genus Heliobacter, Heliobacter - a genus of helical or curved or straight aerobic bacteria with rounded ends and multiple flagella; found in the gastric mucosa of primates (including humans)

Aerobacter, genus Aerobacter - aerobic bacteria widely distributed in nature

genus Rhizobium, Rhizobium - the type genus of Rhizobiaceae; usually occur in the root nodules of legumes; can fix atmospheric oxygen

Agrobacterium, genus Agrobacterium - small motile bacterial rods that can reduce nitrates and cause galls on plant stems

division Eubacteria - one-celled monerans having simple cells with rigid walls and (in motile types) flagella

genus Bacillus - type genus of the Bacillaceae; includes many saprophytes important in decay of organic matter and a number of parasites

genus Clostridium - anaerobic or micro-aerophilic rod-shaped or spindle-shaped saprophytes; nearly cosmopolitan in soil, animal intestines, and dung

genus Nostoc - type genus of the family Nostocaceae: freshwater blue-green algae

genus Trichodesmium - a genus of blue-green algae

genus Pseudomonas, Pseudomonas - type genus of the family Pseudomonodaceae

genus Xanthomonas, Xanthomonas - a genus of bacteria similar to Pseudomonas but producing a yellow pigment that is not soluble in water

family Nitrobacteriaceae, Nitrobacteriaceae - usually rod-shaped bacteria that oxidize ammonia or nitrites: nitrobacteria

genus Nitrobacter, Nitrobacter - rod-shaped soil bacteria

genus Nitrosomonas, Nitrosomonas - ellipsoidal soil bacteria

genus Thiobacillus - a genus of bacteria

genus Spirillum - a genus of bacteria

genus Vibrio - a genus of bacteria

Bacteroides, genus Bacteroides - type genus of Bacteroidaceae; genus of gram-negative rodlike anaerobic bacteria producing no endospores and no pigment and living in the gut of man and animals

genus Corynebacterium - the type genus of the family Corynebacteriaceae which is widely distributed in nature; the best known are parasites and pathogens of humans and domestic animals

genus Listeria - a genus of aerobic motile bacteria of the family Corynebacteriaceae containing small gram-positive rods

genus Escherichia - a genus of bacteria

genus Klebsiella - a genus of bacteria

genus Salmonella - a genus of bacteria

genus Serratia, Serratia - a genus of motile peritrichous bacteria that contain small Gram-negative rod

genus Shigella - a genus of bacteria

genus Erwinia - a genus of bacteria

genus Rickettsia - can cause typhus and Rocky Mountain spotted fever in humans

genus Chlamydia - type genus of the family Chlamydiaceae: disease-causing parasites

genus Mycoplasma - type and sole genus of the family Mycoplasmataceae

genus Actinomyces - type genus of the family Actinomycetaceae

genus Streptomyces - type genus of the family Streptomycetaceae

genus Mycobacterium - nonmotile gram-positive aerobic bacteria

genus Polyangium, Polyangium - type genus of the family Polyangiaceae: myxobacteria with rounded fruiting bodies enclosed in a membrane

genus Micrococcus, Micrococcus - type genus of the family Micrococcaceae

genus Staphylococcus - includes many pathogenic species

genus Lactobacillus - type genus of the family Lactobacillaceae

genus Diplococcus - a genus of bacteria

genus Streptococcus - a genus of bacteria

genus Spirochaeta, Spirochaeta - type genus of the family Spirochaetaceae; flexible undulating chiefly aquatic bacteria

genus Treponema - type genus of Treponemataceae: anaerobic spirochetes with an undulating rigid body; parasitic in warm-blooded animals

genus Borrelia - small flexible parasitic spirochetes having three to five wavy spirals

genus Leptospira - very slender aerobic spirochetes; free-living or parasitic in mammals