Molecular Identification of Biocide Resistant Quaternary Ammonium Compound (QAC) Genes in Multi-Drug Resistant Acinetobacter baumannii Isolated from ICU Patients in Erbil City

: Multidrug resistant Acinetobacter baumannii (MDR-AB) is recognized as one of the most important nosocomial pathogens in Intensive Care Unit (ICU) patients. Disinfectants are frequently used in hospitals to prevent transmission of MDR-AB-related infections. However, the excessive use of disinfectants may impose selective pressure on MDR-AB strains and lead to wide spread of biocide Quaternary Ammonium Compound (QAC) resistance genes. This study aimed to investigate 40 MDR-AB isolates collected from ICU patients for the distribution of QAC genes ( qacE and qacΔE1 ) by Polymerase Chain Reaction (PCR)method and the susceptibility towards benzalkonium (BAC) and Didecyldimethylammonium chloride (DDAC) by Agar Well Diffusion method. Results showed that 32 (80%) and 30 (75%) isolates harbored qacE and qacΔE1 genes, respectively. All isolates showed high susceptibility against tested biocides, in which the mean of growth inhibition zone for each of BAC and DDAC were 24mm and 23 mm, respectively. In conclusion, this study confirms high frequency of QAC genes in MDR-AB isolates. Moreover, efficient microbiological efficacy of these biocide agents was observed as expected according to the manufacture's standards guideline.