<prompt> Largest pathogenic Bacillus organism is -Bacillum subtilisBacillum cereusBacillum anthrocisBacillum megaterism  <response>: The anthrax bacillus is one of the largest of pathogenic bacteria measuring 3-10 x 1-16 um. It resembles a Bamboo stick appearance Ref: Ananthanarayan panikers Textbook of Microbiology 9th edition pg no 244 