Study of the Interactive Effect between Tylosin Tartrate and Colistin for its Use in the Therapy and Prevention of Poultry Diseases in Veterinary Medicine

The pharmacological interaction of antibiotic combinations of tylosin and colistin was studied. For this purpose, an in vitro challenge method was used. The results were used to calculate their interaction using the graphic representation known as ISOBOLOGRAM. The pure salts of tylosin tartrate and colistin sulfate were obtained from the manufacturer of the product, Laboratorios Ecozoo SA de CV Mexico. The bioassay method was used in agar wells and to quantify the results, the following criteria were used: A synergistic effect was defined when the real/theoretical effect (SMF) was greater than 1. The additive effect was defined when the SMF was equal to 1. The area between the antagonism and additive effect was defined as the zone of indifference. When studying the interaction between tylosin and colistin it was observed that the best SMF of this antibiotic combination was 3 to 2 and 2 : 4 (tylosin colistin respectively). It was cocluded that the combination of tylosin with colistin exerts a synergistic effect and can be recommended for oral administration in poultry for the treatment of infections by disease producing germs sensitive to the formula.