Genus: Enterobacter

Enterobacter aerogenes

This Genus is a Lactose Fermenter
Genera of Enterobacter are Gram negative non-spore forming rod

TSI Reactions:

• Yellow Slant - Acid
• Yellow Butt - Acid
• Gas - Possitive (cracks or fissures)

IMViC's Reactions:

• Indole Test -- Negative
• Methyl Red Test -- No change (negativefor acid - remains yellow)
• Voges-Proskauer Test -- Positive
• Citrate Test -- Blue(Positivefor citrate)

Genus: Escherichia

Escherichia coli ( E.coli )

(Genera of Enteric bacteria are lactose fermenters)

TSI Reactions:

• Yellow Slant - Acid
• Yellow Butt - Acid
• Gas - Possitive (cracks or fissures)

IMViC's Reactions:

• Indole Test -- Positive
• Methyl Red Test -- Red (positive for acid)
• Voges-Proskauer Test -- Negative
• Citrate Test -- Green (Negative for citrate)

Genus: Staphylococcus

Gram reaction: Gram Positive (+)
Morphology: Spherical
Arrangement: Grape like clusters

Coagulase Test

Positive (+) reaction => Clot, Species: S. aureus

Negative (-) reaction => No clot, Species: S. epidermis

Protozoa

Kingdom: Protista

Classes

A => Sarcodina – moves by pseudopods (false feet)
B => Ciliophora – moves by cilia
C => Mastigophora – moves by flagella (organisms are outside the cell)
D => Sporozoa – non motile (organism are inside the cell)

Fungi

Fungi

Kingdom: Fungi
Reproduces sexually and asexually

Classes
A => Yeast – oval egg shaped, gram (+), reproduces primarily by budding

B => Mold – cottony texture (called mycelium)

• Hypha (ae) = individual units that gives rise to mycelium

• Medium grown: sabouraud dextrose agar, lawn plate, 25^oC

Todd - Hewitt Broth

Morphology: Coccus

Arrangement: Chains

Gram reaction: Gram Positive

Species:

1. Streptococcus mitis
2. Streptococcus salivarius

Gingival Test

• Medium: Todd – Hewitt Broth (enriched medium – not selective)

Mitis Salivarius Agar

Morphology: Coccus

Arrangement: Chains

Gram reaction: Gram Positive

Species:

1. Streptococcus mitis (Alpha hemolytic)
   
2. Streptococcus salivarius (gamma hemolytic)
   

Gingival Test

• Medium: Mitis Salivarius Agar (selective for streptococcus)

• Selective ingredient: Tellurite

• Indicator: Methylene Blue
  

• Sample source: Oral Cavity (gingival - gums)
  

Contact

Eliza Parlato
Microbiology Tutor Trainee


Available Hours:
T/R 1:00pm to 3:00pm
W/F 1:00pm to 4:pm
Rm. A350


e-mail: eliza.parlato@gmail.com