STUDY ON PATHOLOGY OF TERMINAL ILEUM IN SHEEP WITH PARTICULAR EMPHASIS ON PARATUBERCULOSIS
Loading...
Date
2014-07-19
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CSKHPKV, Palampur
Abstract
The present research work was planned to study the pathology of terminal ileum and associated lymph
nodes in sheep with particular emphasis on paratuberculosis and to detect the antibody against M.
avium subsp. paratuberculosis (MAP) using suitable serological method(s). Out of the 45 sheep
samples collected, 39 were used to study paratuberculosis as the remaining six samples showed
incidental lesions in lymph nodes. On gross examination, the lesions were scored from mild to
moderate on the basis of thickening and corrugation in terminal ileum and enlargement and presence
of greyish-white patches on cut surface of lymph nodes (LNs). A total of 34 (87.18%), 3 (7.70%) and
1 (2.56%) samples were found to be showing lesions suggestive of paratuberculosis and scored as
mild, moderate and severe, respectively. Ziehl-Neelsen (ZN) stained tissue impression smears made
from ileo-caecal lymph node (ICLN), mesenteric lymph node (MLN) and terminal ileum,
demonstrated acid-fast bacilli (AFB) in nine (23.08%) cases. On histological examination, the tissue
samples were graded from 0 to IV on the basis of type and amount of the cellular infiltrates
(macrophages and epitheloid cells) and the nature and extent of granulomatous reaction. The only
(2.56%) Grade I case revealed infiltration of a few macrophages and epitheloid cells with formation of
focally distinct microgranuloma in the lamina propria of the villi as well as in the LNs. Twenty-one
(53.84%) cases with Grade II lesion characterized by moderate infiltration of macrophages and
epitheloid cells in the lamina propria of the villi as well as in the LNs were observed. Thirteen
(33.33%) Grade III cases showed granulomatous enteritis composed of groups of macrophages and
epitheloid cells distributed in a diffuse manner throughout the ileal mucosa and lymph nodes. Grade
IV cases revealed the same lesions as described in Grade III but with presence of giant cell(s). The
focal areas of caseous necrosis, with or without mineralization, were observed in one (Grade II), four
(Grade III), three (Grade IV) sheep. Only one case of Grade III showed AFB on ZN stained ileum and
ICLN tissue sections (paucibacillary type). A varying degree of fibrosis in lymph node sections (ICLN
& MLN) from majority of the cases suggesting replacement of granulomatous reaction was observed
as unique finding. ELISA revealed a total of twenty cases (51.28%) positive, while none of the case
was detected by AGID. In conclusion, histopathological examination was found to be the most
effective method for detection of JD in sheep.
Description
Keywords
null