The pharmacological interaction of the antibiotic combination between erythromycin and colistin was studied. An in vitro method was used for this purpose. The results were used to calculate their interaction using the graphical representation known as ISOBOLOGRAM. The agar bioassay method was used. A synergistic effect was defined when the actual/theoretical effect (SMEF) was greater than 1. The additive effect was defined when the SMEF was equal to 1. The area between the antagonism and additive effect was defined as the zone of indifference. When studying the interaction between erythromycin and colistin, it was observed that the best SMF of this antibiotic combination was 3 : 2 and 1 : 4 (erythromycin colistin respectively).It can be postulated that the use of this combination of erythromycin with colistin exerts a synergistic effect and can be recommended for oral administration in poultry for the treatment of infections by infectious agents sensitive to the formulation.

In this work, the pharmacological interaction of the antibiotic combination between chlortetracycline and thiamulin was studied. For this purpose, an in vitro challenge method was used. The results obtained were used to calculate their interaction using the graphical representation known as ISOBOLOGRAM. The pure salts of chlortetracycline and tiamulin were obtained from the product manufacturer ASTRONOVA SA DE CV. The agar bioassay method was used. The following criteria were used to quantify the results: A synergistic effect was defined when the actual/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 chlortetracycline and tiamulin; and it was observed that the best SMF of this antibiotic combination was 3.1 and 3.0 when the concentration ratio between the antibiotics was 4 : 1 and 3 : 2 (chlortetracycline tiamulin respectively) corresponding to solutions 2 and 3 of this test. Consequently it can be postulated that the use of this combination of chlortetracycline with thiamulin exerts a synergistic effect and can be recommended in pigs for the treatment of infections by infectious agents sensitive to the formulation. NOTE: Because this formulation is well known for its synergistic effect and for being elaborated and recommended in veterinary therapeutics in Mexico. The results of this isobologram are similar and in some cases equal to those previously reported for other laboratories in Mexico.

Beekeeping is an agricultural activity of special social, economic and ecological importance for the preservation of the country's biological diversity and the improvement of agricultural and fruit production. Honey is a bee product that has long been used as a food with a beneficial effect on the human body. The quality of honey is influenced by many factors such as: botanical origin of honey plants, nectar composition, geographical region where honey plants grow, climatic conditions, honey harvest season, time and method of storage, maturity and processing, presence of drugs, pesticides and microorganisms. Climate change cannot be influenced by beekeepers alone, but what they can do to create the preconditions for success is to follow the example of good beekeeping practice and be conscientious in their work. Although rising temperatures and prolonged heating create favorable conditions for the production of HMF, it has been proven that HMF is also formed when storing honey at lower temperatures, only at a much lower rate. In addition to the increase in temperature, the proportion of HMF in honey is significantly affected by the pH value of honey itself, because it has been proven that honey with lower pH has a higher proportion of HMF than honey with higher pH (Marinela et al. 2020).