Activity of plant essential oils against antibiotic resistant Enterococcus faecalis isolated from diarrheic children

Area of Science:

• Microbiology
• Pharmacology
• Phytochemistry

Background:

• Antibiotic resistance in Enterococcus faecalis poses a significant threat to public health, especially in pediatric diarrheal diseases.
• Limited treatment options exist for multidrug-resistant bacterial infections, necessitating the exploration of alternative therapies.

Purpose of the Study:

• To evaluate the antibacterial activity of plant essential oils and their fractions against antibiotic-resistant Enterococcus faecalis isolates from diarrheal children.
• To identify the active compounds and assess the safety of effective essential oil fractions for potential therapeutic use.

Main Methods:

• Characterization of Enterococcus faecalis isolates using polymerase chain reaction (PCR) and 16S rRNA gene sequencing.
• Antibiotic susceptibility testing and determination of zone of inhibition (ZOI) and minimum inhibitory concentration (MIC).
• Gas chromatography-mass spectrometry (GC/MS) analysis to identify active components, with a focus on eugenol.

Main Results:

• Syzygium aromaticum, Cinnamomum verum, and Nigella sativa essential oils exhibited significant antibacterial activity against resistant E. faecalis.
• Syzygium aromaticum showed the lowest MIC (11.39±3.94 mg mL⁻¹), and its n-hexane plus chloroform fraction displayed a high mean ZOI (16.67±2.51 mm).
• Eugenol was identified as the primary active fatty acid in the effective essential oil fractions.

Conclusions:

• Plant essential oils, especially Syzygium aromaticum, possess potent antibacterial properties against multidrug-resistant Enterococcus faecalis.
• The identified active fractions containing eugenol are safe and effective for treating pediatric diarrheal cases caused by E. faecalis.