Drug-resistance Analysis and Clinical Significance of Gram-negative Bacilli Producing Extended-spectrum β-Lactamases in Lower Respiratory Tract Infection

OBJECTIVE To analyse production of Gram negative bacilli producing extended spectrum β lactamases(ESBLs)which infected lower respiratory tract and drug resistance of ESBLs producing strains to 11 kinds of antibacterial drugs.Finally, a suggestion was given to treat lower respiratory tract infection(LRTI)due to drug resistance strains producing ESBLs.METHODS One hundred and Sixty six isolates from clinical lower respiratory tract infectious specimens were screened for the presence of ESBLs by the VITEK ESBL detection test and double disk synergy tests.In vitro antibacterial activity of 11 kinds of antibacterial drugs to strains producing ESBLs were compared .RESULTS In this sample, productive rate of ESBLs was 21.7%, and productive rate of ESBLs in Klebsiella pneumoniae, Escherichia coli,Enterobacter cloacae and Pseudomonas aeruginosa was 36.1%,27.8%,25% and 8.3%, respectively.Imipenem has the most powerful antibacterial activity to drug resistant strains producing ESBLs except P.aeruginosa. Cefoxitin has more antibacterial activity to K.pneumoniae and E.coli producing ESBLs.However,other strains producing ESBLs were all resistant to cefoxitin.Aminoglycosides and fluoroquinolones showed better activity to K.pneumoniae producing ESBLs. CONCLUSIONS LRTI due to Gram negative bacilli producing ESBLs could not neglected.Imipenem could be the first choice to treat LRTI due to drug resistant strains producing ESBLs.