Talaromyces (Penicillium) marneffei — MCQs

An investigator is studying growth patterns of various fungal pathogens. Incubation of an isolated fungus at 25°C shows branching hyphae with rosettes of conidia under light microscopy. After incubation at 37°C, microscopic examination of the same organism instead shows smooth, white colonies with rounded, elongated cells. Infection with the investigated pathogen is most likely to cause which of the following conditions?

A 67-year-old male presents to his primary care physician for evaluation of fever and an unintended weight loss of 25 pounds over the last 4 months. He also has decreased appetite and complains of abdominal pain located in the right upper quadrant. The patient has not noticed any changes in stool or urine. He emigrated from Malaysia to the United States one year prior. Social history reveals that he smokes half a pack per day and has 5-7 drinks of alcohol per day. The patient is up to date on all of his vaccinations. Physical exam findings include mild jaundice as well as an enlarged liver edge that is tender to palpation. Based on clinical suspicion, biomarker labs are sent and show polycythemia and an elevated alpha fetoprotein level but a normal CA 19-9 level. Surface antigen for hepatitis B is negative. Ultrasound reveals a normal sized gallbladder. Given this presentation, which of the following organisms was most likely associated with the development of disease in this patient?

A 27-year-old woman presents to the clinic with severe pain in her left knee of 1-day duration. Physical examination reveals a red, swollen, warm, and tender left knee with a decreased range of motion. The patient affirms that she has been sexually active with several partners over the last year and that 1 of her partners has complained of dysuria and yellow urethral discharge. An arthrocentesis was performed and showed a WBC count of 60,000/µL, with 90% polymorphonuclear leukocytes. Visualization of the patient's synovial fluid is provided in the image. Which of the following is a characteristic feature of the organism causing this condition?

A 44-year-old man comes to the physician because of a 3-week history of productive cough, fever, and lethargy. He also has several skin lesions over his body. His symptoms began 3 weeks after he returned from a camping trip in Kentucky. Three years ago, he underwent kidney transplantation for polycystic kidney disease. Current medications include sirolimus and prednisone. His temperature is 38°C (100.4°F). Diffuse crackles are heard over the lung fields. There are 4 white, verrucous skin patches over his chest and upper limbs. A photomicrograph of a skin biopsy specimen from one of the lesions is shown. Which of the following is the most likely diagnosis?

A 48-year-old man with HIV comes to the physician because of skin lesions over his face and neck for 2 weeks. They are not itchy or painful. He does not have fever or a sore throat. He was treated for candidal esophagitis 3 months ago. He is sexually active with his wife, who knows of his condition, and uses condoms consistently. He is currently receiving triple antiretroviral therapy with lamivudine, abacavir, and efavirenz. He is 175 cm (5 ft 9 in) tall and weighs 58 kg (128 lb); BMI is 18.8 kg/m2. Examination shows multiple skin colored papules over his face and neck with a dimpled center. Cervical lymphadenopathy is present. The remainder of the examination is unremarkable. His hemoglobin concentration is 12.1 g/dL, leukocyte count is 4,900/mm3, and platelet count is 143,000/mm3; serum studies and urinalysis show no abnormalities. CD4+ T-lymphocyte count is 312/mm3 (normal ≥ 500). Which of the following is the most likely cause of this patient's findings?

A study is designed to assess the functions of immune components. The investigator obtains a lymph node biopsy from a healthy subject and observes it under a microscope. A photomicrograph of the cross-section of this lymph node is shown. Which of the following immunologic processes most likely occurs in the region labeled with an arrow?

A 3-month-old girl is brought to the emergency department because of a 2-day history of progressive difficulty breathing and a dry cough. Five weeks ago, she was diagnosed with diffuse hemangiomas involving the intrathoracic cavity and started treatment with prednisolone. She appears uncomfortable and in moderate respiratory distress. Her temperature is 38°C (100.4°F), pulse is 150/min, respirations are 50/min, and blood pressure is 88/50 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 87%. Oral examination shows a white plaque covering the tongue that bleeds when scraped. Chest examination shows subcostal and intercostal retractions. Scattered fine crackles and rhonchi are heard throughout both lung fields. Laboratory studies show a leukocyte count of 21,000/mm3 and an increased serum beta-D-glucan concentration. An x-ray of the chest shows symmetrical, diffuse interstitial infiltrates. Which of the following is most likely to confirm the diagnosis?

A 35-year-old man from Thailand presents with low-grade fever, chronic cough, and night sweats for 3 months. He describes the cough as productive and producing white sputum that is sometimes streaked with blood. He also says he has lost 10 lb in the last 3 months. Past medical history is unremarkable. The patient denies any smoking history, alcohol, or recreational drug use. The vital signs include blood pressure 115/75 mm Hg, heart rate 120/min, respiratory rate 20/min, and temperature 36.6℃ (97.8℉). On physical examination, the patient is ill-looking and thin with no pallor or jaundice. Cardiopulmonary auscultation reveals some fine crackles in the right upper lobe. A chest radiograph reveals a right upper lobe homogeneous density. Which of the following tests would be most helpful in making a definitive diagnosis of active infection in this patient?

A 45-year-old HIV-positive patient (CD4 count 180 cells/µL) from San Joaquin Valley presents with erythema nodosum, arthralgias, and bilateral hilar adenopathy. Coccidioides serology shows IgM positive, IgG negative. He is asymptomatic except for joint pain and skin lesions. He is on antiretroviral therapy with undetectable viral load. Evaluate the clinical presentation and synthesize the appropriate management decision considering immune status and disease manifestations.

A 58-year-old man with acute myeloid leukemia presents with breakthrough fungal infection while on fluconazole prophylaxis. Blood cultures grow yeast that forms germ tubes. Chest CT shows new pulmonary nodules. He has neutropenia (ANC 200/µL) and is 2 weeks post-chemotherapy. His serum creatinine is 2.8 mg/dL. Evaluate and synthesize the optimal therapeutic strategy considering drug resistance, organ dysfunction, and underlying malignancy.