Integrative review on Acinetobacter baumannii as a multidrug-resistant pathogen: resistance mechanisms and therapeutic perspectives in the context of nosocomial infections.

Acinetobacter baumannii is a gram-negative opportunistic pathogen associated with high morbidity and mortality in nosocomial infections, particularly in intensive care units. Multidrug resistance (MDR) is mediated by efflux pumps, lipopolysaccharide modifications, aminoglycoside adenylyltransferases, FosA, structural alterations, and production of enzymes that inactivate antibiotics, such as carbapenemases. These factors limit the therapeutic options and increase clinical challenges, as there are currently few drugs or combinations with therapeutic success against A. baumannii infections. Some strategies and new drugs, such as cefiderocol, eravacycline, sulbactam-darlobactam, tigecycline, and their combinations with colistin, are being tested and have shown apparent advances. This integrative review discusses the current resistance mechanisms and emerging therapeutic strategies aimed at overcoming the growing threat posed by MDR A. baumannii.