How Essential Oils Fight Resistant Bacteria and Break Down Biofilms

Jenn Hoskins
23rd May, 2024

How Essential Oils Fight Resistant Bacteria and Break Down Biofilms

Image Source: Natural Science News, 2024

Key Findings

  • The study from the Center of Biotechnology of Sfax, Tunisia, evaluated the effects of four essential oils on MRSA bacteria
  • Essential oils like Peppermint and Geranium showed significant antiadhesive and eradication activities against MRSA biofilms
  • These oils also inhibited the synthesis of staphyloxanthin, a virulence factor, making MRSA more susceptible to treatments
Staphylococcus aureus, particularly the methicillin-resistant strain (MRSA), presents a significant challenge to public health due to its resistance to many antibiotics[2]. The increasing prevalence of antibiotic-resistant bacteria necessitates alternative strategies for combating bacterial infections. A recent study conducted by the Center of Biotechnology of Sfax, Tunisia, evaluated the effects of four selected essential oils on planktonic cells and microbial biofilms of the Staphylococcus aureus strain (MRSA ATCC 33591)[1]. The essential oils studied were Geranium (Pelargonium graveolens, PgEO), Tea Tree (Melaleuca alternifolia, MaEO), Lemon peel (Citrus limon, ClEO), and Peppermint (Mentha piperita, MpEO). These oils were assessed for their antibacterial and antibiofilm activities. The minimum inhibitory concentrations (MICs) of these essential oils ranged from 1.56 to 12.5 µl/ml, indicating their potential as antibacterial agents. The study found that the essential oils exhibited significant antiadhesive activities against MRSA biofilms. Notably, Peppermint oil (MpEO) at a concentration of 3.12 µl/ml demonstrated an antiadhesive activity of up to 60%, while both Geranium (PgEO) and Peppermint (MpEO) oils achieved an eradication activity of 80% at the same concentration. This is particularly relevant as biofilms, which are structured communities of bacteria encased in a self-produced polymeric matrix, contribute significantly to the persistence and resistance of bacterial infections[3]. The antibiofilm activity was attributed to the binding of essential oil bioactive molecules to the SarA protein, a key regulator in biofilm formation. Previous studies have shown that mutation of the sarA gene results in reduced biofilm formation in several S. aureus strains[3]. This suggests that targeting SarA with essential oil molecules could be an effective strategy for disrupting biofilm formation and enhancing bacterial eradication. In addition to their antibiofilm properties, the essential oils also inhibited the synthesis of staphyloxanthin, a virulence factor produced by S. aureus. Staphyloxanthin is a golden pigment that protects the bacteria from oxidative stress and contributes to its virulence[4]. The study demonstrated that Geranium oil (PgEO) significantly inhibited staphyloxanthin synthesis at a concentration of MIC/2. This inhibition was linked to the binding of PgEO's main molecules, β-citronellol and geraniol, to the CrtM protein, which is involved in the staphyloxanthin biosynthetic pathway. The findings align with previous research indicating that blocking staphyloxanthin synthesis can enhance the susceptibility of S. aureus to treatments. For instance, cold atmospheric plasma (CAP) treatment was found to be more effective against S. aureus strains lacking staphyloxanthin or its intermediates[4]. This suggests that essential oils could be used in combination with other bactericidal strategies to improve their efficacy. In summary, the study by the Center of Biotechnology of Sfax highlights the potential of essential oils as alternative antimicrobial agents against MRSA. By targeting key proteins involved in biofilm formation and virulence factor synthesis, these essential oils could offer a novel approach to controlling Staphylococcus aureus infections. Further research and clinical trials will be necessary to fully understand their mechanisms and optimize their use in medical applications.



Main Study

1) Unveiling the impact of selected essential oils on MRSA strain ATCC 33591: antibacterial efficiency, biofilm disruption, and staphyloxanthin inhibition.

Published 22nd May, 2024

Related Studies

2) The Cell Wall, Cell Membrane and Virulence Factors of Staphylococcus aureus and Their Role in Antibiotic Resistance.

3) Mutation of sarA in Staphylococcus aureus limits biofilm formation.

Journal: Infection and immunity, Issue: Vol 71, Issue 7, Jul 2003

4) Protective Effect of the Golden Staphyloxanthin Biosynthesis Pathway on Staphylococcus aureus under Cold Atmospheric Plasma Treatment.

Related Articles

An unhandled error has occurred. Reload 🗙