Cross-Sensitivity to Various "Mycins"

Reports about cross-sensitivity among the various "Mycins" are contradictory. Sidi, Hincky, and Longueville1,2were the first to report cross-sensitivity between neomycin and streptomycin, and vice versa. Calnan and Sarkany3were not able to confirm this fully, although 2 of their neomycin-sensitive patients also reacted to streptomycin. Pirilä and Wallenius4and Pirilä and Rouhunkoski5,6as well as Hjorth7reported that a great number of their neomycin-sensitive patients were also sensitive to bacitracin. This, however, is not the experience of others. To clarify these matters we investigated experimentally in guinea pigs sensitization to, and cross-sensitivity between, neomycin, kanamycin, streptomycin, and bacitracin. Materials and Methods We set out to sensitize albino guinea pigs, weighing between 400 and 500 gm., in groups of 10, to neomycin, kanamycin, streptomycin, dihydrostreptomycin, and bacitracin. The animals received 4 weekly injections of 5 mg. of the antibiotic mixed with Freund's adjuvant. This technique