Bacteriology — MCQs

A 53-year-old woman, three months after surgery and chemotherapy for breast cancer, developed a cough productive of purulent sputum four weeks ago. Two weeks ago, she noted progressive weakness of her left arm and leg. Chest examination revealed rales over the left upper back with deep breathing, and chest radiography showed a left upper lobe infiltrate. Neurologic examination confirmed left arm and leg weakness, and contrast-enhanced computed tomography revealed two lesions in the right hemisphere. Gram stain of a purulent sputum specimen showed branching Gram-positive rods that were partially acid-fast. Which of the following organisms is the cause of this patient's current illness?

A 4-year-old boy presents with a history of bloody diarrhea and is now hospitalized for oliguria and hypertension. With which organism is he most likely infected?

A patient complained to his dentist about a draining lesion in his mouth. A Gram's stain of the pus showed a few Gram-positive cocci, leukocytes, and many branched Gram-positive rods. What is the most likely causative organism?

Meningococci differ from gonococci in that they

A baker cut his finger while slicing a cake. After a week, the site of the injury is red and swollen, and begins draining pus. While preparing custard pies, he contaminates the dish with drainage from the lesion. The pies were eaten a day later by customers who developed vomiting with no fever within 4 hours. What is the most likely causative agent?

Which of the following is NOT true about Borrelia recurrentis?

What is responsible for Legionella pathogenicity?

Which of the following is NOT a superantigen?

Which of the following is true regarding cholera?

A previously healthy 18-month-old girl is brought to the office with 2 days of irritability, poor appetite, and pulling at her left ear. She has no known allergies, and her temperature is 102.8 F. She is easily consoled by the mother and moves her neck spontaneously without discomfort. There is a clear discharge from the nares. The left tympanic membrane is erythematous, dull, and bulging. Which of the following virulence factors is generally absent in the strains of the causative organism that produce otitis media, compared with those that produce epiglottitis or meningitis?