Pathomorphology of Enteritis in Goat With Special Reference to Rhodococcus Equi

Abstract

Enteritis, one of the most important causes of mortality in goats globally which can be caused due to several etiological agents such as bacteria, protozoa, virus and irritants etc. Rhodococcus equi is one of the important agents well known for causing enterocolitis and pneumonia in foals also gaining zoonotic importance especially in immunocompromised subjects. It has been sporadically reported in swine, bovines, very rare in camelids and caprines. So, the current study is planned with objective to study enteritis and prevalence of R. equi infection in goats of Meerut district. Intestinal samples (n=125) were collected to study the gross and histological alterations while microbiological swabs were collected from mesenteric lymph nodes, GIT and suspected pyogranulomatous lesions for isolation, identification and characterization of R. equi. Current study revealed highest occurrence of catarrhal enteritis (51.2 %) followed by hemorrhagic (30.4 %), necrotic 16.8 %) and ulcerative (1.6 %) while histopathological scoring showed highest severity of Inflammation (1.97±0.05) followed by villi: crypt (1.87±0.05), desquamation of villi epithelium (1.79±0.05), crypt destruction (1.55±0.05), depletion of Peyer’s patches (1.51±0.08), congestion (1.19±0.06) crypt hyperplasia (1.16±0.05), intactness of muscularis mucosae (1.10±0.05) and fibrosis (0.05±0.01). Swabs from mesenteric lymph nodes (n=125) and nodules present on lung (n=1), liver (n=4) and spleen (n=1) showed characteristic R. equi colonies on BHI agar. Staining characteristics was gram positive and acid fast. Gross and histological examination showed typical caseous pyogranulomatous lesions in liver, lung, spleen and lymph nodes of R. equi positive cases. Molecular diagnosis by PCR with species specific primers, sequencing and subsequent NCBI blast analysis revealed highest homology (99.17 %) with R. equi. Phylogenetic analysis by 16S rRNA gene showed highest homology with Indian strains of R. equi. On the basis of histology, cultural isolation, colony characteristics, biochemical tests (primary, secondary and specific) and molecular diagnosis four (4) out of 125 cases were found positive for R. equi infection which revealed 3.2 % prevalence in goats of Meerut district. Presence of R. equi in unusual host (goats) is alarming and emphasizes the importance of one health approach.