RESUMEN
Seventeen strains of Penicillium spp. have been isolated from Poa huecu Parodi from the Zapala zone, exhibiting toxicity to sheet. The following strains have been identified: P. crustosum, cyclopium, notatum, palitans, puberulum, verrucosum, viridicatum and Penicillium spp. The toxigenic capacity of the strains was studied after growing them under suitable conditions. Toxins produced were analysed by thin layer chromatography (TLC). Penitrem A (PA) and Penitrem B (PB) neurotoxins were identified and quantitated in twelve strains; verruculogen (VERR) and fumitremorgen B (FTB) being present in one of them. The effect of these mycotoxins was studied in mice. Neurological symptoms characteristic of the intoxication by tremorgenic toxins and similar to those observed in sheep suffering from 'huecu's disease' were observed. The possible role of these toxins as causative agents of 'huecu's disease' is discussed.
Asunto(s)
Micotoxinas/aislamiento & purificación , Neurotoxinas/aislamiento & purificación , Penicillium/metabolismo , Plantas Tóxicas/microbiología , Poaceae/microbiología , Temblor/inducido químicamente , Animales , Femenino , Ratones , Micotoxinas/biosíntesis , Micotoxinas/toxicidad , Neurotoxinas/biosíntesis , Neurotoxinas/toxicidad , Penicillium/aislamiento & purificaciónRESUMEN
The effects of aflatoxin B1 on the development of the immune response to oil-adjuvanted Bordetella bronchiseptica vaccine and on acquired resistance to bacterial challenge were studied in rabbits. The doses of aflatoxin used were insufficient to produce clinical intoxication. Rabbits were randomly assigned to three groups, each having six animals: control (T), vaccinated (V), and vaccinated plus aflatoxin (VA) at 0.05 mg/kg daily per os. Groups V and VA were vaccinated twice, and the three groups were subsequently challenged with virulent B. bronchiseptica. The average weight gain at weekly intervals was significantly reduced in group VA, and no statistically significant differences were found in the titers of agglutinating antibodies between groups V and VA. There were significant differences between groups V and VA in the extent and severity of the pneumonic process, group VA being most affected. Results indicated that agglutinating antibody titers were not related to the level of protection in the latter group. Other mechanisms, such as alveolar macrophage activity and cell-mediated immunity, were implicated in the impairment of the acquired resistance in rabbits subclinically intoxicated with aflatoxin.
Asunto(s)
Aflatoxinas/farmacología , Vacunas Bacterianas/inmunología , Infecciones por Bordetella/inmunología , Bordetella/inmunología , Aflatoxina B1 , Animales , Anticuerpos Antibacterianos/biosíntesis , Inmunidad Activa/efectos de los fármacos , Pulmón/patología , Conejos , Distribución Aleatoria , Aumento de Peso/efectos de los fármacosRESUMEN
The presence of aflatoxins was determined in 155 samples of chicken feeds, as well as their fungal contamination. Aflatoxins were detected in 3 of the analized samples; one of them contained 1620 micrograms/kg, a highly dangerous amount for chickens. The amount found in the remaining 2 samples was 30 micrograms/kg. A study of toxigenic fungus showed a prevalence of 69.3% of Aspergillus flovus: 72.4% of this percentage corresponded to aflatoxins producing strains. The prevalence of Aspergillus ocraceus was 18.6%; ten per cent of it corresponded to ochratoxin A producing strains. Chicken feeds are an adequate substratum for the formation of aflatoxins; this was demonstrated by raising the humidity contents of initially negative samples, which contained toxigenic Aspergillus flavus spores. The danger of storing chicken feeds under certain humidity and temperature conditions was demonstrated.
Asunto(s)
Aflatoxinas/análisis , Alimentación Animal/análisis , Aspergillus flavus/aislamiento & purificación , Aflatoxinas/efectos adversos , Animales , Aspergillus/aislamiento & purificación , Aspergillus flavus/patogenicidad , Pollos , Humedad , TemperaturaRESUMEN
The presence of aflatoxins was determined in 155 samples of chicken feeds, as well as their fungal contamination. Aflatoxins were detected in 3 of the analized samples; one of them contained 1620 micrograms/kg, a highly dangerous amount for chickens. The amount found in the remaining 2 samples was 30 micrograms/kg. A study of toxigenic fungus showed a prevalence of 69.3
of this percentage corresponded to aflatoxins producing strains. The prevalence of Aspergillus ocraceus was 18.6
; ten per cent of it corresponded to ochratoxin A producing strains. Chicken feeds are an adequate substratum for the formation of aflatoxins; this was demonstrated by raising the humidity contents of initially negative samples, which contained toxigenic Aspergillus flavus spores. The danger of storing chicken feeds under certain humidity and temperature conditions was demonstrated.
RESUMEN
The presence of aflatoxins was determined in 155 samples of chicken feeds, as well as their fungal contamination. Aflatoxins were detected in 3 of the analized samples; one of them contained 1620 micrograms/kg, a highly dangerous amount for chickens. The amount found in the remaining 2 samples was 30 micrograms/kg. A study of toxigenic fungus showed a prevalence of 69.3
of Aspergillus flovus: 72.4
of this percentage corresponded to aflatoxins producing strains. The prevalence of Aspergillus ocraceus was 18.6
; ten per cent of it corresponded to ochratoxin A producing strains. Chicken feeds are an adequate substratum for the formation of aflatoxins; this was demonstrated by raising the humidity contents of initially negative samples, which contained toxigenic Aspergillus flavus spores. The danger of storing chicken feeds under certain humidity and temperature conditions was demonstrated.