Fungal Diseases SABS Exam 4

deep mycosis fungi

apergillosis, cryptococcus, blastomycosis, histoplasmosis

aspergillosis (non-thermal dimorph)

most common, airborne, leads to rhinosinusitis, spreads to eyes/brain

blastomycosis

spores in soil/wood, airborne, lung infection, spread to CNS

cryptococcus

bird droppings, airborne, lung infection, spread to CNS (meningitis)

how cryptococcus crosses BBB

macrophages (Trojan Horses), transcytosis, and paracellular crossing (urea damage)

histoplasmosis

bats/birds, airborne, usually asymptomatic, causes oral lesion in immuno patients

oral histoplasmosis

mostly HIV males,

80% of human fungal infection from

candida albicans and tropicalis attach as yeast (opportunistic and dimorphic) make biofilm with hyphae

candida albicans

found on skin, cuteanous/invasive candidiasis, yeast form when moving, mother to child and via sex

oropharyngeal candidiasis

oral thrush, defective cellular immunity, biofilm formation, acute or chronic

candidiasis risk factors

weakened immune system, oral microbiota change, and dentures

pseudomembranous candidiasis

white patches that can be scraped off, can burn, typically acute

chronic atrophic candidiasis (denture stomatitis)

localized erythema due to dentures (poor oral hygeine or ill fitting) may be painful

erythematous candidiasis (acute atrophic)

rare, from long term antibiotic use, on tongue and roof of mouth (ALWAYS painful)

hyperplastic candidiasis (candidal leukoplakia)

chronic, non scrapeable, white lesions

angular chelitis caused by

c. albicans, strep, and s. aureus

c. albicans and s. mutans

are synergistic or antagonistic

synergistic

s.mutans secretes factors to modulate c.albicans transition to hyphae, c.albicans makes EPS for s.mutans to make biofilm, c.albicans grows on byproducts of s.mutans

antagonistic

c.albicans releases factors to downregulate s.mutans, s.mutans releases signal factors to suppress hyphae formation, c.albicans can feed of lactate, reducing caries

c.albicans promoting caries

acidogenic acetate, aciduric (pH 4), primary colonizer to pellicle

emerging resistant fungus

candidas auris (mostly asymptomatic, may cause chills and organ damage

lung cancer associated with

blastomyces

breast cancer associated with

malassezia

fungal infections with COVID

pulmonary aspergillosis, invasive candidiasis, mucormycosis