[Man's own antibiotics--an innate immune system]

In 1981, Steiner and co-workers of Stockholm described a newly discovered type of potent antibacterial peptides which lack cysteine, so called cecropins, which are spiral-formed molecules of 30-40 amino acids found to kill bacteria within a few minutes by disintegration of the bacterial cell wall, but to do no damage to the membrane of insect or mammalian cells. To date, descriptions have been published of about a hundred peptide antibiotics from various mammals (including man), birds, frogs, many types of insects. Peptide antibiotics exert a bacteriostatic effect on the normal flora of the skin and of the oral cavity and other orifices. It is also possible that peptide antibiotics protect us against many pathogenic organisms.