Penicillin

Penicillin, any one of a group of antibiotics derived from the fungus Penicillium or created by using partially artificial processes. The action of natural penicillin was first observed in 1928 by British bacteriologist Sir Alexander Fleming, but another ten years passed before penicillin was concentrated and studied by German-British biochemist Ernst Chain, Australian pathologist Sir Howard Florey, and other scientists.

Penicillin acts both by killing bacteria and by inhibiting their growth. It does not kill organisms in the resting stage but only those growing and reproducing. Penicillin is effective against a wide range of disease-bearing microorganisms, including pneumococci, streptococci, gonococci, meningococci, the clostridium that cause tetanus, and the syphilis spirochete. The drug has been successfully used to treat such deadly diseases as endocarditis, septicemia, gas gangrene, gonorrhea, and scarlet fever.

Toxic symptoms produced by penicillin are limited largely to allergic reactions that can be anticipated by the use of scratch tests before administration of the drug. In 1980 a group of physicians announced that they had successfully desensitized several penicillin-allergic patients with a procedure that took only three hours; tests of the method on a wider scale were instituted.

Syphilis is detected by symptoms and verified by one of several tests performed on the blood or spinal fluid, the most common of which is the VDRL (venereal disease research laboratory) test. The preferred drug for treatment is benzathine penicillin, which is given in two injections one week apart for all stages but neurosyphilis. For this advanced stage, the antibiotic is given three times at weekly intervals.

Syphilis control includes tracking down all sexual contacts of infected persons and treating those who had contact during the infectious period. Use of condoms offers some protection against contracting syphilis.