36 – Pathogenic Yeasts Flashcards
Microbiological characteristics: Candida
- Budding yeast
- Incubation of culture in serum for 2 hrs leads to growth of germ tubes
Microbiological characteristics: Cryptococcus
- Produces large mucopolysaccharide capsule
o Capsule is anti-phagocytic and immunosuppressive
Microbiological characteristics: Malassezia
- *bottle shapped cells
- M. pachydermatis: first isolated from Rhino with exfoliative dermatitis
- M. furfur complex fluoresces brick red under UV light
Candida spp: natural host or habitat
- Common in environment and associated with host
- Infections often caused by resident organisms
Malassezia pachydermatis: natural host or habitat
- Found on skin of mammals and birds
- Localized to anatomical sites with lots of sebaceous glands
o Anus, ears, lips, interdigital skin
Cryptococcus spp.: natural host or habitat
- C. gatti: associated with trees and soil
- C. neoformans: droppings of pigeons
- Radiotropic, melanized C. neoformans ID which are hypothesized to utilize ionizing radiation for energy
What does Canadida albicans cause in birds?
- Oral and crop candidiasis
- *most commonly causes infections on the mucous membranes where it is normally found
- *seen in variety of agricultural and pet bird species
What birds are most susceptible to Canadida albicans?
- Young birds
- *outbreaks of disease affecting large proportion of flock
o Sometimes seen as sequelae to coccidiostat treatment (‘flock level procedure’)
What are the clinical signs of Canadida albicans?
- Nonspecific
- Chicks don’t grow, listless
o Signs may be masked by predisposing disease
What are the gross lesions of Canadida albicans in birds?
- Raised, focal thickenings in mucosa of GIT
How do you treat Canadida albicans in birds?
- Possibly treating with in feed nystatin
- Individual bird treatment (topical)
- Possible association with vit A deficiency
o Hypovitaminosis A leading to squamous metaplasia
How do you control Canadida albicans in birds?
- Management (diet, concurrent disease, etc)
- Perhaps: dipping eggs in disinfectant
- Segregate affected birds to protect against cannibalism
What does Canadida albicans cause in horse?
- Superficial infections most common
o THRUSH: on mucous membranes - Systemic candidiasis: OPPORTUNISTIC
o Blood, respiratory tract, joints, urine, etc.
What are the 3 syndromes recognized with Canadida albicans in humans?
- Oropharyngeal
- Genital/vulvovaginal
- Invasive
Oropharyngeal syndrome: Canadida albicans in humans
- White plagues on tongue
- Rare in healthy adults
o AIDS defining condition - Also seen in people with cancer
Genital/vulvovaginal syndrome: Canadida albicans in humans
- Women: vulval pruritus, burning, discharge
- Men: penile pruritic rash
- Wearing cotton underwear may reduce risk of infection
- *affects 75% of all adult women at some point in their lifetime