Immune haemolymphs from the giant silkmoth, Hyalophora cecropia and, to a lesser extent, from the tsetse, Glossina morsitans morsitans possess antibacterial activities against several species of bacteria known to be pathogenic to man, animals and poultry, as demonstrated by in vitro bacterial growth inhibition assays. Cecropia immune haemolymph possesses a broader antibacterial spectrum and was found to be active against several Gram-positive and Gram-negative pathogenic bacteria. Mice injected with pre-determined lethal doses of Enterobacter cloacae, Klebsiella pneumoniae and Corynebacterium pseudotuberculosis and then treated with single intraperitoneal or subcutaneous injections of Cecropia immune haemolymph had much lower mortality than untreated controls. A possibility of developing a broad-spectrum antibiotic modelled on insect immune factors is discussed.
