Some Plasmids Can Replicate in Several Distinct Species of Bacteria

question 26

Multiple Choice

Some plasmids can replicate in several distinct species of bacteria.Frequently these plasmids have transposons carrying several different antibiotic resistance genes.In a hospital that has an outbreak of several species of bacteria each carrying resistance to three drugs (streptomycin, gentamicin, and penicillin) , what is the best way to determine whether or not this resistance is due to a single shared plasmid with all three resistance genes?

• A)Demonstrate that all the resistant bacteria have a plasmid.
• B)Isolate plasmids from all resistant bacterial species and demonstrate that drug-sensitive cells from these same species become resistant to all three drugs when this plasmid is transformed.Confirm that the same plasmids are present in all species by sequencing the plasmid DNA.
• C)Sequence the genomes of the resistant species and demonstrate mutations in the same homologous genes.
• D)Isolate plasmids from one resistant species and transform a drug-sensitive strain of the other bacterial species to see if resistance occurs in the transformants.

---

Definitions:

Gratuitous Promise

A promise made without expecting anything in return, which is generally not enforceable in contract law unless it is made in a deed.

Existing Duty

An obligation that is currently in effect under the law or within the terms of a contract.

Consideration

In contract law, something of value promised to another when making an agreement, which is required for the contract to be enforceable.

Racing Bike

A type of bicycle designed for competitive road cycling, characterized by its lightweight frame and components for speed.