Synergistic effects of LFchimera and antibiotic against planktonic and biofilm form of Aggregatibacter actinomycetemcomitans

• Published in: PloS one Vol. 14; no. 7; p. e0217205
• Main Authors: Lachica, Marie Rossini Carmela T, Anutrakunchai, Chitchanok, Prajaneh, Saengsome, Nazmi, Kamran, Bolscher, Jan G M, Taweechaisupapong, Suwimol
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.07.2019; Public Library of Science (PLoS)
• Subjects: Actinomycetes; Adhesion; Aggregatibacter actinomycetemcomitans; Aggregatibacter actinomycetemcomitans - physiology; Amino acids; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics; Antimicrobial activity; Antimicrobial agents; Antimicrobial Cationic Peptides - agonists; Antimicrobial Cationic Peptides - chemistry; Antimicrobial Cationic Peptides - genetics; Antimicrobial Cationic Peptides - pharmacology; Antimicrobial peptides; Bacteria; Bacterial infections; Biochemistry; Biofilms; Biofilms - drug effects; Biofilms - growth & development; Biology and Life Sciences; Chemical compounds; Confocal microscopy; Dentistry; Doxycycline; Drug resistance; Drug Synergism; Gum disease; Humans; Infection; Lactoferrin; Lactoferrin - agonists; Lactoferrin - chemistry; Lactoferrin - genetics; Lactoferrin - pharmacology; Medical research; Medicine and Health Sciences; Metronidazole; Microbial drug resistance; Microscopy; Minocycline; Peptides; Periodontitis; Periodontitis - drug therapy; Periodontitis - microbiology; Pharmacology; Plankton - growth & development; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - pharmacology; Reduction; Risk factors; Scanning microscopy; Studies; Synergism; Synergistic effect; Tetracyclines; Germany; Netherlands; Thailand; Philippines
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0217205

Adjunctive use of antibiotics in periodontal treatment have limitations and disadvantages including bacterial resistance. Antimicrobial peptides (AMPs) are potential new agents that can combat bacterial infection. In this study, antimicrobial activity of different concentrations of conventional antibiotics minocycline (MH), doxycycline (DOX), and antimicrobial peptides LL-37, LL-31, Lactoferrin chimera (LFchimera) and Innate Defense Regulator Peptide 1018 (IDR-1018) against Aggregatibacter actinomycetemcomitans ATCC 43718 were determined using colony culturing assay. Subsequently, in vitro activity of the most effective drug and peptide combination was evaluated by checkerboard technique. Impact of the drug and peptide co-administration on biofilm at different stages, i.e., during adhesion and 1-day old biofilm was compared to each of the agents used alone. Results revealed that the killing effects of all AMPs range from 13-100%. In contrast, MH and DOX at 1 and 5 μM showed no killing activity and instead stimulated growth of bacteria. DOX has better killing activity than MH. LFchimera displayed the strongest killing amongst the peptides. Checkerboard technique revealed that combining DOX and LFchimera yielded synergism. Confocal laser scanning microscopy further showed that the combination of DOX and LFchimera caused significant reduction of bacterial adhesion and reduction of biomass, average biofilm thickness and substratum biofilm coverage of 1-day old biofilm compared to DOX and LFchimera alone. In conclusion, LFchimera alone and in combination with DOX exhibited strong antibacterial and anti-biofilm property against A. actinomycetemcomitans. The findings suggest that LFchimera should be considered for development as a new potential therapeutic agent that may be used as an adjunctive treatment for periodontitis.