Susceptibilities of periodontopathogenic and cariogenic bacteria to antibacterial peptides, {beta}-defensins and LL37, produced by human epithelial cells.
OBJECTIVE
Antimicrobial peptides are one of the factors involved in innate immunity. The susceptibility of periodontopathogenic and cariogenic bacteria to the major antimicrobial peptides produced by epithelia was investigated.


METHODS
Synthetic antimicrobial peptides of human beta-defensin-1 (hBD1), hBD2, hBD3 and LL37 (CAP18) were evaluated for their antimicrobial activity against oral bacteria. They included Actinobacillus actinomycetemcomitans (20 strains), Porphyromonas gingivalis (6), Prevotella intermedia (7), Fusobacterium nucleatum (7), Streptococcus mutans (5), Streptococcus sobrinus (5), Streptococcus salivarius (5), Streptococcus sanguis (4), Streptococcus mitis (2) and Lactobacillus casei (1).


RESULTS
Although the four peptides had bactericidal activity against all bacteria tested, the degree of antibacterial activity was variable against the different strains and species. The antibacterial activity of hBD1 was lower than that of the other peptides. Among the bacteria tested in this study, F. nucleatum was highly susceptible to hBD3 and LL37, and S. mutans was highly susceptible to hBD3. We measured the Zeta-potential, representing the net charge of whole bacteria, to study the relationship between susceptibility to cationic peptide and the net charge of the bacteria. Although we found some correlation in A. actinomycetemcomitans strains, we did not find a definite correlation with all the bacterial species.


CONCLUSIONS
These results indicate that beta-defensins and LL37 have versatile antibacterial activity against oral bacteria.
Ouhara
Kazuhisa
K
Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima 734-8553, Japan.
Komatsuzawa
Hitoshi
H
Yamada
Sakuo
S
Shiba
Hideki
H
Fujiwara
Tamaki
T
Ohara
Masaru
M
Sayama
Koji
K
Hashimoto
Koji
K
Kurihara
Hidemi
H
Sugai
Motoyuki
M
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D054804:Cathelicidins; D003731:Dental Caries / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010510:Periodontal Diseases / Q000382:microbiology*; D012463:Saliva / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology; D023083:beta-Defensins / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D023083:beta-Defensins; D012965:Sodium Chloride