Ultrastructural effect on mastitis pathogens by extract of endophytic fungi associated with ethnoveterinary plant, Hibiscus sabdariffa L.

Three endophytic fungi isolated from different parts of Hibiscus sabdariffa L. were identified using morphological and molecular approaches. Ethanolic extract of endophytic fungi as well as plant extracts were evaluated for in vitro antibacterial activity by using well diffusion method and their minimum inhibitory concentration estimated. The culture extract of one endophytic fungus Glomerella acutata EF15 was found to be potent antibacterial agent against pathogenic coliform bacteria Klebsiella pneumoniae and Escherichia coli responsible for causing clinical mastitis. Scanning electron microscopy (SEM) revealed the ultrastructural alteration in the cells of K. pneumoniae and E. coli when treated with crude ethanolic extract of G. acutata. The ethanolic extract of the endophytic fungus revealed potential to be bioprospected as antibacterial agent against pathogens causing coliform mastitis, the existing havoc of dairy industries.