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Flashcards in Oral Microbiology Deck (192):
1

3 features/capacities of Pathogens:

Host colonization

Overcome host immunity

Replicate within the host

2

Name 5 virulence factors

Adherence
Toxins
Inflammatory mediators
Anti-host enzymes
Bacterial capsules

3

What are the two types of cells

Prokaryotic
(includes archea)


Eukaryotic

4

What is a major virulence factor in Gram negative bacteria?

LPS

*lipopolysaccharide

5

T/F
Bacteria contain no membrane-bound organelles

True

6

How is bacterial genetic material packaged?

circular dsDNA

*one molecule

7

Bacterial Ribosomes ______

Eukaryotic Ribosomes ______

70s

80s

8

What do bacteria use for attachment and conjugation?

Fimbrae

9

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

Capsule

10

Why must bacteria secrete many digestive enzymes?

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

11

The ecological biosystem of bacteria are referred to as...

Biofilms

12

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

True

13

Describe the outer layers of a Gram Positive bacteria?

Thick wall

Single inner plasma membrane

*often 50% wall by weight

14

Describe the outer layers of a Gram Negative bacteria.

Outer membrane (LPS)

Thin cell wall

Cell (inner) membrane

15

Gram+ bacteria have ___ layers

Gram- bacteria have ____ layers

2

3

16

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

Capsule

17

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

What is its primary function?

Cell Wall

Protect from surrounding Osmotic Pressure

18

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

NAG - N-acetylglucosamine

NAM - N-acetylmuramic acid

19

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?

Transpeptidases

20

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

Autolysins

21

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

Endotoxin

22

A Gram- can't hold its alcohol:

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

23

The pattern recognition receptor that binds to LPS is...

TLR-4

24

TNF-alpha is a...

Cytokine

25

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

Disseminated intravascular coagulation

26

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

PGE-2
(osteoclast activator)

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

27

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

Blood pressure falls leading to

Hypovolemic Shock (aka septic shock)

28

What enzyme breaks down starch and glycogen?

Amylase

29

What enzyme breaks down peptidoglycan NAG-NAM molecules?

Lysozyme

30

T/F
ECF matrix often has glucose polymers that make them up

True

31

Bacteria capable or respiration have what?

Heme proteins

*no heme proteins = no respiration

32

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

Obligate aerobes

Facultative

Aerotolerant

Microaerophilic

Anaerobes

33

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

Fermentation

34

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

Superoxide dismutase

Catalase

35

Superoxide dismutase:

Catalase:

radical to hydrogen peroxide

hydrogen peroxide to water and oxygen

36

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

Aerobes and Facultative aerobes

37

T/F
Strict aerobes have neither Superoxide Dismutase or Catalase.

True

38

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

True

39

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

Plasmids

40

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

Innate

41

T/F
Innate immunity includes inflammation

True

*however, inflammation interacts with mechanisms of adaptive

42

What system of immunity is slow and specific and remembers?

What does it use?

Adaptive

Specific B and T lymphocytes

43

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

What do they release?

Sentinal

*Mast cells or Basophils

Releases Histamine

44

The "stop signs" that tell neutrophils to exit circulation in an acute condition are known as...

Tells what to exit during chronic condition?

Cell adhesion molecules
(CAMS)

Lymphocytes and Macrophage

45

S. pneumoniae is Gram...

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

Positive

Meningitis

46

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

Capsule

*CHO

47

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

Specifically?

Immunogenic

Opsonization with antibodies

48

What receptors on S. pneumoniae allow for opsonization?

Fc receptors

49

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

True

50

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

Cytokines

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

51

What causes a Cytokine Storm?

Super-antigen

52

What is the most biologically toxic bacterial product?

A-B toxin

53

What is the most common cold sore treatment?

Acyclovir

54

What increases the potency of vaccines?

Adjuvants

55

Hypersensitivity reactions 1-3 are...

Hypersensitivity 4 is...

Immunoglobulin mediated

T-cell mediated

56

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

True

57

What defines gingival junctional epithelium?
(4 things)

Poor differentiation

not much keratin

not many hydrophobic, granular materials

loosely linked

58

How do Junctional epithelial cells activate T-helper cells?

with HLA class II

*present extracellular antigenic peptides

59

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

Chemokine IL-8

60

Cytokines and chemokines are _____ for PMN's

chemotactic

61

How is junctional epithelium different from sulcular/gingival?

Junctional epithelium allows for easy _____.

Non-shedding

Egress of PMN's

62

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

What does this allow?

Junctional Epithelium

*epithelium that attaches to the tooth

PMN's easy access to the mouth

63

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

Saliva

*sIgA

64

2/3 of the WBC's are..

PMN

*neutrophils

65

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

Fc

C3b

66

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

drooling

*this leads to many side-effects of inflammation

67

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

IgA

IgG

68

What two sources of fluid bathe the oral cavity?

Crevicular fluid

Saliva

69

What are the 2 major defense features of Crevicular fluid?

IgG

PMN's

70

What is a big anti-carie effect of saliva?

Buffers

71

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

When released to mucosa the complex at site is called?

Fc

Secretory component

72

What are 4 unique attributes of sIgA?

Sticks to mucins

Protease resistant

Neutralizes viruses/toxins

Blocks microbe colonization

73

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

Streptococcus

Lactobacillus

Actinomyces

74

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

Treponema
Aggregatibacter
Bacteroides
Tannerella
Porphyromonas/Prevotella

75

How many different species of bacteria call the mouth home?

800

76

What has been shown to inhabit some perio pockets?

Archea

77

Where do most bacteria live in the mouth
(what 2 places)?

Plaque

Tongue crypts

78

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

Facultative

Microaerophilic

79

______ and ______ make up most of the subgingival plaque biofilm

Facultative

Anaerobic

80

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

True

81

Describe Streptococcus Viridans
(7 features)

Alpha Hemolytic
Green on blood agar
Facultative
ECM producer
saccharolytic
Acidogenic

82

What are the 4 subgroups of Streptococcus Viridans?

Which are good/bad?

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

83

Name 2 species in the Streptococcus mutans subgroup

Mutans

Sobrinus

*these 2 species most often associated with dental plaque

84

What Strep. species is a major cause of caries?

Name 3 features of this species

Mutans

insoluble polysaccharides
prefers low pH
Lactic Acid producer

85

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

S. anginosus

86

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

S. mitis

87

Name 4 species in the S. mitis group

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

88

What S. Viridans subgroup colonizes mucosa and not plaque?
(is a good guy)

S. salivarius

89

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

S. salivarius
S. vestibularis

90

T/F
Peptostreptococcus is Anaerobic

True

91

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

Enterococcus

92

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

E. faecalis

93

Streptococcus are all Gram___ cocci arranged in ____

Positive

Chains

94

Subacute Bacterial Endocarditis is often caused by what?

(also pneumonia and caries)

Viridans Strep

95

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

Name a specific species

Actinomyces

A. israelii

96

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)

Lactobacillus acidophilus

97

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

Neisseria

Veillonella

98

Name 4 Oral G+ rods.

Actinomyces
Lactobacillus
Neisseria
Veillonella

99

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

What kind of toxin does it produce?

Aggregatibacter actinomycetemcomitans

Leukotoxin

100

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

Fusobacterium nucleatum

101

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

Bacteroides
Tanerella
Porphyromonas
Prevotella

102

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

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

103

Name an Asachrolytic G- rod.

Porphyromonas gingivalis

104

What species of Prevotella is associated with periodontitis?

What type (G)

*all Prevotella sacharolytic

P. intermedia

G-

105

What very anaerobic species is found in gingivitis and periodontitis?

Treponema denticola

106

2 shapes of viral capsid

Icosahedral
helical

107

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

Budding (envelope with spikes)

Lysis

*enveloped vs. naked

108

5 cellular outcomes of viral infection

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

109

4 binary viral classifications:

helical or icosahedral

enveloped or naked

DNA or RNA

ds or ss

110

The protein shell of a virus is called a...

Capsid

111

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

Replicate their genetic material

Produce +mRNA for protein components

112

What plant infecting nucleic acids lack capsids?

Viroids

113

Horizontal infection:

Vertical infection:

person to person

mother to fetus/neonate

114

No symptoms can lead to a large ______

Iceberg effect

115

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

Enveloped

dsDNA (large - many targets)

116

Where do herpes viruses replicate and assemble?

nucleus

117

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

Before

***this is unique

118

Herpes initially infects the _______ and lasts _____

mucosal epithelium

lifetime

119

Example of an antiviral therapy for Herpes:

Acyclovir

120

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

True

121

HHV 1-4:

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

122

What HHV strains are latent in the neuron?

1-3

123

What HHV is an important congenital infection?

Cytomegalovirus

124

What Herpes virus is Kaposi's sarcoma?

HHV-8

125

DNA viruses can cause...

Tumors

126

What HHV isn't spread through mucosal contact?

Varicella zoster (3)

127

Viremic (first) infections can be dangerous to...

Fetus

128

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

Herpetic Stomatitis

129

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

HSV-1

130

Describe Herpetic Stomatitis

small vesicles
clear liquid
rupture and leave small painful ulcer

131

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

HSV-1 keratitis

132

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

HSV-2

133

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

85%

134

Lesions of HSV-1 present in what 2 places?
(area called what)

gingivostomatitis

herpes labialis

135

What ganglia are typically infected in HSV-1?

HSV-2?

Trigeminal

Sacral

136

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

True

137

The only HHV spread by respiratory droplets is

(infects lung mucosal lining initially)

Varicella Zoster

*zoster is the shingles bit

138

What are the 2 major diseases caused by EBV?

Infections mononucleosis

Burkitt's B Cell Lymphoma

139

Burkitt's lymphoma, aside from having an association with EBV, is associated with...

Malaria

140

Hairy Leukoplakia is caused by what virus?

*benign, which lesion, hyperkeratosis

EBV

141

2 cancers associated with EBV

Burkitt's lymphoma

Nasopharyngeal Carcinoma

142

T-cell leukemia is associated with what virus?

HTLV-1

143

What percentage of young adults infected with EBV develop Mono?

20-50%

144

What is the number 1 cause of retardation?

Cytomegalovirus primary infection when pregnant

145

T/F
Acyclovir works on Cytomegalovirus

False

146

T/F
There is no vaccine for the multiple strains of Cytomegalovirus

True

147

Worldwide ____% seropositive for cytomegalovirus
US ____ %

100% ww

50% US

148

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

20%

149

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

True

150

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

Immunosuppressed

151

Describe the Coxsackie virus

ssRNA
non-enveloped
picornaviridae
common and mild diseases in young

152

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

Herpangina

153

What 2 diseases does the Coxsackie virus cause?

Herpangina

Hand, foot and mouth disease

*both mostly young children

154

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

Measles

155

Describe the measles virus (capsid, genome)

Enveloped

ssRNA

156

Describe the Mumps virus (capsid, genome)

Enveloped

ssRNA

157

The characteristic symptom for mumps is...

Inflammation associated with this does what?

Parotitis

blocks salivary fluids

158

HPV - describe (capsid, genome)

non-enveloped

dsDNA

*warts - hyperplastic epithelial lesions

159

HPV is associated with what type of cancer?

Cervical

160

What is the most common fungal infection relevant to dentistry?

Candida albicans

161

Candidiasis is an _________.

Opportunistic bloom

162

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

Saprobe

163

What is different about a fungal cell membrane?
(compared with human cell mem)

Ergostal instead of cholesterol

164

What inhibits ergostol synthesis?

Azoles

165

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

polyenes

166

What makes up the cell wall of fungi?

cross-linked glucans

*Chitin

167

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

True

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

168

2 basic morphologies of fungus:

Yeast

Hyphae/filamentous

169

The collective term for a mass of hyphae is...

mycelium

170

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

Dimorphic

171

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

C. albicans

172

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

True

173

Why is humoral immunity no good in combating fungi?

Proteases/enzymes of fungi

174

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

True

175

Mycotoxicoses are _____

rare

176

Hay fever and asthma is a Type ____ hypersensitivity

Contact Dermatitis to a fungal product is a Type ____ hypersensitivity

Type I

Type IV

177

T/F
Superficial mycoses typically don't cause pathology

True

178

______, think cutaneous mycoses

Tinea

179

What 3 Dermatophytes cause Tinea (cutaneous mycoses)?

Trichophyton

Micosporum

Epidermophyton

180

T/F
Subcutaneous mycoses are common

False

181

Systemic fungal infections tend to enter via what?

Lungs

(inhaled spores)

182

List 4 opportunistic mycoses from common to rare:

Candidiasis
Cryptococcus
Aspergillosis
Pneumocystis

183

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

True

80%

184

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

Immuno-compromising conditions

(HIV)

185

The yeast or hyphae form of Candida depends on what?

Acidity

*acidic favors yeast, alkaline favors hyphae
**remember it's pseudohyphae for Candida
***Polymorphic

186

A pH switch to alkaline promotes what kind of Candida?

Filamentous

187

Why doesn't humoral immunity do much against fungi?

Antibodies are degraded quickly by enzymes / proteases

188

What type of cells typically respond to fungal antigens?

How?

Th1

stimulate cytokines
(which initiates inflammation, cell turnover, etc)

189

T/F
An immune dysfunction will almost always have thrush

True

190

PMN's attacking Candida can sometimes form what?

Loosely adherent pseudomembranes

*easily wiped off
**diptheria firmly adhere

191

Primary Candidiasis is found where?

Secondary Candidiasis is found where?

Which is seen in immunosuppression and HIV?

Orally (and surrounding)

Other mucosal/cutaneous sites

Secondary

192

4 types of Primary Oral Candidiasis:

Acute Pseudomembranous

Erythematous (acute/chronic atrophic)

Chronic hyperplastic (leukoplakia EBV associated)

Chronic mucocutaneous (immune defect)

Decks in Tim's Cards Class (140):