Submitted to: Journal of Apicultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 10, 2006
Publication Date: May 1, 2006
Citation: Kochansky, J.P., Feldlaufer, M.F., Smith Jr, I.B. 2006. Microbiological screening assay for tylosin in pollen. Journal of Apicultural Research and Bee World. 45(2):37-41.
Interpretive Summary: Tylosin has recently been approved for the treatment of American foulbrood, the most serious of the bee diseases. Application to honey bee colonies has the potential to leave residues in pollen as well as honey. We have developed a screening method for this compound in pollen. Using pollen containing deliberately added amounts of tylosin, this compound was analyzed using a bacterial growth assay. This information is of interest to producers and packers of bee products, scientists, and regulators.
Tylosin residues have been isolated from pollen samples by adsorption on acidic solid-phase extraction cartridges, with subsequent determination using a disk-diffusion microbiological assay. While not providing identification of individual antibiotics present, the presence of a zone of inhibition provides a simple indication of the presence of bacteriostatic/bactericidal residues. Use of Paenibacillus larvae gave reproducible sensitivity to 0.2 mg/kg tylosin, but not reliably below that. Of the strains of bacteria tested, P. larvae and Micrococcus luteus gave the greatest sensitivity and inhibition zone diameter; M. luteus was sensitive to some component of pollen, giving large blanks, and was less sensitive to low concentrations of tylosin, as were the other strains. Sampling provides the greatest source of error in the analysis of pollen.