To explore the expression level of class I integrase (intI 1) mRNA in Acinetobacter baumannii from biofilm cells and planktonic cultured cells ,and to analyze the drug-resistance of Class I integron positive strains.
Acinetobacter baumannii were collected from hospitals,and Class I integron strains were screened by gene amplification. Total RNA of Class I integron positive strains was extracted, and the intI1 mRNA expression in the bioflim cells and planktonic cultured cells was measured by RT-PCR. Susceptibilities to antibiotics of Class I integron positive strains were also examined.
The intI1 gene mRNA was expressed under 2 conditions, and the mRNA expressed in the biofilm cells was about 4 times higher than that in the planktonic cultured cells. Among the 64 strains of Acinetobacter baumannii, 46 strains were Class I integron positive strains. The antibiotic resistance of intI1 gene cassette-positive strains was higher than that of gene cassette-negative strains.
The intI1 gene mRNA can be up-regulated in Acinetobacter baumannii biofilm cells.Class I integron plays an important role in drug resistance. It is much easier to capture gene cassettes for bacteria under biofilm condition.
Zhong nan da xue xue bao. Yi xue ban = Journal of Central South University. Medical sciences 11/2008; 33(10):952-7.