title: Clinical and histological features of brucellin skin test responses in Brucella suis biovar 2 infected pigs.
abstract: Current serological tests for swine brucellosis detect antibodies to the Brucella O-polysaccharide (O/PS). However, when infections by bacteria carrying cross-reacting O/PS occur, these tests suffer from false positive serological reactions (FPSR), and the skin test with Brucella soluble protein extracts is the best diagnostic alternative to differentiate true Brucella suis infections from FPSR in pigs. Since this test has been seldom used in B. suis infected swine, the clinical and histological features involved have not been described properly. Here, we describe the clinical and histological events in B. suis biovar 2 infected pigs skin tested with a cytosoluble O/PS free protein extract from rough Brucella abortus Tn5::per mutant. A similar extract from rough Ochrobactrum intermedium was also used for comparative purposes. No relevant differences were evidenced between the homologous and heterologous allergens, and the main clinical feature was an elevated area of the skin showing different induration degrees. Moreover, an important vascular reaction with hyperemia and haemorrhage was produced in most infected sows 24-48 h after inoculation, thus facilitating the clinical interpretation of positive reactions. Histologically, combined immediate (type III) and delayed (type IV) hypersensitivity reactions were identified as the most relevant feature of the inflammatory responses produced.
authors.affiliation: Unidad de Sanidad Animal, Centro de Investigación y Tecnología Agroalimentaria (CITA) del Gobierno de Aragón, Av. Montañana 930, 50059 Zaragoza, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Dieste-Pérez
authors.affiliation: Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Zaragoza, 50013 Zaragoza, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Barberán
authors.affiliation: Unidad de Sanidad Animal, Centro de Investigación y Tecnología Agroalimentaria (CITA) del Gobierno de Aragón, Av. Montañana 930, 50059 Zaragoza, Spain.
authors.forename: P M
authors.initials: PM
authors.lastname: Muñoz
authors.affiliation: Instituto de Salud Tropical y Departamento Microbiología y Parasitología, Universidad de Navarra, 31008 Pamplona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Moriyón
authors.affiliation: Unidad de Sanidad Animal, Centro de Investigación y Tecnología Agroalimentaria (CITA) del Gobierno de Aragón, Av. Montañana 930, 50059 Zaragoza, Spain. Electronic address: jblasco@unizar.es.
authors.forename: J M
authors.initials: JM
authors.lastname: Blasco
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D002003:Brucella abortus / Q000276:immunology; D041021:Brucella suis / Q000276:immunology; D002006:Brucellosis / Q000175:diagnosis / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D003429:Cross Reactions / Q000276:immunology; D005189:False Positive Reactions; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary; D042041:Ochrobactrum / Q000276:immunology; D012867:Skin / Q000276:immunology / Q000473:pathology; D012882:Skin Tests / Q000662:veterinary; D013552:Swine / Q000276:immunology / Q000382:microbiology; D013553:Swine Diseases / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology / Q000473:pathology*
chemical_list: D000942:Antigens, Bacterial; C005641:brucellin
keywords: Brucellin; Histopathology; Hypersensitivity; Porcine brucellosis