Lecture 6: Opportunistic Fungi Flashcards
Where is pythium insidiosum found around world
tropical/subtropical areas
pythium species generally found as __pathogen
plant
Pythium insidiosum is an oomycete- what is that
water mold
pythium insidosum is a flagellated __ capable of invading __
zoospores, damaged epithelium
pythium insidosum commonly infects where on body
limbs/ abdomen, GI
what species is most commonly infected with Pythium insidiosum
horses
pythium insidiosum life cycle depends on ___to persist in the environment
plant infections
Important part of case hx for Pythium insidiosum is exposure to __
water/flooding
what is pathogenesis for pythium insidiosum
- zoospores adhere to damaged skin or ingested
- spores invade tissue via germ tube, eventually forming aseptate hyphae
- Hyphae extend into tissues, lymphatic, blood vessels and disseminate
- Tissue damage is a result of eosinophilic/ mast cell degranulation
what lesions are seen on horse with pythium insidiosum
granulomatous, ulcerative lesions of the limbs/ abdomen, sometimes enteric with crater like borders
pythium insidiosum is occasionally seen in ___dogs. __ and __ forms can occur
young dogs
Cutaneous and gastrointestinal forms
how do you dx pythium insidiosum
- Clinical hx-exposure to water
- Histology- PAS/GMS/ IHC
- PCR or MALDI
what is tx for pythium insidiosum
surgical debridement, immunotherapeutic vaccination, and amphotericin B
how do you prevent pythium insidosum
limit exposure to wet or swampy areas in endemic areas
sporothrix schenckii inhabits ___rich in organic matter
soil
sporothrix schenckii infection linked to contact with __ or __
plants or infected animals
what is pathogenesis of sporothrix schenckii
- Inoculation of filamentous propgagules into skin
- Yeast form slowly disseminates via lymphoreticular system
What is primary contact with sporothrix schenckii
mycelia in environment
How is sporothrix schenckii horizontally transmitted
yeast forms from infected host
what species is sporothrix schenckii most common in
cats
what lesions are associated with sporothrix schenckii
primary nodular lesions and secondary ulcerative lesions with draining tracts
how do you dx sporothrix schenckii
- Unresponsive to abx
- Impression smears
- PCR or maldi
what is tx for sporothrix schenckii in cats and dogs
itraconazole
what is tx for sporothrix schenckii in horses
systemic iodides
how do you prevent sporothrix schenckii
indoor housing, neuter, proper PPE to prevent zoonosis
pneumocystisi jirovecii was previously classified as Protozoa due to its __ and __ stages
sporozoite and trophozoite
what are some breed predilections to pneumocystis jirovecii and what is it linked to
KCCS, dachshund, Arabian horses with links to immunodeficiencies
what is the source of pneumocystis jirovecii
environmental source
what is the infectious form of pneumocystis jirovecii
trophozoite
what is the generative form of pneumocystis jirovecii in the host
sporozoites/cysts
What is the pathogenesis of pneumocystis jirovecii
- Inhalation and trophozoite attachment to type I pneumocytes
- Cyst formation
clinical disease from pneumocystis jirovecii is rare but __-are thought to serve as reservoirs
immunocompetent animals
what species is pneumocystis jirovecii most common in
dogs
what are some clinical signs of pneumocystis jirovecii
chronic respiratory symptoms- cough, tachypnea, dyspnea
how do you dx pneumocystic jirovecii
BAL, histology/GMS/PAS, PCR
what is tx for pneumocystis jirovecii
trimpethoprim-sulfa, low dose steroids
