Name:............................................. Group 1 17.10.2008.

1. The oral microflora contains at least:

a)250 different cultivable species

b)350 different cultivable species

c)300 different cultivable species

(d)500 different cultivable species

2. Bacteroides species are:

(a)Gram-negative rods

b)Gram-positive rods

c)Gram-positive cocci

d)Yeast-like fungi

3. Please connect above sentences to the particular species

A-S.salivarius (1)important cause of purulent disease (dental and brain abscesses)

B-S.intermedius (2) has a predilection for non-keratinized surfaces in the mouth

C-S.mutans (3)prefers keratinized surfaces, especially the tongue

D-S.mitis (4)most common species isolated and implicated in human caries, colonizes teeth especially in fissures

a) 1A, 2B , 3D, 4C

b) 1D , 2A ,3C ,4B

(c)1B , 2D , 3A , 4C

d) 1B , 2A , 3D ,4C

4. By 24 hours after birth the first ( pioneer ) species colonize the mouth of the newborn, particulary:

a)S.mitis

(b)S.salivarius

c)S.sanguis

d)S.oralis

5. All members of the “oralis group” may act as opportunistic pathogens and are frequently isolated from cases of: I

a)infective conjunctivitis

b)infective periimplantitis

(c) infective endocarditis

d)infective pulpitis

6. This group is isolated mainly from the vestibular mucosa of the human mouth , do not synthesize extracellular polysaccharides from sucrose, that is: I

a)mutans -group

(b)salivarius group

c)milleri-group

d)sanguis-group

7. Fusobacterium species: I

a)Gram-negative rods, obligate anaerobe, found mainly in subgingival plaque, implicated in the aetiology of juvenile periodontitis

b)Gram-positive rods, obligate anaerobe, found mainly in subgingival plaque, implicated in the aetiology of juvenile periodontitis

(c)Gram-negative rods, obligate anaerobe, found mainly in subgingival plaque, implicated in the aetiology of adult periodontitis

d)Gram-positive rods, obligate anaerobe, found mainly in subgingival plaque, implicated in the aetiology of juvenile and adult periodontitis

8. The mutans -group comprises:

a) S.mutans and S.intermedius

b) S.mutans and S.mitis

c) S. mutans and S.oralis

(d)S. mutans and sobrinus

9. The dark-ground microscopy is useful for visualizing very thin cells such as:

a)Neisseria spp.

b)Eikenella spp.

c)Veilonella spp.

(d)Spirochaetes

10. Sabourad's agar is the most widely used isolation medium for:

a)Protozoa

b)Mycoplasma

c)Treponema

(d)Yeasts

Name:............................................. Group 1 17.10.2008.

1. Actinomyces naeslundii is:

(a)Gram-negative rod

b)Gram-positive rod

c)Gram-positive coccus

d)Gram-negative coccus

2. These bacteria form a major proportion of bacteria found in dental plaque , numbers increase in gingivitis and in root surface caries:

a)Staphylococcus species

(b)Actinomyces species

c)Bifidobacterium species

d)Prevotella species

3. Cocci ,early colonizes teeth ,isolated in low numbers from most sites in yhe oral cavity:

a)Veilonella species

b)Staphylococcus species

c)Peptococcus species

(d)Neisseria species

4. Intermedilysin , a protein toxin ,produce some pathogenic strains of:

a)S.oralis

b)S.anginosus

c)S.sanguis

(d) S. intermedius

5. The oral cavity inhabit:

(a) 400-500 bacterial species

b)100-200 bacterial species

c)150-250 bacterial species

d) 500-600 bacterial species

6. Their proportions and prevalence increase in advanced caries lesions both of the enamel and of the root surface:

(a) Lactobacillus species

b)Staphlococcus species

c)Stomatococcus species

d)Corynebacterium species

7. They comprise almost 50% of the total cultivable flora from saliva and the tongue ,cocci , facultative anaerobe or obligate anaerobe:

a)Staphylococcus species

(b)Streptococcus species

c)Stomatococcus species

d)Peptococcus species

8. Non-haemolytic ,colonizes teeth ,especially fissures ,isolated and implicated in human caries ,that'a is:

a)S.intermedius

(b)S.mutans

c)S.salivarius

d)S aureus

9. The oral non-pigmented Prevotella species include:

a) P. buccae , P. oris , P. intermedia

(b) P. buccalis , P. oralis , P. oris

c) P. gingivalis , P. oralis , P. buccae

d) P. intermedia , P. gingivalis , P.buccalis

10. Electron microscopy is necessary for the detection of:

a)bacteria

(b)viruses

c)yeast-like fungi

d)mycoplasma

Name:............................................. Group 1 17.10.2008.

1. Please connect above sentenses to the particular species:

A-Neisseria species 1)cocci, isolated in low numbers from most sites in the oral cavity

B-Streptococcus species 2)comprise almost 50% of the total cultivable flora from saliva and tongue

C-Lactobacillus species 3)form a small percentage of the normal flora, numbers increase of caries lesions

D-Veilonella species 4)cocci, isolated from most surfaces in the oral cavity, isolated in high numbers from dental plaque and tongue

(a)1A , 2B , 3C ,4D

b)1B ,2A , 3D ,4C

c) 1A , 2B ,3D , 4C

d) 1B , 2D , 3A ,4C

2. They form large , convex ,opaque , mucoid colonies , classical gum-drop appearance due to formation of levan from sucrose .That is:

a)S.sanguis

(b)S.salivarius

c)S.anginosus

d)S.gordonii

3. Light microscopy is employed for visualizing:

a)bacteria ,viruses, mycoplasma

b)bacteria, fungi , protozoa

(c)bacteria ,fungi , parasites

d)fungi , viruses ,parasites

4. Alpha haemolytic ,Gram-positive coccus, an early colonizes of smooth surfaces ,produces IgA protease and glucans .That is:

(a)S.oralis

b)S.mitis

c)S.salivarius

d)S.vestibularis

5. Porphyromonas species:

a) obligate anaerobe, Gram-positive rods ,found mainly in subgingival plaque , implicated in the aetiology of adult periodontitis

(b) obligate anaerobe ,Gram-negative rods ,found mainly in subgingival plaque , implicated in the aetiology of adult periodontitis

c)obligate anaerobe ,Gram-positive rods , found mainly in subgingival plaque,implicated in the aetiology of juvenile periodontitis

d)obligate anaerobe , Gram-negative rods , found mainly in subgingival plaque,implicated in the aetiology of juvenile periodontitis

6. The sanguis -group comprises:

a) S.mitis , S. sanguis , S.sobrinus

(b) S.sanguis , S. oralis , S.gordonii

c) S.anginosus , S. gordonii , S. oralis

d) S. anginosus , S. sanguis , S. gordonii

7. Their growth is stimulated by carbon dioxide are isolated in low numbers from most sites in the oral cavity and are among the earliest colonizers of a clean tooth surface:

(a) Neisseria spp.

b)Veillnella spp.

c)Actinomyces spp.

d) Porphyromonas spp.

8. Produce a range of putative virulence factors associated with tissue destruction and evasion of the host defences ,active proteases can degrade host molecules:

(a) P. gingivalis

b) L. acidophilus

c) S. mutans

d) S. milleri

9. The oral pigmented Prevotella species include:

a)P. gingivalis , P. intermedia , P. nigrescens

b)P. intermedia , P. nigrescens , P. buccalis

c) P. intermedia , P. oralis , P. melaninogenica

(d) P. intermedia , P. nigrescens , P. melaninogenica

10. Isolated from most surfaces of the oral cavity , may reduce lactic acid and convert to weaker acids (predominantly propionic acid):

a) Neisseria spp.

b) Streptococcus spp.

c) Staphylococcus spp.

(d) Veilonella spp.

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