Study of antimicrobial resistance of the Gram-negative bacilli isolated from patients in intensive care units

Objective To study the antimicrobial resistance and producing of extended spectrum beta lactamases (ESBLs) of Gram negative bacilli isolated from patients in intensive care units in a hospital. Methods Using E test method to detect the minimal inhibitory concentration (MIC) of various antimicrobial agents against 156 strains of Gram negative bacilli, and double disc synergy test to confirm the ESBLs producing strains. Results The antimicrobial susceptibility rates of the ESBLs negative and ESBLs positive strains of Enterobacteriaceae was 80.46% and 57.69% , respectively. There was significant difference in the resistant rates to cefepime, ceftazidime, gentamycin and ciprofloxacin between the ESBLs positive and ESBLs negative strains of Escherichia coli and Klebsiella pneumoniae (P 0.05 ). Strains of Enterobacteriaceae had the highest resistant rate ( 14.32% ) to the ceftazidime of the third generation cephalosporins, ESBLs positive and ESBLs negative strains of Enterobacteriaceae were all sensitive to imipenem. The resistant rates of Pseudomonas aeruginosa and Acinetobacter spp. to imipenem were 40.52% and 8.82% , respectively. Conclusion It is very important to select antimicrobial agents based on the results of antimicrobial susceptibility tests for the treatment of patients with infection.