A Bacterial Glycoengineered Antigen for Improved Serodiagnosis of Porcine Brucellosis

MARÍA EUGENIA CORTINA; BALZANO PARODI R.; REY SERANTES D.A.; CAILLAVA AJ; ELENA S.; FERREIRA A.C.; NICOLA A.M.; UGALDE JE; COMERCI D. J; CIOCCHINI A. E.

JOURNAL OF CLINICAL MICROBIOLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2016 vol. 54 p. 1 - 8

0095-1137

Brucellosis is a highly zoonotic disease that affects animals and human beings. Brucella suis is the etiological agent of porcinebrucellosis and one of the major human brucellosis pathogens. Laboratory diagnosis of porcine brucellosis mainly relies on serologicaltests, and it has been widely demonstrated that serological assays based on the detection of anti O-polysaccharide antibodiesare 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 ofanti-O-polysaccharide IgG antibodies was developed coupling OAg-AcrA to enzyme-linked immunosorbent assay plates (glycoiELISA).To validate the assay, 563 serum samples obtained from experimentally infected and immunized pigs, as well as animalsnaturally infected with B. suis biovar 1 or 2, were tested. A receiver operating characteristic (ROC) analysis was performed, andbased on this analysis, the optimum cutoff value was 0.56, which resulted in a diagnostic sensitivity and specificity of 100% and99.7%, respectively. A cutoff value of 0.78 resulted in a test sensitivity of 98.4% and a test specificity of 100%. Overall, our resultsdemonstrate that the glyco-iELISA is highly accurate for diagnosis of porcine brucellosis, improving the diagnostic performanceof current serological tests. The recombinant glycoprotein OAg-AcrA can be produced in large homogeneous batches in a standardizedway, making it an ideal candidate for further validation as a universal antigen for diagnosis of ?smooth? brucellosis inanimals and humans.