A patient with a history of neutropenia following chemotherapy develops a severe pneumonia.
Bronchoalveolar lavage fluid reveals the presence of hyaline, septate hyphae with frequent dichotomous branching at acute angles. Culture yields a filamentous fungus that produces conidiophores with a vesicle bearing phialides that release chains of conidia. The MOST likely genus is:

A clinical microbiology laboratory is performing Gram staining on a sputum sample. After adding the crystal violet stain, a delay in the washing step with decolorizer (alcohol-acetone) would MOST likely result in:

A patient presents with a chronic cough, weight loss, and night sweats. Chest X-ray shows cavitarylesions in the upper lobes. Sputum is acid-fast positive. Drug susceptibility testing reveals resistance to isoniazid but susceptibility to rifampin, ethambutol, and pyrazinamide. The MOST appropriate treatment regimen should include:

A patient with a history of recurrent fungal skin infections presents with a scaly, erythematous rash on their feet. Microscopic examination of skin scrapings treated with potassium hydroxide (KOH) reveals septate hyphae and arthroconidia. The MOST likely genus of the dermatophyte is:

A patient develops a severe diarrheal illness after returning from a backpacking trip where they drank untreated stream water. Stool examination reveals motile trophozoites with multiple flagella and a prominent ventral sucking disk. The MOST likely causative agent is: