Cellular fatty acids of Helicobacter pylori have taxonomic, physiological, and pathogenic implications. However, little is known about the fatty acid composition under various culture conditions. H. pylori is usually grown on blood-supplemented complex media, and the fatty acids in the blood may affect the fatty acids in the cells. In addition, frequently subcultivated laboratory-adapted strains may have properties different from those of fresh clinical isolates, which are culturable only for a limited number of passages. Therefore, the cellular fatty acid profiles of laboratory-adapted strains (LAS) and freshly isolated strains (FIS) were compared after growth on agar that was fatty acid free and growth on blood agar that contained fatty acids. LAS ATCC 43504, 51932, and 700392 and the FIS IMMi 88, 89, and 92, each with <10 subcultures, were cultured in parallel on a fatty acid-free agar (ISAF) and on 5% sheep blood agar (SBA), which contained oleic acid (18:1 9c), hexadecanoic acid (16:0), and octadecanoic acid (18:0). ISAF-grown cultures showed no 18:1 9c and no appreciable differences between the profiles of FIS and LAS. After culture on SBA, the strains showed 18:1 9c and increased 16:0 and 18:0 content combined with decreased tetradecanoic acid (14:0) content compared to ISAF-grown cells. The changes in the fatty acid profiles were much more pronounced in FIS than in LAS. LAS are obviously characterized by a lower uptake of the fatty acids from the growth medium than FIS. Furthermore, it could be shown that this LAS behavior is most likely a primary strain attribute that is favored under laboratory conditions. The pronounced uptake of fatty acids by strains with FIS behavior may be associated with the expression of virulence properties.Helicobacter pylori exhibits a unique profile of cellular fatty acids which is markedly different from that of other enteropathogenic gram-negative bacteria (4-7, 11, 21). Tetradecanoic acid (14:0) and methyleneoctadecanoic acid (19:0 cyclo) are major fatty acids, whereas hexadecanoic acid (16:0) is represented in relatively small amounts, and hexadecenoic acid (16:1) cannot be detected at all (4-7, 11, 15). One property that is unusual but characteristic is the fatty acid distribution among the different lipid classes. The phospholipids are predominantly substituted with 14:0 and 19:0 cyclo fatty acids, whereas -hydroxy or unsaturated fatty acids can only be detected, if at all, in small amounts, which may account for unusual membrane properties (4, 15, 18). The lipopolysaccharide (LPS) of H. pylori is predominantly different from those of other bacteria and has octadecanoic acid (18:0) and longer-chain 3-hydroxy fatty acids, like 3-hydroxy-hexadecanoic acid (3-OH 16:0) and 3-hydroxy-octadecanoic acid (3-OH 18:0), which may explain the low endotoxic and biological activities of H. pylori LPS (4, 13-15). Thus, the fatty acid substitution of H. pylori lipids may have physiological and pathogenic implications.It is well known that environmental and physiological factors affec...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.