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

Abstract

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