PLE Category: Microbiology

PLE-3570

A 42-year-old man comes to the emergency department because of a 2-week history of increasingly severe headaches and a 2-day history of nausea, vomiting, neck stiffness, and unsteadiness. He has type 2 diabetes mellitus treated with glyburide. His temperature is 38.1 C (100.5 F). Funduscopic examination shows bilateral papilledema. Neurologic examination shows mild meningismus and diffusely brisk deep tendon reflexes. He walks with a moderately broad-based gait. He is able to recall two out of three objects after 5 minutes and makes several errors on serial sevens. A CT scan of the head shows no abnormalities. Cerebrospinal fluid analysis shows a glucose level of 18 mg/dL, a protein level of 108 mg/dL, and a leukocyte count of 59/mm3 (1% segmented neutrophils and 99% lymphocytes); a cryptococcal antigen assay is positive. What is the most appropriate pharmacotherapy for this patient?

PLE-3568

A 37-year-old man comes to the physician because of a 3-day history of diarrhea. He has had six to eight watery stools daily that occasionally contain streaks of blood. His wife and children do not have similar symptoms. He has not recently traveled. Two weeks ago, he completed a course of oral ciprofloxacin for acute prostatitis. He currently takes no medications. Vital signs are within the normal range. Results of CBC and serum studies are within the reference range. The test for occult blood in the stool is positive. He was started on Metronidazole. What microorganism was the physician entertaining?

PLE-3564

What is the bacteria that causes a distinctive colon infection? It initially presents as 1-2 mm whitish-yellow plaques in the mucosa, which eventually merge to form larger plaques. These plaques can cover the entire colon wall and are primarily acquired due to the use of antimicrobials, leading to the disruption of normal colonic flora.

PLE-3565

What is the gram-negative rod that causes skin and bone infections associated with human bites and clenched fist injuries?

PLE-3566

What is the causative agent of progressive multifocal leukoencephalopathy?

PLE-3567

A 15-year-old girl is brought to the physician because of a 1-week history of vaginal discharge and a 2-day history of sore throat. She has had recurrent candidal infections of the skin and mucous membranes since childhood, along with a 2-year history of type 1 diabetes mellitus and thyroiditis. Physical examination shows oral and vaginal candidiasis. What is the most likely mechanism of her recurrent candidal infections?

PLE-3561

Which of the following is caused by the Coxsackie A virus?

PLE-3562

This is an aerobic, gram-positive, spore-forming rod, with the following virulence factors: a poly-D-glutamate capsule, edema and lethal factor and protective antigen.

PLE-3563

This is a gram positive lancet-shaped cocci in pairs, alpha hemolytic, catalase negative, bile and optochin sensitive, with polysaccharide capsule exhibiting positive quellung reaction:

PLE-3558

Which of the following manifestations is evident in secondary syphilis?