Antibiotic resistance

Antibiotic resistance is the ability of a microorganism to counteract the effects of an antibiotic. Usually, a protein or an enzyme that is coded by a gene conveys the resistance mechanism. Resistance genes can be exchanged between bacteria of the same species via plasmids. If a bacterium carries several resistance genes, it is called multiresistant. Multiresistant bacteria are a danger, especially in hospitals, where multiresistances are favored by natural selection due to the excessive use of antibiotics.