Aspergillus, Pneumocystis carinii, Pythium insidiosum Flashcards
What type of fungus are Aspergillus spp.
ubiquitous
Aspergillosis is caused by what fungi and they produce what
Aspergillus fumigatus and A. flavus (and others) and they produce mycotoxins
Transmission of Aspergillus
inhalation or ingestion of spores
Aspergillosis pathogenesis
Conidia (spores) inhaled and alveolar macrophages usually kill or spores germinate and form hyphae and Neurtophils kill then but they can invade tissue if both those fail causing neutropenia
Aspergillosis in birds- acute
Respiratory pathogen with serious economic concern- causes high morbidity and mortality in young birds inhaling conidia from contaminated litter (poor sanitation) resulting in Acute Avian Asperillosis (airsacculitis)
Aspergillosis in birds- cronic
Disease of older poultry from moldy feed, seen fungus on surface of air sac at slaughter
Aspergillosis in birds treatment
not cost effective
Aspergillosis in Horses disease
Guttural Pouch Mycosis but may damage cranial nerves from there, may see difficulty swallowing (nerve defect), chronic nasal discharge and potential for profuse epistaxis which can cause death in minutes
Aspergillus infection in the cornea from external trauma to cornea
Aspergillosis in dogs disease
Canine Nasal Aspergillosis caused by A. fumigatus which can result in destruction of nasal turbinate bones, will see bloody, purulent nasal discharge with facial swelling and pain and ulceration of nares
Canine Disseminated Aspergillosis caused by A. terreus usually because of immunosuppression but results in osteomyelitis and granulomas in many of the organs, poor prognosis
Aspergillosis abortion?
possible late term abortions in cattle and horses
Pneumocystis carinii was originally classified as what
a protozoan parasite
Pneumocystis carinii features
sphere shaped fungus lacking in ergosterol in cell wall
Pneumocystis carinii disease
pneumonia (PCP) usually in
**immunocompromised animals (foals with Severe Combined Immunodeficiency- SCID- no B or T cells)
Pneumocystis carinii diagnosis
PCR and staining samples, unable to be cultured under normal conditions
Pneumocystis carinii treatment
Antibiotics- trimethoprim/sulfa because it inhibits the dihydrofolate reductase enzyme
Antifungals not used often used but echinocandins will work because it has beta-glucans in cell wall
Pythium insidiosum is what
Eukaryotic saprophytic microbe that lives in water and moist soil and is similar to fungi but lacks chitin and ergosterol in cell wall. Grows as mold on agar but hyphae are produced in vivo
Pythium insidiosum is found where
in southeast US- tropical and subtropical climates
Pythium insidiosum transmission
direct contact or ingestion of motile spores in fresh water
Pythium insidiosum disease in what
Pythiosis aka Swamp Cancer- cutaneous or gastrointestinal disease in dogs and horses
Equine pythiosis presentation
cutaneous form most common with nodular regions and draining tracts and presence of kunkers (large yellow and gritty coral like bodies in lesions made of eosinophils and hyphae of pythium
Equine pythiosis treatment
agressive surgical resection
Canine pythiosis presentation
GI disease most common but if cutaneous disease will see non healing lesions with drainage and a history of swimming in swampy water
Canine pythiosis diagnosis
biopsy and staining
Canine pythiosis treatment
surgical resection of affected GI tract, most antifungals no effect
