To investigate the effect of the ethyl acetate extract of endophytic fungus,
CL-OP 30 against the growth of methicillin-resistant
Time-kill assay was used to examine the effect of the extract on the bacterial growth profile.
The effects of extract on ultrastructure of MRSA and K. pneumoniae
cells were analyzed by scanning
electron microscope (SEM) and transmission electron microscope (TEM).
The time-kill test revealed that the bacteriocidal activity of the extract was both concentrationand
time-dependent. After 12 h treatment, interaction of extract with MRSA cells resulted in the
formation of pit, disintegration of cell wall and membrane, and ultimately cell death, while K.
cells became crumpled, and the cell walls and membranes disintegrated, resulting in
leakage of their cytoplasmic contents.
These data suggest that the Nigrospora sphaerica
CL-OP 30 extract principally affects the
cell wall in growing MRSA and K. pneumonia