A 56-year-old female postal worker sought medical care for fever, diarrhea, and vomiting. She was offered symptomatic treatment and discharged from the community hospital emergency department. Five...

A 56-year-old female postal worker sought medical care for fever, diarrhea, and vomiting. She was offered symptomatic treatment and discharged from the community hospital emergency department. Five days later, she returned to the hospital with complaints of chills, dry cough, and pleuritic chest pain. A chest radiograph showed a small right infiltrate and bilateral effusions but no evidence of a widened mediastinum. She was admitted to the hospital, and the next day her respiratory status and pleural effusions worsened. A computed tomography scan of her chest revealed enlarged mediastinal and cervical lymph nodes. Pleural fluid and blood were collected for culture, and these cultures were positive within 10 hours for gram-positive rods in long chains.

1. The clinical impression is that this woman has inhalation anthrax. What tests should be performed to confirm identification of the isolate?

2. What are the three primary virulence factors found in B. anthracis?

3. Describe the mechanisms of action of the toxins produced by B. anthracis.

4. Describe the two forms of B. cereus food poisoning. What toxin is responsible for each form? Why is the clinical presentation of these two diseases different?

5. B. cereus can cause eye infections. What are two risk factors for this disease?