Prospecting the antibiofilm potential of bioactive secondary metabolites
of fungal endophyte Cephalotheca foveolata (N11) against biofilm-forming
bacteria
Abstract
Biofilms are found in diverse environmental settings and are considered
to be responsible for various recalcitrant infections. One
characteristic feature of biofilms is resistance to antibiotics, which
is the leading cause of recurrent infections and treatment failure.
Eradicating the biofilms necessitates the need for agents with promising
anti-biofilm potentials. In the present study, the secondary metabolites
of the fungal endophyte Cephalotheca foveolata (N11) isolated
from the woody tissues of the medicinal plant Teucrium
stocksianum were investigated for their antibiofilm potential against
the test organisms. For evaluating the antibiofilm activities, in-vitro
assays including biofilm inhibition and eradication assays were
employed. The bioactive metabolites of the N11 strain exhibited the
highest biofilm inhibition and eradication potential of 87.62% and
79.22% respectively against S. epidermidis. The results were
further validated by light microscopy and confocal laser scanning
microscope which revealed considerable distortion of the biofilm
architecture by test agents. Besides, the effect of secondary
metabolites on biofilms of test strain was also observed using Raman
spectroscopy. The Raman spectra of treated biofilms exhibited a
significant reduction in the intensities of the peaks indicating the
denaturation and conformational changes in biomolecules. Furthermore,
the partial purification of antibiofilm metabolites of N11 was carried
out using solvent extraction following TLC and silica column with
further characterization done using FTIR. These findings highlight the
remarkable potential of bioactive secondary metabolites of endophytic
fungi associated with Teucrium stocksianum in disrupting the
biofilms thus suggesting that these metabolites can be exploited for
manufacturing effective agents against biofilm-associated complications.