Reference no: EM133313738

1. A 50-year-old woman returned yesterday from a vacation in Peru, where there is an epidemic of cholera. She went to the doctor because has multiple episodes of diarrhea. Which of the following is MOST compatible with cholera?

Watery diarrhea without blood (rice water) and no organisms in the blood culture.

Watery diarrhea without blood (rice-water), flecks of mucus in the stool, and growth of curved gramnegative rods in the blood culture.

Bloody diarrhea, mucus in the stool, and growth of gram-negative rods in the blood culture

Bloody diarrhea, flecks of mucus in the stool, and no organisms in the blood culture.

2. Patient X is a 22-year-old man with fever, fatigue, and a new diastolic murmur. You suspect endocarditis and do a blood culture. What grew in the BA was a gram-positive coccus arranged in clusters. When subcultured on blood agar, the colonies were surrounded by a zone of beta hemolysis, and a coagulase test was positive.

Which of the following statements is LEAST accurate for these results?

IF he had dental surgery recently, one of the most likely organisms to grow would be a Viridans group Streptococcus.

If he is an intravenous drug user, one of the most likely organisms to grow would be Candida albicans.

If he has a prosthetic aortic valve, one of the most likely organisms to grow would be Streptococcus agalactiae.

If he had colon surgery recently, one of the most likely organisms to grow would be Enterococcus faecalis.

3. Your patient is a 70-year-old woman who had a hysterectomy for carcinoma of the uterus 3 days ago. She has an indwelling urinary catheter in place and now has a fever of 39°C, and the urine in the collection bottle is cloudy. A Gram stain of the urine specimen shows many neutrophils and gram-positive cocci in chains. You also do a urine culture to streak Blood agar and Mannitol Salts agar plates, and a catalase test.

Which one of the following is the MOST likely set of findings on the urine culture?

Nonhemolytic colonies that grow only anaerobically.

B-Hemolytic colonies that do not grow on mannitol salts agar; catalase-negative results.

Gamma-Hemolytic colonies that are catalase-positive.

4. Your patient is a 10-year-old girl who has had pain in her left arm for the past 5 days. On physical examination, her temperature is 38°C, and there is tenderness of the humerus near her deltoid. On X-ray of the humerus, an area of raised periosteum and erosion of bone is seen. You do a blood culture.

Which one of the following is the MOST likely set of findings?

Gram-negative rods that grow on EMB agar, forming purple colonies and a green sheen.

Gram-positive cocci that grow on blood agar, causing a clear zone of hemolysis, salt-tolerant and coagulase-positive.

Gram-positive rods that grow only anaerobically and form a double zone of hemolysis on blood agar.

Gram-negative diplococci that grow on blood agar, present oxidase-positive results, and ferment maltose.

5. Your patient is a 30-year-old man who is HIV antibody positive and has a two-year history of Pneumocystis pneumonia. His job is to clean attics and garages. He now has an ulcerating lesion on the side of his tongue. A Giemsa stain of the biopsy specimen reveals budding yeasts within macrophages. A culture of the specimen grows an organism that is a budding yeast at 37°C but produces hyphae at 25°C Of the following, which one is the MOST likely organism to cause this infection?

Coccidioides immitis

Aspergillus fumigatus

Cryptococcus neoformans

Histoplasma capsulatum

6. Your patient is a 9-year-old boy who was sent home from school because his teacher thought he was acting strangely. This morning, he had a seizure and was rushed to the hospital. On physical examination, his temperature is 40°C and he has no nuchal rigidity. A computed tomography (CT) scan is normal. A lumbar puncture is done, and the spinal fluid protein and glucose are normal. A Gram stain of the spinal fluid reveals no organisms and no polys (aka segs, segmented neutrophils, neutrophils, granulocytes). He is treated with various antibiotics but becomes comatose and dies 2 days later. The blood culture and spinal fluid culture grow no bacteria or fungi. On autopsy of the brain, eosinophilic inclusion bodies are seen in the cytoplasm of neurons.

Of the following, which one is the MOST likely cause?

Prions

Rabies virus

Herpes simplex virus type 1

Neisseria meningitidis