Diagnostic Potential of Three Antigens from Geographically Different Regions of the World for the Diagnosis of Ovine Johne’s Disease in India

Abstract

Cross reactivity of three antigens of Mycobacterium avium subspecies paratuberculosis with sera of sheep endemic for Johne's disease was evaluated. Out of 40 sheep tested by fecal microscopy, 72.5% were shedding MAP. Using protoplasmic antigens (PPA) from three MAP strains isolated from different livestock species and geographical regions, 90, 77.5 and 2.5% sheep were positive in goat (Indigenous g-ELISA) and cattle (b-ELISA) based ELISA kits and ELISA kit for small ruminant (sr-ELISA), respectively. Only 2.5 and 10% sheep were positive and negative in all the four tests. Native species specific (goat origin novel 'Indian Bison Type' MAP) semi-purified whole cell PPA based ELISA (Indigenous g-ELISA) was superior in reacting with sera of native sheep than the commercial PPA of bovine origin (Allied Monitor Inc., USA) and commercial ELISA kit for small ruminants (ID Vet, France). Lower cross reactivity of antigens originated from US and France emphasized the need to develop tests based on local strain of MAP than strains from different livestock species and geographical regions. This is an important finding against the use of 'Global kits' without validating in local conditions. Study showed that kits developed from local strains of MAP were not only superior but also cost effective and will significantly contribute in programs for the control of JD in native sheep population.

Recombinant Proteins based ‘rELISA’ Field Validation for Differential Diagnosis of Johne’s Disease in Goats

“…In our study, the positivity rate of i_ELISA was highest (63.9%) in comparison to smear microscopy (38.7%) and rELISA (34.5%). In-agreement with our observation, superior sensitivity of whole cell protoplasmic antigen-based ELISA over smear microscopy has also been reported earlier (Chaubey et al, 2015). Plausible explanation of this difference might be due to the fact that shedding of bacilli in feces generally occurs intermittently and during clinical stage.…”

Novel recombinant Mce-truncated protein based ELISA for the diagnosis of Mycobacterium avium subsp. paratuberculosis infection in domestic livestock

“…This type of categorization exhibited good correlation with fecal culture in some of our other studies [39,61]. Chaubey et al (2015) compared i-ELISA (Indigenous g-ELISA) with commercial antigen-based b-ELISA and commercial sr-ELISA and found 100% sensitivity. In another report, 91.4% sensitivity of i-ELISA was observed when compared with EV-ELISA kit [57].…”

“…This in house i-ELISA kit has been validated with other commercial ELISA kits (ID-VET, Allied Monitor Inc., USA, antigen based indirect ELISA, Ethanol Vortex ELISA (EV-ELISA), recombinant secretory proteins based cocktail ELISA (c_ELISA) and natural secretory proteins-based ELISA test [10,35,37,56,57] and compared its efficacy in different livestock species (goats, sheep, cattle and buffaloes) [12,58,59]. In this series, Mce-ELISA is the most recently developed ELISA and used for the diagnosis of MAP infection.…”

“…MAP has also been associated with a number of incurable human illnesses such as Crohn's disease / Inflammatory Bowel Disease, diabetes, rheumatoid arnthritis, thyroids, and other auto-immune type disorders [1,2,9]. Control and eradication of JD are challenging due to the insidious nature, long incubation period, and lack of rapid and sensitive diagnostic tests [10]. With the scale and complexity of the expanding problem of MAP, pressure is increasing to find a way to control MAP infections in animals in order to rescue high milk yielding breeds of domestic livestock, and reduce production and economic losses in the livestock, dairy industry and animal farming, and impending threat for large scale human infection by consumpton of milk and milk products contaminated with MAP bacilli [6,11,12].…”