Mycology Flashcards
Single celled forms generally reproduce by ___ while hyphae reproduce by ___
Budding, spores
Fungi grow especially well on ___ which is selective for fungi because of its ___. Further selectivity can be ensured by addition of ___.
Sabouraud’s medium, low pH, antibiotics
Examples of subcutaneous mycoses?
Trichophyton, Microsporum, Epidermophyton, Yeast (Malassezia furfur), Sporotrichosis
Examples of cutaneous mycoses?
Coccidioides, Histoplasma, Blastomyces, Paracoccidioidomycosis, Candida, Cryptococcus, Aspergillus, Penicillin marneffei, Pneumocystis
Dermatophytes cause infections of ___ due to their ability to obtain nutrients from ___. Usually restricted to ___ due to inability to penetrate the viable tissue in an immunocompetent host. Occasionally, invasion into subcutaneous tissues results in ___ development.
Skin, hair and nails
Keratinised material
Non-living cornified layer
Kerion
Trichophyton
T. mentagraphytes var granulare causes _____
T. mentagraphytes var interdigitale causes _____
T. rubrum causes _____
Skin and hair infections
Skin infections of groin and foot (Hong Kong foot) (Spreads via wet surfaces and direct contact)
Skin and nail infections
Most common fungal infection in SG?
Trichophyton rubrum
Microsporum canis causes ___. Acquired from ___.
Scalp and hair infection
Dogs and cats (Cats more common in SG)
Epidermophyton floccusum causes _____ and is spread by ___.
Groin and foot infections, human transmission
Malassezia furfur has a _____ appearance and requires ___ for growth.
Spaghetti and meatball appearance, oil
Clinical presentation of Malassezia furfur?
Tinea versicolor, folliculitis, dermatitis, peritonitis and septicaemia (in newborns), dandruff
Yeast identification: Candida albicans and Cryptococcus neoformans
Candida -> Germ tube positive
Cryptococcus neoformans -> Capsulated
Sporotrichosis is caused by ___ and is found in ___.
Sporothrix schenkii, soil and wood.
Clinical presentation of Sporotrichosis?
Causes local nodules/ulcers
Primary infection of the lungs which can disseminated to bones, joints and meninges
How is Candida distinguished under microscopy?
Pseudohyphae
When do Candida infections occur?
Immunocompromised individuals (eg. Broad spectrum antibiotics in use, catheter use, hyperalimentation, IV, immunosuppressed)
Clinical presentation of Candida albicans?
Oral candida with thrush
UTIs with a thrush with possible retrograde spread to kidney
Lung and GIT infections
Hematogenous or lymphatic spread
Cryptococcus neoformans is found in ___ individuals while Cryptococcus gattii is found in ___ individuals.
Immunocompromised, healthy
Clinical presentation of Cryptococcus?
CNS: Meningitis/ cryptococcoma
Lung: Pneumonia
Others: Sequestered in the prostate
Clinical presentations of Aspergillus?
Allergic bronchopulmonary aspergillosis: Hypersensitivity reaction leading to asthma like symptoms
Invasive aspergillosis: Begins in lung and systemic spreads to other parts of the body
Where is Aspergillus found and how is it spread?
Hay, grain, soil
Airbone spores
Predisposing conditions for Aspergillus?
Immunosuppression, construction activities, diseased lungs
Where is Penicillin marneffei found?
Bamboo rats
How does Penicillin marneffei look like on culture?
Safety pin shaped yeast giving a bright red colour
Clinical presentation of Penicillin marneffei?
Skin lesions especially on AIDS patients. Causes papules and abscesses in disseminated infection.
Clinical presentations of Pneumocystis?
Pneumocystic pneumonia especially in AIDS patients
What is the first complication of AIDS?
Pneumocystic pneumonia
Does Pneumocystis respond to anti-fungals?
No, treat with Cotrimoxazole
Species of Pneumocystis?
Pneumocystis carinii
Pneumocystis jirovecii
