Bacteria resistant to rifampin are isolated after incubating agar plates with rifampin incorporated into the media. The culture plated on the media was a pure culture and no rifampin resistant cells had previously been selected. Which of the following most accurately describes the rifampin resistant bacteria that were isolated?
A. Mutants with a target site alteration mutation
B. Mutants constitutively expressing an efflux pump
C. Plasmid recipients expressing rifampin inactivating enzymes
D. Plasmid recipients expressing a gene for a target site alteration
Answer:A
Bacteria resistant to rifampin are isolated after incubating agar plates with rifampin incorporated into the media. The culture plated on the media was a pure culture and no rifampin resistant cells had previously been selected. Which of the following most accurately describes the rifampin resistant bacteria that were isolated?
A. Mutants with a target site alteration mutation B. Mutants constitutively expressing an efflux pump C. Plasmid recipients expressing rifampin inactivating enzymes D. Plasmid recipients expressing a gene for a target site alteration