Antibiotics - a substance that selectively oppress microorganisms. Under the selective action of antibiotics understand the activity only in respect of microorganisms, while maintaining the viability of host cells and the action is not at all, but in certain genera and species of microorganisms. All antibiotics have a unique characteristics. First, the uniqueness of antibiotics is that, unlike most other drugs, their target receptor is not in human tissues and in microbial cells. Secondly, the activity of antibiotics is not constant, but decreases with time, due to the formation of drug resistance (resistance). Antibiotic resistance is an inevitable biological phenomenon and to prevent it is practically impossible. Third, antibiotic-resistant bacteria pose a danger not only for the patient from whom they were allocated, but also for many other people, even separated by time and space. Therefore, combating antibiotic resistance has now taken on global proportions.