In vitro antimicrobial activity of some medicinal plant and propolis extracts against mulberry silkworm, Bombyx mori L. pathogens

Résumé

This study has been conducted to determine the antimicrobial activity of some medical plant extracts against mulberry silkworm, Bombyx mori L. pathogens. A total of 22 bacterial and 9 fungal isolates were successfully isolated from the external and internal silkworm larvae. Four bacterial species isolated from the infected larvae in this study were identified as follows: Staphylococcus aureus M., Escherichia coli M., Bacillus licheniformis C. and Bacillus thuringiensis B., while 6 fungal species were isolated as follows: Aspergillus niger V., Aspergillus flavus L., Aspergillus terreus T., Aspergillus fumigatus F., Pencillium citrinum F. and Fusarium oxysporum F. The highest activity among medicinal plant extracts against all pathogenic bacterial and fungal isolates was Cinnamomum zeylanicum J. while, Curcuma longa L. and Foeniculum vulgare M., showed no activity against tested pathogenic microorganisms. It is our hope that the data generated will be an addition to the existing pool of biocontrol silkworm pathogens in Egypt.