Tetracycline (redirected from Achromycin)

tetracycline (tĕ'trəsī`klēn), any of a group of antibiotics produced by bacteria of the genus Streptomyces. They are effective against a wide range of Gram positive and Gram negative bacteria, interfering with protein synthesis in these microorganisms (see Gram's stain). Tetracycline is used to treat rickettsial bacterial infections such as Rocky Mountain spotted fever, some eye, respiratory, intestinal, and urinary infections, some kinds of acne, and some diseases where the infecting microorganism is resistant to penicillin (see drug resistance). Tetracycline may cause permanent discoloration of developing teeth, and it is not given to pregnant and lactating women and growing children. Because of the development of strains of microorganisms resistant to the tetracyclines, these antibiotics have lost some of their usefulness. Aureomycin is a trade name for the derivative chlortetracycline, and Terramycin is a trade name for oxytetracycline.

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tetracycline

Any of a class of broad-spectrum antibiotics with a common basic structure, including doxycycline. They may be isolated directly from several species of actinomycetes of the genus Streptomyces or modified from the compounds isolated. They are the drugs of choice in the treatment of cholera, rickettsial infections (see rickettsia), psittacosis, brucellosis, and tularemia; tetracyclines are also used in the treatment of acne. Overuse of these and other antibiotics has led to drug resistance in microorganisms.

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tetracycline [‚te·trə′sī‚klēn]

(microbiology)

Any of a group of broad-spectrum antibiotics produced biosynthetically by fermentation with a strain ofStreptomyces aureofaciensand certain other species or chemically by hydrogenolysis of chlortetracycline.

C₂₂H₂₄O₈N₂A broad-spectrum antibiotic belonging to the tetracycline group of antibiotics; useful because of broad antimicrobial action, with low toxicity, in the therapy of infections caused by gram-positive and gram-negative bacteria as well as rickettsiae and large viruses such as psittacosis-lymphogranuloma viruses.

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Tetracycline 

any of a group of natural and semisynthetic antibiotics of similar chemical structure and biological action. In terms of chemical structure, tetracyclines are a tetracyclic condensed system with various substituents.

The natural tetracyclines—oxytetracycline (terramycin), chlortetracycline (aureomycin), and tetracycline—were discovered and isolated in the 1940’s and 1950’s from the metabolic products of such actinomycetes as Actinomyces rimosus and A. aureofaciens. (In the non-Soviet literature, the genus Actinomyces is called Streptomyces.)

Preparations obtained by the chemical modification of natural tetracyclines, as well as semisynthetic derivatives of tetracycline, are also used in medicine. Examples of the first group are Reve-rin, morphocycline, and glycocycline; among the members of the second are methacycline hydrochloride (Rondomycin), doxycycline (Vibramycin), and minocycline.

Tetracyclines are broad-spectrum antibiotics. They inhibit the growth of gram-positive and gram-negative bacteria, spirochetes, leptospires, rickettsiae, mycoplasmas, several protozoans (amoe-bas and trichomonads), and large viruses of the psittacosis-lym-phogranuloma and trachoma groups. They are inactive or only slightly active against Proteus, Pseudomonas aeruginosa, Mycobacterium tuberculosis, and most fungi and small viruses. The bacteriostatic action of tetracyclines results from the repression of protein biosynthesis in the bacterial cell.

The development of resistance to one of the tetracyclines is accompanied by resistance to all other tetracyclines except minocycline. Preparations combining tetracyclines with antibiotics having a different mechanism of antimicrobial action, such as oleandomycin, are used to prevent the propagation of strains resistant to tetracycline.

Tetracyclines are used for the treatment of diseases of the respiratory organs and the gastrointestinal, urinary, and biliary tracts, as well as infections of the soft tissues, epidemic typhus, and other diseases caused by microorganisms sensitive to these drugs. Tetracyclines are effective in infections caused by microorganisms that are resistant to other antibiotics.

REFERENCES

Chernukh, A. M., and G. Ia. Kivman. Antibiotiki gruppy tetratsiklinov. Moscow, 1962.
Barton, D. H. R. “Novye puti sinteza tetratsiklina.” Zhurnal Vses. khimicheskogo obshchestva im. D. I. Mendeleeva, 1971, vol. 16, no. 2.
Navashin, S. M., and I. P. Fomina. Spravochnik po antibiotikam, 3rd ed. Moscow, 1974.
Finland, M. “Twenty-fifth Anniversary of the Discovery of Aureomycin: The Place of the Tetracyclines in Antimicrobial Therapy.” Clinical Pharmacology and Therapeutics, 1974, vol. 15, no. 1.

L. E. GOL’DBERG