Carbapenem-Resistant Acinetobacter baumannii Biofilms in Hospital-Acquired Infections: Pathogenesis, Clinical Impact, and Therapeutic Challenges

Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as one of the major challenges in modern healthcare settings, ranked by the World Health Organization (WHO) as a critical-priority pathogen requiring urgent development of new antimicrobials. The organism's ability to form robust biofilms on both biotic and abiotic surfaces represents a central pillar of its pathogenicity in hospital-acquired infections (HAIs), including ventilator-associated pneumonia (VAP), catheter-associated bloodstream infections (CABSI), wound infections, and urinary tract infections. This review summarizes recent findings on the molecular mechanisms underpinning biofilm formation in CRAB, encompassing the roles of surface adhesins, quorum sensing, extracellular polymeric substances, and horizontal gene transfer in carbapenem resistance. We further examine the clinical epidemiology of CRAB-associated HAIs, including attributable mortality, morbidity, and economic burden across global healthcare systems. The article critically evaluates current and emerging therapeutic strategies, including polymyxins, tigecycline, cefiderocol, sulbactam-durlobactam, novel bacteriophage-based therapies, anti-biofilm compounds, and photodynamic inactivation approaches. Significant therapeutic gaps persist, underscoring the need for multidisciplinary strategies that integrate robust infection prevention measures, antimicrobial stewardship, and translational research into next-generation anti-biofilm agents. Future directions in genomic surveillance and combination therapy optimization are discussed.

A. baumannii, Drug resistance, Biofilm, Hospital-acquired infections, Antimicrobial resistance, Quorum sensing

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