Читать книгу Cases in Medical Microbiology and Infectious Diseases - Melissa B. Miller - Страница 40

The patient was a 15-year-old male who was brought to the emergency room by his sister. He gave a 24-hour history of dysuria and noted some “pus-like” drainage in his underwear and on the tip of his penis. Urine appeared clear, and urine culture was negative although urinalysis was positive for leukocyte esterase and multiple white cells were seen on microscopic examination of urine. He gave a history of being sexually active with five or six partners in the past 6 months. He claimed that he and his partners had not had any sexually transmitted infections. His physical exam was significant for a yellow urethral discharge and tenderness at the tip of the penis. (A Gram stain done in the emergency room is shown in Fig. 2.1.) He was given antimicrobial agents and scheduled for a follow-up visit 1 week later. He did not return.

1 1. Based on the Gram stain results, with what organism is this patient infected? What is the reliability of the Gram stain for establishing the diagnosis in this patient? How reliable is the Gram stain for detection of this organism in vaginal specimens from infected women? What other direct detection technique is available for laboratory diagnosis of the organism causing this patient’s infection?

2 2. Are his urinalysis and urine culture findings consistent with his illness? Explain.

3 3. Why did his partners have a negative history for sexually transmitted infections? For what complications are his sexual partners (whom he may have infected and/or who infected him) at increased risk?

4 4. What virulence factor(s) made by this organism is responsible for his symptoms?

5 5. Given his history, for what organisms is he at increased risk? Why do you think this patient was asked to return for a follow-up visit?

6 6. What antimicrobial agent(s) was he given in the emergency room? How has antimicrobial therapy for this infection evolved over the past 25 years and why was that evolution necessary?

7 7. Why is there no reliable vaccine against the organism causing this individual’s infection?

Figure 2.1