vitamin-b-12 and Leptospirosis

The spirochete species Leptospira interrogans is the most common cause of leptospirosis, producing acute to chronic infections in most mammalian species. This pathogenic bacterium has an ability to evolve in many ways to occupy various environments and hosts. In this study, we performed chronology analysis to look for insight into the emergence of Leptospira species, focusing on L. interrogans, and investigated gene gain and loss related to their adaptation in strains isolated from asymptomatic dogs. Chronology analysis revealed that the emergence of L. interrogans was around 53.7 million years ago (MYA), corresponding to the Paleogene period that coincided with an optimal climatic temperature and the evolution of suitable mammalian hosts. Gene families encoding for vitamin B2, B12 biosynthesis, cell adhesion and external encapsulating structure were found to be enriched in L. interrogans isolated from the urine of asymptomatic dogs. The activity of these gene families may have favored adaptations resulting in chronic infections.

Topics: Animals; Bacterial Adhesion; Dog Diseases; Dogs; Evolution, Molecular; Genome, Bacterial; Genomics; Leptospira; Leptospirosis; Markov Chains; Multigene Family; Phylogeny; Riboflavin; Vitamin B 12; Whole Genome Sequencing

Stalheim, O. H. V. (University of Wisconsin, Madison), and J. B. Wilson. Cultivation of leptospirae. I. Nutrition of Leptospira canicola. J. Bacteriol. 88:48-54. 1964.-The nutrition of Leptospira canicola was investigated by use of synthetic media of suitable ionic strength. At an incubation temperature of 30 C, the minimal components were calcium, iron, magnesium, and ammonium ions, thiamine, and a fatty acid source; barium and strontium replaced calcium. Aspartic acid, glutamic acid, or methionine stimulated the rate and amount of growth; the best growth occurred in medium containing additional amino acids. Additions of cyanocobalamin or biotin permitted growth at 37 C. The stimulatory effects of added cyanocobalamin, biotin, pyridoxine, pantothenate, lipoic acid, or nicotinic acid were additive at 37 C, but not at 30 C. Fatty acids containing 14, 16, 17, or 18 carbon atoms supported growth; linoleic and linolenic acids were toxic. Glyceryl monooleate or trioleate, or Tween 40, 60, or 80 supported moderate to good growth; a mixture of monoolein and Tween 60, or Tweens 60 and 80 supported the best growth. Ten strains of L. canicola cultivated in a synthetic medium containing Tweens 60 and 80 attained cellular densities per ml of 10(7) to 4.0 x 10(7) organisms. L. canicola cells, resuspended in medium containing oleic-1-C(14) acid, incorporated label primarily into cellular lipids; a lesser amount was located in the protein fraction, and only trace amounts were found in the nucleic acid fraction. The rate of incorporation was not affected by added sodium acetate. L. canicola was found to have fatty acid decarboxylase activity.

Topics: Biotin; Culture Media; Fatty Acids; Iron; Leptospira; Leptospirosis; Magnesium; Polysorbates; Research; Thiamine; Vitamin B 12