tetracycline. In ribosomal protection, a resistance gene encodes a protein that can have several effects, depending on what gene is transferred. Twelve classes of ribosomal protection genes/proteins have been found. Possible mechanisms of action of these protective proteins include: blocking tetracyclines from binding to the ribosome binding to the ribosome and distorting the structure to still allow t-RNA binding while tetracycline is bound binding to the ribosome and dislodging tetracycline Administration When ingested, it is usually recommended that the more water-soluble, short-acting tetracyclines (plain tetracycline, chlortetracycline, oxytetracycline, demeclocycline and methacycline) be taken with a full glass of water, either two hours after eating or two hours before eating. This is partly because most tetracyclines bind with food and also easily with magnesium, aluminium, iron and calcium, which reduces their ability to be completely absorbed by the body. Dairy products, antacids and preparations containing iron should be avoided near the time of taking the drug. Partial exceptions to these rules occur for doxycycline and minocycline, which may be taken with food (though not iron, antacids, or calcium supplements). Minocycline can be taken with dairy products because it does not chelate calcium as readily, although dairy products do decrease absorption of minocycline slightly. History The history of the tetracyclines involves the collective contributions of thousands of dedicated researchers, scientists, clinicians, and business executives. Tetracyclines were discovered in the 1940s, first reported in scientific literature in 1948, and exhibited activity against a wide range of microorganisms. The first members of the tetracycline group to be described were chlortetracycline and oxytetracycline. Chlortetracycline (Aureomycin) was first discovered as an ordinary item in 1945 and initially endorsed in 1948 by Benjamin Minge Duggar, a 73-year-old emeritus professor of botany employed by American Cyanamid – Lederle Laboratories, under the leadership of Yellapragada Subbarow. Duggar derived the substance from a Missouri soil sample, golden-colored, fungus-like, soil-dwelling bacterium named Streptomyces aureofaciens. About the same time as Lederle discovered aureomycin, Pfizer was scouring the globe for new antibiotics. Soil samples were collected from jungles, deserts, mountaintops, and oceans. But ultimately Oxytetracycline (terramycin) was isolated in 1949 by Alexander Finlay from a soil sample collected on the grounds of a factory in Terre Haute, Indiana. It came from a similar soil bacterium named Streptomyces rimosus. From the beginning, terramycin was a molecule enveloped in controversy. It was the subject of the first mass-marketing campaign by a modern pharmaceutical company. Pfizer advertised