Medical Oral Microbiology Topic A - 10
Name: Date:
A10, p. 1
Oral microbiology I
Task 1: Microscopy of strains
There are four strains on the table. Every strain can be causative agent of infections in oral cavity. Stain the
strains with Gram staining and draw the results. On the basis of their attributes write down, which infectious
agents can be considered. Use also results from task 2 and in strains with lacking information fill in which other
tests you would perform to know the result.
Strain A Strain B Strain C Strain D
Other tests which can be performed:
Task 2: Differentiation of yeasts on chromogenic medium
Identify strains with help of chromogenic medium CHROMagar. Write down the character of the colonies
(colour and surface).
Strain ___ is Candida ________________. Colour of colonies is ________________, surface is
________________.
Strain ___ is Candida ________________. Colour of colonies is ________________, surface is
________________.
Task 3: Diagnostic of hepatitis B virus (HBV)
3a) assessment of HBsAg and HBeAg
Read the ELISA reaction of HBsAg and HBeAg, write down the result.
Medical Oral Microbiology Topic A - 10
Name: Date:
A10, p. 2
3b) assessment of anti-HBs and anti-HBe
Read the ELISA reaction of anti-HBs (antibodies against HBsAg) and anti-HBe (antibodies against HBeAg),
write down the result.
Check-up questions:
1. Name at least five species of the genus Streptococcus, which are part of common micro-flora of oral cavity.
2. Which bacteria are considered to be those with higher cariogennic potential and why?
3. What are the differences in subgingival and supragingival teeth plaque as far as microbial composition is
concerned; and why?