Drug-resistant Acinetobacter baumannii: mortality, emerging treatments, and future pharmacological targets for a WHO priority pathogen.

Abstract

SUMMARYAcinetobacter baumannii has emerged as a formidable global health concern and is a major contributor to infection-related mortality in critically ill patients worldwide. This versatile Gram-negative bacterium is notorious for its highly plastic genome, which enables the rapid emergence and dissemination of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains, severely limiting the available treatment options. The genetic flexibility of A. baumannii underpins its arsenal of molecular mechanisms, enabling it to resist a range of antibiotics, from traditional agents to the latest therapeutic advancements available. With the progress made in treatments against Acinetobacter infections and various drugs undergoing clinical trials, the effectiveness of these treatments is often outpaced by the pathogen's swift evolution of resistance, resulting in alarmingly high rates of treatment failure. In this systematic review of literature spanning 2004-2024, we highlight the high mortality rates associated with infections caused by XDR strains and carbapenem-resistant A. baumannii (CRAB). This review provides a comprehensive examination of the resistance mechanisms deployed by A. baumannii, encompassing both conventional antibiotics and novel agents used in global healthcare settings. In addition, we discuss emerging druggable targets and the inherent challenges in their development, offering strategic insights into next-generation therapeutic programs. A deep profound understanding of the pathogen's molecular defenses is essential to guide the design of innovative therapies aimed at mitigating the escalating threat posed by A. baumannii.