<prompt> 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 McFadyeans reaction. The most likely aetiological agent is-Clostridium tetaniLi steria monocytogenesBacillus anthracisActinomyces sp  <response>: Ans. is c i.e., Bacillus anthracis . Mc Fadyeans reaction is used for the presumptive diagnosis of anthrax. . History of skinning a dead animal, development of pustule, the presence of gram ve bacilli in long chains with positive Mc Fadyeans reaction are suggestive of anthrax caused by Bacillus anthracis. 