Pathological investigation on bovine uterus and isolation of associated bacteria

Abstract

Abstract : The study was carried out to determine the occurrence of bacteria as well as pathological lesions in the uteri of slaughtered cattle. A total of 20 samples were selected from 30 cases with grossly identifiable lesions, such as congested, hemorrhagic, and mucus filled uteri for bacteriological isolation, while other 30 cases were used for histopatholgy. The bacteriological swabs were collected from the lumen of the uteri and cultured in nutrient broth followed by staining and different types of biochemical tests of isolated bacteria. The histopathological samples were collected in 10% buffered formalin. The collected tissues were fixed, processed, sectioned, stained, and studied with light microscope. The mostly observed gross lesions were hemorrhagic, congested, and mucus filled uteri. All the gross lesions were not found in all uteri. Among isolated bacteria, 22.92% was Bacillus spp., 12.50% was Streptococcus spp., 25.00% was Staphylococcus spp., 29.16% was Escherichia coli, and 10.417% was Klebsiella spp. Microscopically, acute endometritis was characterized by thickening of the epithelial layer, infiltration of neutrophils in the submucosal layer, dilatation of endometrial glands with neutrophilic infiltration and congestion of blood vessels. In chronic endometritis, infiltration of lymphocytes, macrophages, plasma cells in the submucosal layer and proliferation of fibrous connective tissue within the myometrium were found. In adenomyosis, dilatation of endometrial glands and presence of endometrial glands in the myometrium were recorded. The microscopic lesions were variable among the uteri. The occurrence of acute endometritis was 33.33%, chronic endometritis was 26.66%, and adenomyosis was 6.66%. In acute and chronic endometritis, the isolated bacteria were Bacillus spp., Streptococcus spp., Staphylococcus spp., Escherichia coli and Klebsiella spp., while in adenomyosis, the isolated bacteria were Bacillus spp., Staphylococcus spp., and Escherichia coli. The role of these bacteria in the production of pathological lesions in uteri of cows requires further studies.