micro-organism

(biology) a single-celled microorganism (especially a flagellate protozoan)

harmless microorganisms (as Escherichia coli) that inhabit the intestinal tract and are essential for its normal functioning

(virology) ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein

organisms that typically reproduce by asexual budding or fission and whose nutritional mode is absorption or photosynthesis or chemosynthesis

(microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants

a minute life form (especially a disease-causing bacterium); the term is not in technical use

any disease-producing agent (especially a virus or bacterium or other microorganism)

any of the unicellular protists

free-living or colonial organisms with diverse nutritional and reproductive modes

microscopic plants; bacteria are often considered to be microflora

a large heterogeneous group of RNA viruses divisible into groups on the basis of the virions; they have been recovered from arthropods, bats, and rodents; most are borne by arthropods; they are linked by the epidemiologic concept of transmission between vertebrate hosts by arthropod vectors (mosquitoes, ticks, sandflies, midges, etc.) that feed on blood; they can cause mild fevers, hepatitis, hemorrhagic fever, and encephalitis

a virus that is parasitic (reproduces itself) in bacteria

a plant pathogen that is a virus consisting of a single strand of RNA

an animal pathogen that is a virus

a virus that remains dormant in the body for a long time before symptoms appear

considered ancient life forms that evolved separately from bacteria and blue-green algae

an organism that thrives in a relatively acid environment

a beneficial bacterium found in the intestinal tract of healthy mammals; often considered to be a plant

a rodlike bacterium (especially any of the rod-shaped or branched bacteria in the root nodules of nitrogen-fixing plants)

a large group of bacteria having rigid cell walls; motile types have flagella

a genus of bacterial rods containing only the one species that causes granuloma inguinale

a genus of Gram-negative aerobic bacteria that occur as pathogens and parasite in many animals (including humans)

the pus-producing bacterium that causes gonorrhea

a cell-free filtrate held to be a virus responsible for a specific neoplasm

(genetics) a virus or other agent that is used to deliver DNA to a cell

the motile aerobic rod-shaped Gram-negative bacterium that thrives in central heating and air conditioning systems and can cause Legionnaires' disease

any of the bacteria in the soil that take part in the nitrogen cycle; they oxidize ammonium compounds into nitrites or oxidize nitrites into nitrates

bacteria that are unaffected by penicillin

bacteria that produce pus

any rod-shaped bacterium

Gram-positive bacteria usually occurring in pairs

any of diverse minute acellular or unicellular organisms usually nonphotosynthetic

primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves

a strain of bacteria that is resistant to all antibiotics