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Flashcards in Oral Microbiology Deck (192)
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1
Q

3 features/capacities of Pathogens:

A

Host colonization

Overcome host immunity

Replicate within the host

2
Q

Name 5 virulence factors

A
Adherence
Toxins
Inflammatory mediators
Anti-host enzymes
Bacterial capsules
3
Q

What are the two types of cells

A

Prokaryotic
(includes archea)

Eukaryotic

4
Q

What is a major virulence factor in Gram negative bacteria?

A

LPS

*lipopolysaccharide

5
Q

T/F

Bacteria contain no membrane-bound organelles

A

True

6
Q

How is bacterial genetic material packaged?

A

circular dsDNA

*one molecule

7
Q

Bacterial Ribosomes ______

Eukaryotic Ribosomes ______

A

70s

80s

8
Q

What do bacteria use for attachment and conjugation?

A

Fimbrae

9
Q

What is made of carbohydrate polymers and a major virulence factor for bacteria?

A

Capsule

10
Q

Why must bacteria secrete many digestive enzymes?

A

Only small molecular weight molecules can pass through cell wall and membrane

11
Q

The ecological biosystem of bacteria are referred to as…

A

Biofilms

12
Q

T/F

There is often a battle over Fe resources between host and bacteria

A

True

13
Q

Describe the outer layers of a Gram Positive bacteria?

A

Thick wall

Single inner plasma membrane

*often 50% wall by weight

14
Q

Describe the outer layers of a Gram Negative bacteria.

A

Outer membrane (LPS)

Thin cell wall

Cell (inner) membrane

15
Q

Gram+ bacteria have ___ layers

Gram- bacteria have ____ layers

A

2

3

16
Q

What often slimy secretion do some bacteria surround themselves with that has strong anti-phagocytic properties?

A

Capsule

17
Q

What is the essential, all enclosing, rigid, porous, protective girdle that surrounds the bacterial cell?

What is its primary function?

A

Cell Wall

Protect from surrounding Osmotic Pressure

18
Q

What 2 acetylated amine groups make up the glucose dimers that make the polysaccharide of cell wall?

A

NAG - N-acetylglucosamine

NAM - N-acetylmuramic acid

19
Q

After the export of 20-ish NAG-NAM from the bacterial cell to the cell wall, what cross links the peptides and affixes the new unit to the cell wall?

A

Transpeptidases

20
Q

What constantly synthesizes and degrades the peptidoglycan making up cell wall?

A

Autolysins

21
Q

The toxic LPS found on the outer leaflet of the outer membrane of Gram- bacteria is…

A

Endotoxin

22
Q

A Gram- can’t hold its alcohol:

A

Crystal violet washes off by alcohol/acetone and accounts for lighter stain

23
Q

The pattern recognition receptor that binds to LPS is…

A

TLR-4

24
Q

TNF-alpha is a…

A

Cytokine

25
Q

Large amounts of LPS that activate the clotting system is know as what?

A

Disseminated intravascular coagulation

26
Q

What are 2 important pro-inflammatory mediators produced by Macrophage in response to LPS?

A

PGE-2
(osteoclast activator)

TNF-alpha
(signals NO production, causing pre-capillary sphincters to relax)

27
Q

If TNF-alpha causes too much of an NO reaction, what could happen?

A

Blood pressure falls leading to

Hypovolemic Shock (aka septic shock)

28
Q

What enzyme breaks down starch and glycogen?

A

Amylase

29
Q

What enzyme breaks down peptidoglycan NAG-NAM molecules?

A

Lysozyme

30
Q

T/F

ECF matrix often has glucose polymers that make them up

A

True

31
Q

Bacteria capable or respiration have what?

A

Heme proteins

*no heme proteins = no respiration

32
Q

Bacteria that must have oxygen:

Bacteria that can respire if Oxygen present, use fermentation if Oxygen absent:

Not killed by Oxygen but only ferment:

Like small amounts of oxygen

Always killed by Oxygen

A

Obligate aerobes

Facultative

Aerotolerant

Microaerophilic

Anaerobes

33
Q

What process gains energy by partially breaking down substrate to other organic molecules like lactic acid or alcohol?

A

Fermentation

34
Q

What 2 enzymes are of utmost importance when dealing with toxic oxygen radicals?

A

Superoxide dismutase

Catalase

35
Q

Superoxide dismutase:

Catalase:

A

radical to hydrogen peroxide

hydrogen peroxide to water and oxygen

36
Q

Both Superoxide dismutase and Catalase are found in what type of bacteria?

A

Aerobes and Facultative aerobes

37
Q

T/F

Strict aerobes have neither Superoxide Dismutase or Catalase.

A

True

38
Q

T/F
Supragingival plaque is mostly made up of microaerophilic and facultative bacteria, while sub-gingival plaque is primarily facultative and anaerobic

A

True

39
Q

What inserts into bacterial DNA, can exit, and often carries resistance or toxic coding sequences?

A

Plasmids

40
Q

What system acts in a fast, non-specific way that does not require specific recognition of a pathogen?

A

Innate

41
Q

T/F

Innate immunity includes inflammation

A

True

*however, inflammation interacts with mechanisms of adaptive

42
Q

What system of immunity is slow and specific and remembers?

What does it use?

A

Adaptive

Specific B and T lymphocytes

43
Q

What kind of cells live below all our epithelial barriers and recognize insults?

What do they release?

A

Sentinal

*Mast cells or Basophils

Releases Histamine

44
Q

The “stop signs” that tell neutrophils to exit circulation in an acute condition are known as…

Tells what to exit during chronic condition?

A

Cell adhesion molecules
(CAMS)

Lymphocytes and Macrophage

45
Q

S. pneumoniae is Gram…

S. pneumonia can cross BBB and initiate an inflammatory response called…

A

Positive

Meningitis

46
Q

What blocks phagocytosis by PMN’s and Macrophage and is a major virulence factor in S. pneumonia?

A

Capsule

*CHO

47
Q

The capsule in S. pneumoniae induces what response from the immune systym?

Specifically?

A

Immunogenic

Opsonization with antibodies

48
Q

What receptors on S. pneumoniae allow for opsonization?

A

Fc receptors

49
Q

T/F
Cell surface receptors are utilized by cytokines (which are activated by T-cells)
Cytokines are required for a full and effective adaptive immune response

A

True

50
Q

What causes the T and B cells to divide into clones?

A

Cytokines

*stimulated by T cells that received part of bacteria targeted from presenting cells

51
Q

What causes a Cytokine Storm?

A

Super-antigen

52
Q

What is the most biologically toxic bacterial product?

A

A-B toxin

53
Q

What is the most common cold sore treatment?

A

Acyclovir

54
Q

What increases the potency of vaccines?

A

Adjuvants

55
Q

Hypersensitivity reactions 1-3 are…

Hypersensitivity 4 is…

A

Immunoglobulin mediated

T-cell mediated

56
Q

T/F

Gingival, sulcular, and junctional epithelium are all rapidly dividing, shedding, physical barriers.

A

True

57
Q

What defines gingival junctional epithelium?

4 things

A

Poor differentiation

not much keratin

not many hydrophobic, granular materials

loosely linked

58
Q

How do Junctional epithelial cells activate T-helper cells?

A

with HLA class II

*present extracellular antigenic peptides

59
Q

Junctional epithelial cells have numerous cytokines and chemokines. What one is found in large amounts?

A

Chemokine IL-8

60
Q

Cytokines and chemokines are _____ for PMN’s

A

chemotactic

61
Q

How is junctional epithelium different from sulcular/gingival?

Junctional epithelium allows for easy _____.

A

Non-shedding

Egress of PMN’s

62
Q

What is the exception to epithelia of the mouth being tough, highly keratinized, and mostly impermeable?

What does this allow?

A

Junctional Epithelium

*epithelium that attaches to the tooth

PMN’s easy access to the mouth

63
Q

Outside of the cervicular space, what is a major protective barrier?

A

Saliva

*sIgA

64
Q

2/3 of the WBC’s are..

A

PMN

*neutrophils

65
Q

Name two cell surface receptors PMN’s use to attach foreign microorganisms.

A

Fc

C3b

66
Q

PMN’s either kill pathogens by ingesting them, or ____

A

drooling

*this leads to many side-effects of inflammation

67
Q

Salivary glands are Ig__ dominant and inflamed gingiva (Crevicular fluid) is Ig__ dominant

A

IgA

IgG

68
Q

What two sources of fluid bathe the oral cavity?

A

Crevicular fluid

Saliva

69
Q

What are the 2 major defense features of Crevicular fluid?

A

IgG

PMN’s

70
Q

What is a big anti-carie effect of saliva?

A

Buffers

71
Q

Dimeric IgA cells from B cells are cleaved at what site?

When released to mucosa the complex at site is called?

A

Fc

Secretory component

72
Q

What are 4 unique attributes of sIgA?

A

Sticks to mucins

Protease resistant

Neutralizes viruses/toxins

Blocks microbe colonization

73
Q

Name 3 supragingival plaque film Gram+ bacteria associated with Caries.

A

Streptococcus

Lactobacillus

Actinomyces

74
Q

Name 5 Gram- facultative and anaerobic rods bacteria associated with Periodontal Disease

A
Treponema
Aggregatibacter
Bacteroides
Tannerella
Porphyromonas/Prevotella
75
Q

How many different species of bacteria call the mouth home?

A

800

76
Q

What has been shown to inhabit some perio pockets?

A

Archea

77
Q

Where do most bacteria live in the mouth

(what 2 places)?

A

Plaque

Tongue crypts

78
Q

Supragingival plaque biofilm is primarily made of _______ and _______ bacteria.

A

Facultative

Microaerophilic

79
Q

______ and ______ make up most of the subgingival plaque biofilm

A

Facultative

Anaerobic

80
Q

T/F

Gingivitis usually has both G+ and G- associated with it.

A

True

81
Q

Describe Streptococcus Viridans

7 features

A
Alpha Hemolytic
Green on blood agar
Facultative
ECM producer
saccharolytic
Acidogenic
82
Q

What are the 4 subgroups of Streptococcus Viridans?

Which are good/bad?

A

S. anginosus
S. mutans - the bad guys
S. mitis
S. salivarius

83
Q

Name 2 species in the Streptococcus mutans subgroup

A

Mutans

Sobrinus

*these 2 species most often associated with dental plaque

84
Q

What Strep. species is a major cause of caries?

Name 3 features of this species

A

Mutans

insoluble polysaccharides
prefers low pH
Lactic Acid producer

85
Q

What S. Viridans subgroup is found in plaque, mucosa, and respiratory tract and is pus forming?

A

S. anginosus

86
Q

What S. Viridans subgroup is the pioneer species, making insoluble and soluble polysaccharides, and associated with bacterial endocarditis?

A

S. mitis

87
Q

Name 4 species in the S. mitis group

A

S. sanguinis
S. gornonii
S. oralis
S. mitis

88
Q

What S. Viridans subgroup colonizes mucosa and not plaque?

is a good guy

A

S. salivarius

89
Q

Name 2 species in the S. salivarius subgroup of S. Viridans.

A

S. salivarius

S. vestibularis

90
Q

T/F

Peptostreptococcus is Anaerobic

A

True

91
Q

What bacterial species is an opportunist that causes nosocomial problems and can survive harsh environments?

A

Enterococcus

92
Q

What species of Enterococcus is commonly implicated in endodontic root canal failures and persistent infections

A

E. faecalis

93
Q

Streptococcus are all Gram___ cocci arranged in ____

A

Positive

Chains

94
Q

Subacute Bacterial Endocarditis is often caused by what?

also pneumonia and caries

A

Viridans Strep

95
Q

What type of bacteria is associated with Root caries, ECM production, eats sugars, and tolerates a low pH?

Name a specific species

A

Actinomyces

A. israelii

96
Q

What species of bacteria is correlated with a high-sugar cariogenic diet, dentin caries, and is the Advancing Front of caries lesions?

(also produces ECM, eats sugar, tolerates low pH)

A

Lactobacillus acidophilus

97
Q

What 2 bacteria can metabolize lactate (and theoretically reduce caries)?

A

Neisseria

Veillonella

98
Q

Name 4 Oral G+ rods.

A

Actinomyces
Lactobacillus
Neisseria
Veillonella

99
Q

What G- rod is associated with aggressive Periodontitis in young adults?

What kind of toxin does it produce?

A

Aggregatibacter actinomycetemcomitans

Leukotoxin

100
Q

What G- rod associated with Periodontitis has very long thin rod that other bacteria attach to?

A

Fusobacterium nucleatum

101
Q

Name 4 black pigmenting species of G- rods that (might be) causative agents in Periodontal Disease

A

Bacteroides
Tanerella
Porphyromonas
Prevotella

102
Q

What 3 species form the Red Complex associated with aggressive Perio infections?

A

T. forsythensis (Tannerella)
P. gingivalis (Porphyromonas)
T. denticola (Treponema)

103
Q

Name an Asachrolytic G- rod.

A

Porphyromonas gingivalis

104
Q

What species of Prevotella is associated with periodontitis?

What type (G)

*all Prevotella sacharolytic

A

P. intermedia

G-

105
Q

What very anaerobic species is found in gingivitis and periodontitis?

A

Treponema denticola

106
Q

2 shapes of viral capsid

A

Icosahedral

helical

107
Q

What are the 2 ways a newly replicated virus leaves the cell

A

Budding (envelope with spikes)

Lysis

*enveloped vs. naked

108
Q

5 cellular outcomes of viral infection

A
Abortive (no progeny)
Lysis
Chronic non-lytic
Latent (integration)
Transformation (cell proliferates uncontrollably)
109
Q

4 binary viral classifications:

A

helical or icosahedral

enveloped or naked

DNA or RNA

ds or ss

110
Q

The protein shell of a virus is called a…

A

Capsid

111
Q

What 2 things must a virus do to replicate within the cell?

A

Replicate their genetic material

Produce +mRNA for protein components

112
Q

What plant infecting nucleic acids lack capsids?

A

Viroids

113
Q

Horizontal infection:

Vertical infection:

A

person to person

mother to fetus/neonate

114
Q

No symptoms can lead to a large ______

A

Iceberg effect

115
Q

Herpes viruses are enveloped/naked?
ds/ss?
DNA/RNA?

A

Enveloped

dsDNA (large - many targets)

116
Q

Where do herpes viruses replicate and assemble?

A

nucleus

117
Q

Herpes virus acquires their membrane before/after they reach the cytoplasmic membrane.

A

Before

***this is unique

118
Q

Herpes initially infects the _______ and lasts _____

A

mucosal epithelium

lifetime

119
Q

Example of an antiviral therapy for Herpes:

A

Acyclovir

120
Q

T/F

Herpes is serious if fetus infected, mild if child, and moderate to serious in adults

A

True

121
Q

HHV 1-4:

A

1: cold sores
2: genital
3: Varicella Zoster (chickenpox, shingles)
4: EBV

122
Q

What HHV strains are latent in the neuron?

A

1-3

123
Q

What HHV is an important congenital infection?

A

Cytomegalovirus

124
Q

What Herpes virus is Kaposi’s sarcoma?

A

HHV-8

125
Q

DNA viruses can cause…

A

Tumors

126
Q

What HHV isn’t spread through mucosal contact?

A

Varicella zoster (3)

127
Q

Viremic (first) infections can be dangerous to…

A

Fetus

128
Q

What is the name for the manifestation of HSV-1?

A

Herpetic Stomatitis

129
Q

What is the most common cause of viral encephalitis in the USA?

A

HSV-1

130
Q

Describe Herpetic Stomatitis

A

small vesicles
clear liquid
rupture and leave small painful ulcer

131
Q

What is the leading infectious cause of blindness in the USA?

A

HSV-1 keratitis

132
Q

HIV transmission is increased 2-4 fold with the presence of what?

A

HSV-2

133
Q

In the 1st 5 years of life HSV-1 primarily presents with a lip lesion, but is ____ asymptomatic

A

85%

134
Q

Lesions of HSV-1 present in what 2 places?

area called what

A

gingivostomatitis

herpes labialis

135
Q

What ganglia are typically infected in HSV-1?

HSV-2?

A

Trigeminal

Sacral

136
Q

T/F
Primary HSV-1 and HSV-2 infections can pass to fetus
Secondary recurrences of HSV-2 can pass to fetus during delivery

A

True

137
Q

The only HHV spread by respiratory droplets is

infects lung mucosal lining initially

A

Varicella Zoster

*zoster is the shingles bit

138
Q

What are the 2 major diseases caused by EBV?

A

Infections mononucleosis

Burkitt’s B Cell Lymphoma

139
Q

Burkitt’s lymphoma, aside from having an association with EBV, is associated with…

A

Malaria

140
Q

Hairy Leukoplakia is caused by what virus?

*benign, which lesion, hyperkeratosis

A

EBV

141
Q

2 cancers associated with EBV

A

Burkitt’s lymphoma

Nasopharyngeal Carcinoma

142
Q

T-cell leukemia is associated with what virus?

A

HTLV-1

143
Q

What percentage of young adults infected with EBV develop Mono?

A

20-50%

144
Q

What is the number 1 cause of retardation?

A

Cytomegalovirus primary infection when pregnant

145
Q

T/F

Acyclovir works on Cytomegalovirus

A

False

146
Q

T/F

There is no vaccine for the multiple strains of Cytomegalovirus

A

True

147
Q

Worldwide ____% seropositive for cytomegalovirus

US ____ %

A

100% ww

50% US

148
Q

Of the 1% pregnant that develop primary Cyto infections, ___% develop neural sequelae in fetus

A

20%

149
Q

CMV is the most common cause of intrauterine infections and congenital abnormalities in the US

A

True

150
Q

Primary or reactivation of latent CMV is very serious in what population?

A

Immunosuppressed

151
Q

Describe the Coxsackie virus

A

ssRNA
non-enveloped
picornaviridae
common and mild diseases in young

152
Q

What is the non-specific flu-like illness caused by the Coxsackie virus?

A

Herpangina

153
Q

What 2 diseases does the Coxsackie virus cause?

A

Herpangina

Hand, foot and mouth disease

*both mostly young children

154
Q

What is the most communicable disease worldwide (no iceberg effect)?

A

Measles

155
Q

Describe the measles virus (capsid, genome)

A

Enveloped

ssRNA

156
Q

Describe the Mumps virus (capsid, genome)

A

Enveloped

ssRNA

157
Q

The characteristic symptom for mumps is…

Inflammation associated with this does what?

A

Parotitis

blocks salivary fluids

158
Q

HPV - describe (capsid, genome)

A

non-enveloped

dsDNA

*warts - hyperplastic epithelial lesions

159
Q

HPV is associated with what type of cancer?

A

Cervical

160
Q

What is the most common fungal infection relevant to dentistry?

A

Candida albicans

161
Q

Candidiasis is an _________.

A

Opportunistic bloom

162
Q

What is an organism that lives on dead/decaying matter?

A

Saprobe

163
Q

What is different about a fungal cell membrane?

compared with human cell mem

A

Ergostal instead of cholesterol

164
Q

What inhibits ergostol synthesis?

A

Azoles

165
Q

What drug binds to and forms holes in ergostol-containing membranes?

A

polyenes

166
Q

What makes up the cell wall of fungi?

A

cross-linked glucans

*Chitin

167
Q

T/F

Compared to antibiotics, there are relatively few anti-fungals.

A

True

*Because non-toxic anti-eukaryotic drugs hard to find

168
Q

2 basic morphologies of fungus:

A

Yeast

Hyphae/filamentous

169
Q

The collective term for a mass of hyphae is…

A

mycelium

170
Q

Some yeast are ______ , and can exist in both yeast and filamentous forms

A

Dimorphic

171
Q

What fungus of oral concern can assume a pseudohyphae form and is dimorphic/polymorphic

A

C. albicans

172
Q

T/F

Fungi has a huge cell wall, up to 90% of dry weight

A

True

173
Q

Why is humoral immunity no good in combating fungi?

A

Proteases/enzymes of fungi

174
Q

T/F

Fatty acids, pH, epithelial cell turnover, and normal bactera all help resist against fungal invasions

A

True

175
Q

Mycotoxicoses are _____

A

rare

176
Q

Hay fever and asthma is a Type ____ hypersensitivity

Contact Dermatitis to a fungal product is a Type ____ hypersensitivity

A

Type I

Type IV

177
Q

T/F

Superficial mycoses typically don’t cause pathology

A

True

178
Q

______, think cutaneous mycoses

A

Tinea

179
Q

What 3 Dermatophytes cause Tinea (cutaneous mycoses)?

A

Trichophyton

Micosporum

Epidermophyton

180
Q

T/F

Subcutaneous mycoses are common

A

False

181
Q

Systemic fungal infections tend to enter via what?

A

Lungs

inhaled spores

182
Q

List 4 opportunistic mycoses from common to rare:

A

Candidiasis
Cryptococcus
Aspergillosis
Pneumocystis

183
Q

T/F

Candida albicans, along with being an opportunist, is part of the normal flora

A

True

80%

184
Q

What should a clinician think in an otherwise healthy adult in case of oral thrush?

A

Immuno-compromising conditions

HIV

185
Q

The yeast or hyphae form of Candida depends on what?

A

Acidity

  • acidic favors yeast, alkaline favors hyphae
  • *remember it’s pseudohyphae for Candida
  • **Polymorphic
186
Q

A pH switch to alkaline promotes what kind of Candida?

A

Filamentous

187
Q

Why doesn’t humoral immunity do much against fungi?

A

Antibodies are degraded quickly by enzymes / proteases

188
Q

What type of cells typically respond to fungal antigens?

How?

A

Th1

stimulate cytokines
which initiates inflammation, cell turnover, etc

189
Q

T/F

An immune dysfunction will almost always have thrush

A

True

190
Q

PMN’s attacking Candida can sometimes form what?

A

Loosely adherent pseudomembranes

  • easily wiped off
  • *diptheria firmly adhere
191
Q

Primary Candidiasis is found where?

Secondary Candidiasis is found where?

Which is seen in immunosuppression and HIV?

A

Orally (and surrounding)

Other mucosal/cutaneous sites

Secondary

192
Q

4 types of Primary Oral Candidiasis:

A

Acute Pseudomembranous

Erythematous (acute/chronic atrophic)

Chronic hyperplastic (leukoplakia EBV associated)

Chronic mucocutaneous (immune defect)

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