Euglena, adenovirus, aerobe, aerobic bacteria, amoeba, anaerobe, anaerobic bacteria, animalcule, bacillus, bacterium, bug, coccus, colon bacillus, diatom, disease-producing microorganism, dyad, echovirus, enterovirus, filterable virus, flagellate, fungus, germ, gram-negative bacteria, gram-positive bacteria, microbe, microorganism, microspore, microzoa, mold, monad, nematode, nonfilterable virus, paramecium, pathogen, picornavirus, protozoa, protozoon, reovirus, rhinovirus, rickettsia, salmonella, saprophyte, spirillum, spirochete, spore, sporozoon, staphylococcus, streptococcus, tetrad, triad, trypanosome, vibrio, virus, volvox, vorticellum, zoospore