Juana Liz Vidal Arboleda
University of Antioquia, Colombia
Title: Phylogenetic analysis of the Brucella canis str. Oliveri isolated in Antioquia, Colombia
Biography
Biography: Juana Liz Vidal Arboleda
Abstract
recognized and exhibit different host preference; comparative analysis of this genus have show a close genetic relationship between
species. To study the evolution of these species have developed multiple phylogenetic analyzes on which consensus has been separated
into a clade B. melitensis and B. abortus, in another clade marine species and one species consisting of B. suis and B. canis, recognizing
Brucella ovis as the ancestral species, suggesting that the initial contact to pigs, goats and cattles occurred from contact with infected
sheep.
Objective: To establish the phylogenetic relationships and the time of divergence of Brucella canis strain Oliveri.
Methods: Concatenated sequences of these genes were used: glK, trpE, cobQ, aroA, dnaK, rpoB, gap, gyrB, Omp2a, Omp2b, Omp25 and
Omp3 in 24 species of Brucella, including Brucella canis str. Oliveri. Using the Mega 6 program phylogenetic analysis was performed
by the method of neighbor joining with the substitution model Tamura-Nei and 10000 Bootstraps repetititons. The molecular clock
hypothesis among Brucella species was tested and the test of relative rates of Tajima between Brucella canis str. Oliveri and Brucella
canis ATCC was performed.
Results: Phylogenetic analysis including O. anthropi as out group indicate that Brucella ovis was the first lineage split is the most
basal species. The clade with greater genetic diversity is formed by B. suis where it will also find strains of B. canis suggesting a
recent divergence. B. abortus and B. melitensis appear as sister species, being each one monophyletic. Aquatic species B. ceti and
B. pinnipedialis are part of the same clade but separate from the terrestrial strain. Within B. canis all strains present a simultaneous
divergence since they split from their common ancestor, corroborating the result of the test of relative rates of Tajima with P=0.31731.
The molecular clock hypothesis is rejected between species indicating that the rate of evolution of all species of Brucella is not the
same.
Conclusions: The strain of Brucella canis str. Oliveri like others canis species diverged from Brucella suis. The Brucella canis species
had a similar rate of evolution and a genetic distance, so is not possible define which diverged first.