Microbiology Flashcards
What viruses are in the mouth and where are they found?
Hepatitis (I&II) Saliva and mucosa Coxsackie Saliva and mucosa Papilloma Mucosa Hepatitis’s, HIV – Saliva Cytomegalo Saliva
What fungi are found in the mouth?
Aspergillus spp.
Mucor spp.
What protozoa are found in the mouth?
Entamoeba gingivallis
Tricomonas tenax
Gardia lamblia
What yeast are found in the mouth?
Candida albincans
Candida tropicalis Candida glabrata
What microbes cause caries?
S. Mutans
Actiomyces spp.
Lactobacillus spp.
What microbes cause periodontal disease
Porphyromonas gingivalis Prevotella Fusobacterium Aggerogatibacterium Actinomycetemcomitans Spirocheates Tanerella forsythia Treponema
What are the gram positive bacteria found in the mouth?
Cocci: - Streptococcus Rods: - Actinomyces - Lactobacillus - Eubacterium
What are the gram negative bacteria found in the mouth?
Cocci N.V:
- Neisseria
- Veillonella Rods F.A.P.P.T:
- Fusobacterium
- Actinomyces
- Prevotella (Nigrescens)
- Porpyromonas
- Treponema
What are the streptococcus in the mouth accociated with health?
S. Oralis
S. Mitis
S. Sanguinis
What are the streptococcus in the mouth accociated with abscesses?
S. Intermedius
What are the streptococcus in the mouth accociated with caries?
S. Sorbinus
S. Mutans
What % of microbes in the mouth are culturable?
50%
Which streptococcus are early colonisers of the mouth?
S.Oralis & S mitis are early colonisers of the mouth
Describe common features of streptococcus
Caries
Gram positive
Rod
Alpha haemolytic Catalase negative
Describe common features of actinomyces
Root surface Caries
Gram positive Rods (Branched) Opportunistic
Describe common features of lactobacillus
Advanced caries
Gram positive
Rod
Describe common features of eubacterium
Found in plaque
Gram positive
Rod
Describe common features of neisseria (Early coloniser of tooth)
Gram negative Coccus
Aerobic
Describe common features of veillonella (utilises lactic acid in plaque)
Gram negative Coccus
Anaerobic
Describe common features of fusobacterium (Key bridging organism between early and late colonisers)
Gram negative Rod/filament Anaerobic
Describe common features of treponema (periodontal disease)
Gram negative Rod
Strictly anaerobic
What bacteria aren’t present in the mouth when teeth are removed?
S. Mutans
S. sanguinis
Strict anaerobes
but with dentures these return
What bacteria develop in the oral microflora over time?
Streptococcus salivarius Streptococcus oralis Streptococcus mitis (biovar 1)
What bacteria develop following eruption?
S. Sanguinis Prevotella spp. Actinomyces spp. Rothia spp. Neisseria Fusobacterium nucleatum Veillonella Lactobacillus spp.
What is selective media?
Provides nutrients for specific species of bacteria to grow.
e.g. Vancomycin Blood agar for Gram negative bacteria
What is non-selective media?
Provides nutrients for as many species of bacteria to grow as possible e.g. blood agar
How do you differentiate between colonies?
Colonies that look the same are the same species/organism
Colonies that look different are different species
What are the stages of culture?
Transport to laboratory in reduced transport fluid
Dispersion – sonication; vortex mixing with glass beads
Serial dilution in reduced transport fluid
Incubation under appropriate conditions (temperature, gas, etc)
Colony counts on selective and non-selective agar plates
Sub-culture and identification
What is the numerical change in redox potential for media?
From 100-200mV to -100mV
What is the numerical change in redox potential for plaque?
From 200mV to -147 mV
What is the numerical change in redox potential for gingival crevice?
From 73 mV to -48 mV
What is the pH change for exogenous nutrients such as sucrose?
Falls below 5 (goes acidic)
What is the pH change for endogenous nutrients such as those in GCF?
Goes from 6.9 to 7.25/7.5
What is the function of the antibiotic Trimethoprim?
Synthesis of essential metabolites
What is the function of the antibiotic Tetracycline?
Protein synthesis
What is the function of the antibiotic Metronidazole?
Activity against anaerobes
What is the function of the antibiotic Nystatin?
Membrane function
What is the function of the antibiotic Penicillin?
Cell wall synthesis
What is the function of the antibiotic Rifampin?
DNA replication
What are the stages of plaque formation?
Conditioning film Transport of molecules to tooth surface Reversible phase Irreversible phase Co-adhesion/ co aggregation Growth Detachment
What does conditioning film contain?
Mucins Agglutinins Immunoglobulins PRP’s Amylase Statherin
Describe the adhesin – receptor interactions of streptococcus spp.
Streptococcus spp. binds to Antigen I/II before producing salivary agglutinin
Describe the adhesin – receptor interactions of streptococcus mutans
Streptococcus mutan binds to glucan- binding protein and then produces glucan
Describe the adhesin – receptor interactions of Actinomyces naeslundii
Actinomyces naeslundii binds to type 1 fimbriae which produces PRP
What is the less cariogenic metabolic pathway for glucose?
Glucose to lactate to (veillonella) to actetate + proponate
What is the metabolic pathway for N sucrose using GTF?
N sucrose to (glucan)n + n-fructose
What is the metabolic pathway for N sucrose using FTF?
N sucrose to (fructan)n
+ n-glucose
What is the nature of the bacteria cultures at the Labial, retro molar space and the soft palate?
Mainly gram positive facultatives
E.g. Steptococcus + Antinomyces
What is the nature of the bacteria cultures at the Lingual?
Gram positive streptococci(40% are rods)
Gram negative anaerobes
What is the nature of the bacteria cultures in the plaque?
Gram positive & Gram negative Facultative + obligate anaerobes
- Prevotella
- Actinomyces
- Veillonella
- Neisseria
- Streptococcus
What is the nature of the bacteria cultures in the fissures?
Gram positive
Facultative anaerobes (S.A)
- Streptococcus
- Actinmyces
What is the nature of the bacteria cultures in the Gingival crevises?
Gram positive and gram negative Obligate anaerobes - Spirocheates - Streptococuus - Actinocmyes - Fusobacterium - Eubacterium - Prevotella
What is a facultative anaerobe?
An organism that can use oxygen but also has anaerobic methods of energy production.
What does GCF contain?
Glycoproteins
Hame
Proteins