Sequencing and comparative genomics of Leptospira interrogans serovar pomona and Leptospira kirschneri serovar grippotyphosa.

Abstract

Virulence genes that include methyl-accepting chemotaxis protein, flagellar basal body-associated protein, flagellar motor switch protein, Lig A protein, thermolysin, multiple antibiotic resistance protein, acriflavine resistance protein, and rfb-related genes were identified and compared among the four Leptospira species: pomona, grippotyphosa, lai, and copenhageni. Based on the unique distribution of their virulence genes, grippotyphosa and pomona can be paired while copenhageni and lai similarly can be grouped. This pairing correlates well with their respective host ranges.

The ∼ 4.7Mb genomes of Leptospira interrogans serovar pomona and Leptosrira kirschneri serovar grippotyphosa respectively were sequenced to understand the molecular basis of leptospiral physiology, virulence, and pathogenesis in leptospirosis.

Nearly 50 metabolic pathways, including glycolysis, pentose phosphate, TCA cycle, oxidative phosphorylation, and ATP synthesis, have been reconstructed for four Leptospira species using KEGG. Domain analysis, isozymes search, and literatures mining confirmed that all these pathways investigated were identical in L. pomona, grippotyphosa, lai, and copenhageni.

3,733 genes were predicted in L. pomona and 3,828 genes were predicted in L. grippotyphosa and compared with those of L. lai and copenhageni. The large chromosomes of L. pomona, grippotyphosa, lai, and copenhageni encode 133, 205, 854, and 98 species specific genes, respectively while 77, 99, and 66 genes are species specific in the small chromosomes of L. pomona, grippotyphosa, and lai, respectively, but none are specific in the copenhageni small chromosome.