Unraveling the Interplay of Temperature Adaptation, Lipidomics, and Environmental Factors in Acinetobacter baumannii Clinical Strains.

Acinetobacter baumannii has gained prominence due to its heightened antibiotic resistance and adaptability within healthcare settings. Unlike other Acinetobacter species, A. baumannii predominantly thrives within healthcare environments, where its persistence is underscored by physiological adaptations, including homeoviscous adaptation that modifies glycerophospholipids (GPL) to enhance membrane flexibility. The bacteriums substantial genetic diversity highlights the paramount importance of prudent strain selection for research involving drug resistance and virulence. This study investigates the lipid composition of six clinical A. baumannii strains, incorporating the highly virulent model strain AB5075 with multiple antibiotic resistances. Our objective is to scrutinize the adaptations of glycerophospholipids (GPL) and glycerolipids (GL) within these isolated strains, each characterized by unique antibiotic resistance profiles, under variable temperature conditions mimicking environmental and physiological scenarios. The strains differential performance in motilities and biofilm formation across varying temperatures reveals intriguing patterns. Notably, the study uncovers a consistent elevation in palmitoleic acid (C16:1) content in five of the six strains at 18{degrees}C. Utilizing LC-HRMS2 analysis, we elucidate shifts in GPL and GL compositions as temperatures oscillate between 18{degrees}C and 37{degrees}C for all strains. Exploration of lipid subspecies further exposes disparities in PE and PG lipids containing C16:1 and oleic acid (C18:1). This investigation not only provides insights into the physiological attributes and survival strategies of A. baumannii but also deepens our comprehension of its adaptive responses to temperature changes. By unraveling the dynamics of lipid composition and fatty acid profiles, this study enriches our understanding of the bacteriums ecological fitness and behavior in diverse environments. IMPORTANCEAcinetobacter baumannii, a bacterium known for its resistance to antibiotics, is a concern in healthcare settings. This study focused on understanding how this bacterium adapts to different temperatures and how its lipid composition changes. Lipids are like the building blocks of its cell membranes. By studying these changes, scientists can gain insights into how the bacterium survives and behaves in various environments. This knowledge helps us better understand its ability to cause infections and resist treatments. The studys findings contribute to our broader understanding of how Acinetobacter baumannii functions, which is important for developing strategies to combat its impact on patient health.