| GRAM-POSITIVE BACTERIA |
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Staphylococcus |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
cocci in grape-like clusters |
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Oxygen relationship: |
facultatively anaerobic bacteria |
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Motility: |
nonmotile |
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Catalase test: |
catalase-positive |
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Oxidase test: |
negative* |
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Spores: |
non-spore forming |
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* Some species (non-human isolates) are positive |
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Streptococcus |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
cocci in chains (liquid media)
or pairs |
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Oxygen relationship: |
facultatively anaerobic bacteria |
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Motility: |
nonmotile |
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Catalase test: |
catalase-negative |
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Oxidase test: |
negative |
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Spores: |
non-spore forming |
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Enterococcus |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
cocci or ovoid cocci in pairs, clusters or short chains (liquid media) |
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Oxygen relationship: |
facultatively anaerobic bacteria |
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Motility: |
nonmotile or motile |
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Catalase test: |
catalase-negative
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Oxidase test: |
negative |
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Spores: |
non-spore forming |
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Listeria |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
short rods (sometimes coccoid forms), single or in chains |
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Oxygen relationship: |
facultatively anaerobic bacteria |
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Motility: |
motile (at 20-25°C)*; peritrichous flagella |
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Catalase test: |
catalase-positive |
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Oxidase test: |
negative |
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Spores: |
non-spore forming |
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* optimal growth temperature at 30-37°C |
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Corynebacterium |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
rods, often broader at one end
("club" shape), grouped together
in a characteristic way ("V", "palisades", "Chinese letters") |
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Oxygen relationship: |
facultatively anaerobic bacteria |
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Motility: |
nonmotile |
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Catalase test: |
catalase-positive |
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Oxidase test: |
negative |
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Spores: |
non-spore forming* |
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*metachromatic granules are often present. |
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Bacillus |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
rods in chains |
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Oxygen relationship: |
aerobic or facultatively anaerobic bacteria |
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Motility: |
motile (peritrichous flagella) or nonmotile (e.g., B.anthracis) |
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Catalase test: |
catalase-positive |
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Oxidase test: |
negative |
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Spores: |
spore forming (endospores) |
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Lactobacillus |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
rods in chains or palisades |
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Oxygen relationship: |
facultatively anaerobic or anaerobic bacteria |
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Motility: |
nonmotile (most of them) |
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Catalase test: |
negative |
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Oxidase test: |
negative |
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Spores: |
non-spore forming |
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|
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Streptomyces |
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Gram stain: |
Gram-positive |
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Microscopic appearance: |
rods; form substrate and aerial mycelium |
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Oxygen relationship: |
aerobic bacteria |
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Motility: |
nonmotile |
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Catalase test: |
positive |
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Oxidase test: |
negative |
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Spores: |
spore forming (aerial mycelium) |
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Clostridium |
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Gram stain: |
Gram-positive (young cultures), often Gram-variable |
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Microscopic appearance: |
rods (in pairs or chains) |
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Oxygen relationship: |
anaerobic bacteria |
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Motility: |
usually motile (peritrichous flagella) |
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Catalase test: |
negative |
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Oxidase test: |
negative |
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Spores: |
spore forming (endospores) |
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| GRAM-NEGATIVE BACTERIA |
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Neisseria |
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Gram stain: |
Gram-negative |
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Microscopic appearance: |
diplococci, cocci |
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Oxygen relationship: |
aerobic bacteria |
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Motility: |
nonmotile
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Catalase test: |
positive |
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Oxidase test: |
positive |
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Spores: |
non-spore forming |
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Moraxella (Branhamella) |
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Gram stain: |
Gram-negative |
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Microscopic appearance: |
diplococci, cocci, cocobacilli |
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Oxygen relationship: |
aerobic bacteria* |
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Motility: |
nonmotile
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Catalase test: |
positive |
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Oxidase test: |
positive |
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Spores: |
non-spore forming |
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* some facultatively anaerobic |
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Bordetella |
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Gram stain: |
Gram-negative |
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Microscopic appearance: |
small rods or cocobacilli |
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Oxygen relationship: |
aerobic bacteria |
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Motility: |
nonmotile or motile
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Catalase test: |
positive |
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Oxidase test: |
positive |
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Spores: |
non-spore forming |
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Haemophilus |
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Gram stain: |
Gram-negative |
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Microscopic appearance: |
small pleomorphic rods |
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Oxygen relationship: |
facultatively anaerobic bacteria |
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Motility: |
nonmotile
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Catalase test: |
variable |
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Oxidase test: |
variable |
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Spores: |
non-spore forming |
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Pseudomonas |
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Gram stain: |
Gram-negative |
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Microscopic appearance: |
rods |
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Oxygen relationship: |
aerobic bacteria |
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Motility: |
motile (rarely nonmotile)
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Catalase test: |
positive |
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Oxidase test: |
positive or negative |
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Spores: |
non-spore forming |
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Enterobacteriaceae
E.coli,
Salmonella,
Klebsiella,
Enterobacter,
Proteus,
Serratia,
Yersinia
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|
Gram stain: |
Gram-negative |
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Microscopic appearance: |
rods |
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Oxygen relationship: |
facultatively anaerobic bacteria |
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Motility: |
motile (peritrichous flagella) or nonmotile |
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Catalase test: |
positive |
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Oxidase test: |
negative (with exception of Plesiomonas spp.) |
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Spores: |
non-spore forming |
| ACID-FAST BACTERIA |
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|
Mycobacterium |
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Gram stain: |
- (acid - fast) |
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Microscopic appearance: |
rods; sometimes cocobacilli or filaments |
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Oxygen relationship: |
aerobes |
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Motility: |
nonmotile |
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Catalase test: |
positive |
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Oxidase test: |
negative |
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Spores: |
non-spore forming |
| NON GRAM-POSITIVE/NEGATIVE |
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Borrelia |
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Gram stain: |
Not classified as either Gram-positive or Gram-negative
(the cells stain a weak Gram-negative)
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Microscopic appearance: |
Spirochetes |
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Oxygen relationship: |
microaerobic |
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Motility: |
motile
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Catalase test: |
- |
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Oxidase test: |
- |
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Spores: |
non-spore forming |
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