[Changes of antimicrobial resistance among clinical isolates of Escherichia coil in Shanghai 1990-2004].
OBJECTIVE
To investigate the trend of resistance to antimicrobial agents among clinical isolates of Escherichia coli 1990-2004.


METHODS
Agar diffusion test was used to analyze the changes of drug susceptibility of 33,495 strains of E. coli isolated from 11 hospitals in Shanghai to 21 antimicrobial agents 1990-2004.


RESULTS
The resistance rates of 33,495 E.coli isolates to 21 antimicrobial agents mostly increased 1990-2004. The resistance rates to ampicillin and piperacillin increased from 69% and 30% to 85% and 71.4% respectively. The resistance rates to cephalosporins, except ceftazidime and cefepime, all increased, e. g., the resistance rates to cefazolin (24.0%-->48.3%), cefuroxime (18.0%-->45.7%), and cefaclor (33.3%-->46.8%), especially that to cefotaxime (6.0%-->35.2%). The resistance rate to fluoroquinolones increased from 11.0% to 55.4%. The resistance rate to gentamicin increased from 44.0% to 54.0%. The resistance rates to tetracycline, chloramphenicol, SMZ/TMP remained at high levels. However, ceftazidime, cefepime, imipenem, amikacin, beta-lactams/beta-lactamase inhibitors, and nitrofurantoin remained active against the E.coli isolates. The detectable rate of extended-spectrum beta-lactamase-producing strains in E. coli increased from 14.7% to 36.5%.


CONCLUSIONS
The trend of resistance of E. coli to commonly used antimicrobials was upward 1990-2004.
Zhang
Ying-yuan
YY
Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai 200040, China.
Zhu
De-mei
DM
Hu
Fu-pin
FP
Wu
Shi
S
Wang
Fu
F
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001424:Bacterial Infections / Q000382:microbiology; D002681:China; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000639:trends
D000900:Anti-Bacterial Agents