DNA binding peptide CF-14 enhances bactericidal efficacy of eugenol/ carvacrol nanoparticles to Escherichia coli

To evaluate the bactericidal action of antimicrobial peptide CF-14, Eugenol (EU) and carvacrol (CAR) nano particles (NPs) less than 200 nm were surface-modified with CF14, gaining approximately 200 nm of EU-CF and CAR-CF NPs with swollen morphology. EU-CF and CAR-CF NPs were bactericidal to E. coli at dosage of 0.09% and 0.07% (v/v), respectively; while they were just bacteriostatic to Staphylococcus aureus at 0.10% and 0.08% (v/v). Spectral variations in bacterial carbohydrates (1185-900 cm 1), lipids (3000-2800 cm-1) and DNA (1500-1185 cm-1) were obvious as evident from Fourier transform infrared spectroscopy (FTIR). A higher percentage of membrane damaged (non-revivable) E. coli than S. aureus was found, which indicated electrostatic interactions between Gram-negative E. coli with cationic CF conjugated NPs leading to DNA disintegration. Interestingly, EU-CF and CAR-CF NPs inhibited E. coli growth in orange juice without impacting flavour compounds.

Automated summary

The surface-modified nanoparticles of Eugenol (EU) and carvacrol (CAR), known as EU-CF and CAR-CF NPs, respectively, displayed bactericidal effects on E. coli and bacteriostatic effects on Staphylococcus aureus. Fourier transform infrared spectroscopy (FTIR) analysis revealed significant changes in bacterial carbohydrates, lipids, and DNA. The CF conjugated NPs showed better membrane damage and DNA disintegration in Gram-negative E. coli than in Gram-positive S. aureus. Furthermore, the presence of EU-CF and CAR-CF NPs inhibited the growth of E. coli in orange juice without affecting the flavor compounds.