Study On The Resistance Mechanisms Of Cephalosporins-resistant To Clinical Isolated Of Pseudomonas Aeruginosa

Objectives: To study the resistance of Pseudomonas aeruginosa to several β-lactam antibiotics and the resistance mechanisms of cephalosporins-resistant to clinic isolated of Pseudomonas aeruginosa.Methods: The susceptibility testing was performed with agar dilution test; hydrolyzing Nitrocefin method to testify β-lactamases; screening and confirmatory test for extended-spectrum β-lactamases (ESBLs) and three-dimensional test for AmpC enzyme; DNA was sequenced by PCR amplification to identify the type of β-lactamases; modified three-dimensional test was used to evaluate the effect of β-lactamase inhibitors(clavulanic acid, sulbactam, tazobactam, EDTA and oxacillin); transformation to testify the transfer of β-lactamase gene; the experiment of CCCP inhibition and reverse transcription-polymerase chain reaction (RT-PCR) were used to detecte active efflux pump.Results: The resistant rates to imipenem, melopenem, cefepime, ceftazidime, cefoperazone, cefotaxime and ceftriaxone were 45.16%, 29.03%, 27.42%, 30.64%, 58.06%, 58.06% and 67.64% in the 62 strains of...