aac(6')-Ⅰ b gene in drug-resistant strains of Pseudomonas aeruginosa / 中华临床感染病杂志

ABSTRACT

Objective To investigate the distribution of aminoglycoside modifying enzyme genes (AMEs) and 16S rRNA methylase genes in drug-resistant strains of Pseudomonas aeruginosa. Methods Twenty strains of drug-resistant Pseudomonas aeruginosa were isolated from sputum and wound secretion samples collected from the First People's Hospital of Huai' an in Jiangsu province. Eight AMEs [aac(3)-Ⅰ , aac(3)-Ⅱ, aac(6')-Ⅰb,aac(6')-Ⅱ, ant{2)-Ⅰ ,ant(3)-Ⅰ , ant(4')-Ⅰ , aph(3')-Ⅱb] and 6 16S rRNA methylase genes (armA, rmtA, rmtB, rmtC, rmtD, npmA) were analyzed by PCR and verified by DNA sequencing. Results Out of 20 strains of Pseudomonas aeruginosa, aac(6')-Ⅱ was positive in 8 strains (40.0% ) , ant2- Ⅰ in 8 strains (40.0% ) , aac(3)-Ⅱ in 5 strains (25.0% ) , aac(6')- Ⅰ b in 2 strains (10.0% ) and rmtB in 1 strains (5.0% ) , respectively. The rest 9 genes were not detected. Among 2 strains harboring aac(6')- Ⅰ b, DNA sequencing confirmed that 1 was aac(6')- Ⅰ b (the clssical type) and another was aac(6')- Ⅰ b-cr. Conclusion Gene aac(6')- Ⅰ b-cr exists in drug-resistant Pseudomonas aeruginosa, and it has modifying effect on both aminoglycosides and quinolones.