Corynebacterium pseudotuberculosis is a gram-positive, facultative intracellular, non-sporulating
and non-encapsulated bacterium, it is non-motile although it has fimbriae, and can assume
coccoid or filamentous forms (pleomorphic). Its optimum growth temperature is 37°C. This
pathogen has two biovars: ovis, which usually affects small ruminants and causes caseous
lymphadenitis, and biovar equi, more common in equines, bovines, camelids and bubalines,
causing ulcerative lymphangitis. Its infection can lead to carcass condemnation and reduction in
wool production (in ovines and caprines), milk production and meat production and,
consequently, economic losses for the agricultural industry worldwide. Currently there is no
effective vaccine against those illnesses. To obtain a better understanding of these species
biologically, the main objective of this work is to analyze, using comparative genomics, the strain
C. pseudotuberculosis 226 biovar ovis, isolated from a caprine in California, comparing it to
other strains from biovars ovis and equi. The synteny analysis revealed highly conserved gene
order between strain 226 and other biovar ovis strains. Phylogenomic analyses showed that the
strains I19 and 267 are, respectively, the closest and the more distant phylogenetically from strain
226. Among biovar equi strains, the one with the greater phylogenomic proximity to strain 226
was strain 1/06-A. Eight pathogenicity islands were predicted, with C. pseudotuberculosis best
characterized virulence genes in literature being present in island 1. No new regions related to
virulence genes could be found compared to other strains. 248 orthologous genes could be found
between strains I19, 267 and 226, while 282 orthologous genes could be found between strains
258, 1/06-A and 226. Based in this study it is possible to assume that strains from biovar ovis
have a little varied gene repertory and strains from biovar equi have less genes shared with strain
226, reinforcing the genetic diversity between these biovars.
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