RESUMEN

Several studies have been developed using the Gallus gallus embryo as an experimental model to study the toxicity of drugs and infections. Studies that seek to standardize the evaluated parameters are needed to better understand and identify the viability of CEs as an experimental model. Therefore, we sought to verify whether macroscopic, histopathological, blood count, metabolites and/or enzymes changes and oxidative stress in CE of different ages are specific to the model. To achieve this goal, in ovo assays were performed by injecting a virus (Gammacoronavirus) and two drugs (filgrastim and dexamethasone) that cause known changes in adult animals. Although congestion and inflammatory infiltrate were visible in the case of viral infections, the white blood cell count and inflammation biomarkers did not change. Filgrastim (FG) testing did not increase granulocytes as we expected. On the other hand, CE weight and red blood cell count were lower with dexamethasone (DX), whereas white blood cell count and biomarkers varied depended on the stage of CE development. Our work reinforces the importance of standardization and correct use of the model so that the results of infection, toxicity and pharmacokinetics are reproducible.

RESUMEN

A wide variety of microorganism species have been used as probiotics to improve the intestinal microbial balance, control and prevent the colonization of pathogenic bacteria and promote growth in animal production. Based on the various beneficial factors of probiotic agents, this study aimed to evaluate the effectiveness of three different formulations of probiotics strains through the analysis of antagonistic capacity against common pathogens from chickens gastrointestinal tract. Three formulations composed by Bacillus, Lactobacillus, Saccharomyces, Enterococcus, Bifidobacterium and Pediococcus were tested in vitro by the method of probiotic culture spot in plates seeded with inocula of Escherichia coli, Salmonella Heidelberg and Campylobacter jejuni. The inhibition halos were measured and classified according to the degree of pathogenic bacteria inhibition. The formulation containing an association among Bacillus, Lactobacillus and Saccharomyces presented better results when compared to the other formulations.

Asunto(s)

Animales , Pollos/microbiología , Probióticos/administración & dosificación , Microbioma Gastrointestinal/efectos de los fármacos , Saccharomyces , Salmonella , Campylobacter jejuni , Escherichia coli , Lactobacillus

RESUMEN

This work describes the development of a gastroresistant antimicrobial formulation composed of two carriers, pectin and liposomes, intended to improve the efficiency of norfloxacin (NOR) against multi-resistant bacterial strains. The formulations showed physicochemical stability for 180 days (4 °C) in terms of size, polydispersity, and zeta potential of the vesicles, prolonging the in vitro release of NOR for 11 h. The hybrid nanocarriers improved the in vitro antimicrobial activity against different multidrug-resistant bacterial strains, such as Salmonella sp., Pseudomonasaeruginosa, E. coli and Campylobacterjejuni, in comparison to commercial NOR and liposomal suspensions. The in vivo toxicity assay in chicken embryos revealed that the hybrid systems were not toxic in any of the different parameters analyzed, a result also corroborated by the analyses of biochemical biomarkers of the chicken-embryos liver function.