Bacilli specifically refers to a taxonomic class of bacteria. It includes two orders, Bacillales and Lactobacillales, which contain several well-known pathogens like Bacillus anthracis , Streptococcus, and Staphylococcus. All members of class Bacilli are gram-positive. There are several related concepts that make use of similar words, and the ambiguity can create considerable confusion. The term "Bacillus" is also the name of a genus that, among many other genera, falls within...