Lecture 48 - GI mycology Flashcards
what are 4 important GI fungal pathogens
- Histoplasma capsulatum
- candida spp.
- pythium insidiosum
- aspergillus spp.
describe H. capsulatum
- dimorphic fungi
- soil contamination from bats/birds
- endemic to ohio and Mississippi river valley
what are the clinical signs of H. capsulatum
- fever, lethargy, depression
- respiratory, GI, ocular signs
- enlarged ln, spleen, and liver
what are the GI signs of H. capsulatum
- decreased appetite
- weight loss from malabsorption
- large and small bowel D+
describe candida spp.
- budding yeast with oval appareance
- commensal
- acquired through birth canal and found in environment
what are the clinical signs of candida spp.
- stomatitis
- crop mycosis
- mastitis
- urogenital infections
describe pythium insidiosum
- poorly septate hyphal oomycetes
- pyogranulomatous and eosinophilic lesions
- in southeast USA
what are pythiosis clinical signs
GI - thickening of GI tract, mesenteric ln enlargement
weight loss, V+, bloody D+
describe aspergillus spp.
- leads to respiratory disease
- some spp. have hematogenous spread
- bones, kidneys, and CNS primarily affected
You are doing an externship at the Ohio State University. Which fungal infection would you prioritize as a cause of weight loss and bloody D+ in a dog from Columbus, Ohio?
Histoplasmosis
You are doing an externship at the University of Florida. Which fungal infection would you prioritize as a cause of weight loss and abdominal mass in a dog from Gainesville, FL?
Pythiosis
disseminated aspergillosis is most commonly seen in which breed of dogs
German Shepherd
what are the 3 pathogenesis and risk factors of fungal infections
- environment
- opportunistic due to immunosuppression or abx use
- breed dispositions
what is the pathogenesis of histoplasmosis
- inhale fungal elements
- localize in alveolar macrophages
- spreads to GI tract leading to pyogranulomatous inflammation
with respect to histoplasmosis pathophysiology, histoplasma capsulatum first becomes localized into macrophages in which organ?
lungs
soil contaminated with feces from which species is associated with increased risk of histoplasma capsulatum?
bat
how is histoplasma capsulatum diagnosed
- rectal scrapings
- FNA of lesion
- biopsy
- antigen test (urine)
- serology
- culture
- PCR
which body sample is preferred for histoplasma capsulatum testing in dogs
urine
culture is not recommended as a method of diagnosing histoplasma. why?
samples are biohazard
