Characterized of class I integron in Acinetobacter baumannii isolated from upper respiratory tract

Abstract:

Abstract:［Objective］ To characterize the class Ⅰ integron in Acinetobacter baumannii and to analyze the correlation between integron and drug resistance． ［Methods］ In total 187 strains were collected between 2008 and 2009. All strains were tested by Kirb-Bauer disk diffusion test for drug resistance． PCR and DNA sequencing were used to detected classⅠintegrase gene and to clarify the context of gene cassette．［Results］ Class Ⅰ integrase gene was detected in 100 (53.4%) of the isolates analyzed． Seven different gene cassettes were identified，including a new integron (GenBank: HQ322622) carrying an unknown protein probably associated with recombination． The vast majority of the cassettes encoded amonoglycoside resistance gene，including aacA4，aadA1，aacC1，aac6Ⅱ，aadA2. Susceptibility data show that strains carrying classⅠintegron were significantly more resistant to all of the antibiotics tested than isolates lacking classⅠ integron． The correlation between the presence of integron and the multidrug-resistance of A． baumannii was statistically significant.［Conclusion］Drug resistance genes integrated by Class Ⅰ integron were widespread in A． baumannii． Class Ⅰ integron plays an important role in resistance of A． baumannii．

Key words:Keywords: multi-drug resistance，Acinetobacter baumannii，classⅠ integron