Abstract

1. Elucidation of virulence factors of Leptosrirakirschneriserovargrippotyphosa using comparative genomics. Stephanie Lepp, JiaxinQu, Fares Najar, and Bruce Roe Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Ok 73160 Abstract Genome Features Leptospirosis is a zoonotic disease of global significance. In the United States 15-20% of cattle and swine are infected with leptospira, and leptosprosis is the primary cause of abortions and stillbirths in livestock (1?). The disease is a major threat to animal health and the livestock industry. Moreover, leptospirosis can produce deadly infections in accidental hosts such as humans (2,3). Tens of millions of humans become infected each year worldwide, and in some areas the death rate from infection is as high as 25% (4). Because leptospires are difficult to culture in vitro (5) genomic sequence analysis is a powerful tool for studying these pathogens. In this study we used comparative genomics to elucidate virulence factors of Leptosrirakirschneriserovargrippotyphosa. The study revealed that Leptosrirakirschneri might utilize lipopolysacharide as an endotoxin to elicit immune response since the metabolic pathway for LPS synthesis is complete. Additionally, outer membrane proteins that may enable Leptosrira to adhere to host cell surfaces were identified. The study also revealed the presence of motility and chemotaxis proteins that might allow Leptosrira to penetrate host tissues rapidly. The use of in silico analysis in recognizing virulence factors in various leptospiraserovars is an important complementary tool to biochemical methods as it aids in formulating hypothesis for molecular and biochemical tests which ultimately will help generate vaccines and other drugs to fight Leptospirosis. Methods Enter through cut or mucosal membrane8 Leptospira evades immune response Quickly enter lymphatic and circulatory system9 6 10 Pathogenesis LipL4117 (orf 2309) OmpL117 (orf 1019) Attach to epithelial cells, in liver, kidney, lungs, heart etc.9 11 Evoke immune response causing major inflammatory problems8,9. 12 Toxin mediated capillary vasculitis8 and jaundice9. 6 References • Website • Ren, S. X. et al. Unique physiological and pathogenic features of Leptospirainterrogans revealed by whole-genome sequencing. Nature 2003, 422 (6934), 888-93 • Gamberini, M.; Gomez, R. M.; Atzingen, M. V.; Martins, E. A.; Vasconcellos, S. A.; Romero, E. C.; Leite, L. C.; Ho, P. L.; Nascimento, A. L., Whole-genome analysis of Leptospirainterrogans to identify potential vaccine candidates against leptospirosis. FEMS MicrobiolLett2005, 244 (2), 305-13. • Ganoza, C. A.; Matthias, M. A.; Collins-Richards, D.; Brouwer, K. C.; Cunningham, C. B.; Segura, E. R.; Gilman, R. H.; Gotuzzo, E.; Vinetz, J. M., Determining risk for severe leptospirosis by molecular analysis of environmental surface waters for pathogenic Leptospira. PLoS Med 2006, 3 (8), e308. 5. Lux, R., Moter, A., and Shi, W. 2004. Chemotaxis in Pathogenic Spirochetes: Directed Movement Toward Targeting Tissues? J. Mol. Microbiol. Biotechnol. 2: 355-364. • Kanehisa, M.; Goto, S., KEGG: kyoto encyclopedia of genes and genomes. Nucleic Acids Res 2000, 28 (1), 27-30. • Altschul S.F., Gish W., Miller W., Myers E.W. and Lipman D.J. (1990)
Basic local alignment search tool. J. Mol. Biol. 215: 403-410. • Dolhnikoff, M.; Mauad, T.; Bethlem, E. P.; Carvalho, C. R. R., Pathology and pathophysiology of pulmonary manifestations in leptospirosis. Brazilian Journal of Infectious Diseases 2007, 11, 142-148. • Levett, P. N., Leptospirosis. ClinMicrobiol Rev 2001, 14 (2), 296-326. • Yuri, K.; Takamoto, Y.; Okada, M.; Hiramune, T.; Kikuchi, N.; Yanagawa, R., Chemotaxis of leptospires to hemoglobin in relation to virulence. Infect Immun1993, 61 (5), 2270-2. • Rosa, P. A.; Tilly, K.; Stewart, P. E., The burgeoning molecular genetics of the Lyme disease spirochaete. Nat Rev Microbiol2005, 3 (2), 129-43. • Matsunaga, J.; Barocchi, M. A.; Croda, J.; Young, T. A.; Sanchez, Y.; Siqueira, I.; Bolin, C. A.; Reis, M. G.; Riley, L. W.; Haake, D. A.; Ko, A. I., Pathogenic Leptospira species express surface-exposed proteins belonging to the bacterial immunoglobulin superfamily. Mol Microbiol2003, 49 (4), 929-45. • Wiese, A.; Brandenburg, K.; Ulmer, A. J.; Seydel, U.; Muller-Loennies, S., The dual role of lipopolysaccharide as effector and target molecule. BiolChem1999, 380 (7-8), 767-84. • Nascimento, A. L.et al. Comparative genomics of two Leptospirainterrogansserovars reveals novel insights into physiology and pathogenesis. J Bacteriol2004, 186 (7), 2164-72. • Trent, M. S.; Stead, C. M.; Tran, A. X.; Hankins, J. V., Diversity of endotoxin and its impact on pathogenesis. J Endotoxin Res 2006, 12 (4), 205-23. • Hauk, P.; Macedo, F.; Romero, E. C.; Vasconcellos, S. A.; de Morais, Z. M.; Barbosa, A. S.; Ho, P. L., In LipL32, the major leptospiral lipoprotein, the C terminus is the primary immunogenic domain and mediates interaction with collagen IV and plasma fibronectin. Infect Immun2008, 76 (6), 2642-50. • Guerreiro, H.; Croda, J.; Flannery, B.; Mazel, M.; Matsunaga, J.; Galvao Reis, M.; Levett, P. N.; Ko, A. I.; Haake, D. A., Leptospiral proteins recognized during the humoral immune response to leptospirosis in humans. Infect Immun2001, 69 (8), 4958-68. • Stevenson, B.; Choy, H. A.; Pinne, M.; Rotondi, M. L.; Miller, M. C.; Demoll, E.; Kraiczy, P.; Cooley, A. E.; Creamer, T. P.; Suchard, M. A.; Brissette, C. A.; Verma, A.; Haake, D. A., Leptospirainterrogansendostatin-like outer membrane proteins bind host fibronectin, laminin and regulators of complement. PLoS One 2007, 2 (11), e1188. 7 7