Actinomyces and Candida Flashcards
What are actinomycetes?
Gram +ve filaments - some branching
5 most common actinomycetes that cause disease
- A. Israeli
- A. Oris
- A. Odontolyticus
- A. Gerencseriae
- A.Meyeri
What do actinomycetes cause?
Responsible for infections (often painful and slow growing)
Enter via mucosal break
Who are actinomycetes more likely to affect?
Those w/ poor OH, dental tx, perio
What histology would you expect to see with actinomycetes?
Locules of pus surrounded by fibrous septa
Spiendore- hoeppli reaction - club shaped cationic protein in liquid complex
Sulphur granules
Pathogenic factor actinomycetes?
Chronic inflammation and walling off from defences
Tx actinomycetes?
Attempt as surgical drainage
Ab 6-8 week (PAT - penicillin, amoxicillin, tetracycline)
What is candida?
Dimorphic fungus - blastopore = yeast or hyphae form
How would you culture/ identify candida?
Sabouraud’s dextrose medium - creamy colonies
Sugar utilisation test
What is candidiasis?
Affect mucosa/ skin inc. oral/ vulvo-vaginal
Rarely systemic
When can candidiosis linked to other conditions?
HIV = acute pseudomembranous - cells can’t be removed
Denture stomatitis = chronic atrophy
Pathogenesis of candidiasis?
Hyphae = invasive structure (anti-inflammatory cytokines) Blastopore = pro-inflammatory cytokines
Yeast form coverted into hyphae form - pathogenic
Hyphae secrete candidalysin - pore forming toxin that kills human cells
What conditions are necessary for hyphae transition?
pH less 6 favour yeast, pH >7 favour hyphae
Tx candidiasis?
Antifungal drugs
Topical - nystatin (polyenes)/ miconazole (imidazole)
Systemic - flucanazole (imidazole)/ amphotericin (polyene)
What is a polyene and imidazole?
Polyene - cause membrane leak
Imidazole - inhibit membrane synthesis
