Resistances of Acinetobacter baumannii Contamination: New Strategies for Contention

Abstract

Acinetobacter baumannii has emerged as one of the most formidable nosocomial pathogens of the twenty-first century, distinguished by its extraordinary capacity to acquire and sustain resistance to virtually all classes of conventional antibiotics. Carbapenem-resistant A. baumannii (CRAB) in particular constitutes a critical public health threat, carrying attributable mortality rates that frequently exceed 40% in intensive care settings and imposing substantial burdens on healthcare systems worldwide. The organism's success as a hospital pathogen derives from the convergence of intrinsic microbiological attributes—including desiccation tolerance, biofilm-forming capacity, and a highly plastic genome—with acquired resistance mechanisms such as OXA-type carbapenemases, aminoglycoside-modifying enzymes, and efflux pump overexpression. Conventional treatment options, historically anchored in polymyxin-based regimens and high-dose carbapenems, are increasingly undermined by resistance to last-resort agents, rendering the therapeutic landscape dangerously precarious. This review critically evaluates the principal mechanisms underpinning the multidrug-resistant and extensively drug-resistant phenotypes of A. baumannii, examines the global epidemiology of resistant strains, and analyses therapeutic strategies currently employed. It further appraises emerging and novel interventions—including sulbactam-durlobactam, cefiderocol, bacteriophage therapy, antimicrobial peptides, nanoparticle-based agents, quorum sensing inhibitors, immunotherapeutic approaches, and CRISPR-Cas-based systems—alongside advances in infection prevention and antimicrobial stewardship. The critical synthesis presented here demonstrates that no single emerging strategy is likely to resolve the A. baumannii resistance crisis in isolation, and that a multi-layered, coordinated approach spanning basic science, clinical innovation, and public health governance represents the most credible path forward.