In vitro
antibacterial activity of EM from EFI after 48 h of cultivation. The MDR
bacteria against which crude EM were used are noted bellow the plates.
Article abstract: Aims: To evaluate antimicrobial activity of extracellular metabolites (EM) of endophytic fungal isolates (EFI) from Azadirachta indica.
Methods: EFI were identified by ITS sequencing. Antimicrobial activity, and MIC and MBC were determined using agar diffusion and microdilution method, respectively.
Results: Seventeen EFI were isolated from different organs of Azadirachta indica. Eight of them were identified based on ITS sequencing. The EM of EFI inhibited the growth of six MDR bacterial superbugs and three phytopathogenic fungi. The MDR bacterial superbugs are resistant to six commercial antibiotics of different generations but susceptible to EM of EFI. The MIC (0.125 to 1.0 µg/µL), MBC (0.5 to 4.0 µg/µL) and MFC (1.0 to 4.0 µg/µL) of the EM from EFI are lower enough.
Conclusions: The EM of the EFI has promising antimicrobial activity against MDR bacteria and phytopathogenic fungi.
Funding
This work was partially supported by a grant in aid (LS/2020/1/17) from the Research Centre, Shahjalal University of Science and Technology, Sylhet, Bangladesh.