Tetracyclines are a class of antibiotics that may be used to treat infections caused by susceptible microorganisms such as gram positive and gram negative bacteria, chlamydiae, mycoplasmata, protozoans, or rickettsiae.
They were discovered in the 1940s and the first tetracyclines were obtained or derived from Streptomyces bacteria.
Tetracyclines inhibit protein synthesis in the microbial RNA (an important molecule that acts as a messenger for DNA). They are primarily bacteriostatic which means that they prevent bacteria from multiplying but don't necessarily kill them.
Although tetracyclines are still widely used in human and veterinary medicine, the emergence of bacterial resistance has limited their effectiveness and is of major concern.
