Research Article | Veterinary Clinical Medicine

Comparative evaluation of faecal microscopy, serum iELISA, and faecal IS900TaqMan® probe Real time PCR for detection of Mycobacterium avium subspecies paratuberculosis (MAP) causing Johne's disease in

Division of Animal Health, ICAR-Central Institute for research on Goats, Makhdoom, Farah (P.O.), Mathura-281122, Uttar Pradesh

Abstract

A total no of 221 goats were sampled (serum, n=221; fecal, n= 221) from an organized farm located in Uttar Pradesh of India over a period of five years (2017-2022). Faeces and serum samples were collected and screened by Acid fast ZN staining and indigenous iELISA respectively. 37.55% (n=83) samples showed positive, based on the SP ratio in iELISA and further investigated by faecal Acid fast ZN microscopy of which 21.71% (n=48) were positive. The IS900 gene TaqMan® probe based Real time PCR assay found only 4.07 percent (n=9) faeces positive for MAP infection.Hence, in the current study combinations of three diagnostic tests viz., microscopy, iELISA and IS900TaqMan® probe Real time PCR were compared for kappa agreement and McNemar’s test which showed fair agreements with extreme significance in all the three test combinations compared. This further implies the fact that TaqMan® probe realtime PCR targeting IS900 gene detects the true MAP infection with high sensitivity and specificity.

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