Distribution and antimicrobial resistance of gram-negative bacilli isolated from patients in ICU

Objective To investigate the characteristics of distribution and antimicrobial resistance of gram-negative bacilli isolated from patients in ICU,and provide reference for antimicrobial rational application in clinic.Methods Bacteria isolated from clinical specimens(blood,urine and sputum,etc) of patients in ICU from November 2005 to October 2006 were identified and performed antimicrobial susceptibility tests,extended-spectrum β-lactamases(ESBLs),AmpC and metallo-β-lactamases were detected.Results One hundred and seventeen strains were isolated,the commonly isolated bacteria were: Acinetobacter baumannii(31.63%),Escherichia coli(22.22%),Pseudomonas aeruginosa(18.81%) and Klebsiella pneumoniae(8.55%);among 15 kinds of antimicrobial agents,gram-negative bacilli had the lowest resistant rate to imipenem(15.38%),followed by piperacillin/tazobactam(36.75%),amikacin(42.74%) and ceftazidime(45.30%);the resistant rates to the other antimicrobial agents were more than 50%,Gram-negative bacilli isolated from patients in ICU had higher antimicrobial resistant rates than the bacteria isolated from the other departments during the same period.ESBLs-producing rate in Escherichia coli and Klebsiella pneumonia was 23.08% and 20.00% respectively;AmpC-producing rate in Enterobacter was 20.00%(2/10),metallo-β-lactamases-producing rate in Pseudomonas aeruginosa was 9.09%(2/22).Conclusion The main gram-negative bacilli isolated from patients in ICU were Acinetobacter baumannii,Escherichia coli,Pseudomonas aeruginosa and Klebsiella pneumoniae,antimicrobial resistance of bacteria are serious,the proper measures should be taken to reduce the occurrence of antimicrobial resistance.