Prevalence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) phenotypes of Gram-negative bacilli isolated in clinical specimens at Centre Hospitalo-Universitaire (CHU) Ibn Rochd, Morocco

Introduction: antimicrobial resistance in gram negative bacilli is one of the major concerns in public health. We aimed to evaluate gram negative bacilli epidemiology, antimicrobial profiles, and the resistance & PRIME;s mechanism for Enterobacteriaceae isolated from specimens of hospitalized patients in wards of University Hospital Center Ibn Rochd of Casablanca, Morocco. Methods: a prospective study of the patient's specimens, collected from December 2016 to 31stMarch 2017. Isolation and identification were performed using conventional biochemical tests. According to the European Committee on Antimicrobial Susceptibility Testing guidelines, antibiotic susceptibility was determined. Polymerase Chain Reaction (PCR) was used to detect 8-lactamase and carabapenemase genes: CTX-M, SHV, TEM, OXA-48, NDM, and VIM among the Enterobacteriaceae. Results: according to inclusion criteria, 38 Enterobacteriaceae, 25 A. baumannii, and 10 P. aeruginosa were included during the study period; these bacteria were mainly responsible for bacteremia. Fifty-five percent of enterobacteria were extended-spectrum 8-lactamase (ESBL), 42% EBSL and carbapenemase, and 3% carbapenemase, with high coresistances. Eighty-four percent of A. baumannii were XDR. All P. aeruginosa were MDR; amikacin showed the best activity (70% susceptibility). The genotypic approach revealed the presence of blaCTX-M, blaSHV, blaTEM in 68%, 22%, and 11% respectively. Of the 22 carbapenemaseproducers, 41% were blaOXA-48and 18% blaNDM; none had blaVIM. Furthermore, various genes coexistence were detected: blaCTX-M+blaOXA-48; blaCTX-M+blaNDM; blaCTX-M+blaSHV+blaOXA-48; and blaSHV+blaOXA-48. Conclusion: findings revealed highly resistance rate among isolates. This raises the need to control antibiotics and regular screening to identify dynamics promoting resistance. Thus, we recommend developing antimicrobial stewardship programs and improving hygiene systems to prevent the nosocomial spreading of these in our center.