The protective activity of lime juice against cholera was suggested in a recent case-control study from Guinea-Bissau. On the basis of these findings, we investigated the vibriocidal properties of juice from lime (Citrus aurantifolia) fruits added to well water, tap water, and food samples. Well-water samples showed initial pH values from 3.5 to 4.9 whereas water samples from municipal or private taps showed initial pH values between 7.5 and 8.3. A 5-log reduction in Vibrio cholerae O1 counts to <100 CFU/ml of well water was shown for two test strains after exposure to 0.5% lime juice (pH 3.3) for 12 min. In tap water, no significant reduction in CFU of V. cholerae was found after exposure to 0% (pH 8.3) and 0.5% (pH 5.6) lime juice whereas exposure to 1.0% lime juice (pH 4.4) for 120 min caused a 5-log reduction to <100 CFU/ml of tap water for the test strains. A 3-log reduction of V. cholerae was found in food samples containing 3.5% and 5.0% lime juice after 120 min exposure. Our results show that during epidemics of cholera in areas without safe sources of drinking water, juice from citrus fruits added to water and food in palatable concentrations may be appropriate measures in reducing the transmission of cholera. However, local characteristics of the water, in particular its alkalinity, should be considered before applying this measure.

We examined the hypothesis that histidine is a regulator of short-term food and water intake in rats and that this control is through histidine's action as a precursor for histamine. The primary objectives were to measure food and water intake after histidine monohydrochloride monohydrate (His-HCl) given by intragastric (IG) and intraperitoneal (IP) routes of administration and to measure feeding and drinking responses to histidine when given after blockade of the histaminergic pathway by chlorpheniramine (CPA) and alpha-fluoromethylhistidine (FMH). Eight experiments were conducted using a back-to-back design. Rats were given treatment by IP or IG administration, and food and water intake was measured during time periods of 0-1, 1-2, 2-3 and 3-14 h. Histidine consistently reduced food intake with the sensitivity to IP much greater than to the IG route. The effect of histidine given by IP or IG on water intake was similar, generally causing an increase at least in the first hour. Histidine's action was not accounted for by its energy, pH or nitrogen content. Because FMH, which blocks the enzyme converting histidine to histamine, partially reversed the effect of histidine on food and water intake, those results support the hypothesis that histidine regulates food and water intake, at least in part, through its precursor control of histamine.

Se han medido el pH y la aw de distintos preparados alimenticios elaborados en establecimientos dedicados a la restauracion social. Ambos parametros son considerados como factores inhibidores del desarrollo microbiano. Los alimentos elaborados o semielaborados se clasificaron en varios grupos: hortalizas, legumbres, cereales y derivados -arroz y pasta-, pescados y mariscos, carnes y productos carnicos, huevos y ovoproductos y miscelaneos -salsas, sopas...-.

Se estudiaron 100 muestras de Pleurotus ostreatus procedentes de distintos establecimientos minoristas de alimentacion de la ciudad de Cordoba durante los anos 1995 y 1996, en las que se determino la humedad y se detecto en el 6 por ciento un posible fraude por adicion de agua.