Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BDS3 > Microbiology and Oral Pathology > Flashcards

Microbiology and Oral Pathology Flashcards

1
Q

Cariogenic microorganisms

A

Strep mutans
Veillonella
Actinomyces

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

Appropriate clinical specimen to study cariogenic microorganisms in children

A

Oral swab or rinse

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

Examples of oral biofilm diseases

A

Caries
Endo infections
Perio infections
Oral malodour
Mucosal infections - thrush, angular chelitis, denture stomatitis

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

What are host factor influences on oral microflora?

A

Systemic disease, antibiotics, OH, genetics, smoking, pregnancy, puberty,

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

What factors of diet affect oral microflora?

A

Chemical composition
Physical consistency
Frequency of intake

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

How does saliva affect oral microflora?

A

Flow rate
pH balance
Antimicrobial factors

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

How does gingival crevicular fluid affect oral microflora?

A

Antimicrobial components and humoral immunity

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

How do microbial interaction affect the oral microflora?

A

Competition and cooperation

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

What about the gaseous environment affects the oral microflora?

A

Oxygen concentrations

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

Oral biofilm diseases

A

Caries
Oral malodour
Endo infections
Mucosal infections
Periodontal infections

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

Influences on oral microflora

A

Host factors - systemic disease, antibiotic use, OH
Diet - chemical composition, physical consistency, frequency of intake
Saliva - flow rate, pH balance, antimicrobial factors
Gingival crevicular fluid - antimicrobial components and humoral immunity
Microbial interactions - competition and cooperation
Gaseous environment - oxygen conc

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

How does biofilm in mouth change from health to disease?

A

Beneficial bacteria, immune surveillance and tissue homeostasis in health
Pathogenic bacteria, non protective immune responses, disruption of tissue homeostasis in disease

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

What causes periodontitis?

A

High concentration of periodontopathogenic bacteria
Sever inflammation and pocket formation, degradation of soft and bone tissue as a result

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

Microbial progression expected from periodontal health to disease

A

Gram positive, aerobic bacteria -> gram negative, anaerobic bacteria

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

Important microorganisms in healthy biofilm

A

Oral streptococci
Actinomyces
Veillonella
Haemophilus
Neisseri
Fusobacterium

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

Important microorganisms in gingivitis

A

Actinomyces
Prevotella intermedia
Becteroides
Fusobacterium nucleatum

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

Important microorganisms in periodontitis

A

PORPHYROMONAS GINGIVALIS
Tannerella forsythia
Treponema denticola
Prevotella intermedia
AA

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

Effects of microbial competition

A

Metabolic products - acids, oxidants
Bacteriocins
Receptor antagonism

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

Effects of microbial cooperation

A

Metabolic products - saccharides, peptides, growth factors
Adhesion substrates
Immune avoidance

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

P gingivalis in periodontal disease

A

Increased number in PD
Suppressed or undetectable in successfully treated lesions

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

Size of candida compared to bacteria

A

Much bigger
Can be 100x the size

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

Risk factors for developing candidiases

A

Immuno compromised
Immunosuppresive drugs
Advanced HIV
Intra-abdominal surgery
Central venous catheter
Parental nutrition
Broad spectrum antibiotics
Dialysis
Colonisation at a sterile site
Diabetes
Burn unit pt
Trauma patient
Longterm coritcosteroid

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

Candidiasis infection types

A

Periodontits
Dental implants
Denture stomatitis
CF lung infections
Ventilator associated pneumonia
UTI
Infectious kidney stones/biliary tract infections
Mucoskeletal infections/osteomyelitis
Chronic wounds
Sutures
Endocarditis
Implant/medical device
Catheters and stent

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

Classification of oral candidosis

A

Confined to mouth and commisure - pseudomembrane (thrush), erythematous (atrophic HIV related, denture related), hyperplastic angular chelitis - candidial leukoplakia

Generalised candidosis with oral manifestation - chronic mucotaneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Management of chronic hyperplastic oral candidosis
Biopsy Usually long term anti fungals
26
Newton's types of denture stomatitis
Newton's type 1 - localised inflammation Newton's type II - diffuse inflammation Newton's type III - granular inflammation
27
Denture induced stomatitis
Adhere and colonise on acrylic surfaces, co aggregation, biofilm formation Signs and symptoms Inflamed mucosa Burning Discomfort Bad taste Most pts unaware of the problem
28
Opportunistic pathogenic yeasts
CANDIDA GLABRATA CANDID ALBICANS Candida parapsilosis Candida tropicalis
29
Main difference between candida albicans and candida glabrata
CA - sensitive to fluconazole and metraconazole CG - not
30
Candida albicans
Present in 71% of healthy individuals Variable anatomical sites (oral carriage 35-55%) Nutrient limitation/competition with bacteria keep it in check, when broad spectrum antibiotics given, can cause thrush
31
Microscopic difference between albicans and glabrata
Albicans has hyphae
32
What is used to treat candida glabrata
Nystatin
33
Two functions of microbiology lab
Clinical - diagnosis of infection in an individual for everyday management of infections Epidemiological - Support for infection prevention and control in searching for source and route of transmission of healthcare associated infections
34
Minimal requirements for microbiology services
1 Set up inside the facility - if not possible, negotiate contract for diagnostic microbiology with the nearest lab 2 Available every day including sundays and holidays, ideally 24h 3 Able to examine blood, cerebrospinal fluid, urine, stool, wound exudate or swabs, respiratory secretions and perform basic serological tests 4 Identify common bacteria and fungi to species level 5 Perform susceptibility testing using disc-diffusion methodology 6 Perform basic phenotyping such as serotyping and biotyping
35
Clinical specimens for oral biofilm infections
Swab for wound/lesion usually taken chairside, culture on agar plate with incubation
36
What clinical sample would be taken for an abscess?
Pus
37
Roles of microbiology lab in prevention and control of HAIs
Outbreak investigation Surveillance of HAIs Alert microorganisms reports Designing antibiotic policy
38
Chain of infection
Infectious agent - bacteria, fungi, virus Source - people, equipment, water Exit - Aerosols, splatter Mode of transmission - direct contact, inhalation, airborne Portal of entry - mucous membrane, resp tract, broken skin Susceptible host
39
Bacterial involvement in caries
Bacteria produces acid from fermentable carbohydrate
40
Organism most associated with caries
Strep mutans
41
Microbial flora associated with caries examples
Actinomyces Abiotrophia Atopobium Bifidobacterium Lactobacillus Veillonella Proprionibacterium Prevotella Strep mutans
42
Endodontic infection
Normally, intact enamel and dentine protect pulp - no infection Infections to pulp generally secondary to tooth infections/trauma - e.g. caries, streptococci and lactobacilli Endodontic infections derived from endogenous microflora Opportunistic infections
43
Cause of endodontic infection
Acute immune response followed by chronic immune response to bacteria at apex
44
Bacteria involved with endodontic infection examples
Bacteroides Prevotella Streptococcus Clostridium Fusobacterium Lactobacillus Propionibacterium
45
Enterococcus faecalis
Important endo bacteria Primary endo infections are polymicrobial, dominated by grain negative anaerobic rods, enterococcus faecalis in 4-40% Secondary endodontic infections are composed of one or a few bacterial specie Predominantly gram +ve 9 times more likely to find enterococcus faecalis
46
Virulence factors
Factors making more damaging pathogens Endotoxins Adhesins Collagenases Hyaluronidase Immune evasion
47
Enterococcus faecalis
Gram +ve coccus (single or pairs) Facultative anaerobe Aggregative, adhesion Superoxide formation Gelatinase Cytolysin Lipotechoic acid
48
Bacteria associated with root canal infections
Porphyromonas endodontalis Fusobacterium nucleatum
49
Bacterial detection methods
Microbiological culture - on agar medium, isolate bacteria, identify by characterisation of enzyme activities, sugar fermentation tests Molecular biological - DNA probes, PCR
50
How to ID anaerobes
Sensitivity to metronidazole disc
51
Advantages and disadvantage of culture methods
Advantages - yields bacterial isolates for future testing and study (such as antibiotic sensitivities) Disadvantages - required viable cells, insensitive, only small numbers analysed at once, inconclusive results, labour intensive
52
DNA probes
Segments of DNA that have been labelled with chemoluminescent, fluorescent or radioactive agents Types = whole genomic, cloned gene, oligonucleotide (20-50- bases)
53
16s ribosomal RNA
Found in all bacteria Essential for survival Gene sequenced for all known bacteria Highly variable regions provide unique signatures to any bacterium -> species specific probes or primers Conserved regions -> broad range probes or PCR primers
53
16s ribosomal RNA
Found in all bacteria Essential for survival Gene sequenced for all known bacteria Highly variable regions provide unique signatures to any bacterium -> species specific probes or primers Conserved regions -> broad range probes or PCR primers
54
PCR
Highly specific, sensitive, can be used to directly detect bacteria in clinical specimens Double stranded DNA mixed with primers, dNTPs, DNA polymersase, then denatured Primers bind to target sequences, polymerase synthesises the other strand Repeat cycle
55
PCR primers
Usually target 16s rRNA gene Types - general bacterial primers, group specific primers, species specific primers
56
Advantages and disadvantages of DNA probes and PCR
Less time consuming than culturing Very sensitive Can directly detect bacterial DNA within clinical samples Do not require viable cells Can detect uncultivatable species BUT May detect dead cells Detect only pre-selected species
57
Why is it important to subtype bacteria?
Sufficient genetic diversity exists to allow ID of different clones (strains) among isolates of the same species Track routes of transmission during disease outbreaks Study pathogenicity of specific strains
58
What are serotyping and biotyping?
Traditional methods for subtyping bacteria Limited discriminatory capacity Organism specific methods Specialised reagents required
59
Molecular (genetic) typing methods
Restriction enzyme analysis REA- digest whole genome with restriction enzymes, too many fragments obtained makes interpretation difficult Gene probe typing - can reduce number of DNA fragments generated by using a suitable gene probe Ribotyping - use E.coli rRNA operon as DNA probe following REA, rRNA operon present in multiple copies in bacterial genomes, well conserved in structure and sequence, variation in number and size of fragments in bacterial DNA 16s-23s intergenic spacer region - very variable sequence, amplified by PCR using consensus primers, digest PCR product with restriction enzymes to obtain strain specific fingerprints DNA sequencing - ultimate typing method, can detect single base differences
60
Molecular identification of uncultivable and novel bacteria
Genomic DNA extracted from sample PCR amplifies 16s rRNA gene from bacterial DNA in specimen 16s rRNA genes are cloned 50 clones are randomly chosen and sequenced Clone sequences are analysed to determine bacterial identity
61
Appropriate clinical specimen to study cariogenic microorganisms in population of 4-5 year olds
Oral swab of saliva or tooth surface
62
What organisms are important to detect in a study of cariogenic microorganisms?
Streptococcus mutans Lactobacillus species
63
What sample would you investigate in gingivitis patient?
Paper point from gingival crevice, subgingival plaque biofilm
64
What organisms are important for gingivitis patient?
Porphyromonas gingivalis
65
Microorganisms associated with denture stomatitis
Candida albicans Candida glabrata Any oral bacteria
66
What specimen would be taken to study denture stomatitis microorganisms?
Oral rinse or swab from area, or foam pad
67
Systemic danger of denture stomatits
Aspiration, pneumonia
68
Pt with throbbing swelling on lower right Face tender and swollen Elevated temp and evidence of abscess
Microbiological concerns - systemically unwell Pus sample (needle aspirate?) Possible oral anaerobes Standard plate culture and microscopy used to ID microorganism

BDS3 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions