ISOLATION AND IDENTIFICATION OF CORYNEBACTERIUM SP. FROM THE CASES OF CLINICAL MASTITIS IN COW AT DINAJPUR DISTRICT OF BANGLADESH
Date
2011-02
Authors
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Publisher
HAJEE MOHAMMOD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR
Abstract
The present study was conducted to isolate and identify Corynebacterium sp. from the
cases of clinical mastitis in cows at Dinajpur district of Bangladesh. For this, a total of 20
milk samples were collected from clinically mastitis affected cows of different dairy
farms and rural domestic holdings at Dinajpur district in Bangladesh. The study was
carried out during the period of September’2010 to February’2011. The milk samples
were collected and brought to the Department of Microbiology, Faculty of Veterinary and
Animal Science, Hajee Mohammad Danesh Science and Technology University,
Dinajpur and subjected to different bacteriological tests for isolation and identification of
bacteria based on morphology, staining, cultural and biochemical properties. Antibiotic
sensitivity of the isolated organism was also studied. The isolated bacteria were
Staphylococcus spp. (25%), Streptococcus spp. (15%), Escherichia coli (20%),
Corynebacterium sp. (25%) and 15% were unidentified. On nutrient broth, the
Corynebacterium sp. showed enough whitish turbidity and on nutrient agar the colonies
were grayish in color while on blood agar the colonies were grayish in color about 1mm
in diameter and surrounded by a small zone of hemolysis. In Gram’s staining technique
the Corynebacterium sp. revealed Gram positive, violet color, short cocco-bacilli and
arranged in bundles or clusters and singly also. In sugar fermentation tests (dextrose,
lactose and maltose), the organism produced acid but no gas. In hanging drop slide
method, the organism was nonmotile. Results of antibiotic sensitivity showed that
Corynebacterium sp. was highly sensitive to gentamicin and ciprofloxacin, and some
degree of resistance to tetracycline, ampicillin, penicillin and amoxycillin. The present
study dictates that the Corynebacterium sp. was one of the important agents responsible
for the clinical mastitis in cows at Dinajpur district of Bangladesh.
Description
Livestock plays an important role in the subsistence agro-based economy of Bangladesh.
Cattle population in Bangladesh is about 24 million (FAO, 2003). Nearly, 85 percent of
the populations are engaged in agriculture and livestock sector (Raha, 2000). The number
of milking cows in Bangladesh is 3.75 million, which is 35 percent of the total cattle
population in Bangladesh. The annual milk production in Bangladesh is nearly 1.62
million metric ton which is very low in respect of our demand which is nearly 9.0 million
metric ton (DLS, 1998). The milk production in Bangladesh is very low due to low
productive cows and various infectious and noninfectious diseases in the dairy farm.
Mastitis is the most important one affecting the cows.
Keywords
Preparation of culture media and broth:, Nutrient broth medium, Nutrient agar medium, Blood agar medium