PLE Category: Microbiology

PLE-3675

A 34-year-old Mexican fruit picker presents to a free clinic with subcutaneous nodular lesions along the lymphatics from the initial site of trauma 3 weeks ago caused by a plum thorn puncture. What is the nature of the most likely causative agent?

PLE-3676

A 35-year-old female drug abuser has an abscess on her jaw where she lost a tooth from being struck in the face 2 weeks ago. She did not get medical help. You lance the lesion, express some lumpy material with difficulty, and send a swab of the organism to the lab for Gram stain, culture, and susceptibilities. The predominant organism in the Gram stain is a filamentous bacterium that is Gram positive, yet nothing grows in the lab. What is the most likely explanation for why it did not grow?

PLE-3677

A 35-year-old man presents at your office with complaints of breathing difficulty, headache, and joint and lower back pain. He is experiencing a fever of 101°F and a noticeable cough. During the history taking, it was discovered that he recently engaged in an unusual activity of thoroughly cleaning an old hunting shack. This cleaning process included removing old food containers, pots, and bedding, as well as dealing with rodent nests. Additionally, he set up new mouse traps. Based on this history, what is the most likely agent causing his symptoms?

PLE-3678

A 35-year-old man presents with focal central nervous system signs. Imaging shows a brain abscess. The dominant organism is an anaerobe normally found as part of the oral flora. Which of the following best fits that description?

PLE-3679

A 35-year-old man who immigrated to the United States 15 years ago and lived in a crowded resettlement camp before coming to the United States presents with a cough that has been bothering him for several weeks. He has also lost 10 pounds. A gamma interferon release blood test is positive. Which of the following factors is known to be most important in triggering the granulomatous reaction to wall off and contain the infection?

PLE-3671

A 28-year-old worker at a day care center has recently been feeling tired, has a slight fever, and has felt nauseated and vomited several times. Yesterday, she had abdominal pain and chills, and today she voided dark urine. Lab tests for serum enzymes indicated elevated AST and ALT. The genetic material of the virus most likely to cause her symptoms is

PLE-3672

A 29-year-old man compromised by chemotherapy now has a life-threatening meningitis caused by Histoplasma capsulatum. Which of the following antifungal drugs is fungicidal?

PLE-3673

A 29-year-old neutropenic woman with Pseudomonas aeruginosa septicemia develops shock. What triggers the shock?

PLE-3667

A 27-year-old woman presents with high fever, painful and frequent urination, and left flank pain. The isolate is a Gram-negative, rod-shaped, facultative anaerobe that is oxidase-negative and ferments both glucose and lactose. From these data, what genus is most likely?