Comparison of Metabolomic Profile Between Colistin Susceptible and Colistin Resistant Strains of A. baumanni

Abstract Acinetobacter baumannii, has emerged as a critical nosocomial pathogen with the ability to develop resistance to all available antimicrobials, including colistin. Metabolomics tools may aid in the observation of the low molecular weight compounds in biochemical pathways yielding additional information about drug-resistant bacteria. The objective of this work was to compare the differential expression of metabolites between colistin-susceptible and resistant clinical strains of A. baumannii. The Q-TOF LC/MS method was used together with multivariate data analysis, Annotation of identified metabolites was performed along with the analysis of the metabolic pathways. Our results revealed that colistin-susceptible and colistin-resistant A. baumannii Strains have different metabolic profiles. Some of the identified metabolites were found to be involved in multiple biochemical pathways, such as cell wall biosynthesis and recycling, astaxanthin biosynthesis, and nucleotide metabolism. Cell wall recycling and nucleic acid degradation-related metabolites were up-regulated in colistin-sensitive strains. The lipid profile was down-regulated in colistin-resistant strains. On the other hand, a virulence factor that can serve as a drug target was found to be up-regulated in resistant strains. Our findings can provide a basis for further research on the elucidation of metabolites' role in resistance mechanisms and the determination of novel drug targets that would aid in the development of effective therapeutics against A. baumannii.