adenovirus
aerobe
aerobic bacteria
amoeba
anaerobe
anaerobic bacteria
bacillus
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
spore
staphylococcus
streptococcus
trypanosome
vibrio
virus
eubacteria
eubacterium
true bacteria
borrelia
borrelia burgdorferi
leptospira
lime disease spirochete
treponema