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Gram-Negative Bacteria

Definition:	Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.
Notes:	GEN: avoid; prefer specifics; do not use as a routine coord for a gram-negative bact; infection = GRAM-NEGATIVE BACTERIAL INFECTIONS; DF: GRAM NEG BACT
Previously Indexed:	Bacteria (1966-1983)

Gram-Negative Bacteria Categories.

	Anaplasmataceae - A family of bacteria which inhabit RED BLOOD CELLS and cause several animal diseases.
	Arcobacter - A genus of gram-negative, aerotolerant, spiral-shaped bacteria isolated from water and associated with diarrhea in humans and animals.
	Bartonellaceae - A family of small gram-negative bacteria whose organisms are parasites of erythrocytes in man and other vertebrates and the etiologic agents of several diseases.
	Buchnera - A genus of gram-negative bacteria which are obligately intracellular endosymbionts of APHIDS. The bacteria are found within specialized cells in the aphid body cavity.
	Campylobacter - A genus of bacteria found in the reproductive organs, intestinal tract, and oral cavity of animals and man. Some species are pathogenic.
	Chlamydiales - An order of obligately intracellular bacteria that have the chlamydia-like developmental cycle of replication. This is a two-stage cycle that includes a metabolically inactive infectious form, and a vegetative form that replicates by binary fission. Members of Chlamydiales are disseminated by aerosol or by contact. There are at least four recognized families: CHLAMYDIACEAE, Parachlamydiaceae, Simkaniaceae, and Waddliaceae.
	Gastrospirillum - A genus of gram-negative, spiral-shaped bacteria that is pathogenic and has been isolated from the GASTRIC MUCOSA of MAMMALS, including humans.
	Gram-Negative Aerobic Bacteria - A large group of aerobic bacteria which show up as pink (negative) when treated by the gram-staining method. This is because the cell walls of gram-negative bacteria are low in peptidoglycan and thus have low affinity for violet stain and high affinity for the pink dye safranine.
	Gram-Negative Anaerobic Bacteria - A large group of anaerobic bacteria which show up as pink (negative) when treated by the Gram-staining method.
	Gram-Negative Facultatively Anaerobic Rods - A large group of facultatively anaerobic, rod-shaped bacteria that show up as pink (negative) when treated by the gram-staining method.
	Gram-Negative Oxygenic Photosynthetic Bacteria - Widely distributed unicellular or multicellular bacteria. The CYANOBACTERIA use chlorophyll a and phycobilins for oxygenic photosynthesis while genera in the PROCHLORALES use both chlorophyll a and b but not phycobilins.
	Helicobacter - A genus of gram-negative, spiral-shaped bacteria that is pathogenic and has been isolated from the intestinal tract of mammals, including humans.
	Lawsonia Bacteria - A genus of gram-negative, obligate intracellular bacteria causing a proliferative enteritis in animals, especially pigs, deer, horses, and rabbits.
	Methylosinus - A genus of gram-negative rods which form exospores and are obligate methanotrophs.
	Mollicutes - A class of gram-negative bacteria consisting of cells bounded by a plasma membrane. Its organisms differ from other bacteria in that they are devoid of cell walls. It contains a single order, MYCOPLASMATALES.
	Oceanospirillaceae - A family of gram-negative bacteria in the order Oceanospirillales.
	Piscirickettsiaceae - A family of gram-negative bacteria, in the order Thiotrichales.
	Rhodobacter - A genus of gram-negative bacteria widely distributed in fresh water as well as marine and hypersaline habitats.
	Rhodomicrobium - A genus, in the family HYPHOMICROBIACEAE, comprised of ovoid-shaped bacteria with polar growth and a characteristic vegetative growth cycle. Cells grow preferably photoheterotrophically under anaerobic conditions in the light, but will also grow under microaerobic or aerobic conditions in the dark. (From Bergey's Manual of Determinative Bacteriology, 9th ed)
	Rhodovulum - A genus of facultatively or obligately anaerobic marine phototrophic bacteria, in the family RHODOBACTERACEAE.
	Rickettsiaceae - A family of small, gram-negative organisms, often parasitic in humans and other animals, causing diseases that may be transmitted by invertebrate vectors.
	Roseobacter - A genus of obligately aerobic marine phototrophic and chemoorganotrophic bacteria, in the family RHODOBACTERACEAE.
	Spirillaceae - A family of gram-negative bacteria in the order Nitrosomonadales. It formerly included the genera CAMPYLOBACTER and SPIRILLUM, then was abandoned, and is now reinstated as a family with a single genus SPIRILLUM.

Gram-Negative Bacteria Definitions and Terms

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