Leptospira spp.

Abstract

Genomics (Huang et al. 2014; Ren et al. 2003; Zuerner 1991): Leptospira interrogans serovar Lai str. 56,601 chromosome CI: 4,332,241 bp; 4,360 predicted ORFs Leptospira interrogans chromosome CII: 358,943 bp; 367 predicted ORFs Cell morphology: Thin (0.1 $μ$m), long (6--20 $μ$m) spirochete: Hooked ends -- ``question marks'' (interrogans) (Fig. 21.1) Two endoflagella (axial filaments): Anchored at both ends of the cell and run lengthwise between the inner and outer membranes in the periplasmic space; enclosed in outer sheath Causes twisting motion used for motility; important for dissemination in host Endoflagella subunits (Lambert et al. 2012): FlaA1, FlaA2: outer sheath FlaB1, FlaB2, FlaB3, FlaB4: core polymer Gram stain: Gram negative Growth: Anaerobic or microaerophilic growth. Slow grower (30--50 h doubling time); metabolically crippled: No Krebs cycle or electron transport chain; gets ATP from glycolysis No genes for synthesis of nucleotides, fatty acids, vitamins, cofactors, or amino acids; gets most of its nutrients through transport, not biosynthesis Reservoir: almost all-known mammals; humans are not reservoirs. At least 19 species: 13 are pathogenic and 6 are saprophytic; > 250 serovars: Leptospirosis: L. interrogans (predominant), L. borgpetersenii, L. santarosai, L. noguchii, L. weilli, L. kirschneri, L. alexanderi