Treatment of Oral Biofilms by a D-Enantiomeric Peptide

Abstract

Almost all dental diseases are caused by biofilms that consist of multispecies communities. DJK-5, which is a short D-enantiomeric, protease-resistant peptide with broad-spectrum anti-biofilm activity, was tested for its effect on oral multispecies biofilms. Peptide DJK-5 at 10 μg/mL effectively prevented the growth of these microbes in culture media in a time-dependent manner. In addition to the prevention of growth, peptide DJK-5 completely killed both Streptococcus mutans and Enterococcus faecalis suspended from biofilms after 30 minutes of incubation in liquid culture media. DJK-5 also led to the effective killing of microbes in plaque biofilm. The proportion of bacterial cells killed by 10 μg/mL of DJK-5 was similar after 1 and 3 days, both exceeding 85%. DJK-5 was able to significantly prevent biofilm formation over 3 days (P = 0.000). After 72 hours of exposure, DJK-5 significantly reduced and almost completely prevented plaque biofilm production by more than 90% of biovolume compared to untreated controls (P = 0.000). The proportion of dead biofilm bacteria at the 10 μg/mL DJK-5 concentration was similar for 1- and 3-day-old biofilms, whereby >86% of the bacteria were killed. DJK-5 was also able to kill >79% and >85% of bacteria, respectively, after one-time and three brief treatments of 3-day-old biofilms. The combination of DJK-5 and chlorhexidine showed the best bacterial killing among all treatments, with ~83% and >88% of bacterial cells killed after 1 and 3 minutes, respectively. No significant difference was found in the percentage of biofilm killing amongst three donor plaque samples after DJK-5 treatment. In particular, DJK-5 showed strong performance in inhibiting biofilm development and eradicating pre-formed oral biofilms compared to L-enantiomeric peptide 1018. DJK-5 was very effective against oral biofilms when used alone or combined with chlorhexidine, and may be a promising agent for use in oral anti-biofilm strategies in the future.

Antibiofilm peptides against biofilms on titanium and hydroxyapatite surfaces

“…In the long-term exposure test, significantly more microorganisms were killed at the higher concentration (10 μg/mL) of DJK-5 and 1018 than at the lower concentration (2 μg/mL) ( Fig. 4 ; p < 0.05) on both Ti and HA disks, as also shown in previously studies [ 27 , 28 ]. Interestingly, exposure of pre-formed biofilms to DJK-5 after 24 h of biofilm growth showed a higher proportion of killed bacteria on both disks, compared to biofilms grown only for 6 h ( Fig.…”

Difference in virulence and composition of a cariogenic biofilm according to substratum direction

“…The original confocal data was uploaded to Imaris 8.0.2 software and the intensity of green and red fluorescence in full thickness of biofilm layers were captured automatically. The software reconstructed the 2-dimentional intensity of fluorescence in all the layers to a 3-dimentional volume stack 22 .…”

Reprogramming biological peptides to combat infectious diseases

“…In this series, the D-peptides presented the most promising low cytotoxicity against mammalian cells, which is an expected effect of the insertion of D-amino acids on lytic peptides sequences, 47 and inhibitory activity at low concentrations (10 mg mL À1 ) against the formation of biofilms by multidrug-resistant P. aeruginosa strains. 48,49 Biofilms are aggregates of microorganisms in which cells are embedded in a self-produced matrix of extracellular polymeric substances that are adhere to each other and to a surface 50 (Fig. 8A).…”

“…We have reported several classes of AMPs as versatile antibiofilm agents. 48,[61][62][63][64][65][66][67][68][69][70][71] LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) and its fragment sequence 1037 (RFRIRVRV-NH 2 ) were two of the first AMPs described as antibiofilm peptides against P. aeruginosa laboratory strains under dynamic continuous flow conditions 72 and also against pathogens isolated from cystic fibrosis patients. 61 Later, the bactenecin-derived AMP 1018 (RLIVAVRIWRR-NH 2 ) and additional analogs were also described as antibiofilm peptides with higher activity against biofilms than planktonic bacteria, and more active than other active molecules, such as LL-37 and 1037, under the same conditions.…”