Surveillance of bacterial resistance in Shanghai hospitals during 2006

Objective To investigate the resistance of clinical isolates in Shanghai hospitals from January through December in 2006.Methods Antimicrobial susceptibility testing of 31 316 clinical isolates were carried out by means of Kirby-Bauer (KB) method.Results Of the 31 316 clinical isolates, gram-negative bacilli and gram-positive cocci accounted for 63.6% and 36.4% respectively. About 64.6% of S. aureus and 82.2% of coagulase negative Staphylococcus isolates were identified as methicillin-resistant. No VISA or VRSA isolate was found. Majority (96.0%) of the S. pneumoniae isolates from adults were penicillin-susceptible (PSSP), but only 13.0% of the S. pneumoniae isolates from children were PSSP. Most of the S. pneumoniae from children were penicillin-nonsusceptible (PISP+PRSP) [87.0% (PISP 73.2% and PRSP 13.8%)]. Only 4.0% (PISP 4.0% and PRSP 0) of the S. pneumoniae from adults were penicillin-nonsusceptible. Three strains of E. faecium were identified as vancomycin-resistant (VRE). The prevalence of ESBLs-producing strains in E. coli, Klebsiella spp. and P. mirabilis isolates was 53.0%, 51.1% and 19.5% respectively. The resistance rates of P. aeruginosa to imipenem and meropenem were 24.4% and 15.5% respectively and 15.5% and 17.0% for Acinetobacter spp. respectively. Some panresistant isolates of P. aeruginosa (2.7%), A. baumannii (3.4%) and C. freundii emerged.Conclusions The emerging bacterial resistance and pan-drug resistance in P. aeruginosa, A. baumannii, and C. freundii warrants further enhancing the surveillance of bacterial resistance and characterization of panresistance mechanism to inform the rational use of antimicrobial agents and containment of bacterial resistance.