A Bacterial Glycoengineered Antigen for Improved Serodiagnosis of Porcine Brucellosis

MARÍA EUGENIA CORTINA; BALZANO, RODRIGO E; DIEGO REY SERANTES; CAILLAVA, ANA JOSEFINA; ELENA, SEBASTIAN; FERREIRA, AC; NICOLA, AM; UGALDE, JUAN E; COMERCI, DIEGO J; CIOCCHINI, ANDRÉS E.

JOURNAL OF CLINICAL MICROBIOLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2016 vol. 54 p. 1448 - 1455

0095-1137

Brucellosis is a highly zoonotic disease that affects animals and human beings. Brucella suis is the etiological agent of porcine brucellosis and one of the major human brucellosis pathogens. Laboratory diagnosis of porcine brucellosis mainly relies on serological tests and it has been widely demonstrated that serological assays based on the detection of anti O-polysaccharide antibodies are the most sensitive tests. Here we validate a recombinant glycoprotein antigen, an N-formylperosamine O-polysaccharide-protein conjugate (OAg-AcrA), for diagnosis of porcine brucellosis. An indirect immunoassay based on the detection of anti O-polysaccharide IgG antibodies was developed coupling OAg-AcrA to ELISA plates (glyco-iELISA). To validate the assay, 563 serum samples obtained from experimentally infected and immunized pigs as well as naturally infected animals with B. suis biovar 1 or 2 were tested. A receiver-operating characteristic (ROC) analysis was performed and based on this analysis the optimum cut-off value was 0.56, which resulted in a diagnostic sensitivity and specificity of 100 and 99.7 %, respectively. A cut-off value of 0.78 resulted in a test sensitivity of 98.4% and a test specificity of 100%. Overall, our results demonstrate that the glyco-iELISA is highly accurate for diagnosis of porcine brucellosis improving the diagnostic performance of currently serological tests. The recombinant glycoprotein OAg-AcrA can be produce in lager homogenous batches in a standardized way making it an ideal candidate for further validation as a universal antigen for diagnosis of ?smooth? brucellosis in animals and humans.