AUTHOR=Helms Alyssa B. , Balogh Orsolya , Franklin-Guild Rebecca , Lahmers Kevin , Caswell Clayton C. , Cecere Julie T. 

TITLE=Presumptive Identification of Smooth Brucella Strain Antibodies in Canines

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.697479

DOI=10.3389/fvets.2021.697479

ISSN=2297-1769

ABSTRACT=<p>Brucellosis is a zoonotic disease caused by a Gram-negative coccobacillus. There are four <italic>Brucella</italic> strains of zoonotic importance in our domestic species, subdivided by their culture phenotypes: <italic>Brucella abortus</italic> (<italic>B. abortus</italic>), <italic>B. melitensis, B. suis</italic> (smooth strains) and <italic>B. canis</italic> (rough strain). Dogs can serve as hosts for all four of the zoonotic strains; however, routine serologic testing in dogs has been limited to the identification of <italic>B. canis</italic> antibodies. The aim of our study was to identify smooth <italic>Brucella</italic> strain antibodies in canines. We hypothesize that the <italic>Brucella abortus</italic> Fluorescence Polarization Assay would be successful in identifying smooth Brucella strain antibodies in canines. Ninety-five dogs, including forty-five hog hunting dogs were screened for circulating antibodies to any of the four zoonotic strains of the bacteria utilizing a combination of Canine <italic>Brucella</italic> Slide Agglutination Test (CBSA), <italic>Brucella canis</italic> Agar Gel Immunodiffusion II test (AGIDII), <italic>Brucella abortus</italic> Card Agglutination Test (BCA), and the <italic>Brucella abortus</italic> Fluorescence Polarization Assay (FPA). Test interpretation results yielded a 0% (0/95) smooth <italic>Brucella</italic> strain seropositivity rate, with 2% (2/95) of dogs yielding inconclusive rough <italic>Brucella</italic> strain serology results (0–2% rough strain seropositivity rate). Additionally, a retrospective portion of the study was performed to identify sera containing circulating antibodies to any of the smooth strains of <italic>Brucella</italic> by testing previously banked canine serum samples stored at Cornell's Veterinary Diagnostic Laboratory from 2018 to 2019 via <italic>Brucella abortus</italic> FPA. Of the 769 serum samples tested, 13/769 (1.7%) yielded an inconclusive result, 725/769 (94.2%) were negative, 30/769 (4%) yielded a positive FPA test result, and 1/769 (0.1%) had to be excluded due to insufficient sample remaining to perform the diagnostic test. Of the 30 FPA positive canine serum samples, 97% (29/30) also tested positive on the CBSA test. Additionally, there was a statistically significant (<italic>p</italic> &lt; 0.0001) likelihood of altered (spayed/neutered) and mixed breed dogs to be FPA positive when compared to intact, purebred dogs, respectively.</p>