MBIO 850
Case 1 (10 points)
Antibiotic-Resistant Salmonella
Chia Lee, Ph.D., Joe Lutkenhaus, Ph.D

1. What evidence suggests that antibiotic-resistant strains of salmonella evolve in livestock in the United States?

The evidence is this case is circumstantial and is as follows. The child had the same strain of Salmonella as one of the herds. An expanded spectrum cephalosporin is approved for use and is widely used in domestic animals including cattle.

2. List three bacteria other than Salmonella that can cause gastroenteritis.

  • E. coli
  • Campylobacter species
  • Yersinia species
  • Vibrio cholera or parahaemolyticus
  • Shigella species
  • Aeromonas species
  • Clostridium species or Bacillus cereus
3. If the child had been treated with another broad spectrum antibiotic for the sinus infection, is it possible that the child would have acquired salmonellosis? Explain briefly.

Yes, because the ability of the normal microbial flora of the patient's intestine to compete with the ingested Salmonella has been reduced.

4. What is a conjugation plasmid?

Plasmid contains the genes needed for transferring between bacteria by direct cell to cell contact.

Last modified: April 12, 2003