Isolation and Identification of Etiological Agents from Diarrhoeic Goats
Md. Mamunul Haque,
Md. Emdadul Islam,
Md. Mahmudur Rahman
The present research was undertaken to isolate and identify the etiological agents responsible for diarrhoea in goats. For this purpose, faecal samples were cultured and subcultured in basic medium named Nutrient agar medium and Blood agar medium to obtain pure cultures of separate genera. From pure cultures, bacterial colonies were picked up and further cultured in different selective medium viz. MacConkey agar medium, Bacto fluid thioglycollate broth, Cooked meat broth, Brain-heart infusion broth, Eosin methylene blue agar medium and Salmonella-Shigella agar medium to observe the cultural characteristics of the isolates. In different selective medium, bacterial genera were identified on the basis of their cultural morphology (in case of solid media) and change of color and gas production (in case of liquid media). By Gram staining, short, single or paired gram positive and gram negative bacteria were observed under the electric microscope in the smears prepared from the pure colonies from basic and selective medium. Finally Biochemical tests viz., Catalase, Voges-Proskauer, oxidase, citrate utilization, Coagulase, Oxidation-fermentation, Carbohydrate fermentation test were performed to confirm the specific bacterial genera. Of the 20 experimented faecal samples, Salmonella sp. (5.0%), Staphylococcus sp. (10.0%), Escherichia coli (25.0%), Bacillus sp. (85.0%) and Clostridium sp. (65.0%) were identified as single or mixed infection. 5.0% diarrhoea were found non-bacterial infection. Therefore the present study provides opportunities for the characterization of such bacteria as well as for the prevention of diarrhoea and thus help in goat farming.
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