Surveillance of bacterial resistance from hospitals in Shanghai in 2007

Objective To investigate the resistance of clinical isolates in Shanghai hospitals from January to December in 2007.Methods Antimicrobial susceptibility testing of 35 907 clinical isolates were carried out according to an agreed protocol using Kirby-Bauer (K-B). Results were analyzed according to CLSI 2007. Results Of the 35907 clinical isolates,gram negative bacilli and gram positive cocci accounted for 63.0% and 37.0% respectively. The prevalence of MRSA was 61.1% in S. aureus. The prevalence of MRCNS was 75.9% in coagulase negative Staphylococcus. No vancomycin-intermediate S. aureus (VISA) or vancomycin-resistant S. aureus (VRSA) was identified. About 11.7% of the S. pneumoniae isolates from children were penicillin-susceptible (PSSP). The remaining 88.3% (PISP 73.9% and PRSP 14.4%) of S. pneumoniae strains were nonsusceptible to penicillin. Two strains of vancomycin-resistant Enterococcus (VRE) were identified in E. faecium. ESBLs-producing strains accounted for 58.0%,53.9% and 14.7% in E. coli,Klebsiella spp. and P. mirabilis,respectively. About 26.7% and 18.8% of the P. aeruginosa isolates were resistant to imipenem and meropenem respectively. And 21.0% and 22.5% of the Acinetobacter isolates were resistant to imipenem and meropenem respectively. Some pan-resistant isolates were found in P. aeruginosa (2.8%),A. baumannii (5.5%),C. freundii (6.0%) and K. pneumoniae (0.1%).Conclusions Bacterial resistance is still on the rise. It is important to strengthen the detection of resistant bacteria in routine work,screen carriers of resistant bacteria,and take further steps to conduct research on the mechanism of antibiotic resistance,which are useful for rational use of antimicrobial agents and containment of bacterial resistance.