<prompt> Which of the following is gram-positive bacillus-StaphylococcusStreptococcusListeriaMeningococci  <response>: Listeria is gram-positive bacillus.Staphylococcus and streptococcus are also gram-positive, but they are cocci not bacilli.Meningococci are gram-negative cocci.Also knowClinically important spore-forming bacteria are gram-positive Clostridium, Bacillus.Listeria is the only gram-positive bacteria that has endotoxin. Endotoxin is present only in gram-negative organisms.Of the gram-negative organisms, only two groups are cocci - Neisseria meningococcus gonococcus, veillonella.All other gram-negative organisms are bacilli including coccobacilli.Amongst medically important bacilli 6 are gram ve Actinomycetes, clostridium, mycobacteria, Bacillus, Listeria, Corynebacterium.All other medically important bacilli are gram-negative. 