Oral Microbiology

Question 1

What are the two main bacteria that cause impetigo?

Answer 1

1-Streptococcus Pyogenes

2-Staphylococcus Aureus

Question 2

What are the main causes of “Strep Throat” (tonsillitis/pharyngitis)?

Answer 2

1-Group A beta-hemolytic stretococci
2-Influenza,
3-Epstein-barr virus

*Majority are caused by a virus

Question 3

What are two sequelae of strep throat?

Answer 3

1-Scarlet fever

2-Rheumatic fever (rheumatic heart disease, acute glomerulonephritis)

Question 4

What condition is caused by disseminated Group A beta-hemolytic streptococcal infection and presents with a strawberry tongue?

Answer 4

Scarlet Fever

Question 5

What organism causes diphtheria?

Answer 5

Cornebacterium diphtheriae

*grey or white necrotic tissue

Question 6

What organism causes syphilis?

Answer 6

Treponema pallidum (spirochete)

*Syphilis is characterized by chancre that develops

Question 7

Scattered foci of granulomatous inflammation, a type of necrosis, is called what?

Answer 7

Gumma

*intraoral lesions usually affect the palate or tongue

Question 8

Purulent discharge and dysuria are common in gonorrhea and is caused by what organism?

Answer 8

Neisseria gonnorhoeae

Question 9

What test is used to stain for tuberculosis causing mycobacterium tuberculosis?

Answer 9

Acid fast bacillus

Question 10

What is the main host of leprosy causing mycobacterium leprae?

Answer 10

9 banded Armadillo in their ears.

*82% of leprosy is in Brazil, india, indonesia, myanmar and nigeria

Question 11

Sulfur granules are typical of actinomycosis caused by actinomyces israelii. what three places can this bacteria colonize in healthy patients?

Answer 11

1-Tonsilar crypts
2-Plaque
3-Carious dentin

Question 12

What organism causes Cat-Scratch disease?

Answer 12

Bartonella henselae

*Starts in skin and spreads to adjacent lymph nodes

Question 13

Candidiasis primarily caused by candida albicans is found in what two forms (dimorphism)?

Answer 13

Yeast form (innocuous)
Hyphal form (invasion of host tissue)

*by far the most common oral fungal infection in humans

Question 14

Noninvasive in normal hosts, what condition results in a mass of fungal hyphae called a mycetoma?

Answer 14

Aspergillosis

*Can be extensive in immunocompromised patients

Question 15

What are two common species that cause aspergillosis?

Answer 15

1-A. fumigatus (90%)

2-A. flavus

Question 16

What are the two forms of herpes simplex virus (DNA virus) of which humans are the only natural reservoir?

Answer 16

1-HSV-1 (oral, spread through saliva or active perioral lesions)
2-HSV-2 (Spread primarily through sexual contact)

Question 17

What are three less common variations of HSV-1?

Answer 17

1-Herpetic whitlow (thumbs or fingers)
2-Herpes gladiatorum or scrumpox (wrestlers/rugby)
3-Herpes barbae (shaving spreads across face)

Question 18

What are the two conditions caused by varicella-zoster virus?

Answer 18

• Chickenpox as primary infection

- Herpes zoster (shingles) is recurrence

Question 19

Which virus targets CD4 T helper lymphocytes, is transmitted sexually, and is found in bodily fluids?

Answer 19

HIV/AIDS

Question 20

What are 5 strongly HIV/AIDS associated oral manifestations?

Answer 20

1-Candidiasis
2-Hairy leukoplakia (EBV)
3-Kaposi's sarcoma (HHV-8)
4-Non-hodgkins lymphoma
5-Periodontal diseases