A man, after skinning a dead animal, developed a pustule on his hand. A smear prepared from the lesion showed the presence of gram-positive bacilli in long chains which were positive for McFadyean's reaction. The most likely etiological agent is:

Ans. is 'c' i.e., Bacillus anthracisIt is a typical presentation of cutaneous anthrax. When a blood film from an animal suspected to die of or suffering from anthrax is stained with Polychromic methylene blue and examined under microscope the chains of bacilli are seen surrounded by an amorphous purplish material representing the capsular material. It is the McFadyean's reaction.