Moravec Anna R, Siv Andrew W, Hobby Chelsea R, Lindsay Emily N, Norbash Layla V, Shults Daniel J, Symes Steven J K, Giles David K
Department of Chemistry and Physics, The University of Tennessee at Chattanooga, Chattanooga, Tennessee, USA.
Department of Biology, Geology and Environmental Science, The University of Tennessee at Chattanooga, Chattanooga, Tennessee, USA.
Appl Environ Microbiol. 2017 Oct 31;83(22). doi: 10.1128/AEM.01415-17. Print 2017 Nov 15.
The pathogenic species (, , and ) represent a constant threat to human health, causing foodborne and skin wound infections as a result of ingestion of or exposure to contaminated water and seafood. Recent studies have highlighted 's ability to acquire fatty acids from environmental sources and assimilate them into cell membranes. The possession and conservation of such machinery provokes consideration of fatty acids as important factors in the pathogenic lifestyle of species. The findings here link exogenous fatty acid exposure to changes in bacterial membrane phospholipid structure, permeability, phenotypes associated with virulence, and consequent stress responses that may impact survival and persistence of pathogenic species. Polyunsaturated fatty acids (PUFAs) (ranging in carbon length and unsaturation) supplied in growth medium were assimilated into bacterial phospholipids, as determined by thin-layer chromatography and liquid chromatography-mass spectrometry. The incorporation of fatty acids variably affected membrane permeability, as judged by uptake of the hydrophobic compound crystal violet. For each species, certain fatty acids were identified as affecting resistance to antimicrobial peptide treatment. Significant fluctuations were observed with regard to both motility and biofilm formation following growth in the presence of individual PUFAs. Our results illustrate the important and complex roles of exogenous fatty acids in the membrane physiology and virulence of a bacterial genus that inhabits aquatic and host environments containing an abundance of diverse fatty acids. Bacterial responses to fatty acids include, but are not limited to, degradation for metabolic gain, modification of membrane lipids, alteration of protein function, and regulation of gene expression. species exhibit significant diversity with regard to the machinery known to participate in the uptake and incorporation of fatty acids into their membranes. Both aquatic and host niches occupied by are rife with various free fatty acids and fatty acid-containing lipids. The roles of fatty acids in the environmental survival and pathogenesis of bacteria have begun to emerge and are expected to expand significantly. The current study demonstrates the responsiveness of , , and to exogenous PUFAs. In addition to phospholipid remodeling, PUFA assimilation impacts membrane permeability, motility, biofilm formation, and resistance to polymyxin B.
致病性物种（、和）对人类健康构成持续威胁，因摄入或接触受污染的水和海鲜而导致食源性和皮肤伤口感染。最近的研究强调了从环境来源获取脂肪酸并将其同化到细胞膜中的能力。拥有和保留这种机制促使人们将脂肪酸视为物种致病生活方式中的重要因素。此处的研究结果将外源性脂肪酸暴露与细菌膜磷脂结构、通透性、与毒力相关的表型变化以及可能影响致病物种生存和持久性的应激反应联系起来。通过薄层色谱法和液相色谱 - 质谱法测定，生长培养基中提供的多不饱和脂肪酸（PUFAs，碳链长度和不饱和度各异）被同化到细菌磷脂中。根据疏水性化合物结晶紫的摄取判断，脂肪酸的掺入对膜通透性有不同程度的影响。对于每个物种，某些脂肪酸被确定会影响对抗菌肽治疗的抗性。在单独的PUFAs存在下生长后，观察到运动性和生物膜形成方面都有显著波动。我们的结果说明了外源性脂肪酸在栖息于富含多种脂肪酸的水生和宿主环境中的细菌属的膜生理学和毒力方面的重要而复杂的作用。细菌对脂肪酸的反应包括但不限于为代谢获取而进行的降解、膜脂的修饰、蛋白质功能的改变以及基因表达的调控。物种在参与将脂肪酸摄取并掺入其膜中的机制方面表现出显著的多样性。所占据的水生和宿主生态位都充满了各种游离脂肪酸和含脂肪酸的脂质。脂肪酸在细菌环境生存和发病机制中的作用已开始显现，预计还会大幅扩展。当前的研究证明了、和对外源性PUFAs的反应性。除了磷脂重塑外，PUFA同化还会影响膜通透性、运动性、生物膜形成以及对多粘菌素B的抗性。
