ABSTRACT
Objective To investigate the profile of antimicrobial resistance in clinical isolates from the patients in Peking Union Medical College Hospital during 2012.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 WHONET 5.6 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 and 73.4% 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.faecium and E.faecalis.No lin-ezolid 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-re-sistant strains of K.pneumoniae (0.7%,4/615)were iden-tified.About 20.3% and 13.6% of the P .aeruginosa isolates were resistant to imipenem and meropenem,respectively.P . aeruginosa isolates 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.baumannii isolates showed relatively low resistance rate to cefoperazone-sulbac-tam (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.
ABSTRACT
OBJECTIVE To study 40 kinds of resistant-related genes in a pan-resistant Pseudomonas aeruginosa.METHODS To detect the susceptibility of antimicrobial agents by MIC,40 resistant-related genes including 29 ?-lactamases genes,porin oprD2 genes,6 aminoglycoside-modifying enzymes(AMEs)genes,chlorhexidine/sulfadiazine resistant gene(qacE△1-sul1)and intergron(intⅠ1,2,3),etc,form 1 strain of P.aeruginosa were measured by PCR,and verified by DNA sequencing.RESULTS In the strain,there were positive of 6 kinds of resistant-related genes(blaTEM,blaOXA10,aac(6′)-Ⅱ,aac(3)-Ⅱ,qacE△1-sul1 and intⅠ1),but without oprD2 genes.Twenty-seven kinds of ?-lactamases genes,4 kinds of AMEs(aac(6′)-Ⅰb,aac(3)-Ⅰ,ant(3″)-Ⅰ and ant(2″)-Ⅰ),and 2 kinds of intⅠ(intⅠ2 and intⅠ3) were negative.CONCLUSIONS The multi-resistant mechanisms of pan-resistant P.aeruginosa are mainly related to 7 kinds of resistant-related genes(blaTEM,blaOXA10,oprD2,aac(6′)-Ⅱ,aac(3)-Ⅱ,qacE△1-sul1 and intⅠ1).