- Poster presentation
- Open Access
Nematicidal Effect of Bacillus Thuringiensis on Trichostrongylus Colubriformis Infesting Rabbits
© The Author(s); licensee BioMed Central Ltd. 2003
Published: 31 March 2003
The field of biological control has been recently established in many countries trying to minimize the hazards of insecticides and chemicals and to help for environmental and human protection. The present study was directed towards the use of non- harmful non- pathogenic bacteria, bacillus thuringiensis (B.T) as nematicide towards Trichostrongylus colubriformis in rabbits. Eggs and larvae of adult nematode worms, T. colubriformis were obtained and exposed to six dilutions of B.T. Kurstaki 0.3, 0.6,1,1.5,2 and 2.5 mg and toxin. The biologically treated eggs and larvae were incubated at 28°C and examined for development, activity and motility. The ovicidal and larvicidal activity of B.T. Kurstaki and its toxin were recorded. Also anthelmintic activity of B.T. Kurstaki against T. colubriformis infection in rabbits were evaluated by s/c injection of infected rabbits with a dose of 5 mg/kg body weight. Both treated infected rabbits and control ones were sacrified after 2 weeks post treatment and the intestine was prepared for worm detection. The data were subjected to statistical analyis based on the work of Polo- Pc (Robertson et. al. 1980) to determine LD50 values.
The ovicidal and larvicidal activities were higher with prolonged exposure of parasitic eggs and larvae to bacteria and its toxins. The ovicidal activity of bacteria and toxin were increased to be 93.71% and 93.66% respectively at 2.5 mg concentration. The larvicidal effects of bacteria reached to 100% and 98% for bacteria and toxin respectively at 2 mg. Also the anthelmintic activity of B.T. kurstaki against T. colubriformis in rabbits showed a daily gradual decrease in number of eggs/gm. Feces and disappearances of eggs after 10 days post treatment. Also the intestines of sacrificed infected rabbits were free from adult nematode. The study revealed the successful biological treatment of infected rabbits with T.colubriformis by non- harmful bacteria, B.T. kurstaki
This work was supported by the national research center, Egypt (Biological control research project: 3-1-3-2).
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.