An Evaluation of Oleandomycin as a Control of American Foulbrood Disease of Honey Bees

Abstract

Oleandomycin is a relatively new antibiotic produced by Sterptomyces antibioticus, a fungus belonging to the Actinomycetes. These fungi are widely found in soils and composts, in air and on dust particles and in close association with plants. Oleandomycin was first described in 1954 under the designation P.A. 105. Chemically it is a basic compound composed of the sugars L-oleandrose and desosamine, glycosidically attached to a complex lactone nucleus, termed oleandolide. The approximate empirical formula is C37H31NO12. This chemical is used medicinally in the treatment of a number of bacterial infections of man. It has also been shown to be effective against viruses, rickettsia and certain protozoa. Combinations of oleandomycin with other antibiotics, primarily with terramycin, are popular, and there are indications that certain combinations achieve both synergistic action and a suppression of the development of resistant bacteria (Colville et al. 1959). The colonies of bees used in this experiment were obtained by the local bee inspector from several beekeepers. They were in both 8 and 10 frame hives with one to three honey supers. All were infected with American foulbrood. Four levels of oleandomycin were tested. They were 0.125, 0.25, 0.5 and 1 gram of oleandomycin per treatment. Each treatment was replicated three or more times. The oleandomycin used was a 25 per cent concentrate obtained from Chas. Pfizer & Company. Each test level of oleandomycin was thoroughly mixed in one-fourth cup of powdered sugar by sifting 4 times through a kitchen flour sifter. A simple method of application of the antibiotic was used (Fig. 1). The hives were opened, exposing the brood nest, and the mixture of oleandomycin and powdered sugar was dusted with a flour sifter evenly over the top bars of the brood frames. Applications were repeated in this manner at one to two week intervals until the disease disappeared. No manipulation of the hive to induce brood rearing in all brood frames or super frames was attempted. No honey, which could harbor disease spores, was removed from the hive. This simplified method of treatment was selected because if successful it would be practical in comnmercial beekeeping. The method required the minimum of time for the treatment, was inexpensive, and disrupted the colony as little as possible, thereby preventing robbing and a chance of spreading disease through the apiary. Observations were made of each hive at time of treatment. Records were kept as to the amount of disease present, the population of the hive, conditions of the brood and queen, and the amount of honey in the hive.