Mycology I Flashcards
The important structures of yeasts and molds
- Solitary –> germ tube –> Hyphae –> Mycelium
- Solitary –> Blastoconidia –> pseudohyphae
What are the important structures in Sporangiospores?
Rhizoids Sporangiophore Columella Sporangium Sporangiospore
What are the important structures in Conidia?
Septate Hyphae Conidiophore Vesicle Phialide Conidia
Risk factors for Fungi
- Person to Person
- Contact with environment
- Contact with animals
Clinical manifestations of Candida
- Mucocutaneous infection
- Vulvovaginal candidiasis
- Chronic mucocutaneous candidiasis
- Candida endopthalmitis
- Candida Esophagitis
Describe mucocutaneous infection by Candida
Thrush is a yeast infection that causes white patches in the mouth and on the tongue
How does someone get vulvocandidiasis?
-Candida overgrowth [due to certain medicines or uncontrolled diabetes]
What is chronic mucocutaneous candidiasis?
- Hereditary immunodeficiency disorder due to malfunction of T cells
- usually begin during infancy
How is candida endopthalmitis acquired?
- Exogenously or endogenously
- vitreous is infected and can lead to loss of sight
What are some other Candida infections?
- Fungemia
- Endocarditis
- Pulmonary Infection
- Urinary tract infection
- Meningitis
- Endophthalmitis
How do you test for Candida albicans?
Direct exam by Gram stain or calcofluor stain
What are the morphological features of Candida?
- Budding yeast in bodily fluids
- Pseudohyphae in tissue
- Germ tubes for hyphae upon inoculation
- Asexual spores [chlamydospores]
Morphology of Aspergillus
- Conidia
- dichotomous branching
- septate hyphae
Clinical manifestations of Aspergillus
- Allergic aspergillosis
- Fungus ball in pre-existing cavity
- Invasive aspergillosis
- Dissemination infection
What is the common aspergillus species?
Fumigatus
How do you identify aspergillus?
color and structures
Where do you find agents of mucormycosis?
common components of decaying organic debris commonly found on fruit, bread, and in soil
Clinical syndromes of mucormycosis
- Rhinocerebral mucormycosis
- Pulmonary involvement
- GI Tract involvement
- Cutaneous
- Disseminated disease
What is rhino cerebral mucormycosis?
- Most frequent presentation overall and classically affects diabetics with ketoacidosis
- Presents with facial and/or eye pain, proptosis and progressive signs of involvement of orbital structures (muscles, nerves, and vessels)
- usually results in death within a few days (mortality rate is approximately 85%)
What is pulmonary mucormycosis?
- occurs most frequently among neutropenic patients
- presents with nonspecific symptoms such as fever, cough, dyspnea; hemoptysis may occur with vascular invasion
What is GI murcomycosis?
- usually affects patients with severe malnutrition
- may involve stomach, ileum, and colon
- clinical picture mimics intra-abdominal abscess [diagnosis often made at autopsy]
What is cutaneous mucormycosis?
necrotic lesions progressively evolve from the epidermis into dermis and muscle
Morphology of mucormycosis
- broad, non septate hyphae
- growth is wooly white to grey
- sporangia
What is dermatophytosis?
Fungal infection of keratinized tissues (skin, hair, nails) caused by a group of specialized fungi
-invasion of subcutaneous or deep tissues is very rare
