Study of antibiotic resistance in ESBLs-producing strains

OBJECTIVE To investigate the productive status and the antibiotic resistance of extendedspectrum beta lactamases(ESBLs) in Escherichia coli and Klebsiella pneumoniae so as to provide necessary grounds to the clinical practice.METHODS A total of 854 strains of E.coli and 300 strains of K.pneumoniae were collected from clinical specimens.ESBLs production was performed by the standard disk diffusion method;drug susceptibility was detected by Kirby-Bauer disk diffusion method.RESULTS ESBLs productive rate of E.coli(K.pneumoniae) increased significantly from 26.4%(21.9%) to 48.6%(47.7%) at our hospital,during the years from 1999 to 2005.No strains were found to be resistant to imipenem.The resistance rates of ESBLs-producing E.coli strains to amikacin and nitrofurantoin were 17.9% and 6.2%,respectively,and over 74.4% to other antibiotics at 2005.The resistances of ESBLs-producing strains to most antimicrobials were much higher than that of non ESBLs-producing strains.CONCLUSION Antibiotics should be used rationally in the treatment of infections caused by ESBLs-producing strains. Imipenem could be of the first choice to treat the infection caused by ESBLs-producing strains.