[Investigation of presence of class 1 integrons in clinical isolates of carbapenem-resistant Acinetobacter baumannii].
Acinetobacter species, particularly Acinetobacter baumannii, are important opportunistic pathogens responsible for nosocomial infections. They are often resistant to a wide range of antibiotics, including broad-spectrum beta-lactams, aminoglycosides and quinolones. This study was aimed to investigate the presence of class 1 integrons in nosocomial A.baumannii isolates. Eighty-nine carbapenem resistant nosocomial A.baumannii strains recovered from various clinical samples at Ankara Numune Teaching and Research Hospital during September 2006-August 2007, were included in the study. To determine the presence of integrons in Acinetobacter isolates, a chromosomal DNA region that consists of internal variable gene sequences restricted to two conserved regions, was amplified by using 5'CS and 3'CS primers. Class 1 integrons were demonstrated in 93.3% (83/89) of the strains. The range of inserted gene cassette sizes detected varied from 100 to 3000 base pairs. Recent studies have shown that the majority of integrons belong to class 1 among Acinetobacter species. This study also indicated that class I integrons were present in 93.3% of the A.baumannii isolates. The isolates were genotyped by pulsed-field gel electrophoresis (PFGE) and found to be distributed into 13 different groups, two of the groups predominated the isolates (group A: 29, group C: 21 isolates). Five of 6 isolates that did not have the class 1 integron (6/89; 6.7%) exhibited the same PFGE pattern (group C). Since integrons are important for the dissemination of antibiotic-resistance genes among nosocomial Acinetobacter species, the investigation of integrons by polymerase chain reaction method seems to be a rapid and simple technique for revealing the epidemic potential of A.baumannii isolates.
Ankara Üniversitesi Tıp Fakültesi, Tıbbi Mikrobiyoloji Anabilim Dalı, Ankara, Türkiye. dolapci@medicine.ankara.edu.tr
Iştar
I
Dolapçı
Zeynep Ceren
ZC
Karahan
Ipek
I
Mumcuoğlu
Ebru
E
Us
Derya
D
Cöloğlu
Mehtap
M
Ulusoy
Alper
A
Tekeli
D000151:Acinetobacter Infections / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D015780:Carbapenems / Q000494:pharmacology*; D003428:Cross Infection / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D032023:Integrons / Q000235:genetics*; D016133:Polymerase Chain Reaction
D015780:Carbapenems; D004269:DNA, Bacterial