?-Lactam Resistance Genes of Multidrug-resistant Pseudomonas aeruginosa / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To study the existence of the ?-lactamase gene produced by multidrug-resistant Pseudomonas aeruginosa isolated from respiratory tract. METHODS Antimicrobial susceptibility was tested by K-B method. A modified three-dimensional test was used to detect the ?-lactamase phenotypes. The genotypes were analyzed by PCR amplification and product sequencing. RESULTS ?-Lactamases were detected in 29 out of the 46 isolates. Twenty-one isolates produced AmpC ?-lactamase,two of them harboring CARB-3 gene. Two isolates produced ESBLs harbored TEM gene. Six isolates produced other type of ?-lactamases. Four out of 6 harbored CARB-3 gene and three IMP gene. The oprD2 gene was deleted in 34 isolates. CONCLUSIONS Chromosomal-mediated AmpC ?-lactamase is the major ?-lactamases produced by multidrug-resistant P. aeruginosa and CARB-3 is second. Lack oprD2 gene is popular.