Treatment Strategies of Colistin Resistance Acinetobacter baumannii Infections

Abstract

Acinetobacter baumannii has emerged as a pressing challenge in clinical practice, mainly due to the development of resistance to multiple antibiotics, including colistin, one of the last-resort treatments. This review highlights all the possible mechanisms of colistin resistance and the genetic basis contributing to this resistance, such as modifications to lipopolysaccharide or lipid A structures, alterations in outer membrane permeability via porins and heteroresistance. In light of this escalating threat, the review also evaluates available treatment options. The development of new antibiotics (cefiderocol, sulbactam/durlobactam) although not available everywhere, and the use of various combinations and synergistic drug combinations (including two or more of the following: a polymyxin, ampicillin/sulbactam, carbapenems, fosfomycin, tigecycline/minocycline, a rifamycin, and aminoglycosides) are discussed in the context of overcoming colistin resistance of A. baumannii infections. Although most studied combinations are polymyxin-based combinations, non-polymyxin-based combinations have been emerging as promising options. However, clinical data remain limited and continued investigation is essential to determine optimal therapeutic strategies against colistin-resistant A. baumannii.

Colistin: Lights and Shadows of an Older Antibiotic

“…The clinical usage of colistin alone and in combination with other antimicrobials with scarce and/or limited antimicrobial activity has recently reinvented its role in clinical practice [136,137]. Also, considering the limited antimicrobial options against these pathogens, colistin was defined as the "last-hope resource" for the treatment of DTR infections, especially among critical-ill patients [8].…”