Microbiology - candida/caries/perio Flashcards
(20 cards)
Patients at risk of candidal inf
Immuno-compromised patients Immunosuppressive drugs Advanced HIV infection Intra-abdominal surgery Central venous catheter Parenteral nutrition Broad-spectrum antibiotics Dialysis Colonization at a sterile site Diabetes Burn unit patient Trauma patient Long-term corticosteroid use
classifications of oral candidosis
- pseudomembranous - thrush
- erythematous - denture induced stomatitis
- Hyperplastic - chronic hyperplastic candidosis
- angular chelitis
denture induced stomatitis - classification
Newton’s classsification
- 1 - localised inflam
- 2 -diffuse inflam
- 3 - Granular inflam
signs/symps of denture induced stomatitis
Signs and symptoms • Inflamed mucosa – particularly under upper denture • Burning sensation • Discomfort • Bad taste • In most cases patients are unaware of the problem!
name some candida species
Candida albicans
• Candida glabrata
• Candida parapsilosis
• Candida tropicalis
name some hydrolytic enzymes
Phospholipase Lipid Host cell penetration
Haemolysin Red blood cells Facilitates hyphal invasion
Proteinase Proteins Adhesion to epithelial cells
antifungal drugs and their action
-what drugs are sensitive
-
-Nystatin - all species sensitive/poor patient compliance
NOT ANTIBACTERIAL
- miconazole - variable sensitivity/ANTI STAPHLOCOCCAL
- Fluconazole - C. GLABRATA IS RESISTANT
what branch of antifungals are INEFFECTIVE against biofilms
AZOLES
what is plaque
‘a diverse microbial community (predominantly bacteria) found on the tooth surface, embedded in a matrix of polymers of bacterial and salivary origin
what is the SDCEP treatment for pseudomembranous and erythematous candidosis
- local
- antifungal
- local - if inh user - wash out with water after use and brush teeth after
- antifungals
- fluconazole 50mg capsules
- miconazole - oromucosal gel 20mg
- Nystatin oral suspension - 100,000 units
treatment for denture induced stomatitis
- local
- antifungals
denture OHI
- fluconazole 50mg capsules
- micoazole oromucosal gel
- nystatin oral suspension 100,000u
why is miconazole used in cases of angular chelitis
miconazole is affective against gram positive cocci and candida species, except those on statins
treatment for angular chelitis
miconazole cream - 2%
sodium fusidate ointment 2%
miconazole cream 2% and hydrocortisone cream 1%
miconazole cream2% and hydrocortisone ointment 1%
name some cariogenic bacteria
Streptococcus mutans
– Lactobacillus acidophilus
– Actinomyces viscosus
– Nocardia spp.
caries progression - biofilm stages
adhesion/survival and growth/biofilm production/complex plaque/acid/caries
virulence factors of strp mutans
Adhesins
– SpaP (AgB, AgI/II, PI) – makes up fibrillar layer of cell wall
• Binding proteins
– glucosyltransferases, frucosyltransferases, glucan binding protein
• Sugar modifying enzymes
– Fructanase, dextranase
• Polysaccharides
– Protection (matrix) and storage (glycogen)
• Acid tolerance and adaptation
– ATPase (F1F0 ATPase or H+ ATPase)
critical pH of mouth - caries
pH 5.5
acid tolerance properties
Maintains pH balance
– Extrusion of H+ ions through a proton translocating F1-F0
ATPase (maintains physiological pH levels)
• Alters cell membrane
– Increase in the proportion of mono-unsaturated
membrane fatty acids – decreased proton permeability
• Protection and repair mechanisms
– Up-regulation of molecular chaperones, proteases and
DNA repair mechanisms
virulence factors of P ging
Host cell 0ssue adherence and invasion – Fimbriae • Elabora0on of proteases – ‘cocktail of degrada0ve enzymes’ – collagenase – fibrinolysin – phospholipase A – phosophatases • Endotoxin (LPS) • Capsular polysaccharide & outer membrane vesicles • Tissue toxic metabolic by-products – hydrogen sulfide – ammonia – faey acids
how does perio disease manipulate the host immune system
Biofilm lifestyle
• Gingipains
– Degrada0on of innate receptors
– Degrada0on of cytokines – e.g. IL-8, ICAM-1
• Induc0on of 0ssue destruc0on – MMP’s
• Subversion – intracellular and ‘tricking’ host
immunity
