Chestnut Honey and Bacteriophage Application to Control Pseudomonas aeruginosa and Escherichia coli Biofilms: Evaluation in an ex vivo Wound Model

Abstract

Chronic skin wounds represent a major burn both economically and socially. Pseudomonas aeruginosa and Escherichia coli are among the most common colonizers of infected wounds and are prolific biofilm formers. Biofilms are a major problem in infections due to their increasingly difficult control and eradication, and tolerance to multiple prescribed drugs. As so, alternative methods are necessary. Bacteriophages (phages) and honey are both seen as a promising approach for biofilm related infections. Phages have specificity toward a bacterial genus, species or even strain, self-replicating nature, and avoid dysbiosis. Honey has gained acknowledgment due to its antibacterial, antioxidant and anti-inflammatory and wound healing properties. In this work, the effect of E. coli and P. aeruginosa phages vB_EcoS_CEB_EC3a and vB_PaeP_PAO1-D and chestnut honey, alone and combined, were tested using in vitro (polystyrene) and ex vivo (porcine skin) models and against mono and dual-species biofilms of these bacteria. In general, colonization was higher in the porcine skins and the presence of a second microorganism in a consortium of species did not affect the effectiveness of the treatments. The antibacterial effect of combined therapy against dual-species biofilms led to bacterial reductions that were greater for biofilms formed on polystyrene than on skin. Monospecies biofilms of E. coli were better destroyed with phages and honey than P. aeruginosa monospecies biofilms. Overall, the combined phage-honey formulations resulted in higher efficacies possibly due to honey's capacity to damage the bacterial cell membrane and also to its ability to penetrate the biofilm matrix, promoting and enhancing the subsequent phage infection.

Vitamin C Enhances the Antibacterial Activity of Honey against Planktonic and Biofilm-Embedded Bacteria

“…In the case of biofilm-embedded bacteria, honey becomes less effective, and a high concentration of a honey solution is needed to eradicate the bacteria within the biofilm. To facilitate improvements in the antibacterial efficacy of honey, particularly against bacterial biofilms, honey has been supplemented with several distinct substances, including antimicrobial peptides [15], bacteriophages [26,27], and essential oils [17]. In the present study, we showed that supplementation of different types of honey with sub-MICs of Vit C resulted in a significant enhancement of the antibacterial activity against P. aeruginosa and E. coli.…”

Using Bacteriophages as a Trojan Horse to the Killing of Dual-Species Biofilm Formed by Pseudomonas aeruginosa and Methicillin Resistant Staphylococcus aureus

“…Bacteriophages (phages) have regained interest as promising therapeutic option in fighting biofilmrelated infections due to their rapid bactericidal activity, the self-amplification ability and potential biofilm degradative properties (Harper et al, 2014). However, there are only limited studies investigating the activity of phages against polymicrobial biofilms (Sillankorva et al, 2010;Kay et al, 2011;Chhibber et al, 2015;Oliveira et al, 2018;Melo et al, 2019) and just recently Akturk et al (2019) evaluated the simultaneous and staggered administration of a P. aeruginosa-targeting monophage and conventional antibiotics on S. aureus/P. aeruginosa dualspecies biofilms.…”

Bacteriophages for Chronic Wound Treatment: From Traditional to Novel Delivery Systems

“…In this model, the phage challenge was significantly more effective than in an in vitro model. A previous study by Oliveira et al [122] showed that phages and chestnut honey action against biofilms formed in non-damaged porcine skin explants (which closely mimicked scratch wounds) increased with time against E. coli and P. aeruginosa mono and dual-species biofilms. The combined therapy resulted in bacterial reductions that were more effective on E. coli than on P. aeruginosa biofilms.…”