Antimicrobial and Antibiofilm Activity and Machine Learning Classification Analysis of Essential Oils from Different Mediterranean Plants against Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa is a ubiquitous organism and opportunistic pathogen that can cause persistent infections due to its peculiar antibiotic resistance mechanisms and to its ability to adhere and form biofilm. The interest in the development of new approaches for the prevention and treatment of biofilm formation has recently increased. The aim of this study was to seek new non-biocidal agents able to inhibit biofilm formation, in order to counteract virulence rather than bacterial growth and avoid the selection of escape mutants. Herein, different essential oils extracted from Mediterranean plants were analyzed for their activity against P. aeruginosa. Results show that they were able to destabilize biofilm at very low concentration without impairing bacterial viability. Since the action is not related to a bacteriostatic/bactericidal activity on P. aeruginosa, the biofilm change of growth in presence of the essential oils was possibly due to a modulation of the phenotype. To this aim, application of machine learning algorithms led to the development of quantitative activity–composition relationships classification models that allowed to direct point out those essential oil chemical components more involved in the inhibition of biofilm production. The action of selected essential oils on sessile phenotype make them particularly interesting for possible applications such as prevention of bacterial contamination in the community and in healthcare environments in order to prevent human infections. We assayed 89 samples of different essential oils as P. aeruginosa anti-biofilm. Many samples inhibited P. aeruginosa biofilm at concentrations as low as 48.8 µg/mL. Classification of the models was developed through machine learning algorithms.

Biofilm-inhibition activities of fractions of Senna Siamea (LAM) Irwin Barneby leaf against Escherichia coli

“…This observation is similar to that of Gislene et al (2000) where it was reported that plant extracts like Syzygyum joabolanum inhibited the growth of resistant bacteria at lower concentration. Supporting this fact is the work of Artini et al (2018) where it was reported that different essential oils extracted from mediterranean plants were able to destabilize biofilm at very low concentration without impairing bacterial viability.…”

Antibiofilm potential of purified environmental bacteriophage preparations against early stage Pseudomonas aeruginosa biofilms

“…Artini et al . () reported that essential oil extracts from Mediterranean plants were able to destabilize P. aeruginosa biofilms without affecting bacterial viability.…”

“…For example, Papa et al (2015) reported the antibiofilm but nonbiocidal effects of supernatants from Arctic and Antarctic bacteria against Staphylococcus aureus, Staphylococcus epidermidis and P. aeruginosa. Artini et al (2018) reported that essential oil extracts from Mediterranean plants were able to destabilize P. aeruginosa biofilms without affecting bacterial viability.…”

Antimicrobial and anti-biofilm activity of olive oil by-products against Campylobacter spp. isolated from chicken meat

“…A large proportion of European chicken production is contaminated with Campylobacter (EFSA/ECDC, 2017) and since poultry meat is highly perishable and consumption is growing globally (Daniel et al, 2011;Roila et al, 2018), its microbiological safety is of the utmost importance. Consumer concern about food safety has increased and, in this regard, there is growing interest in the use of natural antibacterial compounds like plant extracts rich in phenols (Artini et al, 2018;Silván et al, 2013). Such compounds have been demonstrated to exhibit antimicrobial properties and could represent an innovative approach to providing consumers with safer food products in the post-antibiotic era.…”