Juvenile Capri-Paratuberculosis (JCP) in India: Incidence and characterization by six diagnostic tests

Abstract

Johne's considered a disease of adult goats was studied in young kids using six tests (direct microscopy, fecal culture, tissue culture, ELISA, histo-pathology, and PCR) to establish incidence of Juvenile Capri-Paratuberculosis. Cumulatively, 62.0% kids were positive from organized herds in direct microscopy (38.0%) and fecal culture (56.0%). Incidence by tissues culture was 60.0% (43.6% intestine and 40.0% MLN). In tissues culture, 27.2 and 67.3% kids were positive from organized and farmer's herds (slaughterhouse, Agra), respectively. In direct microscopy, 20.0 and 23.3% kids were positive from intestine and mesenteric lymph nodes, respectively. Age-wise, 6.6, 86.3 and 40.6% kids were positive in tissues culture, from 15 days to <2, 2–4 and 4–6 months age groups, respectively. Cultures were obtained both from weak and apparently healthy kids. Colonies usually appeared around 75 and 60–90 days post-inoculation in fecal and tissues cultures, respectively. Pauci-bacillary condition was more frequent both in fecal and tissues culture. Isolation of Mycobacterium avium subsp. paratuberculosis was 61.5, 24.1 and 50.0% from highly, moderately and slightly enlarged mesenteric lymph nodes, respectively. Two antigens (native protoplasmic antigen from indigenous Map genotype ‘Bison type’ of goat origin and commercial purified antigen from Map ‘Bovine’ were used in ELISA. Sero-incidence in kids was 47.9 and 1.4% with native and commercial antigens, respectively. Native antigen detected 35.4 and 58.6% and commercial, nil and 3.5% sero-positive kids from farmer's and organized herds, respectively. In kids, incidence of Map was 47.9, 60.0 and 56.0% by ELISA, tissues and fecal culture, respectively. Large numbers of mononuclear cells along with few epitheloid cells were present in cortical and medullary regions of mesenteric lymph nodes. Villi of ileum showed mild degeneration in lining epithelial cells, which turned into goblet cells appearing as globular structure, filled with unstained homogenous mass. Peyer's patches located in the mucosal area were hyper-cellular with occasional presence of epitheloid cells. Clumps of Map bacilli were seen in epitheloid cells of lamina propria of intestine. Of the 17 DNA samples from decontaminated pellets and Map colonies, 64.7% were amplified in IS 900 PCR. The 229 bp band of amplified DNA was characteristic for Map. Samples detected in PCR were also positive in culture and histo-pathologically. Map strains isolated from Juvenile Capri-Paratuberculosis were genotyped as ‘Bison type’ using IS 1311 PCR-REA. It is the first report on incidence and characterization (genotyping) of Map from Juvenile Capri-Paratuberculosis in India.