CLASSIFICATION OF PATHOGENIC BACTERIA

Cell shape	Characteristics	Genus	Family
Gram negative bacteria
Cocci	Aerobic	Neisseria Veilonella	Neisseriaceae
Coccobacilli	-	Brucella Bordetella Pasteurella, Mannheimia Haemophilu s	Brucellaceae
Bacilli	Facultative anaerobic, motile with peritrichous flagella or non motile	Escherichia, Shigella, Salmonella, Proteus, Erwinia, Yersinia, Enterobacter, Serratia	Enterobacteriaceae
	Aerobic, motile with peritrichous flagella or non motile	Azotobacter Rhizobium	Azotobacteraceae
	Aerobic, motile with polar flagella	Nitrosomonas, Nitrobacter, Thiobacillus, Pseudomonas, Acetobacter, Legionella	Rhizobiaceae
	Facultative anaerobic with polar flagella	Campylobacter, Zymomonas, Aeromonas	Nitrobacteraceae Pseudomona-daceae
	Curved rods with polar flagella	Vibrio, Spirillum, Desulfovibrio	Spirillaceae
Gram positive bacteria
Cocci	Cells in irregular clusters	Staphylococcus, Micrococcus, Sarcina	Micrococcaceae
	Cells in chains	Streptococcus, Leuconostoc	Streptococcaceae
Bacilli	Aerobic Spore forming Anaerobic Spore forming	Bacillus Clostridium	Bacillaeceae
	Lactic fermentation Propionic fermentation	Lactobacillus Propionibacterium	Lactobacillacaeae Propioni-bacteriaceae
	Oxidative, weakly fermentative	Corynebacterium Listeria Erysipelothrix	-
Other major groups
Acid-fast rods Ray-forming rods	-	Mycobacterium Actinomyces, Nocardia, Streptomyces	Actinomycetales
Spiral organisms	motile	Treponema Borrellia Leptospira Spirocheta	Spirochetales
Small pleomorphic	lack rigid wall	Mycoplasma	Mollicutes
Small intracellular parasites	-	Rickettsiae Coxiella Chlamydia	Rickettsiaceae Chlamydiaceae
Intracellular parasites	borderline with protozoa	Bartonella	Bartonellaceae