title: Comparison of agar gel immunodiffusion test, rapid slide agglutination test, microbiological culture and PCR for the diagnosis of canine brucellosis.
abstract: The performance of the rapid slide agglutination test, with and without 2-mercaptoethanol (RSAT and 2ME-RSAT) and agar gel immunodiffusion test (AGID) was evaluated for the diagnosis of brucellosis in naturally infected dogs. The microbiological culture, PCR and clinical parameters were used as reference. A total of 167 dogs were clinically examined and tested by blood culture, culture of semen/vaginal swab and PCR in blood and semen/vaginal swab. According to the results observed the 167 dogs were divided into three groups: Brucella canis infected dogs (Group 1), B. canis non-infected dogs (Group 2) and dogs with suspected brucellosis (Group 3). The dogs were then tested by RSAT, 2ME-RSAT and AGID. Groups 1 and 2 were used to calculate the diagnostic sensitivity and specificity of the serological tests and the results observed in Group 3 were also discussed. The diagnostic sensitivity of RSAT, 2ME-RSAT and AGID was respectively 70.58%, 31.76%, and 52.94%. The diagnostic specificity of RSAT, 2ME-RSAT and AGID was respectively 83.34%, 100%, and 100%. In dogs with suspected brucellosis 15% were RSAT positive, none was 2ME-RSAT positive and 5% were AGID positive. Although the serological tests are the most commonly used methods for brucellosis diagnosis, a significant proportion of false-negative results were observed highlighting the importance of the direct methods of diagnosis, like blood culture and PCR to improve the diagnosis of canine brucellosis.
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo (USP), Avenue Prof. Dr. Orlando Marques Paiva 87, 05508-900 São Paulo, SP, Brazil. larakeid@yahoo.com.br
authors.forename: Lara B
authors.initials: LB
authors.lastname: Keid
authors.forename: Rodrigo M
authors.initials: RM
authors.lastname: Soares
authors.forename: Silvio A
authors.initials: SA
authors.lastname: Vasconcellos
authors.forename: Jane
authors.initials: J
authors.lastname: Megid
authors.forename: Vanessa R
authors.initials: VR
authors.lastname: Salgado
authors.forename: Leonardo J
authors.initials: LJ
authors.lastname: Richtzenhain
mesh_terms: D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D041002:Brucella canis / Q000235:genetics / Q000302:isolation & purification*; D002006:Brucellosis / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004283:Dog Diseases / Q000175:diagnosis / Q000382:microbiology*; D004285:Dogs; D005260:Female; D005779:Immunodiffusion / Q000662:veterinary; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D004269:DNA, Bacterial