Abstract
Brucella canis is pathogenic for dogs and humans. Serological
diagnosis is a cost-effective approach for disease surveillance, but a
major drawback of current serological tests is the cross-reactivity with
other bacteria that results in false positive reactions, and development
of indirect tests with improved sensitivity and specificity remain a
priority. A western blotting assay was developed to define the serum
antibody patterns associated to infection using a panel of positive and
negative dog sera. B. canis positive sera recognized
immunogenic bands ranging from 7 to 30 kDa that were then submitted to
ESI–LC-MS/MS and analyzed by bioinformatics tools. A total of 398B. canis proteins were identified.. Bioinformatics tools
identified 16 non cytoplasmic immunogenic proteins predicted as
non-homologous with the most important Brucella cross-reactive
bacteria and 9 B. canis proteins non-homologous to B.
ovis ; among the latter, one resulted non-homologous to B.
melitensis . The western blotting test developed was able to distinguish
between infected and non-infected animals and may serve as confirmatory
test for the serological diagnosis of B. canis . The mass
spectrometry and in silico results lead to the identification of
specific candidate antigens that pave the way for the development of
more accurate indirect diagnostic tests.
Keywords: Bioinformatics, Brucella canis ; Western
blotting; Mass spectrometry; Protein identifi-cation