Identification of Sero-Diagnostic Antigens for the Early Diagnosis of Johne’s Disease using MAP Protein Microarrays

Authors

Lingling Li, Pennsylvania State UniversityFollow
J. P. Bannantine, USDA-ARS, National Animal Disease CenterFollow
Joseph J. Campo, Pennsylvania State University
Arlo Randall, Pennsylvania State University
Yrjo T. Grohn, Cornell UniversityFollow
Megan A. Schilling, Pennsylvania State UniversityFollow
Robab Katani, Pennsylvania State UniversityFollow
Jessica Radzio-Basu, Pennsylvania State UniversityFollow
Laurel Easterling, Pennsylvania State UniversityFollow
Vivek Kapur, Pennsylvania State UniversityFollow

Date of this Version

2019

Citation

Scientific Reports (2019) 9:17573 | https://doi.org/10.1038/s41598-019-53973-x

Comments

The Author(s) 2019

Abstract

Considerable effort has been directed toward controlling Johne’s disease (JD), a chronic granulomatous intestinal inflammatory disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) in cattle and other ruminants. However, progress in controlling the spread of MAP infection has been impeded by the lack of reliable diagnostic tests that can identify animals early in the infection process and help break the transmission chain. To identify reliable antigens for early diagnosis of MAP infection, we constructed a MAP protein array with 868 purified recombinant MAP proteins, and screened a total of 180 well-characterized serum samples from cows assigned to 4 groups based on previous serological and fecal test results: negative low exposure (NL, n = 30); negative high exposure (NH, n = 30); fecal- positive, ELISA-negative (F + E−, n = 60); and both fecal- and ELISA-positive (F + E+, n = 60). The analyses identified a total of 49 candidate antigens in the NH, F + E−, and F + E+ with reactivity compared with the NL group (p < 0.01), a majority of which have not been previously identified. While some of the antigens were identified as reactive in only one of the groups, others showed reactivity in multiple groups, including NH (n = 28), F + E− (n = 26), and F + E+ (n = 17) groups. Using combinations of top reactive antigens in each group, the results reveal sensitivities of 60.0%, 73.3%, and 81.7% in the NH, F + E−, and F + E+, respectively at 90% specificity, suggesting that early detection of infection in animals may be possible and enable better opportunities to reduce within herd transmission that may be otherwise missed by traditional serological assays that are biased towards more heavily infected animals. Together, the results suggest that several of the novel candidate antigens identified in this study, particularly those that were reactive in the NH and F + E− groups, have potential utility for the early sero-diagnosis of MAP infection.