Quizziz 1: Introduction to mycology

Case 1 A 28 years old male backpacker is referred to ID clinic for prolonged fever , with non-productive cough He went to Canada last month and has spent some times in Ontario, including camping at riverside . Physician examination shows crepitation at mid zone of his right lung The are papulo-noducular lesions on his nose and left forearm CXR show haziness at right mid and lower zones BAL was performed A punch biopsy of skin lesion of his arm was taken Direct examination of the BAL fluid ( KOH) reveals moderate size yeast with broad-based buds. HPE of the punch biopsy shows a mixture of inflammatory reaction with large numbers of neutrophils mixed with multinucleated and epithelioid histiocytes. A periodic acid-Schiff stain confirmed the presence of large fungal spores with broad-based budding What is the diagnosis?

• Paracoccidioidomycosis

• Coccidioidomycosis

• Blastomycosis

• Histoplasmosis

Case 1 How could he has possibly acquired the infection ?

• Inhalation of the conidia during his camping trip
• Acquired it while in Malaysia
• Acquired the fungal infection from his cat
• All the above

Case 2 •40 years old lady, she came to clinic complaining of nodular lesions on her right arm, from dorsum of hand to below elbow. The nodules varies from 1 -2 cm, tender, firm , no discharge, lesions were along the lymphatic pathway. There were axillary lymphadenopathy. •She denies history of recent travelling. She has no pets but she feeds the stray animals in her neighbourhood. Quite often, the cats scratched her hands as she was feeding them. •Biopsy of the skin nodules were performed •HPE : There are multiple inflammatory infiltrates with giant cells and histiocytes. PAS stained was positive for yeast cells with narrow based buddings . Asteroid bodies seen occasionally ( star-like eosinophilic material surrounding the yeasts) Tissue fungal culture confirmed the diagnosis What is the likely etiology of the fungal infection ?

• Histoplasma capsulatum
• Blastomyces dermatitidis
• Sporothrix schenckii complex
• Coccidioides immitis

Case 2 What is the diagnosis?

• Fixed cutaneous spororichosis

• Lymphocutaneous sporotrichosis

• Disseminated sporotrichosis

• Systemic sporotrichosis

Case 3 34 years old MSM presented with fever , loss of weight and pancytopenia HIV combo ELISA was positive , CD4 was 75 cells/uL Blood fungal culture was taken. At day four of incubation , fungal culture flagged positive, and fungal hyphae was found in blood smear. The specimen was then transferred to Sabouraud dextrose agar White colonies were visible after two days of incubation . The colonies grew as a mould at 25°C and as yeast at 37°C. The next day, the mould colony became grayish white and there was presence of a soluble red pigment that diffuses into the agar making the reverse side appears either pink . What is the likely etiology of the fungus infection ?

• Histoplasma capsulatum
• Talaromyces marneffei
• Aspergillus flavus
• Mucor spp

Case 3 The disease is caused by a dimorphic fungus commonly seen in Southeast Asia, southern China, or eastern India, but uncommon in western countries .

• Yes

• No

Case 4 25 year old Australian traveller arrived Kuala Lumpur a week ago. He presented to emergency department with headache and fever. COVID-19 test was negative. He had no medical illness and no high risk behaviour. Lumbar puncture was done. The CSF findings as below: Opening pressure 30cm H2O WBC raised, predominantly lymphocytes, low glucose and high protein. What is the likely aetiology?

• Cryptococcus neoformans
• Cryptococcus Gatti
• Toxoplasmosis
• Neisseria meningitidis

Last question Fungi that are a yeast at 37 °C and a mold at 30 °C are described as:

• Saprophytic
• Imperfect
• Dimorphic
• Perfect