RESUMEN
Silage is the best method for forage conservation, keeping it in a fresh condition and with high nutrient content. In order to study the natural evolution of maize silage without additives during 50 days after sealed, pH, temperature changes, number and type of the indigenous bacteria were studied every 5 days. The initial pH decreased from 6.40 to 4.10 and temperature stabilized at 26 degrees C. The mesophilic aerobic bacteria were quickly reduced across time. Enterococci were descended gradually. Clostridia remained in a low quantity. The microorganisms most frequently isolated were Escherichia coli, Clostridium butyricum, Enterococcus faecalis and Lactobacillus plantarum; this acid lactic bacteria was the principal cause of the abundant production of anaerobic fermentation of sugars in the forage reaching the pH which maintained the silage in adequate conditions.
Asunto(s)
Bacterias , Ensilaje , Zea mays , Ácido Láctico/biosíntesis , Bacterias , Técnicas de Tipificación Bacteriana , Clostridium , Enterococcus , Escherichia coli , Especificidad de la Especie , Fermentación , Calor , Concentración de Iones de Hidrógeno , LactobacillusRESUMEN
From January 1990 to July 1992 a prospective study on the salmonellosis form of presentation, reservoirs and transmission in Tandil was carried out. Forty strains of Salmonella enterica were isolated with the following distribution: 28 humans (17 children and 11 adults), 6 in foods (1 in raw milk, 3 in well water, 1 in home made mayonnaise and 1 in chicken salad) and 6 in animals (1 in cow, 2 in chicken and 2 in calves). Salmonella Enteritidis was the most frequent isolate. Disease was evident only in a few susceptible hosts and the epidemiological chain could not be determined in all the cases.