Author: Anonymous

Why are pili an important virulence factor in the production of gonorrheal disease?

The most serious infections caused by Hemophilus influenzae have which capsular antigen serological type?

Case 1: The patient was a 3 1/2 week-old male who was born at term. He required intubation at that time and continued to require respiratory support. Over a 24-hour period, the infant developed bulging anterior fontanelles (the “soft spots” in the skull), increased respiratory and heart rates, wide fluctuations in blood pressure, difficulties maintaining adequate tissue oxygenation, and his peripheral white blood cell count increased from 6,300 to 13,700/ml (high abnormal). The child began to have focal seizures as well. A cerebrospinal fluid (CSF) examination showed 3,900 WBC/ml (increased) with 92% neutrophils, glucose 2 mg/dl (decreased), and protein of 350 mg/dl (increased). Gram staining of the child’s CSF showed many gram-positive cocci. Case Study 1 Question 3: On a sheep blood agar, the colonies showed hemolysis.  What causes hemolysis in this particular organism?

Match each organism to the most likely method of transmission:

Which of the following organisms is a definitive pathogen?

Case Study 1: This 19-year-old student was in his usual state of health until the evening prior to admission, when he went to bed with a headache. He told his mother that he felt feverish, and on the following morning his mother found him in bed, moaning and lethargic. He was brought to the emergency room, where he appeared toxic and drowsy, but oriented. His temperature was 40C, his heart rate was 126/min., and his blood pressure was 100/60 mm Hg. He had an impressive purpuric rash (bruise-like), not blanching, most prominent on his trunk, legs and wrists. A gram stain of the material taken from one of the patient’s skin lesions showed gram-negative diplococci. His white blood cell count was 26,000/ml (high) with 25% band forms (high). The platelet count was 80,000/ml (low). Blood cultures were obtained and the patient was begun on intravenous Ceftriaxone. Blood cultures subsequently grew the organism seen on the gram stains of the lesions. Case Study 1 Question 5:  What virulence factor of this organism is probably responsible for the purpuric rash?

A 4-year-old was bitten on her hand by her pet cat. Two days later, the bite area was swollen and had some drainage. A Gram’s stain of the pus revealed small gram-negative coccobacilli. The most likely identity of this organism is:

Assuming the teacher was unwilling to change the common pencil box practice, what is the most effective way to break the chain of infection caused by this classroom behavior?

Case Study 4:   An 8-year-old female was brought to the walk-in clinic by her mother. For the last three days she has been complaining that her ear has been bothering her and last night she developed a low fever.  Her vaccinations are all up to date, her medical history is unremarkable, and she has had no previous illness; she is a healthy girl. Her mother mentions that she is very active in sports, alternating between swimming and soccer competitions every weekend. The physician collected a culture and stat gram stain of the outer ear canal. The gram stain showed many white blood cells and gram-negative bacilli.  The physician then gave the girl antibiotic drops to use twice a day for seven days without waiting for the culture results. Case Study 4 Question 1:  What infection does the little girl have?

Within 5 hours of returning home from lunch at your favorite all-you-can-eat buffet restaurant you feel very sick and are vomiting. The most likely cause is: