- antibiotic resistance
Bacterial defense mechanism against antibiotics. Resistance may consist of an antibiotic being inactivated with the help of enzymes or of an antibiotic being extruded from the cell using different transport mechanisms before it can unfold its pharmacologic potential. Genes that bestow resistance are often found on a plasmid-a circular piece of bacterial DNA that is separate from the bacterial chromosome. Since bacteria are capable of exchanging plasmids with each other, antibiotic resistance genes can quickly be passed on. This way, antibiotics are gradually rendered ineffective.