RESUMEN
A mycotoxin-producing strain of Fusarium moniliforme was isolated from southern leaf blight-damaged corn seed. A water-soluble toxin, subsequently purified from the fungus, had an oral median lethal dose of 4.0 milligrams per kilogram in 1-day-old cockerels. The toxin also produced plant growth-regulating and phytotoxic effects on plant systems. Physical and chemical data presented for the toxin suggest a structurally new toxin. The trivial name "moniliformin" has been assigned to the toxin.
RESUMEN
'Argentine', 'Early Runner' and 'Florigiant' peanut cultivars were grown in methyl bromide treated soil in field microplots inoculated with: (i) Aspergillus flavus or (ii) A. flavus + Meloidogyne hapla. Nematode infection produced heavy root galling and light pod galling equally on all cultivars. A. flavus, A. niger, Cephalosporium spp., Colletotrichum sp., Curvularia spp., Fusarium spp., Penicillium spp. and Trichoderma viride were isolated from shells and kernels. A significantly greater incidence and density of A. flavus was obtained from kernels of plants inoculated with both organisms than from kernels of plants receiving only the fungus. Differences were not significant, however, for incidence and density of A. flavus in shells or for the total of all fungal propagules in shells and kernels. Shells of 'Early Runner' contained significantly greater incidence and density of A. flavus than the other two cultivars; also, kernels of this cultivar contained more fungal propagules than kernels of 'Argentine.' A significantly larger number of total fungi was isolated from kernels of 'Argentine' than from 'Florigiant.' Aflatoxins were found only in two shell samples and not in kernels.
Asunto(s)
Alimentación Animal , Fusarium , Neumonía Intersticial Atípica de los Bovinos/etiología , Verduras , Animales , Bovinos , Enfermedades de los Bovinos/etiología , Femenino , Enfermedades Transmitidas por los Alimentos/etiología , Enfermedades Transmitidas por los Alimentos/veterinaria , Masculino , Micotoxinas , Neumonía Intersticial Atípica de los Bovinos/patologíaRESUMEN
Five isolates of Aspergillus ochraceus, obtained from peanuts, were grown separately on sterile, moist corn for 14 days and fed to 1-day-old Babcock B-300 cockerels to evaluate their toxic effects. Two isolates were highly toxic, causing death of all birds during the 1st week of the experiment. Two isolates were moderately toxic, causing severe growth suppression with some deaths occurring throughout the 3-week test period. One isolate had no apparent effect. When the two most toxic isolates (diets) were diluted, survival time increased but severe growth suppression was evident. Postmortem examinations revealed a few small hemorrhages in the proventriculi of birds which died between the 2nd and 5th days. Emaciation, dehydration, and dry, firm gizzard linings were observed throughout the experiment. Extensive hepatic injury consisting of either fatty changes or necrotic foci was the principal microscopic finding. Suppression of bone marrow activity and depletion of lymphoid elements in the spleen and bursa of Fabricius were also found. The severity of the histopathological changes was directly related to the concentration of ochratoxin A in the diets.
Asunto(s)
Aspergillus , Micotoxinas/envenenamiento , Animales , Arachis , Aspergillus/aislamiento & purificación , Peso Corporal/efectos de los fármacos , Médula Ósea/patología , Bolsa de Fabricio/patología , Pollos , Medios de Cultivo , Molleja de las Aves/patología , Hígado/patología , Masculino , Intoxicación/mortalidad , Intoxicación/patología , Bazo/patología , Zea maysRESUMEN
One hundred thirty-seven single-conidium isolates of Alternaria longipes were tested for pathogenicity to tobacco leaves and for toxicity to 1-day-old chicks. Of 58 isolates pathogenic to tobacco, 43 (74.3%) had a significant effect on test chicks. Of 79 nonpathogenic isolates, 59 (74.7%) were nontoxic, 7 were toxic, and 13 were lethal. A relationship between pathogenicity and toxicity is suggested.
Asunto(s)
Hongos Mitospóricos/patogenicidad , Micotoxinas/toxicidad , Animales , Pollos/efectos de los fármacos , Hongos Mitospóricos/citología , Hongos Mitospóricos/crecimiento & desarrollo , Enfermedades de las Plantas , Plantas Tóxicas , Especificidad de la Especie , NicotianaRESUMEN
Isolates of Aspergillus chevalieri, A. flavus, A. ochraceus, A. repens, and Penicillium funiculosum and complexes of P. citrinum-P. implicatum isolated from moldy pecan meats were toxic to chicks.
Asunto(s)
Aspergillus/patogenicidad , Pollos , Microbiología de Alimentos , Nueces , Penicillium/patogenicidad , Aflatoxinas/análisis , Aflatoxinas/biosíntesis , Aflatoxinas/toxicidad , Animales , Aspergillus/análisis , Aspergillus/aislamiento & purificación , Aspergillus/metabolismo , Pollos/efectos de los fármacos , Cromatografía en Capa Delgada , Dieta , Conservación de Alimentos , Nueces/análisis , Ocratoxinas/análisis , Ocratoxinas/biosíntesis , Ocratoxinas/toxicidad , Penicillium/análisis , Penicillium/aislamiento & purificación , Penicillium/metabolismoRESUMEN
Ochratoxins A and B were given to 1-day-old Babcock B-300 cockerels to evaluate acute toxic effects. Two trials with ochratoxin A gave 7-day oral median lethal dose estimates of 116 mug (3.3 mg/kg) and 135 mug (3.9 mg/kg) per chick. Chicks given daily oral doses of 100 mug of ochratoxin A died on the second day. Single subcutaneous doses of 400 mug of ochratoxin A were also lethal. The 7-day oral median lethal dose of B was estimated at 1,890 mug (54 mg/kg) per chick. Chicks given oral doses of 100 mug of ochratoxin B daily for 10 days survived. Sublethal doses of both ochratoxins A and B resulted in growth suppression which was proportional to the amount of ochratoxin given. Visceral gout was the principal gross finding. Microscopic examinations revealed acute nephrosis, hepatic degeneration or focal necrosis, and enteritis. Suppression of hematopoiesis in the bone marrow and depletion of lymphoid elements from the spleen and bursa of Fabricius were frequently seen. Both ochratoxins appeared to have similar pathological effects. This is the first report on the toxicity of ochratoxin B.
Asunto(s)
Pollos/efectos de los fármacos , Cumarinas/toxicidad , Micotoxinas/toxicidad , Administración Oral , Animales , Peso Corporal , Cumarinas/envenenamiento , Enfermedades Transmitidas por los Alimentos , Técnicas Histológicas , Inyecciones Subcutáneas , Masculino , Micotoxinas/envenenamiento , Ocratoxinas/toxicidad , Especificidad de Órganos , Intoxicación/mortalidad , Intoxicación/patologíaRESUMEN
Six isolates of Helminthosporium maydis, obtained from southern leaf blight-damaged corn, were grown separately on autoclaved corn and fed to chicks and mice to evaluate their toxigenicity. Two-, three-, and four-week-old culture filtrates from three pathogenic isolates grown separately on modified Fries medium were also evaluated for toxigenicity. None of the invaded corn samples or culture filtrates affected the weights of chicks or mice when compared to controls. Postmortem examinations did not reveal significant gross lesions. H. maydis was not toxigenic under our experimental conditions.