ISOLATION, IDENTIFICATION AND ‘ CHARACTERIZATION OF BACTERIA CAUSING CALF DIARRHOEA

Abstract

Calf diarrhosea is a common problem in cattle farms of Bangladesh. Indiscriminate use of antibiotic to control the disease results drug resistance and limits the therapeutic possibilities in the treatment of the disease. The research work was conducted to Isolate , Identify and characterize the bacterial pathogens causing calf diarhoea. The study was conducted on 125 faecal samples collected directly from the rectum of diarrhoeic calves during the period of December, 2011 to June, 2011 brought for the treatment in the District and Upazilla hospitals under Nilphamari District to find out the occurrence of pathogenic bacteria. Out of 125 fecal samples exmined for bacterial isolates, the number and frequency of distribution in percentage for positive samples were 35 (28%) for E.coli, 11(8.8%) for Salmonella spp and 79 (63.2%) was negative for bacteria (Nutritional and other than bacterial causes involved).The frequency response of E.coli and Salmonella to microscopic examination and specific biochemical tests were 79.54% and 20.46% respectively. Isolation and identification of the microorganisms were confirmed on the basis of their morphology staining, cultural, biochemical and serological properties. Antibiotic sensitivity of the isolated organisms were also studied. All the E.coli isolates were found to produce bright pink colonies on MacConkey agar and characteristic yellow green metallic sheen colonies on EMB agar. Salmonella produced opaque, translucent and colorless colonies on SS agar but on BGA it produced pale, pink color colonies against pinkish background.The results of MR and Indole tests of E.coli isolates were positive, V-P test was negative. In case of Salmonella MR test was positive but V-P and Indole test were negative. The antibacterial sensitivity study revealed that these two isolates were highly sensitive to Ciprofloxacin, Levofloxacillin, Azithromycin, Cefotaxime; moderately sensitive to Gentamicin, Pefloxacin, Cefotaxime, Colistin sulphate, Erythromycin, Carbinicillin; Less sensitive to Tobramycin, Bacitracin, Erythromycin, Colistin sulphate, Doxycycline, Carbinicillin, Cefotaxime and resistant to Amoxycillin , Ampicillin & Tetracycline. The findinings of the experiment indicates that the use of Ciprofloxacin, Levofloxacin, Azithromycin, Cefotaxime may have the preference to be choice in clinical control of Salmonella and E.coli causing calf diarrohoea in Bangladesh.