PLE Category: Microbiology

PLE-3669

A 28-year-old woman developed an erythema at the insertion site of her intravenous line. Culture of the catheter tip indicates that a biofilm is present on the catheter. What is the most likely causative agent?

PLE-3670

A 28-year-old woman with acquired immunodeficiency syndrome has severe, nonresolving watery diarrhea. It is not gray or greasy. Acid-fast oocysts are seen in the stools. What is the most likely causative agent?

PLE-3664

A 27-year-old man presents with cellulitis two days after he is bitten by his girlfriend’s cat. What is the most likely dominant organism involved in the infection?

PLE-3665

A 27-year-old man who is heterozygous for Rh factor marries an Rh- woman. What would genetic theory predict about their offspring?

PLE-3666

A 27-year-old woman presents with diarrhea containing both blood and pus. The lab cultures on a special medium incubated at 42°C under microaerophilic conditions grow a Gram-negative spiral-shaped organism that is isolated. What is the most likely genus?

PLE-3663

A 27-year-old man presents with an infected foot from stepping on a nail 2 days ago. The nail penetrated through the sole of his tennis shoe. He sprayed some antiseptic on it and did not seek medical help because he had his last tetanus booster about 1 year ago and he thought that would take care of the wound. The foot is quite inflamed around the wound with a little blue-green pus on the bandage. The organism isolated is a Gram-negative rod that is oxidase positive and does not ferment any carbohydrates. Which organism is most likely?

PLE-3660

A 25-year-old man hospitalized in a coma for 2 weeks now has developed erythema around his catheter. You order the catheter to be pulled, the tip cultured, and a new line to be started on the opposite side of the body. The report comes back that it is Staphylococcus epidermidis, which does not surprise you, as it is noted for the production of a loose network of polysaccharide sticking to catheters. What is this layer on the cell called?

PLE-3661

A 25-year-old Peace Corps worker is sent back to the United States from East Africa because he has had a very high fever. African sleeping sickness is diagnosed. How is it transmitted?

PLE-3662

A 26-year-old resident presents to the emergency department with severe eye pain. She has not been home for 2 days and has had the current pair of contacts continuously in her eyes for 6 weeks. What is the most likely causative agent of the resident’s eye infection?