Surveillance of antimicrobial resistance in Guangzhou hospitals in 2007

Abstract

Objective To investigate antimicrobial resistance of clinical isolates from 15 hospitals submitted to Guangzhou Surveillance of Antimicrobial Resistance (GSAR) in 2007,and to learn the feature of bacterial resistance in Guangzhou.Methods Disc diffusion test (K-B methods) was employed to study the antimicrobial resistance.Results Of 18 500 clinical isolates,Gram negative bacilli and Gram positive cocci accounted for 68.4% and 31.6%,respectively,and 45.7% isolates in Gram negative bacilli belonged to non-fermentative bacilli.The detection rotes of methiciHin-resistant strains was 55.9% in Staphylococcus aureus and 75.9% in coagulase negative Staphylococcus.All of the Staphylococcus pneumoniae isolates were penicillin-susceptible (PSSP) according to 2008 CLSI criterion.One strains of Enterobacter faecium were identified as vancomycin-resistance (VRE).The resistant rates of Enterobacter to imipenem and merpenem were the lowest.The prevalence of ESBLs-producing strains in Enterobacter coli and Klebsiella spp.isolates was 43.8% and 39.8%,respectively.Against all the ESBLs strains in Enterobacter coli and Klebsiella spp,meropenem,imipenem,cefoperazone/sulbactam,and piperacillin/tazobactam showed the lowest resistant rates,ranging from 0 to 14.1%,20.4%,24.4% and 25.4% isolates of Pseudomonas aernginosa were resistant to efoperazone/sulbactam,piperacillin/tazobactam and meropenem,while 75.6%,72.4% and 63.2% isolates of Pseudomonas aeruginosa were susceptible to piperacillin/tazobactam,meropenem and cefoperazone/sulbactam,respectively.The resistance rates of Acinetobacter spp.to cefoperazone/sulbactam and meropenem were 2.6% and 5.1%,respectively.Some panresistant isolates of Pseudomonas aeruginosa (5.5%) and Ac/naobacter baumannii (1.5%) emerged.The resistance of Pseudomonas aeruginosa and Aeinetobacter baumannii isolated from sputum sample was higher than those from blood sample.Conclusions The increase of isolated rates of non-fermentative Gram-negative bacilli and the emerging bacterial resistance and oandrug resistance in Pseudomonas aeruginosa and Acinetobacter baumannii warrants further enbancing the local surveillance of bacterial resistance and characterization of panresistance mechanism to inform the rational use of anfimicrobial agents and containment of bacterial resistance. Key words: Bacterial resistance; Anfimicrobial agent; Bacterial susceptibility testing