[show abstract] [hide abstract]
ABSTRACT: A total of 62 Acinetobacter baumannii isolates including 29 imipenem resistant, 23 imipenem susceptible and 10 environmental isolates were analyzed based on integron and integron gene cassette array (I-GCA) PCR and DNA sequences. Two types of class 1 integron were found based on their cassette arrays. The integron class 1 with a 2.6 kb size (Int1-A ) has the cassette order of aaC(6’)-Im followed by another gene cassette aadA1 disrupted by IS26 transposase, while the another class 1 integron with 2.8 kb size (Int1-B) has the gene cassette order of aacC1 followed by orfX, orfX’, IS 26 transposase and aadA1. PCR mapping detect the distribution of such integron types within the isolates. Integron gene cassette array PCR (I-GCA PCR) typing gave 20 profiles while PFGE typing gave 18 profiles with 16 types and 2 sub-types. The major profile I of I-GCA PCR equivalent to profile A of PFGE was the dominant profile covering most of the clinical and environmental imipenem resistant isolates while the second largest profile XII of I-GCA PCR or profile M of PFGE was found in the imipenem susceptible isolates. Both integron types Int1-A and Int1-B were mostly restricted to imipe-nem resistant outbreak strains of the major profile I of I-GCA PCR or profile A of PFGE. I-GCA PCR based typing gave similar result to that of PFGE by sharing all the imipenem resistant strains of distinct profile I of I-GCA PCR in the profile A of PFGE which was responsible for the present A. baumannii outbreak. These results indicate that I-GCA PCR alone or coupled with other typing method would be a rapid tool for epidemiological study for bacteria that bear integron.
Biomedical Research - http://www.indmedica.com/journals.php?journalid=12&issueid=146&articleid=1965&action=article. 01/2011; 22:2011-01 - 2011-03.