Characterization of imipenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa clinical isolates in a Moroccan hospital

Acinetobacter baumannii and Pseudomonas aeruginosa are two pathogens with an important power of adaptation to antibiotics thus, both pose a real public health problem. Our study investigated epidemiological characteristics, antibiotic sensitivity profile and resistance genes of imipenem resistant A. baumannii and P. aeruginosa. This was a retrospective study carried out in the bacteriology laboratory of Mohammed V military training hospital, spanning from January 2018 to April 2021. Antibiotic susceptibility was studied by Mueller Hilton agar diffusion method with OXOID?? type antibiotic discs and interpreted according to the recommendations of EUCAST 2021. Carbapenemase detection was performed by CarbaNP-test??. The molecular study was performed using conventional PCR. During the study period, we collected 1,072 imipenem-resistant isolates namely, 820 A. baumannii and 252 P. aeruginosa. The molecular study showed that out of 108 A. baumannii isolates 102 carried the blaOXA-51 and 100 isolates carried the blaOXA-23 gene. The coexistence of blaOXA-23 and blaNDM genes was detected in only 4 isolates. Altogether 50% of P. aeruginosa strains carried blaVIM-2. All investigated A. baumannii and P. aeruginosa strains were colistin susceptible in this study. Multiresistant bacterial infections are associated with longer hospitalization, higher hospital costs and higher mortality rates. Therefore, a collective action including the different actors of the healthcare system is necessary.