Detection of Plasmid Type AmpC β-Lactamase DHA Gene in Pseudomonas aeruginosa

OBJECTIVE To analyze plasmid type AmpC β-lactamase DHA gene in 35 strains of Pseudomonas aerug-inosa simultaneousy resistant to cefazidime, cefotaxime, cefoxitine and aztreonam. METHODS P. aeruginosa plasmid type AmpC β-lactamase DHA gene was detected by PCR, the positive strains as PCR product were directly se-quenced subsequently. RESULTS It was indicated that the two P. aeruginosa strains DHA genes were positive in all 35 strains, one of them was sequenced as DHA- Ⅰ type. CONCLUSIONS The P. aeruginosastrains simultaneous resistant to cefazidime, cefotaxime, cefoxitine and aztreonam have gained DHA gene in our country, plasmid type AmpC β-lactamase DHA gene can be transferred in homogeneity or in different genera of bacteria by transforming or integrating and easy to be transferred, the intensive attention should be paid to avoid DHA gene being prevalent in Gram-positive bacteria in some areas.