Paratuberculosis: Diagnostic Methods and their Constraints

Abstract

Paratuberculosis (Johne's disease) is a chronic intestinal disease of ruminants and the disease is caused by Mycobacterium avium subspecies paratuberculosis (MAP). The disease has a prolonged pre-patent period and the clinical symptoms of the disease are apparent only during the later stages of the disease. However, the infected animal can shed the organism much before the clinical disease with the risk of spreading the disease to other susceptible animals. The disease manifestation is in four stages with each of these stages requiring a different diagnostic method. During the early stages of the disease Cell mediated immune response (CMI) is higher, and shedding of the organism and serum antibody response is absent or minimized. Delayed type hypersensitivity (DTH) response upon injection of Johnin purified protein derivative (Johnin PPD) in the skin of the animal and interferon gamma release assay (IGRA) is the common CMI based tests for the diagnosis of paratuberculosis. As the disease progress, CMI response reduces and humoral response predominates with progressively increased shedding of the organism. ELISA based tests are commercially available to detect the MAP specific antibodies in serum or milk, and nucleic acid detection methods are used to identify the organism. However, all these CMI and humoral antibody based tests have advantages and disadvantages. It is essential to apply a combination of these tests to detect or rule out the disease in farms of endemic countries.

Seroprevalencia a Mycobacterium avium subsp. paratuberculosis en bovinos criollos colombianos Romosinuano y Costeño Con Cuernos

“…Cuando se estudia paratuberculosis teniendo en cuenta la variable edad, la especificidad del ensayo se convierte en un reto; en ganado de leche se ha demostrado, que el tiempo trascurrido desde la infección, generalmente en un ternero, hasta la enfermedad clínica puede variar de uno hasta 12 años, (19); adicionalmente, el serodiagnóstico suele ser negativo en animales menores de un año debido a que durante las primeras etapas de la enfermedad, predomina la respuesta inmune mediada por células, mientras que la respuesta de anticuerpos séricos es mínima o ausente (20).…”

Bioprospective Role of Ocimum Sanctum & Solanum Xanthocarpum against Emerging Pathogen: Mycobacterium Avium Subspecies Paratuberculosis

“…As previously established, MAP invasion triggers T helper cells, which secrete IFN-γ. The utilization of cultures supernatants from day-old blood specimens treated with Johnin and co-stimulated with human IL-2and/or bovine IL-12 can also be used to diagnose JD using an enzyme-linked immune sorbent test (ELISA) [74]. Unfortunately, cross-reactivity issues arise because in the INF-test, MAP pure proteins analogs are often used as antigens.…”

Bioprospective Role of Ocimum sanctum and Solanum xanthocarpum against Emerging Pathogen: Mycobacterium avium Subspecies paratuberculosis: A Review

“…The immunological response of the host to infection is the basis for diagnostic MAP tests based on indirect detection. A Johnin pure protein derivative was used to produce the delayed-type hypersensitivity skin test [73].…”