CHARACTERIZATION AND ANTIBIOGRAM STUDY OF CLOSTRIDIUM CHAUVOEI ISOLATED FROM FIELD CASES OF BLACK LEG IN CATTLE

Abstract

Clostridium chauvoei is the etiological agent of black quarter (BQ), an infectious disease affecting mainly young cattle and sheep. The present study was designed with a view to isolate and identifies Cl. chauvoei from field cases. A total of 4 clinically suspected samples were collected during the period from January 2013 to November 2013 from Monohardi, Narshindi (n=1); Sujanagar, Pabna (n=1) and Veterinary Clinic of Bangladesh Agricultural University, Mymensingh (n=2). The samples were processed and were cultured anaerobically on blood agar. Gram stain and hanging drop techniques were performed with the cultured bacteria. Biochemical properties of the isolates were studied, and antibiotic sensitivity test was done by disk diffusion method. In Gram stain, all isolates showed numerous short, thick, straight, round-ended, gram positive rod occurs singly or in short chains. The spores of the organism were elongated, oval, sub terminal or terminal and wider than the cell, giving a typical pear-shaped appearance. All the Cl. chauvoei isolates fermented dextrose, maltose, lactose and sucrose and produced acid and gas. In case of mannitol fermentation, only acid was produced. Catalase, oxidase, methyl red, Voges-Proskauer and indole tests were found to be negative. All isolates were resistant to oxytetracycline, amoxicillin and ciprofloxacin, whereas the isolates were sensitive to penicillin and gentamicin. In conclusion, penicillin and gentamicin can be the drugs of choice for effective treatment of BQ in cattle of Bangladesh.