Mapping the Threat: A Scoping Review of Acinetobacter baumannii –Associated Hospital Infections and Resistance Mechanisms

Acinetobacter baumannii is a major cause of hospital‐associated infections (HAIs) globally, particularly in intensive care units (ICUs). Its remarkable environmental resilience and ability to acquire extensive antimicrobial resistance (AMR) have made it a critical threat to patient safety and a top priority pathogen according to the World Health Organization. This scoping review synthesizes global evidence on (1) the epidemiological distribution of A. baumannii –associated HAIs, (2) the genetic mechanisms underlying its multidrug‐resistant (MDR) and extensively drug‐resistant (XDR) phenotypes, and (3) the structural interconnectivity of resistance determinants. We systematically reviewed 34 epidemiological and 30 molecular studies published between 2007 and 2024 from four databases (PubMed, Scopus, Web of Science, and Google Scholar), following PRISMA‐ScR and Joanna Briggs Institute guidelines. Data on infection types, resistance phenotypes, and molecular mechanisms were extracted and analyzed. A structured resistance network was constructed using Cytoscape to visualize co‐occurring resistance genes. A. baumannii was frequently implicated in ventilator‐associated pneumonia, bloodstream infections, urinary tract infections, and wound infections, with ICU settings being the most affected. Thirty studies analyzing A. baumannii isolates revealed widespread MDR and XDR profiles. The most frequent resistance genes included blaOXA‐23‐like, blaNDM, and blaOXA‐58‐like, alongside aminoglycoside‐modifying enzymes (e.g., aph(3 ′ )‐Ia and aac(6 ′ )‐Ib) and efflux pumps (AdeABC and adeR/S). Methyltransferases (armA and rmtB) and mobile elements such as ISAba1 were commonly codetected. Resistance extended across aminoglycosides, carbapenems, β ‐lactams, fluoroquinolones, and sulfonamides, reflecting a multifactorial resistance mechanism among clinical isolates. A. baumannii poses a severe and evolving threat to healthcare systems due to its multifaceted resistance mechanisms and nosocomial adaptability. Enhanced molecular surveillance, integrated diagnostic systems, and novel therapeutic strategies targeting resistance networks are urgently needed to combat this high‐priority pathogen.