Fungal Respiratory Diseases Flashcards
What are the two main forms fungi can take ?
unicellular (yeast)
- narrow based budding
- broad based budding
- dimorphic or pseudohyphae
(sometimes capsulated)
branching hyphae (moulds)
- septate
- non-septate
Fungus diagnosis
cytology
histology and fungus appearance
culture (may be hazardous!!)
also PCR, NAAT, ELISA, LatFlow
Aspergillus main species
A. fumigatus
Aspergillus structure
hyphate fungi
Mycotic rhinitis / Sinonasal Aspergilosis CS and diagnosis
variable CS (sneezing, stertor, discharge, haemorrhage)
can distort nasal bones and extend into adjacent tissues if there for long enough (exophthalmos and neruo signs)
diagnosed by biopsying plaques and observing
- focal yellow/green/black plaque like mats or masses
- hyperaemia oedematous mucosa
Define guttural pouch mycosis
Aspergillus spp. may be found sitting along the carotid artery in horses
may cause haemorrhage and epistaxis
may be fatal
Cryptococcosis structure and main features
yeast
most common systemic mycosis of cats
causes sporadic, non-contagious disease (often chronic nasal)
may also cause ulcerative skin lesions, ocular disease, pneumonia, brain lesions, ascending mastitis, gelatinous masses and facial swelling (common in the nares)
yeast produced melanin to scavenge ROS
infection does not always mean disease
Cytology of cryptotoccosis
non-staining capsule
narrow-based budding
filamentous form in environment
Pneumocystis CS and key features
chronic cough and weight loss, commonly seen in CKCS
histology see foamy material in alveoli, made up of clear fungal bodies with basophilic centres
Histoplasma capsulatum key features
asymptomatic
may see granulomatous lesions in the lung
acute cases fatal
dogs have ulcerative intestinal lesions
Blastomyces dermatitidis key features
infectious, noncontagious disease of dogs and humans
dimorphic fungus
not contagious in yeast form
multifocal 0.3-3cm firm grey-white nodules in lung (granulomatous inflammation). can become caseous or liquefy.
