Detection of carbapenemases-producing Acinetobacter baumannii: The phenotypic approaches

Abstract

© Faculty of Pharmacy, Mahidol University (Thailand) 2020. Antimicrobial resistance among Acinetobacter species represents one of the most critical challenges within healthcare settings. Acinetobacter baumannii primarily causes hospital-acquired infections affecting patients with prolonged hospitalization and with long-term administration of antimicrobials. A. baumannii can develop antimicrobial resistance, especially to carbapenems, the last-line of antimicrobial agents to treat serious infections. Several resistance mechanisms have been reported including antimicrobial-degrading enzymes, efflux pumps, target modification and porin deficiency which likely work synergistically. Among those, the most prevalent mechanism is enzymatic degradation by carbapenemases, β-lactamase enzymes that are capable to hydrolyse carbapenems. Currently, spreading of carbapenem-resistant A. baumannii has been increasing worldwide. A high prevalence of A. baumannii with multidrug-resistance including carbapenems leads to conventional failure of common antibiotic therapy treatments. Therefore, accurate and rapid detection techniques of carbapenemases-producing A. baumannii are extensively required to screen and prevent the outbreak of this microorganism. Both phenotypic and genotypic methods have been developed aiming to detect carbapenemases enzymes. This review summarizes the concepts and practical approaches for phenotypic detection of this enzyme which are applicable to practise in developing countries.