Detection of Insertion Sequence ISAba1 Among Clinical Isolates of Carbapenems-Resistant Acinetobacter baumannii

Abstract

Abstract:Acinetobacter baumannii is an opportunistic pathogen with increasing clinicalimportance, especially in immunocompromised patients, causing nosocomial infections of thelungs, urinary tract and surgical wounds. Carbapenems are important antibiotics for treatingmultidrug resistant A. baumannii infections. Insertion sequence ISAba1 has been detected incorrelation with many antimicrobial agent resistance genes in A. baumannii. The aim of thisstudy was to investigate existence of insertion sequence (ISAba1) in clinical isolates ofcarbapenem-resistant A. baumannii isolated from hospitals in Baghdad city.Seventy Acinetobacter baumannii isolates were obtained from clinical samples (42from sputa and 28 from blood) between September 2012 and March 2013.Antibiogramtowards several groups of antimicrobial agents including: β- Lactams; aminoglycosides;fluoroquinolone ; and sulfa; as well as the combination of amoxicillin / β-Lactamase inhibitorusing disc diffusion method was carried out. Multi-drug resistant isolates were observed inalmost all the studied isolates .Minimum inhibitory concentration values were demonstratedusing agar dilution method for imipenem antibiotic. Forty eight (68.57%) of 70 isolates wereresistant to imipenem with values of MIC ranging between (16-256) μg/ml.ISAba1 sequenceamong imipenem resistant isolates using PCR technique were identified in 44 isolates(91.66%). Sequencing of amplified product (549 bp) was performed to ensure the occurrenceof the ISAba1 sequence in the studied carbapenem-resistant A.baumannii.