adenovirus
aerobe
aerobic bacteria
amoeba
anaerobe
anaerobic bacteria
bacteria
bacterium
bug
coccus
disease-producing microorganism
echovirus
enterovirus
filterable virus
fungus
germ
gram-negative bacteria
gram-positive bacteria
microbe
microorganism
mold
nonfilterable virus
pathogen
picornavirus
protozoa
protozoon
reovirus
rhinovirus
rickettsia
spirillum
spirochete
spore
staphylococcus
streptococcus
trypanosome
vibrio
virus
bacilli
clostridium
cocci
dysentery
epidemic
subtilis
amaryllis
lactobacillus