Juana Liz Vidal Arboleda
University of Antioquia, Colombia
Title: Characterization of the genetic variability of field strains of Brucella canis isolated in Antioquia, Colombia between 2005-2013
Biography
Biography: Juana Liz Vidal Arboleda
Abstract
Introduction: Brucella canis, a facultative intracellular pathogen is responsible for canine brucellosis, a zoonotic disease that
affects canines causing abortions and reproductive failures, human infection may cause mild, asymptomatic or serious medical
conditions. Since 2005 the presence of Brucella canis was demonstrated in Antioquia and the circulating strains were identified
as B. canis type-2, besides recognizing in them the operon virB. In order to learn more about the circulating strains the entire
genome of a wild strain of Brucella canis denoted Oliveri was sequenced, which showed insertions and deletions speciesspecific.
Objective: Characterize the genetic variability of field strains of Brucella canis isolated in Antioquia during 2005-2013.
Methods: A set of six pairs of primers that would allow identification of indels identified in the strain of B. canis str. Oliveri was
designed, after this conventional PCR and sequencing of the amplified products was performed on 30 strains of Brucella canis,
Brucella suis 1330 and bv. 1, Brucella melitensis 16M and vaccine strains of Brucella abortus S19 and RB51.
Results: 5 of 30 field strains studied share indels with the sequenced strain, the remaining 25 strains differ in a deletion exclusive
from the Oliveri strain. Inside the deletions a related one with a critical epimerase for the synthesis of carbohydrates from the
surfaces is present, which is related to the rough characteristics of the colonies like those presented by the field strains. A second
deletion is related to N-acetyltransferase, which prevents the action of aminoglycosides, its absence could facilitate the action
of these antibiotics in the bacteria. A third 6 bp deletions in chromosome II, is related to the ABC transporters superfamily,
which perform the transport of nutrients through the membrane and it is corresponded with a unique characteristic of the
species metabolism. A final deletion related to a glutamic acid tranference RNA is the only exclusive in Oliveri strain, this
deletion may result from the adaptation of the bacteria to intracellular lifestyle more secure and stable with a constant supply
of nutrients, additional we could talk about the effect of speciation and host specific adaptation or as in other Brucella species a
possible recombination process. Inside the insertions studied, one related with an anti prophage repressor which interacts with
prophage repressor genes facilitating horizontal gene transfer was presented; a second insertion evaluated as 60 bp is part of a
hypothetical protein with no specific function but that facilitates differentiation of Brucella canis from other species.
Conclusions: The field strains isolated in Antioquia present genotypic variations from the sequenced strain Oliveri, indicating
that this is not the only strain circulating in the region,which would be useful in future studies to