ISOLATION, IDENTIFICATION AND ANTIBIOGRAM STUDY OF ETIOLOGICAL AGENT FROM RECENT OUTBREAKS OF FOWL CHOLERA IN LAYER CHICKENS

Abstract

The research work was under taken with a view to isolate and identify the etiological agent from recent outbreaks of fowl cholera in layer chickens with antibiogram study of identified field isolate. The entire research work was conducted in the Bacteriology Laboratory of the Department of Microbiology, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur. The samples were collected aseptically and brought to the respective laboratory for proper isolation and 65 identification by cultural, morphological and biochemical examinations. For this purpose, a total of 96 samples (liver, spleen, heart) were collected from suspected live (46 samples) and dead layer chickens (50 samples) from different areas of Dinajpur district. From these 96 samples, 25 (42%) were found to be positive for Pateurella multocida in live sick birds and 11 (24%) in dead birds. The isolated organism from chickens produced whitish, opaque, round, flat, translucent colonies of sticky mucoid or dry consistency about 1-3 mm in diameter on Nutrient Agar and whitish, opaque, round, translucent colonies without hemolysis on Blood Agar and were able to ferment dextrose, mannitol and sucrose but unable to ferment lactose and maltose on biochemical examinations. The field isolates were identified by observing colony morphology in different culture media, presence of rod shaped, bipolar Gram (-ve) organism in Grams staining technique and different biochemical reaction. The identified isolate were subjected to antibiogram study. In this study, it was observed that the field isolate were highly sensitive to Ciprofloxacin, Levofloxacin and Neomycin respectively. On the other side, the organisms were resistant to Amoxycillin, Tetracycline and Bacitracin respectively. It was evident that Ciprofloxacin, Levofloxacin and Clindamycin could be of better choice for the treatment of fowl cholera in layer chickens.