RESUMO
OBJECTIVE: In order to understand the role of integron, fluorescent quantitative polymerase chain reaction (FQ-PCR)was developed to measure the changes in int I 1 gene expression of Pseudomonas Aeruginosa in biofilm and planktonic cells. METHODS: Three clinical strains of P. aeruginosa with int I 1 gene (SW07, R07 and TH12) were cultured in planktonic cells and biofilm cells. The total RNA of these cultured bacteria were extracted by the conventional method. The FQ-PCR was developed to measure the changes in int I 1 mRNA expression of the P. aeruginosa with bacterial 16s rRNA as an internal control. RESULTS: The three clinical strains of P. aeruginosa expressed int I 1 mRNA in both biofilm and planktonic cells, but with different levels. The int 1 mRNA expressed by the RO7, SW07 and TH12 strains in the biofilm cells were 1.4, 5.7 and 128 times higher than in the planktonic cells, respectively. CONCLUSION: The int I 1 gene expression of P. aeruginosa in the biofilm is up-regulated at mRNA level. The integron may capture and accumulate drug resistance gene cassettes more effectively in the biofilm condition.
