ABSTRACT
Objective To evaluate the effect of azithromycin on class Ⅰ integron-integrase gene (intI 1 )mRNA expression in biofilm-forming (BF)Pseudomonas aeruginosa (PA).Methods intI 1 of 10 PA strains isolated from a hospital were detected,1 strain with positive BF+intI 1 was selected for culture,blank control group and three az-ithromycin trial groups (divided according to 3 concentrations:16 mg/L,32 mg/L,and 64 mg/L)were set,experi-ments were repeated 5 times,expression of intI 1 mRNA were detected by RT-PCR.Results Relative expression of intI 1 mRNA in azithromycin groups of 16 mg/L,32 mg/L,64 mg/L,and control group were (1 .15 ±0.04), (12.47±3.10),(19.71 ±0.78 ),and (1 .00 ±0.00),respectively,there were significant difference among four groups(F =163.82,P 0.05),but among other groups were significantly different (P <0.05 ),intI 1 mRNA expression in azithromycin groups increased with the enhancing concentration of azithromycin in culture so-lution .Conclusion Expression of intI 1 gene mRNA in BF PA can be up-regulated by the present of azithromycin, which may improve the probability of drug-resistant genes,and promote drug-resistant gene recombination.