Reynaldi, F., g. Albo, e. Avellaneda & r. Rule, 2017.

Evaluation of kinetic behaviour of two preparations of tylosin administered in beehives for American foulbrood control.

Bulg. J. Vet. Med., 20, No 3, 264–270.  DOI: 10.15547/bjvm.1024

We compared the kinetic behaviour of tylosin administered to beehives by dusting or paper-pack placement through three treatment protocols (D, PP, CONTROL). D (dusting): tylosin, divided in four portions, was sprinkled over the ends of the hives' top bars weekly for four weeks (n=3); PP (paper-pack placement): tylosin in paper packs was administered at two-week intervals (n=3); CONTROL (control): the hives were left untreated (n=3). In every inspection, from each of the nine hives, fifty young (2-day-old) larvae were sampled for drug analysis. The concentration of tylosin in the young larvae was determined by a microbiological assay with Geobacillus stearothermophilus ATCC 12980 as test organism. The (mean±SD) maximum concentration (C_max) for D was 136.0±194.0 and for PP – 144.0±187.4 µg/ml; the time to reach C_max (t_max) was 1.5±0.9 h for D and 1.8 ± 1.8 h for PP. The area under the tylosin behaviour kinetics curve between 0–1392 h with D was 308.7±185.2 and with PP: 326.4±141.0 µg/h/mL, indicating no statistical difference between the treatments (p>0.05). The shorter duration of paper-pack-administered tylosin observed in the larvae implied a lower risk of antibiotic residues in the resulting honey.

Key words: American foulbrood, beehives, kinetics, tylosin