Detection of plasmid-mediated quinolone resistance genes in Acinetobacter baumannii clinical isolates in Suez Canal University Hospitals in Ismailia

Abstract

Background: The Gram-negative bacterium, Acinetobacter baumannii (A. baumannii) has emerged as a significant threat in healthcare settings, causing severe opportunistic infections. This research aimed to identify plasmid-mediated quinolone resistance (PMQR) genes in A. baumannii clinical isolates in Suez Canal University Hospitals (SCUHs). Methods: A. baumannii isolates were collected and identified by conventional methods. The minimum inhibitory concentration index of ciprofloxacin was determined using the agar dilution method, and efflux pump activity was detected after the addition of carbonyl cyanide 3-chlorphenhydrazone (CCCP) efflux inhibitor. The PMQR genes were detected using conventional PCR. Results: The study included 44 A. baumannii isolates collected from 650 patients at a rate of 6.7%. The highest isolation was from the intensive care unit (56.8%) and respiratory specimens (52.3%). The highest antibiotic resistance was to ceftazidime and cefepime (95.5% and 86.4% respectively), and fluoroquinolones (FQs) (82%), and the lowest resistance was to doxycycline and tetracycline (45.5% and 54.5% respectively). After using efflux inhibitor, thirteen strains (36%) of quinolone-resistant isolates showed efflux pump activity. Using conventional PCR, the aac (6’)-Ib-cr gene showed the highest frequency (89 %), oqxB gene (53 %), qepA gene (47 %) and oqxA gene (30.5%). Conclusion: Most PMQR genes were detected at unforeseen high levels. Strict adherence to infection control measures is important to restrain the horizontal spread of these genes. The addition of the newest arsenal of antibiotics to the Egyptian market becomes a national demand, that may partially solve this critical situation.