Researchers analyzed 61 commercial essential oils to assess their ability to modulate the biofilm formation of 6 Pseudomonas aeruginosa clinical strains, which have been identified as inducing chronic infections in patients with cystic fibrosis (CF). The study, published in Microorganisms, sheds light on the chemical components of essential oils that might underlie biofilm formation in this disease.

“In the airways of CF patients, P. aeruginosa persists, inducing a chronic infection,” the authors wrote. “The ability to form a biofilm plays a pivotal role in CF airway colonization by P. aeruginosa. Indeed, among its various virulence factors, the ability to produce highly structured biofilms confers important advantages, including phenotypic resistance to host defenses, antibiotics, and disinfectants.”

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The team aimed to derive a new strategy to combat P. aeruginosa infection by identifying compounds that act on biofilm formation, thereby potentially enhancing the effectiveness of therapies to treat chronic infections in patients with CF. Essential oils have been demonstrated to modulate biofilm production in various pathogens, including Staphylococcus aureus, Staphylococcus epidermidis, and P. aeruginosa strains.

The researchers applied machine learning algorithms including clustering to evaluate 61 essential oils on 40 isolates of S. aureus and P. aeruginosa strains from patients with CF. The results showed that among the 61 essential oils, thymol, p-cymene, citronellal, and carvacrol were all involved in stimulating biofilm production in the CF isolates, while linalool endowed essential oils with antibiofilm formation properties.

The researchers caution that essential oils are complex molecules and further studies are required to confirm the role of individual molecules and their synergistic effects on biofilm formation in CF. Nevertheless, the identification of compounds that can inhibit biofilm formation could signal a significant advance in targeting a primary cause of persistent infections in these patients.

Reference

Artini M, Papa R, Sapienza F, et al. Essential oils biofilm modulation activity and machine learning analysis on Pseudomonas aeruginosa isolates from cystic fibrosis patients. Microorganisms. Published online April 24, 2022. doi:10.3390/microorganisms10050887