Reference no: EM132621550

Knowledge-Based Activity: Mechanism of Action for Antibiotic Resistance

That title sounds like something out of the Terminator movies! In actuality, it isn't that far off. Bacteria have the ability to adapt to their environment just like other living organisms. We come at them with antibiotics to kill them or slow their growth, and they in turn adapt ways to resist the drugs.

In this activity, you will learn firsthand how bacteria evolve mechanisms of resistance. Please read the description or conjugation and complete the questions below.

Bacteria can contain plasmids, extrachromosomal DNA, which can confer resistance to some types of antibiotics. This process is how bacteria can introduce a bit of genetic variance into their populations (because bacteria reproduce via asexual means). The process of conjugation is as follows:

1. A bacteria containing a plasmid (donor bacteria) constructs a pilus (a hollow tubular structure that can attach to a recipient bacteria).

2. The recipient bacteria is on the other end of the pilus.

3. The donor bacteria begins to replicate the plasmid. One strand of the DNA stays in the donor, one strand of the DNA enters the pilus and travels to the recipient bacteria.

4. Since DNA is a double helix, each bacteria, donor and recipient, make a complementary strand so the plasmid is a double helix. Now both bacteria have the plasmid and all of the genetic information it contains.