Surveillance of bacterial resistance in Shanghai hospitals during 2010

Objective To investigate the antibiotic resistance of clinical isolates in Shanghai hospitals from January to December in 2010.Methods Antimicrobial susceptibility testing was carried out for 41 326 clinical isolates according to an agreed protocol using Kirby-Bauer(KB) method.Results were analyzed according to the breakpoints of CLSI 2010.Results Of the 41 326 clinical isolates,gram negative bacilli and gram positive cocci accounted for 69.7% and 30.3%,respectively.The prevalence of MRSA in S.aureus were 57.9%,and 78.9% of the coagulase negative Staphylococcus isolates were methicillin-resistant(MRCNS).No staphylococcal isolate was found resistant to vancomycin,teicoplanin or linezolid.Seven of the 656 strains of S.pneumoniae were isolated from cerebrospinal fluid(meningitis strain).The remaining were nonmeningitis strains.The prevalence of penicillin-susceptible S.pneumoniae(PSSP) was 71.2% in the nonmeningitis strains from children.Penicillin-intermediate S.pneumoniae(PISP) and penicillin-resistant strains accounted for 17.0% and 11.8%,respectively.The prevalence of PSSP and PISP were 97.0 % and 3% in the nonmeningitis strains from adults.Fifteen strains of E.faecium and 6 strains of E.faecalis were found resistant to vancomycin.Eleven of the 15 E.faecium strains and 5 of the 6 E.faecalis strains showed van A-type resistance.The remaining strains were van B-type resistance.ESBLs production was confirmed in 56.8% of E.coli,40.8% of Klebsiella spp.(K.pneumoniae and K.oxytoca) and 19.7% of P.mirabilis isolates.Enterobacteriaceae isolates were still highly sensitive to carbapenem antibiotics.The percentage of the strains resistant to imipenem or meropenem was 5%.The resistance rate of Acinetobacter spp.to imipenem and meropenem was increasing.About 49.6% and 51.2% of the strains were resistant to imipenem and meropenem,respectively.Compared with the data of year 2009,the prevalence of pan-drug resistant K.pneumoniae and A.baumannii strains increased markedly.Conclusions Bacterial resistance is still increasing,which poses a serious threat to clinical practice.It is urgent to take effective infection control measures.