RESUMO
Six single-flow continuous cultures were used to study the effects of the mycotoxins patulin (PAT) and zearalenone (ZEN) alone or in combination on rumen microbial fermentation. In each of the four 7-d periods, the fermenters were supplemented in a 2 × 3 factorial arrangement with two levels of PAT (0 and 20 mg/l) and three levels of ZEN (0, 5 and 10 mg/l). The treatments did not affect the apparent and true digestibility of organic matter. PAT alone decreased the digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) (p < 0.01), but in the presence of 5 or 10 mg/l of ZEN, there were no effects of PAT. In contrast, the digestibility of NDF and ADF was decreased at 10 mg/l of ZEN in the absence of PAT (p < 0.05). The pH of the fermenters increased after 2 and 3 d of PAT treatment (p < 0.01). PAT decreased the concentration of total volatile acids (VFA), the molar proportion of acetate and the acetate:proportionate ratio (p < 0.01). The molar concentrations of other VFA were unchanged. Ammonia N (NH3-N) flow increased (p < 0.05) and there was a tendency to a higher NH3-N concentration (p < 0.1) in fermenters with PAT. Total N, non-ammonia N and bacterial N as well as efficiency of microbial protein synthesis and efficiency of N utilisation were not affected by treatments. PAT was nearly completely degraded during incubation. The mean recovery of ZEN, α-zearalenol and ß-zearalenol expressed as a proportion of administered ZEN was less than 50% in effluents from fermenters receiving only ZEN and ZEN plus PAT, respectively. With exception of fibre digestion, the co-administration of PAT and ZEN did not elicit interaction effects on most measured parameters of rumen metabolism.
Assuntos
Bactérias/efeitos dos fármacos , Fermentação/efeitos dos fármacos , Fusarium/química , Micotoxinas/farmacologia , Patulina/farmacologia , Penicillium/química , Zearalenona/farmacologia , Animais , Reatores Biológicos , Bovinos , Feminino , Rúmen/metabolismo , Rúmen/microbiologia , Zeranol/análogos & derivados , Zeranol/farmacologiaRESUMO
Integrons are one of the genetic elements involved in the acquisition of antibiotic resistance. The aim of the present research is to investigate the presence of integrons in commensal Escherichia coli (E. coli) strains, isolated from pigs at different stages of production system and from the environment in an Argentinian farm. Five sows postpartum and five randomly chosen piglets from each litter were sampled by rectal swabs. They were sampled again at day 21 and at day 70. Environmental samples from the farm were also obtained. E. coli containing any integron class or combination of both integrons was detected by polymerase chain reaction in 100% of sows and in piglets at different stages of production: farrowing pen stage 68.1%;, weaning 60%, and growing/finishing 85.8%, showing an increase along the production system. From environmental samples 78.4% of E. coli containing any integron class was detected. We conclude that animals and farm environment can act as reservoirs for potential spread of resistant bacteria by means of mobile genetic elements as integrons, which has a major impact on production of food animals and that can reach man through the food chain, constituting a problem for public health.
RESUMO
El glutatión (GSH) es una molécula única que participa en aspectos esenciales de la homeostasis celular, teniendo un rol central en la defensa contra el daño oxidativo. El GSH (L-g-glutamil-L-cisteinil-glicina) es un tripéptido hidrosoluble formado por los aminoácidos ácido glutámico, cisteína y glicina que se encuentra presente en el citoplasma de todas las células. La forma oxidada de la molécula, GSSG, se encuentra principalmente en forma extracelular. Las concentraciones de GSH y GSSG y su relación molar son indicadores de la funcionalidad celular y su alteración está relacionada con varios procesos patológicos en el hombre y en los animales de compañía. En esta revisión se abordan importantes aspectos de la homeostasis, las principales funciones biológicas y las metodologías analíticas disponibles para el análisis de GSH en sangre y plasma.
Glutathione is a unique molecule that participates in key cellular homeostasis, having a central role in defense against oxidative damage. GSH (L-g-glutamyl-L-cysteinyl-glycine) is a water soluble tripeptide composed of amino acid glutamic acid, cysteine and glycine. GSH is present in every cell cytoplasm. The oxidized form of the molecule, GSSG, is found primarily in extracellular form. GSH and GSSG concentrations and their molar ratio are indicators of cell function and its alteration is associated with several disease processes in humans and in companion animals. This review focuses on important aspects of homeostasis, major biological functions and available analytical methodologies for the analysis of GSH in blood and plasma.
A glutationa (GSH) é urna molécula única envolvida em aspectos essenciais da homeostase celular, tendo um papel central na defesa contra o dano oxidativo. O GSH (L-g-glutamil-L-cisteinil-glicina) é um tripeptídeo hidrossolúvel formado pelos aminoácidos: ácido glutámico, cisteína e glicina que se encontra presente no citoplasma de todas as células. A forma oxidada da molécula, GSSG, acha-se principalmente em forma extracelular. As concentragoes de GSH e GSSG e a sua relagáo molar sao indicadores da funcionalidade celular e a sua alteragao está relacionada com vários processos patológicos no homem e nos animais de estimagáo. A presente revisáo aborda questoes importantes da homeostase, as principais fungoes biológicas e as metodologias analíticas disponíveis para a análise de GSH em sangue e plasma.
Assuntos
Humanos , Glutationa/sangue , Homeostase , Homeostase/fisiologia , Técnicas Hemostáticas , Estresse Oxidativo , PlasmaRESUMO
Wheat (as bran) and corn (as dry grain or fermented feed) are main ingredients of feedstuffs used in local cattle and pig farms in the South of the Buenos Aires Province (Argentina). Therefore, determining mycobiota and mycotoxins in wheat and corn is of prime importance for developing feed management techniques to optimise animal production and to minimize toxicity. Then, a mycological survey was carried out in the Southeastern part of the Buenos Aires Province, in order to identify the mycobiota and the main mycotoxins present in fermented feed, wheat grain and corn grain samples. Samples were cultured for fungal quantification, isolation and identification, and analysed for deoxynivalenol (DON), zearalenone (ZEA), T-2 toxin and aflatoxins (AFLA). Penicillium (74%), Aspergillus (32%) and Scopulariopsis (21%) were the prevalent genera in fermented feed. Penicillium (70%), Fusarium (47%) and Aspergillus (34%) were the most frequent fungi isolated from corn. Penicillium (42%), Fusarium (27%) and Alternaria (25%) were the most frequently recovered genera from wheat. DON was detected in 59% of the corn samples, in 45% of the wheat samples and in 38% of the silage samples. ZEA was detected in 36% of the corn samples, in 49% of the wheat samples and in 16% of the silage samples. T-2 toxin and aflatoxin B1 were each detected in 4% of the corn samples. Eighteen percent of the fermented feed samples showed T-2 contamination. Fermented feed and wheat samples were negative for AFLA.
Assuntos
Contaminação de Alimentos , Microbiologia de Alimentos , Fungos/isolamento & purificação , Micotoxinas/isolamento & purificação , Silagem/microbiologia , Triticum/microbiologia , Zea mays/microbiologia , Aflatoxina B1/análise , Animais , Argentina , Bovinos , Fermentação , Especificidade da Espécie , Suínos , Tricotecenos/análise , Zearalenona/análiseRESUMO
El presente trabajo tiene como objetivo describir las características farmacocinéticas, metabólicas y toxicológicas de los ácidos asimétricos aril-2-propiónicos y mostrar la importante variabilidad inter-especies existentes. Además se explican las derivaciones metabólicas del proceso de inversión quiral (camino metabólico de crucial importancia para estos compuestos) y las consecuencias toxicológicas relacionadas con su naturaleza quiral