Exam 11: Travelers Diarrhea: Identifying the Causative Agent

In the lab, a dense mixture of the above patient's isolate with plasma on a slide shows clumping. This test correlates with which early process in the pathogenesis of acute endocarditis in a healthy heart?

2,5A synthetase is induced by

In March, a nursery school reports an outbreak among the children of a disease characterized by a high-grade (38.8°C to 40°C) fever that starts suddenly and rapidly falls. The children develop a short-lived (1 to 2 days) maculopapular rash that begins on the trunk and spreads to the extremities; the face is spared. The children have mild malaise, but otherwise do not appear ill. The most likely causative agent is

What is the most likely causative agent of the resident's eye infection in question 31?

Which of the following statements characterize $\gamma2?2$ antibody?

A Brazilian who left poverty and moved to Los Angeles 10 years ago has died suddenly of heart failure. Autopsy showed cardiomyopathy due to Chagas' disease. Which vector transferred the trypanosomes?

A 15-month-old child living in a religious community that does not vaccinate their children develops meningitis. A Gram-negative rod is seen in the cerebrospinal fluid. What is the most likely causative agent?

An autoimmune disease characterized by absence of T cells, hypocalcemia, and tetany with lowered cell-mediated immunity is

Which of the following genetic mechanisms is responsible for the conversion of nontoxigenic strains of Corynebacterium diphtheriae to toxigenic strains?

Which of the following complement components attaches to the crystallizable fragment of immunoglobulin M?

A non-vaccinated 5-year-old British child just returning from Africa presents with a severe sore throat but little fever. The throat has a grayish exudate on the sides of the pharynx and the child has a swollen neck. Clinical suspicion is of a disease with a circulating toxin inhibiting protein synthesis. What additional tissues are frequently involved?

What bacteria can use fermentation pathways but also contain superoxide dismutase?

Both division and differentiation of B cells leading to production of plasma cells require

An 18-year-old college freshman living in a university residence hall develops severe headache, neck stiffness, and fever. When he cannot be aroused, he is transported to the hospital where a Gram stain of a centrifuged cerebral spinal fluid shows Gram-negative diplococci. A latex particle agglutination test confirms the etiological cause of the bacterial meningitis. Which causative agent is most likely?

When complement is fixed by antigen-antibody complexes, what chemotactic factor for neutrophils is released?

A 33-year-old Mexican fruit picker presents to a free clinic with subcutaneous nodular lesions along the lymphatics from the initial site of trauma 3 weeks ago caused by a plum thorn puncture. What is the nature of the most likely causative agent?

An arthropod vector is involved in infection by

A 29-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?

A neonate with very low Apgar scores dies 2 hours after birth. Autopsy reveals disseminated granulomatous lesions throughout; some are caseating, but they are not calcified. During her pregnancy, the mother most likely had a septicemia caused by

The individual most likely to progress to chronic liver disease following an acute infection is