem,meropenem and ertapenem.The percentage of P.aeruginosa strains resistant to imipenem and meropenem was 20.0% and 15.3%,respectively.The percentage of A.baumannii strains resistant to all the antibiotics tested was above 59% except minocycline(17.7%).The prevalence of methicillin-resistant Staphylococcus aureus(MRSA) and coagulase-negative Staphylococcus(MRCNS) was 43.4% and 78.8%,respectively.No strains were found resistant to vancomycin,teicoplanin or linezolid in Staphylococcus spp.The percentage of E.faecium strains resistant to most of the antibiotics tested was higher than that of E.faecalis.The prevalence of penicillin resistant Streptococcus pneumoniae(PRSP) was 76.0% in the isolates from children,which was significantly higher than in the isolates from adults.Hemolytic Streptococcus strains were more sensitive to most antibiotics except erythromycin and clindamycin.Conclusions Bacterial resistance is still on the rise.We should pay more attention to resistance surveillance and improve the rational use of antibiotics.