Multi- and Extensive-Drug Resistant Acinetobacter baumannii in ICUs: Risk Factors, Antimicrobial Resistance Profiles and co-harboring of gyrA and parC mutations

Abstract

Background: Acinetobacter baumannii is a gram-negative organism that is implicated in hospital acquired infections. It confers high resistance to many classes of antibiotics. Objectives: To assess the prevalence of multi and extensive drug-resistant (MDR & XDR) Acinetobacter baumannii, their risk factors, antimicrobial resistance patterns and the presence of gyrA and parC gene mutations of quinolone resistance. Methodology: The study included 106 ICU patients (56 males & 50 females), samples were collected according to sites of infections, Acinetobacter baumannii was identified by morphology, biochemical reactions &API 20NE. Antimicrobial susceptibility testing was performed by disc diffusion method. The E-test was used to detect MIC of Ciprofloxacin & Levofloxacin, then a polymerase chain reaction- restriction fragment length polymorphism was performed to detect the occurence of gyrA and parC gene mutations of Quinolone resistance. Results: Thirty isolates were identified as Acinetobacter baumannii, most of which from respiratory infections (P=0.005) prolonged hospitalization, antibiotic use, urinary catheters & ventilator supports were found to be risk factors of infections. Acinetobacter baumannii isolates showed high resistance to most of the tested antibiotics (29 MDR & 28 XDR). All isolates were resistant to Ciprofloxacin & Levofloxacin with the co-presence of gyrA and parC mutations in all isolates (P<0.001). Conclusions: There is an increased prevalence of MDR & XDR Acinetobacter baumannii among ICU infections. The co-occurrence of gyrA and parC mutations is associated with high resistance to Quinolones.