Actinomyces Flashcards
(21 cards)
Actinomyces are gram…. filaments
Stained unevenly
Sometimes grow …
positive
branches
Most frequent actinomyces is
A. Isrealii, sometimes with a.a.
Culture for growing Actinomyces
Fastidous
Microaerophilic/ facultatively anaerobic
Slow growing 3-7 days, molar colonies
Actinomycosis is a
rare infection, painful slow growing absesses in mouth
Large absesses can penetrate the bone
Diagnosis of actinomycosis
Microbiological culture, immunoassay, MRI
Virulence factors of actinomyces
no toxins
Induction of chronic inflammation
Walling of defences- stop leukocytes from entering centre
Slow growth
How to treat actinomycosis
tetracycline, penicillin, amoxycillin (all for 6 weeks)
Drainage of pus, if possible
What is Candida?
A dimorphic fungus (maybe trimorphic)
As fungus is trimorphic, what are the 3
Blastospore (yeast) can turn into hyphae
Hyphae
Chlamydospores
Name 3 different Candida species
C albicans
C tropicalis
C auris
What medium can you grow Candida on?
What do the colonies look like
Sabourauds dextrose medium- Creamy colonies
What test can we do to identify C albicans
Germ tube test, 3 hours in serum at 37 degrees
Other that culturing what other test ca you do?
Sugar utilisation test (see if a carbohydrate can be fermented)
What are the predisposing factors for Candidosis
-Prostheses (dentures)
Low saliva
Antibiotics
Immune suppression
What is known as thrush
Acute pseudomembranous, associated with poor immune system- mainly T cells, often HIV, Rub white patches off and its red underneath
Give a type of candidosis, associated with cracked corners of mouth
Angular Cheilitis
Which candidosis is associated with dentures
chronic atrophic may just look red due inflammation
Candida can cause the following complications
Bronchopulmonary - candida causing pneumonia
Systemic - endocarditis
Pathogenic factors of candida
Hyphae: blastospores (proinflammatory cytokines) Hyphae (anti-inflammatory cytokines)
Proteases- secreted aspartyl proteases
C. albicans main virulence factor is
Candidalysin - ECE-1 factor
Treatment of candida
Remove the cause/prostheses
Antifungal drugs: Miconazole Fluconazole
