Microbiology 9th Edition by Laura Black, Jacquelyn Black

Exercise 17

Imagine that you are a scientist working for the local health de partment. Your microbiology laboratory has recently received several cultures of different Gram-negative enteric bacteria, Salmonella typhimurium, Salmonella enteriditis, Escherichia coli, and Shigella species that are all resistant to the same four different antibiotics. What could explain how all these different bacteria acquired resistance to the same four antibiotics? What would you look for to confirm your hypothesis?