Surveillance of bacterial resistance in Shanghai hospitals during 2011

Objective To summarize the resistance profile of the bacterial strains isolated in Shanghai hospitals from January through December 2011. Methods Antimicrobial susceptibility testing was conducted with the clinical isolates collected from 23 hospitals according to an agreed protocol using Kirby-Bauer (K-B) method. Results were analyzed according to the breakpoints of CLSI 2011. Results Of the 56 032 clinical isolates, gram positive cocci and gram negative bacilli accounted for 28. 7% and 71. 3%, respectively. The prevalence of methicillin-resistant strains was 56. 9% in S. aureus (MRSA) and 79. 9% in coagu-lase-negative Staphylococcus (MRCNS). No staphylococcal strain was found resistant to vancomycin, teicoplanin or linezolid. Seven among the 798 strains of Streptococcus pneumoniae were isolated from meningitis. The prevalence of penicillin-susceptible S. pneumoniae (PSSP), penicillin-intermediate S. pneumoniae (PISP) and penicillin-resistant S. pneumoniae (PRSP) was 70. 0%, 13. 7% and 16. 3% in the nonmeningitis strains isolated from children. Vancomycin resistance was found in 32 E. faecium strains, including vanA type (12 strains), vanB type (10 strains) and vanF type (7 strains) and 4 E. faecalis strains, including vanA type and vanB type (1 strain each). ESBLs were produced in 57. 9% of the E. coli strains, 39. 6% of the Klebsiella strains (K. pneumoniae and K. oxytoca) and 14. 3% of the P. mirabilis strains. Enterobacteriaceae strains were still very sensitive to carbapenem antibiotics. Overall, the percentage of the Enterobacteriaceae strains resistant to imipenem or mer-openem was lower than 5%. The percentage of the Acinetobacter strains resistant to imipenem and meropenem increased to 53% and 55%, respectively. A few pandrug-resistant strains were identified in E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa. Fosfomycin showed good activity against the enterococcal strains and E. coli (including ESBLs-producing and multidrug-resistant strains) isolated from urine. Conclusions Antibiotic resistance is still rising in the clinical isolates in Shanghai hospitals, which poses a serious threat to the clinical practice. It is a top priority to carry out epidemiological survey and implement active and effective intervention in the clinical setting with relatively heavy burden of multiple-resistant bacteria.