ABSTRACT
Objective To investigate the changing pattern of antimicrobial resistance among gram-negative bacilli isolated from respiratory intensive care unit (RICU) for rational use of antimicrobial agents.Methods Antimicrobial susceptibility of 1 047 isolates of gram-negative bacilli from 2000 to 2004 was tested by disk diffusion method.WHONET 5.3 software was used to analyze the data.Results The most common pathogens were Pseudomonas aeruginosa (42.9%),Stenotrophomonas malto- philia (17.1%),Acinetobacter baurnannii (10.0%) and Klebsiella pneumoniae (6.5%).The susceptibility rate of P.aerug- inosa was relatively higher to ceftazidime (50%-74%),amikacin (33.3%-81.0%),piperacillin-tazobactam (30.4%-64.6%) and cefoperazone-sulbactam (33.5%-47.5%),while the susceptibility to imipenem decreased.The susceptibility rate of S. maltophilia was relatively higher to cefoperazone-sulbactam (47.2%-78.6%) and ticarcillin-clavulanic acid(28.3%-86.6%). More than 90% of Acinetobacter baumannii isolates were susceptible to imipenem.The susceptibility rates of K.pneumoniae to imipenem and cefepime were 92.9%-100% and 55.6%-80.0%,respectively.The susceptibility rate to piperacillin-tazobac- tam decreased from 58.3% to 21.7%.The prevalence of extended-spectrum?-lactamases (ESBLs) in K.pneumoniae increased from 11.1% in 2002 to 47.8% in 2004.Conclusions Most pathogens show significant resistance to the most commonly used an- tibiotics.It is very important to select antibiotics for the treatment of infections in ICU based on the results of susceptibility.