Fungal Infections Flashcards
What are fungi?
How do they differ from bacteria?
How do they differ from mammals?
What are the differeny types of fungi?
Eukaryotic cells with cell walls containing chitin and glucans
Differ from bacteria due to:
- being able to reproduce sexual and asexual i.e. bacteria only asexual
- produce spores
Differ from mammals due to:
-membranes containing ergosterol
Unicellular= yeasts eg Candidiasis Multi-cellular= molds eg Aspergilles Dimorphic= mold in environment but yeast in body
What are examples of dermatophyte (tinea) infections?
How are they treated?
Athletes foot= tinea pedis
Ring worm= tinea corpis
Treatment:
-topical terbinafine, ketoconazole, clotrimazole
What are the 2 main classifications of candida infection?
What are 2 common sites for thrush infection?
C albicans = main type of infection clinically
Non-albicans
Oral/oesophageal
Vaginal
What are the risk factors for developing oral/oesophageal candidiasis?
How might someone present?
How is it treated?
Infants
Denture wearers i.e. candida colonises the dentures
Inhaled steroids i.e. COPD or asthma
Immunocompromised. I.e. AIDS-defining infection
Painful mouth
White plaques
Inflamed mucosa
Painful swallow (if oesophageal)
Topical nystatin mouth wash, clotrimazole, miconazole
Oral fluconazole
What are risk factors for developing vaginal thrush?
How might someone with vaginal thrush present?
How is vaginal trush treated?
Increased levels of oestrogen
Antibiotics
Steroids
DM
Vulval itch
Soreness
Dysuria
Discharge -> cottage cheese
Uncomplicated:
- clotrimazole cream or pessary
- single dose fluconazole
Complicated: (i.e. current and not cleared by normal methods)
-fluconazole every 3 days for 3 doses
What is invasive candidiasis? What are the risk factors for developing this infection? Where does this infection manifest? How is it diagnosed? How is it treated?
Opportunisitc nosocomial infection commonly associated with non-albicans
Mucosal break due to CVC, mucositis (associated with chemo) and bowel perf
Immunosuppressed state -> neutropenic or septic
Induces candidaemia (blood) and also visceral deposits in liver, spleen, heart, kidneys, brain, eyes, skin I.e. can be the cause of infective endocarditis in IVDU
Blood or tissue culture
Beta-D-glucans
PCR
Echinocandin = for non-albicans
Fluconazole
Amphotericin B
What is cryptococcosis yeast infection?
Who is at risk of these infections and why do they occur?
What clinical infections are assocaited with this yeast infection
Encapsulated yeast found in bird and trees which leads to opportunistic infections
People with impared immune systems
-pathogens normal phagocytosed in alveoli and removed but this doesn’t occur in immune compromised people
I.e. leads to dissemination of yeast into lungs and CNS
Meningitis
Atypical pneumonia
What is aspergillus?
What different disorders are associated with aspergillus?
It is a spore forming mould which is acquired through inhalation
Allergic bronchopulmonary aspergillosis (ABPA)
Chronic pulmonary aspergillosis
Invasive aspergillosis
What is allergic bronchopulmonary aspergillosis?
How might someone with ABPA present?
What should you test for if ABPA is suspected?
How is it treated?
Hypersensitivity airways reaction to fungi leading to mucoid impaction of bronchi which occurs in asthmatics and CF
(NOT infection of lung tissue)
Present as asthmatic who has frequent exacerbations, brown mucus plugs and haemoptysis
IgE-> total IgE will be raised due to it being an allergic reaction
Could also measure aspergillus IgE
Prednisolone -> decreases inflammation
Itraconazole -> antifungal
What is chronic pulmonary aspergillosis?
How is likely to get chronic pulmonary aspergillosis?
What might you see on imaging and why?
How might someone present?
What should be tested for in microbiology?
How is it treated?
Aspergillus infection of lung -> slow progressive nodule formation
People with chronic lung disease i.e. COPD or TB
Consodilation
Cavitation-> due to aspergilloma (ball of fungus)
Fibrosis
Weight loss
Cough
SOB
Haemoptysis
Aspergillus IgG
Itraconazole
Surgery for large aspergilloma
What is invasive aspergillosis? Who does this usually affect? How might someone present? How is it diagnosed? How is it treated?
Rapidly progressive disease where aspergillos invades lung tissue and can spread to multiple regions
Severely immunocompromised people
- prolonged neutropenia
- SCT for haematological condition
- GvHD
Fever w/ localised resp symptoms (tends to be haematological patients)
Histopathology + culture
Galactomannan-> found in aspergillos
Beta-D-glucan
PCR
Voriconazole
Amphotericin B
What is mucormycosis?
How does it affect?
How do people typically present?
What is the treatment and why is it aiming to stop?
Aggressive rhino-orbital cerebral infections causes by variety of moulds
Haematological patients
People on high dose steroids
DKA-> high glucose
Febrile
Face pain
Swollen red eye
Radical surgery and antifungal therapy (amphotericin B)
-aims to prevent the infection tracking back into brain
What is characteristic about histoplasma fungus?
It is DIMORPHIC
-mold in environment and yeast in body
What are the 2 main drug targets for anti-fungal drugs?
What are the 4 main types of anti-fungals?
Ergosterol
Cell walls
Amphotericin B
Azoles
Echinocandins
Flucytosine
For more info see antimicrobials mindmap
