Antibiotic Resistance

Resistance to antibiotics is brought about either by enzymatic inactivation of the antibiotic, or modification of the target, or active efflux of the substance or sequestration by binding to special proteins. Today, antibiotic resistance in the major infectious agents may be up to 98%, depending on the agent and the antibiotic used. Genes in bacterial plasmids and transposons generally determine it. The antibiotic producing organisms have some special means (proteins) to protect themselves against their products. The mechanisms of resistance vary: penicillins and cephalosporins (β-lactamase hydrolysis); chloramphenicol (detoxification by chloramphenicol transacetylase that acetylates the hydroxyl groups or interferes with uptake); tetracyclines (interference with uptake or maintenance of the molecules); aminoglycosides (streptomycin, kanamycin, etc. enzymatic modification of the drug [phosphorylation] interferes with uptake or action); erythromycin, lincomycin (methylation