Lec 05.1 Microbiology of Fungi and Opportunistic Pathogens Flashcards
Why is there an increasing number of opportunistic mycoses?
- increasing clinical awareness by physicians
- improved diagnostic procedures
- better identification techniques
- increase in the number of immunocompromised patients
What are the predisposing factors for infection with opportunistic systemic mycoses?
malignancies, drug therapy, antibiotics, therapeutic procedures, other risk factors (trauma, DM)
What is the most commonly encountered opportunistic mycosis worldwide?
candidiasis (Candida spp. is part of the normal flora)
What is the main treatment for Candida infections apart from Candida albicans?
Amphotericin B
What surface molecule is present in Candida spp. that allows it to adhere to surfaces?
mannan
(T/F) blood culture is highly sensitive for disseminated candidiasis
F
How are skin and nail samples of Candida prepared for direct microscopy?
10% KOH and Parker ink or calcofluor white mounts
How are tissue samples of Candida prepared for direct microscopy?
stained using PAS digest, Grocott's methenamine silver (GMS) or Gram stain
How are colonies of Candida described when cultured?
white to cream colored with a smooth, glabrous to waxy surface
What are the 4 serotypes for Cryptococcusis?
A - neoformans (common)
D - neoformans (rare, linked w/ primary cutaneous)
B,C - gattii
Which variant of C. neoformans can be found in old pigeon droppings?
C. neoformans var neoformans
What is the most common clinical manifestation of Cryptococcusis?
meningitis
What specimens may be taken when checking for C. neoformans?
CSF, biopsy tissue, sputum, bronchial washings,
pus
What us the most common etiology for Aspergillosis?
Aspergillus fumigatus
What samples may be taken when considering Aspergillosis?
Sputum, Bronchial washings, Tracheal aspirates,
Tissue biopsies
