A suspension containing the total protein extract of Bacillus thuringiensis of five strains (kurstaki HD-1, thompsoni HD-542, neoleonensis T-24-001, israeliensis HD-500 and israeliensis WHO-2013-9) was obtained. The concentration (mg/ml) of each strain was determined by the Biuret method. The nematicidal activity was evaluated in Petri plates facing eggs and infective larvae (L3) of Nematodirus spathiger against the suspension of total protein extract (1.2 ml). Five treatments (strains) and 10 repetitions were used. The control group contained only the nematodes. The Petri dishes were incubated at 25 °C for 24, 48 and 72 h. Kurstaki HD-1 strain in a concentration of 5.042 mg/ml showed the best anthelmintic efficiency in the three incubation times, obtaining 44.7% mortality in eggs and 45.6% in larva. The total protein extract of B. thuringiensis kurstaki HD-1 contains the nematicidal to...

A suspension containing the total protein extract of Bacillus thuringiensis of five strains (kurstaki HD-1, thompsoni HD-542, neoleonensis T-24-001, israeliensis HD-500 and israeliensis WHO-2013-9) was obtained. The concentration (mg/ml) of each strain was determined by the Biuret method. The nematicidal activity was evaluated in Petri plates facing eggs and infective larvae (L3) of Nematodirus spathiger against the suspension of total protein extract (1.2 ml). Five treatments (strains) and 10 repetitions were used. The control group contained only the nematodes. The Petri dishes were incubated at 25 °C for 24, 48 and 72 h. Kurstaki HD-1 strain in a concentration of 5.042 mg/ml showed the best anthelmintic efficiency in the three incubation times, obtaining 44.7% mortality in eggs and 45.6% in larva. The total protein extract of B. thuringiensis kurstaki HD-1 contains the nematicidal to...

El control del parasitismo gastrointestinal en rumiantes con antihelmínticos químicos tradicionales, viene ocasionando peligrosos efectos adversos en los ecosistemas naturales, el surgimiento de la resistencia antihelmíntica y efectos nocivos sobre organismos no blanco. Ante este problema se renueva el interés por la búsqueda de alternativas de control de nemátodos gastrointestinales, en concordancia con el equilibrio del medio ambiente y el desarrollo sustentable. La actividad nematicida del extracto proteico total de Bacillus thuringiensis (Bt) contra huevos y larvas L3 infectivas de Nematodirus spathiger (Ns) fue evaluado en pruebas in vitro. Los huevos o larvas L3 infectivas de Ns fueron colocados junto a 1.2 ml de la suspensión del extracto proteico total de Bt en placas de Petri considerando 10 repeticiones y el mismo número de repeticiones con solo nemátodos, para el grup...