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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Infectious Bacterial Diseases Research » Research » Publications at this Location » Publication #188696
Title: Comparative Analysis of Pathogenic Leptospira Genomes

Author
item Zuerner, Richard
item BULACH, DIETER - MONASH UNIV.
item SEEMANN, TORSTEN - MONASH UNIV.
item COPPEL, ROSS - MONASH UNIV.
item ADLER, BEN - MONASH UNIV.

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 1/17/2006
Publication Date: 11/1/2006
Citation: Zuerner, R.L., Bulach, D.M., Seemann, T., Coppel, R.L., Adler, B. 2006. Comparative Analysis of Pathogenic Leptospira Genomes. In: Cabello, F.C., et al., editors. Molecular Biology of Spirochetes. Amsterdam, Holland: IOS Press. p. 101-115.

Interpretive Summary: Leptospirosis causes significant economic loss in the livestock industry through reproductive failure and reduced milk production. The bacteria that cause this disease can also cause disease in humans and companion animals. Vaccines to prevent infection have limited ability to provide protection against infection by these diverse bacteria. To understand more about the biology of the bacteria responsible for leptospirosis, we analyzed published genomic sequences of two strains of L. interrogans to identify features that may affect disease transmission and bacterial survival in the environment. This study complements ongoing genomic studies to develop new ways to treat and prevent leptospirosis.

Technical Abstract: The presence of two chromosomes makes Leptospira unusual amongst its closest relatives in the bacterial world. The Leptospira genome is in a state of flux, as indicated by the presence of many chromosomal rearrangements that alter genetic organization between individual serovars. It is, therefore, somewhat remarkable that at least two Leptospira loci (LPS biosynthetic genes and the S10-spc-alpha ribosomal protein operon) form large, extended operons that are among the longest bacterial operons reported to date. Insertion sequences (IS) are distributed throughout Leptospira genomes contribute to the formation of rearrangements. These elements can transpose and disrupt the integrity of genes, or alternatively, can activate cryptic genes by providing promoter activity to genomic sequences downstream of the insertion site. Bioinformatics and experimental functional genomic analyses were used to help characterize Leptospira interrogans to gain insight into this organism’s biology. Quantitative analysis of the L. interrogans serovars Lai and Copenhageni genomes showed these bacteria are proficient in environmental sensing and response, and in nutrient transport. These data support epidemiological evidence that L. interrogans is transmitted primarily by passage through environmental sources. Few pseudogenes were detected in either strain, suggesting there is sufficient selective pressure to maintain a highly functional genome.