Antibiofilm efficacy of honey and bee-derived defensin-1 on multispecies wound biofilm

Abstract

Many clinically relevant biofilms are polymicrobial. Examining the effect of antimicrobials in a multispecies biofilm consortium is of great clinical importance. The goal of this study was to investigate the effect of different honey types against bacterial wound pathogens grown in multispecies biofilm and to test the antibiofilm activity of honey defensin-1 (Def-1) in its recombinant form. A modified Lubbock chronic wound biofilm formed by four bacterial species (Staphylococcus aureus, Streptococcus agalactiae, Pseudomonas aeruginosa and Enterococcus faecalis) was used for evaluation of honey and recombinant bee-derived Def-1 antibiofilm efficacy. Recombinant Def-1 was prepared by heterologous expression in Escherichia coli. We showed that different types of honey (manuka and honeydew) were able to significantly reduce the cell viability of wound pathogens (Staphylococcus aureus, Streptococcus agalactiae and Pseudomonas aeruginosa) in mature polymicrobial biofilm. None of the tested honeys showed the ability to eradicate Enterococcus faecalis in biofilm. In addition, recombinant Def-1 successfully reduced the viability of Staphylococcus aureus and Pseudomonas aeruginosa cells within established polymicrobial biofilm after 24 and 48 h of treatment. Interestingly, recombinant Def-1 did not affect the viability of Streptococcus agalactiae cells within the biofilm, whereas both natural honeys significantly reduced the viable bacteria. Although Enterococcus faecalis was highly resistant to Def-1, Def-1 significantly affected the biofilm formation of Enterococcus faecalis and Streptococcus agalactiae after 24 h of treatment, most likely by inhibiting its extracellular polymeric substances production. In conclusion, our study revealed that honey and Def-1 are effective against established multispecies biofilm; however, Enterococcus faecalis grown in multispecies biofilm was resistant to both antimicrobials.

Exosome-like vesicles in Apis mellifera bee pollen, honey and royal jelly contribute to their antibacterial and pro-regenerative activity

“…Therefore, the antibiofilm effect of beederived ELVs on S. aureus, paired with their pro-migratory activity, could potentially be used in treatments to improve wound healing in clinics. Some previous studies have reported antibiofilm activity of honey and honey-derived defensin-1 on wound pathogens and species (Majtan et al, 2014;Sojka et al, 2016); however, our results are the first to demonstrate that ELVs possess a biofilm-inhibitory effect on S. aureus, across all three bee-derived compounds tested.…”

Honey-sensitive Pseudomonas aeruginosa mutants are impaired in catalase A

“…Both types of honey were found effective against P. aeruginosa (Blair et al, 2009;Kacaniova et al, 2011). Recently, the antimicrobial power of Manuka honey against multi-species biofilm has been compared with that of HD honey (Sojka et al, 2016), and also in this case, both honeys were able to significantly reduce the cell viability of this micro-organism. Our results are thus consistent with the above-mentioned observations.…”

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

“…faecalis together with Enterococcus faecium demonstrate an intrinsic resistance to common antibiotics and they readily acquire resistance to other novel classes of antibiotics due to a plastic genome [28]. In our previous study [29], within a multispecies biofilm, E. faecalis was shown to be resistant to honeydew honey and manuka honey, as well as to the antibacterial peptide defensin-1. These results are in agreement with those of other studies, where E. faecalis exhibited the highest resistance among the nosocomial and foodborne pathogens against Corsican and Italian honeys [30,31].…”

“…We used the previously described modified Lubbock chronic wound biofilm model according to Sojka et al (2016) [29]. First, 6 mL of medium, containing Bolton broth base (Sigma-Aldrich, Germany), 1% gelatin, 50% porcine plasma, and 5% porcine erythrocytes lysed by freeze-thawing, was dispensed into sterile 1.6 × 10 cm glass tubes.…”