Comparative Antimicrobial Efficacy of Eucalyptus camaldulensis, Berberis lycium, and Capsicum annuum Extracts Against Multidrug-Resistant Escherichia coli, Salmonella typhi, and Malassezia furfur

Abstract

The emergence of multidrug-resistant pathogens necessitates alternative antimicrobials. This
study evaluated ethanolic and methanolic extracts of Capsicum annuum, Berberis lycium,
and Eucalyptus camaldulensis from Bhakkar, Punjab against E.
coli, Salmonella spp., Malassezia spp. and five ATCC bacterial and four fungal strains by agar-
well diffusion and broth microdilution. Total phenolic (TPC) and flavonoid content (TFC)
were highest in E. camaldulensis leaf methanol extract (142.6 mg GAE/g, 89.4 mg QE/g).
ANOVA showed highly significant effects of plant, extract and dilution (p<0.001). E.
camaldulensis methanolic 1.0 mL showed maximum inhibition (13.3 mm E. coli, 26.3 mm S.
aureus ATCC, MIC 1.56 mg/mL), while B. lycium ethanolic 1.0 mL was most effective
against Malassezia spp. (13.7 mm). Activity was dose-dependent and strongly correlated with
TPC (r=0.89). E. camaldulensis is the most promising broad-spectrum candidate. The study
concludes that methanolic extract of Eucalyptus camaldulensis at 1.0 mL dilution is highly
effective against E. coli and Salmonella spp., while ethanolic extract of Berberis lycium at 1.0
mL is highly effective against Malassezia spp. Capsicum annuum shows minimum activity.
Results validate ethnomedicinal uses and indicate E. camaldulensis as promising candidate for
antimicrobial drug development, and B. lycium as novel antifungal against Malassezia