Microbiology And Antimicrobials Flashcards

1
Q

What type of bacteria is Streptococcus Angiosus?

A

Gram Positive Cocci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Give an example of a gram positive cocci bacteria:

A

Streptococcus Anginosus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What type of bacteria is Veillonella Species?

A

Gram Negative Cocci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is an example of a gram negative cocci bacteria?

A

Veillonella Species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What type of bacteria is Actinomyces Israeli?

A

Gram Positive Bacilli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is an example of a Gram Positive Bacilli bacteria?

A

Actinomyces Israelii

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an example of a Gram Negative Bacilli bacteria?

A

Prevotella Intermedia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of bacteria is Prevotella Intermediate?

A

Gram Negative Bacilli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What type of bacteria is Prevotella Intermediate?

A

Gram Negative Bacilli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the meaning of an Aerobic Growth condition?

A

Growth in the presence of Oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the meaning of a Capnophilic growth condition?

A

Growth in the presence of Carbon Dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the meaning of a facultative growth condition?

A

With and Without oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the meaning of Strictly Anaerobic growth conditions?

A

Without oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which growth condition for bacteria does metronidazole have effect?

A

Strictly Anaerobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which growth condition for bacteria does metronidazole have effect?

A

Strictly Anaerobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the definition of Antimicrobial Resistance?

A

Occurs when microorganisms such as bacteria, viruses, fungi and parasites change in ways that render the medications used to cure the infections they cause ineffective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the definition of Antimicrobial Resistance?

A

Occurs when microorganisms such as bacteria, viruses, fungi and parasites change in ways that render the medications used to cure the infections they cause ineffective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the two types of resistance?

A

Intrinsic and Acquired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are two examples of acquired resistance?

A

Mutation and Acquisition of new DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is an example of resistance by altered target site?

A

S.mitis
Penicillin resistance due to modified penicillin binding proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is an example of antibiotic resistance?

A

Enzymatic Inactivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What two species of bacteria demonstrate resistance by enzyme inactivation?

A

Prevotella and Fusobacterium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Define: Endogenous Infection

A

The infectious agent is derived from the host flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the ideal specimen for a dental abscess?

A

Pus Aspirate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why is a pus aspirate the ideal sample for a dental abscess?

A

Prevents contamination with saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the treatment principles for a localised infection?

A

Establish a diagnosis and document it
Remove the source of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which two bacterias are commonly associated with dental abscesses?

A

Streptococcus Anginosus
Prevotella Intermedia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which two bacterias are commonly associated with Periodontal Abscesses?

A

Anaerobic Streptococci
Prevotella Intermedia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which bacterias are associated with Pericoronitis?

A

Mixed oral Anaerobes (P Intermedia)
S Anginosus group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which bacterias are associated with Pericoronitis?

A

Mixed oral Anaerobes (P Intermedia)
S Anginosus group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the recommended antibiotic for systemic pericoronitis?

A

Metronidazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What type of bacteria is associated with localised alveolar osteitis?

A

Mixed oral flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is Osteomyelitis of the Jaws predisposed by? (5)

A

Bisphosphonate therapy
Impaired vascularity of the bone (radiotherapy, Paget’s disease)
Foreign bodies (implants)
Compound fractures
Impaired host defences (diabetes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What types of bacteria are associated with Osteomyelitis of the Jaw (4)?

A

Anaerobic gram negative rods
Anaerobic streptococci
Streptococcus Anginosus
Staphylococcus Aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What bacterias are associated with M/BRONJ? (3)

A

S. Anginosus
Mixed anaerobes
Actinomyces Israelii

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What two bacterias are associated with Salivary Gland infection?

A

S. Aureus
Mixed Anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the treatment for Salivary Gland infection?

A

Drainage
Flucloxacillin and Metronidazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the four stages of Documentation when administering antibiotics?

A
  1. Document diagnosis
  2. Document Ab choice, dose, route and duration
  3. Document a review date
  4. Document deviation from guidance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does SOI stand for?

A

Severe Odontogenic Infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the definition of Ludwig’s Angina?

A

Bilateral infection of the submandibular space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Which three bacterias are commonly associated with Ludwigs Angina?

A

Anaerobic gram negative bacilli
Streptococcus Anginosus
Anaerobic Streptococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the definition of sepsis?

A

Life threatening organ dysfunction caused by a dysregulated host response to infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are the two components of a sepsis diagnosis?

A

SIRS and suspected/confirmed infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What does SIRS stand for?

A

Systemic Inflammatory Response Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are the four features of SIRS?

A

Temperature <36 or >38
Pulse >90/min
Respiratory rate >20/min
White Cell Count <4 or >12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

How many people die from sepsis per year in Scotland?

A

3,500

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the treatment principles of Severe Odontogenic Infections?

A

Diagnose
Seek advice/help

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are the 4 factors to consider in Severe Odontogenic Infection diagnosis?

A

Patient looks unwell
Family or carer is very concerned
There is ongoing deterioration
Physiology is abnormal for this patient (check HR, Oxygen Saturation and Blood Pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are the eight red flags in Severe Odontogenic Infection diagnosis?

A

New deterioration in Glasgow Coma Scale/ AVPU
Systolic SP <= 90mmHg (or >=40 below normal)
Heart rate >= 130 per minute
Respiratory rate >= 25 per minute
Needs oxygen to keep SpO2 92% (88% in COPD)
Non-blanching rash or mottled/ashen/cyanotic
Not passed urine in last 18 hours
Recent chemotherapy (within 6 weeks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What are the sepsis six?

A

Give high flow oxygen
Take blood cultures
Give IV antibiotics
Give a fluid challenge
Measure lactate
Measure urine output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What does S stand for in microbiology results?

A

Susceptible at a standard dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What does I stand for in microbiology results?

A

Susceptible at increased exposure/dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What does R stand for in microbiology results?

A

Resistant, even with increased exposure/dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the definition of a breakpoint?

A

A chosen concentration (mg/L) of an antibiotic which defines whether a species of bacteria is susceptible or resistant to the antibiotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the definition of clinical resistance?

A

When infection is highly unlikely to respond even to maximum doses of antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are the laboratory confounding variables of resistance testing?

A

Inoculum size
Planktonic phase
PH
Atmosphere
Biofilm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the clinical confounding variables of resistance testing?

A

Co-morbidities
Pus collections
Foreign bodies
Site of infection
Biofilm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is exposure a function of?

A

Mode of administration
Dose, dosing interval, infusion time
Distribution/excretion of the antibiotic
Interactions with bacteria at site of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the aim of antimicrobial stewardship?

A

To preserve antimicrobial medicines by taking measures to promote their control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What are the five strategic objectives of Antimicrobial Stewardship?

A

Improve awareness and understanding
Strengthen the knowledge through surveillance and research
Reduce the incidence of infection
Optimise the use of antimicrobial medicines
Ensure sustainable investment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the definition of antimicrobial stewardship?

A

A coherent set of actions which promote using antimicrobials responsibly

62
Q

What is the role of the Scottish Antimicrobial Prescribing Group (SAPG)?

A

Coordinates the national antimicrobial stewardship programme in humans

63
Q

What is Penicilin V most active against?

A

Oral streptococci
Anaerobes
Selected gram negative cocci

64
Q

What is amoxicilllin most active against?

A

Oral streptococci
Anaerobes
Gram negative cocci
Members of the enterobacteriaceae family

65
Q

What antimicrobials is anginosus streptococci invariably sensitive to?

A

Penicillin V
Amoxicillin

66
Q

What is the first line antimicrobial for dental infection?

A

Phenoxymethylpenicillin (penicillin V)

67
Q

What is the recommended dose of penicillin V?

A

500mg every 6 hours for 5 days

68
Q

What are four factors that cause candidosis?

A

Poor denture hygiene
Hospitalisation
Immunocompromised
Poor oral hygiene
HIV

69
Q

What are the 3 features of Candida albicans?

A

Hyphae
Hydrolytic enzymes
Adhesions

70
Q

What are the 3 features of Candida albicans?

A

Hyphae
Hydrolytic enzymes
Adhesions

71
Q

What type of fungus is candida?

A

A dimorphic fungus present both as yeast (blastosporic) and filamentous (hyphae)

72
Q

What is the size of a yeast cell in comparison to a bacteria?

A

Yeast cells are 25-50x bacteria cells

73
Q

What are the risk factors of candidiasis?

A

Immunocompromised patients
Advanced HIV infection
Central venous catheter
Broad spectrum antibiotics
Colonisation at a sterile site
Trauma patient
Immunosuppressive drugs
Intra-abdominal surgery
Parenteral nutrition
Dialysis
Burn unit victim
Long term corticosteroid use

74
Q

What is the classification of oral candidiosis?

A

Pseudomembranous- thrush
Erythematous- atrophied (HIV-related), denture related
Hyperplastic- candida leukoplakia
Angular cheilitis

75
Q

What are the three Newton’s type for denture induced stomatitis?

A

Newtons Type 1: localised inflammation
Newtons Type 2: diffuse inflammation
Newtons Type 3: granular inflammation

76
Q

What are the two main species of candida?

A

Candida albicans
Candida glabrata

77
Q

What are the 4 features of Candida albicans?

A

Adhesion and colonisation
Hyphal penetration and invasion
Vascular dissemination
Endothelial colonisation and penetration

78
Q

What do hydrolytic enzymes do?

A

Catalyse the hydrolysis of a substrate through the addition of water

79
Q

What do phospholipases do?

A

Lipids that allow host cell penetration

80
Q

What do haemolysins do?

A

RBCs
Facilitates hyphal invasion

81
Q

What do proteinases do?

A

Protein
Adhesion to epithelial cells

82
Q

What are five methods of collection for laboratory diagnosis?

A

Smear
Oral rinse
Swab
Foam pad
Biopsy

83
Q

What are the three types of antifungal?

A

Echinocandins: active against biofilms
Azoles: ineffective against biofilm
Polyenes: active against biofilms

84
Q

What are three examples of echinocandins?

A

Caspofungin
Micafungin
Aniduafungin

85
Q

What are three examples of azoles?

A

Fluconazole
Voriconazole
Pocaconazole

86
Q

What are three examples of polyenes?

A

Nystatin
Amphoteicin B
Liposomal AmB

87
Q

What antifungals are Candida albicans sensitive against?

A

Fluconazole and Metaconazole

88
Q

What antifungal is candida glabrata sensitive to?

A

Nystatin

89
Q

Which microbes are associated with periodontitis?

A

P. Gingivalis
T. Denticola
T. Forsythia

90
Q

Which microorganisms are associated with gingivitis?

A

Actinomyces
Prevotella intermedia
Bacteriodes
Fusobacterium nucleatum

91
Q

What are the influences on microflora?

A

Host factors
Diet
Saliva
Gingival crevicular fluid
Microbial interactions
Gaseous environment

92
Q

What is the preferred clinical specimen for oral biofilm infections?

A

Swab for wound/lesion taken chair side
Cultured on agar plate for incubation

93
Q

What is the preferred clinical sample for an abscess?

A

Pus

94
Q

What are the six features of the chain of infection?

A

Infectious agent
Reservoir
Portal of exit
Portal of entry
Mode of transmission
Susceptible host

95
Q

What microorganisms are associated with endodontic infections?

A

Bacteriodes
Streptococcus
Fusobacterium nucleatum
Prevotella
Clostridium
Lactobacillus
Porpphyomonas endodontalis

96
Q

What microbe is associated with 4-40% of endodontic infections?

A

Enterococcus faecal is

97
Q

What are examples of virulence factors?

A

Endotoxins
Adhesions
Collagenases
Hyalurnates
Immune evasion

98
Q

What are bacterial detection methods associated with microbial culture?

A

Agar medium
Isolate bacteria
Identify by characterisation of enzyme activities
Sugar fermentation tests

99
Q

What are bacterial detection methods associated with molecular biology?

A

DNA probes
PCR

100
Q

How can we identify anaerobes?

A

They have a sensitivity to metronidazole

101
Q

What are the advantages of culture methods?

A

Yields bacterial isolates for future testing and study

102
Q

What are the disadvantages of culture methods?

A

Required viable cells
Insensitive
Only a small number analysed at once
Inconclusive results
Labour intensive

103
Q

What are the 3 stages of PCR?

A

Denature (94-95C)
Annealing (50-56C)
Extension (72)

104
Q

What are the advantages of PCR?

A

Less time consuming than culturing
Very sensitive
Can directly detect bacterial DNA within clinical samples
Does not require viable cells
Can detect uncultivable species

105
Q

What are the disadvantages of PCR?

A

May detect dead cells
Detects only pre-selected species

106
Q

What are the disadvantages of PCR?

A

May detect dead cells
Detects only pre-selected species

107
Q

How does a restriction enzyme analysis work?

A

Digests whole enzyme with restriction enzymes

108
Q

What are the molecular (genetic) typing methods?

A

Restriction enzyme analysis
Gene probe typing
Ribotyping

109
Q

How does ribotyping work?

A

Use E-coli rRNA as a DNA probe following restriction enzyme analysis (REA)
rRNA operon present in multiple copies in bacterial genomes

110
Q

What is the mode of action of azole antifungals?

A

Indirectly target the ergosterol in the fungi cell wall by interrupting the activity of the enzyme that produces it: 14-alpha demethylase
Fungistatic effect

111
Q

What is an example of a polyene anti fungal?

A

Nystatin

112
Q

What is the mode of action of polyenes?

A

Directly targets the ergosterol and causes perforation and leakage of intracellular contents
Fungicidal effect

113
Q

What is an example of an echinocandin?

A

Micafungin

114
Q

What effect do echinocandins have?

A

Fungicidal

115
Q

What are the factors of chlorhexidine substantivity?

A

Adsorption to oral surfaces
Maintainacne of antimicrobial activity
Slow neutralisation of antimicrobial activity

116
Q

What is the treatment for erythematous candidiasis

A

Thorough cleaning of denture: milton soak

117
Q

What is the treatment for pseudomembranous candidiasis?

A

Nystatin
Topical MW 4x daily
Chlorhexidine adjunct

118
Q

What is the treatment for hyperplasticity candidiasis?

A

Systemic antifungals
Fluconazole 50mg or Itraconazole 10-20mg

119
Q

What is the treatment for angular chelitis?

A

Chlorhexidine and miconazole crea, (50mg 7 days)

120
Q

What type of substance is chlorhexidine?

A

Bisbiguanide

121
Q

What is the mode of action of chlorhexidine?

A

Dicationic: 1 cation is dental pellicle, 1 cation is bacterial membrane

122
Q

How does chlorhexidine perform at a low concentration?

A

Increases cell permeability

123
Q

How does chlorhexidine perform at a high concentration?

A

Causes cytoplasmic and cell death

124
Q

What is the substantivity of chlorhexidine?

A

12 hours

125
Q

What does substantivity mean?

A

Persistence of action

126
Q

What is substantivity dependent on?

A

Absorption to oral surfaces
Maintenance of antimicrobial activity
Slow neutralisation

127
Q

What are the dosing options for chlorhexidine?

A

0.2% 10ml 2x day
0.12% 15ml 2x day

128
Q
A
129
Q

What are the virulence factors of candida?

A

Adhesions
Hyphae
Hydrolytic enzymes

130
Q

What are the mechanisms of antimicrobial resistance?

A

Biofilm too thick for penetration
Antimicrobial inactive against non-growing organisms
Antimicrobial broken down and destroyed by enzymes

131
Q

What are the stages of biofilm development?

A

Adhesion
Colonisation
Accumulation
Complex Community
Dispersal

132
Q

What are the key organisms associated with caries?

A

Streptococcus mutans
Lactobacillus acidophilus
Actinomyces

133
Q

What are the virulence factors for microorganisms associated with caries?

A

Binding proteins
Acid tolerance
Adaption
Sugar modifying enzymes
Adhesions
Effluent pumps

134
Q

What are the features of acid tolerance?

A

Maintains pH
Alters cell membrane
Protection and repair mechanisms

135
Q

What are the side effects of chlorhexidine?

A

Anaphylaxis
Hypersensitivity
Brown staining
Tongue discolouration
Burning gums
Impairs perio healing

136
Q

What does a biofilm compose of?

A

Aggregate of micro-organisms whose cells adhere to one another and embed in a surface
The adherent cells become embedded within a self produced matrix of extracellular polymeric substances which allow adherence to a surface

137
Q

What is a niche?

A

The role a species plays in its environment and how it meets its need for food and shelter

138
Q

What is the role of fimbrillar adhesions?

A

Virulence factors
Help invade membrane vesicles of host cells by binding to cellular integrins

139
Q

What are lipopolysaccharides?

A

A distinct cell wall component of gram negative bacteria with the potential structural diversity to mediate specific adherence

140
Q

What is lipotechoic acid?

A

A cell wall component of gram-positive bacteria involved in specific or non-specific adherence

141
Q

What are protein fimbrae?

A

Filamentous proteins on the surface of bacterial cells that may act as adhesions for specific adherence

142
Q

What are lectins?

A

Any proteins that bind to a carbohydrate

143
Q

What are examples of host receptors?

A

Glycolipid
Integrins
Glycoproteins
Collagen

144
Q

What are factors that contribute to successful colonisation?

A

Adherence, substrate (energy) and a liable environment
Mucosa surface, pellicle, acid rich police proteins, minerals and lectins
Mechanical washing, bacteriocidal enzymes, buffering and secretor IgA
Adhesions, LTA, protease, virulence factors

145
Q

What bacteria is associated with NUG/NUP?

A

Anaerobic fusospirochetal bacteria

146
Q

When are antibiotics not indicated?

A

When there is no infection associated with systemic signs

147
Q

What systemic signs provide clear evidence of spreading infection?

A

Trismus
Lymphadenopathy
Difficulty swallowing
Pyrexia
Tachycardia

148
Q

What is a risk associated with spreading infections in the canine space?

A

Potential to cause intracranial bacterial infections

149
Q

What signs associated with referral indicate referral to A&E?

A

Signs of septicaemia such as grossly elevated temperature (39.5C, lethargy, tachycardia)
Spreading cellulitis
Swelling that may compromise the airway or cause difficulty in swallowing or closure of the eye
Dehydration
Significant trismus associated with a dental infection
Failure to respond to previous treatment
An uncooperative patient

150
Q
A