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D2 - FALL - PAR 1 > Microbiology > Flashcards

Microbiology Flashcards

1
Q

supragingival plaque is dominated by what type of organisms?

A

saccharolytic, facultative, and adhesive organisms; G+/-

*saccharolytic = lowers pH of a glc-based growth medium

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2
Q

subgingival plaque is dominated by what type of organisms?

A

asaccharolytic, anaerobic, weakly adherent, & motile organisms; dominated by G-

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3
Q

what is the predominant of the supra-gingival bacteria? the types of it?

A

streptococci

4 main groups:
mutans
salivarius
Anginosus (viridans)
mitis
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4
Q

S. salivarius?

A

most areas of mouth; prefers mucosal surfaces, esp tongue

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5
Q

S. viridans?

A
  • in mucosal surfaces & plaque
  • opportunistic pathogen (in abscesses)
  • earliest colonizers of cleanse tooth surf
  • cause of sub-acute bacterial endocarditis (prophylatic AB required for some pts undergoing oral procedures)
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6
Q

S. gordonii/sanguis?

A
  • member of viridans
  • G(+)
  • pioneer bacterium
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7
Q

streptococcus intermedius?

A
  • in biofilms
  • produces hyaluronidase (breaks down ECM of CT)
  • periodontal disease can result
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8
Q

peptostreptococcus?

A

G+, anaerobic streptococci, which can cause carious dentine, in pulp chambers, root canals, and advanced periodontal disease

  • ONLY genus among anaerobic G+ cocci encountered in clinical infections
  • infections - can be in all body sites
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9
Q

lactobacillus types and etc?

A
  • L. casei, L. fermentum, L. acidophilus
  • inc in advanced caries of enamel & root surf (pit & fissure, dentinal caries)
  • most aciduric oral species
  • G+
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10
Q

eubacterium?

A
  • pleomorphic rods/filaments in caries & periodontal disease

- 50% of anaerobes of periodontal pockets

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11
Q

propionibacterium?

A
  • G+, strict anaerobic bacilli
  • rod-shaped or branched (pleomorphic)
  • root surf & plaque
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12
Q

where is actinomyces commonly found?

A

supragingival plaque

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13
Q

A. naeslundii?

A
  • another early recolonizer of clean teeth
  • coaggregates w/ streptococci, fusobact, and veillonella
  • provides attachment for certain G- anaerobes
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14
Q

A. odontolyticus?

A

in deep dentinal caries

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15
Q

Most frequent causative agent of Actinomycosis?

A

A. israelii

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16
Q

fusobacterium nucleatum?

A
  • associated w/ gum disease
  • key comp of periodontal plaque & gingivitis
  • can adhere to wide range of G+/- plaque MOs
  • crucial! if can block this, then can prevent most other periodontal pathogens
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17
Q

bacteroides group?

A

B. fragilis
Porphyromonas
Prevotella
Tanarella

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18
Q

poryphyromonas & prevotella?

A
  • G(-), black (heme accum.) colonies

- unusual endotoxin (LPS)

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19
Q

tanarella forsythia?

A
  • anaerobic, non pigmented
  • periodontal disease
  • member of RED complex
  • secretes trpysin-like proteases
  • in progression of bone loss
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20
Q

porphyromonas gingivalis?

A
  • periodontal disease
  • member of RED complex
  • proteolytic enzymes: gingipains, collagenases, dipeptidyl aminopeptidase IV
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21
Q

prevotella intermedia?

A
  • periodontal disease

- imp in necrotic ulcerative gingivitis

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22
Q

aggregatibacter actinomycetemcomitans (Aa)?

A
  • in dental plaque, periodontal pockets, gingival sulcus
  • preadolescents localized juvenile & advanced aggressive periodontal disease
  • produces leukotoxin, chemotaxis inhibiting factor, & collagenase
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23
Q

Eikenella corrodens?

A

infrequent human pathogen capable of causing extraoral infections

24
Q

capnocytophaga?

A
  • G(-) facultative anaerobes

- occasional pathogen found in oral diseases & brain abscesses

25
Q

spirochetes?

A
  • present in advanced periodontitis
  • genus Treponema
  • absent from mouth until teeth erupt
  • greatly inc gingivitis
26
Q

treponema denticola?

A
  • member of RED complex
  • spirochete; periodontal disease
  • adheres to fibroblasts & epithelial cells, ECM
  • produces methyl mercaptan—contribute to halitosis
27
Q

sequence of events information of plaque?

A
  1. pellicle formation
  2. primary colonization
  3. secondary colonization
  4. tertiary colonization
28
Q

diff betw early and late colonizers?

A
  • early = utilize O2 and produce CO2

- late = produce H2 & reducing agents

29
Q

oxidation-reduction potential rises w/ plaque age. t/f?

A

FALSE, it falls w/ plaque age

*decreasing Eh correlates w/ increasing anaerobes

30
Q

3 theories proposed for etiology of caries?

A
  1. Miller’s Chemico - parasitic theory
  2. Proteolytic theory
  3. Proteolysis - chelation theory
31
Q

what are the 3 factors involved in Miller’s chemico-parasitic theory?

A

carb substrate, acid, oral micro organisms

32
Q

objections to miller’s?

A
  1. can’t predict specific sites of caries
  2. initiation of smooth surface caries not explained.
  3. unable to explain caries-free and caries-prone pop.
33
Q

polysaccharides are less easily fermented than monosaccharides by the plaque organisms. T/F?

A

true

34
Q

S. mutans & Lactobacilli species attack the ____ fissures, while A. naeslundi and A. viscosus prefer ____ surfaces.

A

pit; root

35
Q

______ and ________ also show preference to deep dentinal lesions.

A

Lactobacilli, A. naeslundi

36
Q

composition of dental plaque?

A

80% water; 20% solids

37
Q

proteolytic theory?

A

caries = essentially a proteolytic process; breakdown of proteins

38
Q

proteolysis-chelation theory?

A

caries = result of simultaneous degradation of organic substances (proteolysis) and dissolution of tooth minerals by a process called chelation.

39
Q

chelation?

A

process of complexing of a metallic ion to a complex substance

40
Q

surfaces of teeth in order of likelihood of caries?

A

occlusal, buccal, mesial, lingual, distal

41
Q

most susceptible teeth in order?

A

MD 1st, MX 1st, MD & MX 2nd molars

42
Q

chlorhexidine?

A

an effective oral agent; broad spectrum vs yeasts, fungi, G+/- bact

43
Q

ribosomes for bacteria?

A

70s ribosomes (16S and 23S subunits)

44
Q

L-Phase/Forms bacteria?

A

bacteria w/ cell walls that lack peptidoglycan.

45
Q

Techoic acids are exclusive to what type of bacteria?

A

Gram +

46
Q

Lysozyme is a glycosidase that hydrolyses ..?

A

MurNac - GlcNac bond and disrupts peptidoglycan structure.

47
Q

What activates the alternate complement pathway?

A

techoic acid

48
Q

Certain pili (______) has a retraction mechanism.

A

Type IV

49
Q

Certain pili (sex pili) are involved in ______.

A

bacterial conjugation

50
Q

H antigen?

A

flagella

51
Q

K antigen?

A

Capsule

52
Q

what recognizes PAMPs?

A

TLRs

53
Q

CCW rotation of flagella results in what type of movement? CW rotation?

A

CCW - fwd movt, run

CW - reorientation, tumble

54
Q

what type of penicllin would you give to a pt w/ stomach probs?

A

penicillin V

55
Q

following respiration, what is the major end product of glc catabolism

A

co2 & h2o

56
Q

what layer is the endotoxin found in?

A

endotoxin in the outer leaf of the lipid bilayer

D2 - FALL - PAR 1 (5 decks)

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