Exam 11: Travelers Diarrhea: Identifying the Causative Agent

A strain of Influenza A virus is resistant to treatment with oseltamivir. The most likely mechanism for this resistance is

A cofactor in Burkitt's lymphoma is

In the following pairs of organisms, which two are easiest to distinguish from each other by Gram stain?

A 19-year-old college freshman has a sore throat, sore and enlarging cervical lymph nodes, and a fever. The student is also greatly fatigued. A diagnosis of infectious mononucleosis is made. Which of the following factors is present?

Following neonatal thymectomy, you would expect

A 6-month-old infant has had watery diarrhea for 6 days; he vomited a couple of times. The stools have no blood and no pus. He is dehydrated. He has not been outside of Cincinnati. Two other toddlers who visited for a day also are sick. What is most likely causing this?

A 70-year-old woman presents with complaints of fatigue, nausea, fever, anorexia, and abdominal pains. Her travel history shows that she is recently back from a trip to western and central rural Mexico where she ate what everyone else was eating, including raw oysters from the coast. Physical examination shows a yellow tinge to her eyes, and her urine is dark. Lab studies show elevated liver enzymes. Blood cultures are negative for Vibrio vulnificus. Hepatitis serologies are: Antibody to hepatitis A virus: positive IgM antibody to hepatitis B core antigen: negative IgG antibody to hepatitis B core antigen: positive IgM antibody to hepatitis B surface antigen: negative IgG antibody to hepatitis B surface antigen: positive HBsAg: negative What is most likely causing her current problems?

A hospitalized burn patient develops toxic shock syndrome. An enterotoxin secreting Staphylococcus is isolated from the burn lesion. This superantigen acts by

A 7-year-old boy develops vesicular skin lesions on his trunk, which quickly spread to his extremities and appear on the scalp. Scrapings from the vesicles show multinucleated cells and Cowdry type A inclusion bodies. This disease could have been prevented with a vaccine composed of

The hospital blood bank desires to isolate stem cells from a patient with multiple myeloma for transplantation following his radiation treatment. The cell marker important for isolating and identifying human stem cells is

An 18-year-old male college student came to the Student Health Services complaining of a sore throat, fatigue, and difficulty in swallowing. A physical examination showed an enlarged spleen; a palpable, tender liver; and swollen cervical lymph nodes. His blood is positive for heterophile antibody. What would you expect to see in a blood smear?

A new reverse transcriptase has been discovered. In addition to its effect on HIV disease, it should be checked for its potential in treating

A 9-year-old girl presents with bloody diarrhea following a neighborhood barbeque. Her mother said the hamburgers were undercooked. Ultimately, a diagnosis of O157 strain of E. coli is made. Where are the O antigens found? In

A typical IgG antibody molecule has all of the following characteristics except

HLA II molecules play an important role in the immune response. One of their functions is

An antibiotic that has a $\beta$ -lactam ring in its structure is

Pepsin digestion of the IgG antibody against tetanus toxoid will

Which of the following interleukins is an endogenous pyrogen?

A patient with a cough of several weeks' duration but no fever has radiological signs of a coin lesion. The needle biopsy shows large, broad-based budding yeasts with a very thick cell wall. Most of the yeasts are extracellular. What is the most likely diagnosis?

Joe has been HIV positive for the past 6 years. His disease has been slowly progressing. Mike, his only partner for the past 3 years, is free of the disease. A plausible explanation for Mike's lack of infection would be