Surveillance of bacterial resistance in Peking Union Medical College Hospital during 2012

Objective To investigate the profile of antimicrobial resistance in clinical isolates from the patients in Peking Union Medical College Hospital during2012.Methods A total of 6 662 nonduplicate clinical isolates were collected.Disc diffusion test or Kirby-Bauer method and automated systems were employed to study the antimicrobial resistance.The data were analyzed by WHONET5.6 software according to CLSI 2012 breakpoints.Results Of the 6 662 bacterial strains included in this analysis,gram negative organisms and gram positive cocci accounted for 66.7%(4 446/6 662)and 33.3%(2 216/6 662),respectively.The top 10 most frequently isolated microorganisms were E.coli(17%),P.aeruginosa(11.4%),A.baumannii(11.4%),S.aureus(11.2%),K.pneumoniae(9.2%),E.faecalis(8.4%),E.faecium(4.1%),coagulase negative Staphylococcus(3.3%),E.cloacae(3.1%)and S.maltophilia(3.1%).About 39.9%of the S.aureus strains and73.4%of the coagulase negative Staphylococcus were methicillin-resistant.No staphylococcal strains were found resistant to vancomycin,teicoplanin or linezolid.A few of vancomycin-or teicoplanin-resistant strains were identified in both E.faeciumand E.faecalis.No linezolid resistant strains were found.ESBLs-producing strains accounted for 53.0%,25.7% and 27.0%in E.coli,Klebsiella spp.(K.pneumoniae and K.oxytoca)and P.mirabilis,respectively.The Enterobacteriaceae strains were still highly susceptible to carbapenems.Overall,less than 2.6% of these strains were resistant to carbapenems.A few pan-resistant strains of K.pneumoniae(0.7%,4/615)were identified.About 20.3%and 13.6% of the P.aeruginosaisolates were resistant to imipenem and meropenem,respectively.P.aeruginosaisolates showed the lowest resistance rate(7.2%)to amikacin.And 72.8% and 75.2% of A.baumannii strains were resistant to imipenem and meropenem.A.baumanniiisolates showed relatively low resistance rate to cefoperazone-sulbactam(51.2%)and minocycline(30.2%).The prevalence of pan-resistant strains was 43.5%in A.baumannii and 1.4%in P.aeruginosa.Conclusions Bacterial resistance is still increasing,especially pan-resistant A.baumannii strains.It is mandatory to take effective measures to control hospital infections and improve rational antibiotic use.