Effects of antimicrobial peptide DJK-5 on cariogenic virulence factors of Streptococcus mutans biofilm
- 1Department of Orthodontics, The Affiliated Stomatological Hospital of Jiujiang University, Jiujiang 332000, China
Abstract
Objective To investigate the effect of DJK-5 on the bactericidal efficacy and cariogenic virulence factors of Streptococcus mutans (S. mutans) biofilms. Methods S. mutans suspensions were treated with DJK-5 at concentrations of 0, 5, 10, 20, and 40 μg/mL, and bacterial growth was observed. S. mutans biofilms were treated with sterile deionized water (Control group), 2% chlorhexidine (CHX group) and DJK-5 at concentrations of 10, 20, 40 μg/mL. The structural changes in biofilm were observed using laser confocal microscopy. The production of water-insoluble extracellular polysaccharide (IEPS) and pH values were quantified using the anthrone-sulfuric acid method and a pH meter, respectively. Additionally, the effects of 10 μg/mL DJK-5 on the expression of cariogenic virulence genes in S. mutans biofilms were detected by RT-qPCR. Results DJK-5 at concentrations ≥10 μg/mL exhibited an inhibitory effect on the growth of planktonic S. mutans. The higher the concentration of DJK-5, the more pronounced the inhibitory effect. The volume ratios of dead bacteria in the DJK-5 groups were significantly higher than those in the control and chlorhexidine group. The disruption of spatial structure became more severe with increasing DJK-5 concentrations. The pH values in DJK-5-treated biofilms were significantly higher than those in the control group, and the pH levels in the 20 and 40 μg/mL DJK-5 groups were significantly higher than those in the NaF group. The production of IEPS in DJK-5-treated biofilms was significantly lower than that in the control group. The 10 μg/mL DJK-5 group produced significantly more IEPS than the 40 μg/mL DJK-5 group and the NaF group. DJK-5 promoted the expression of gtfC and gbpB genes, while suppressed the expression of ldh, comDE, and relA genes. Conclusion DJK-5 significantly inhibits acid production and IEPS synthesis in biofilms by targeting and modulating the cariogenic virulence factors of S. mutans, thereby demonstrating highly efficient bactericidal activity against biofilms.
Related
- Global Carriage of Antimicrobial Resistance Genes and Virulence Factors Among Physicians in Cirrhosis Care
- Phosphorylation of RpoD upregulates suilysin and enhances Streptococcus suis virulence.
- In Ovo Exposure to Phenanthrene Promotes Antimicrobial Resistance Genes and Hemolysin Virulence Factor in Guts of Chicken Embryos
- Population-scale analysis of prophages and defense systems reveals distinct evolutionary routes for virulence and antimicrobial resistance in Staphylococcus aureus
- Two-component system VraSR senses host defense peptide PMAP-36 to promote Streptococcus suis pathogenicity through regulating accD expression
BibTeX
@article{hongfeng2026effects,
title = {{Effects of antimicrobial peptide DJK-5 on cariogenic virulence factors of Streptococcus mutans biofilm}},
author = {HONG Feng, CHENG Junxiang, DUAN Qinyan, PAN Le, HU Yajun},
journal = {Kouqiang yixue},
year = {2026},
month = oct,
doi = {10.13591/j.cnki.kqyx.2026.10.006},
url = {https://doi.org/10.13591/j.cnki.kqyx.2026.10.006},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Effects of antimicrobial peptide DJK-5 on cariogenic virulence factors of Streptococcus mutans biofilm
AU - HONG Feng, CHENG Junxiang, DUAN Qinyan, PAN Le, HU Yajun
PY - 2026
DA - 2026/10/28
JO - Kouqiang yixue
DO - 10.13591/j.cnki.kqyx.2026.10.006
UR - https://doi.org/10.13591/j.cnki.kqyx.2026.10.006
AB - Objective To investigate the effect of DJK-5 on the bactericidal efficacy and cariogenic virulence factors of Streptococcus mutans (S. mutans) biofilms. Methods S. mutans suspensions were treated with DJK-5 at concentrations of 0, 5, 10, 20, and 40 μg/mL, and bacterial growth was observed. S. mutans biofilms were treated with sterile deionized water (Control group), 2% chlorhexidine (CHX group) and DJK-5 at concentrations of 10, 20, 40 μg/mL. The structural changes in biofilm were observed using laser confocal microscopy. The production of water-insoluble extracellular polysaccharide (IEPS) and pH values were quantified using the anthrone-sulfuric acid method and a pH meter, respectively. Additionally, the effects of 10 μg/mL DJK-5 on the expression of cariogenic virulence genes in S. mutans biofilms were detected by RT-qPCR. Results DJK-5 at concentrations ≥10 μg/mL exhibited an inhibitory effect on the growth of planktonic S. mutans. The higher the concentration of DJK-5, the more pronounced the inhibitory effect. The volume ratios of dead bacteria in the DJK-5 groups were significantly higher than those in the control and chlorhexidine group. The disruption of spatial structure became more severe with increasing DJK-5 concentrations. The pH values in DJK-5-treated biofilms were significantly higher than those in the control group, and the pH levels in the 20 and 40 μg/mL DJK-5 groups were significantly higher than those in the NaF group. The production of IEPS in DJK-5-treated biofilms was significantly lower than that in the control group. The 10 μg/mL DJK-5 group produced significantly more IEPS than the 40 μg/mL DJK-5 group and the NaF group. DJK-5 promoted the expression of gtfC and gbpB genes, while suppressed the expression of ldh, comDE, and relA genes. Conclusion DJK-5 significantly inhibits acid production and IEPS synthesis in biofilms by targeting and modulating the cariogenic virulence factors of S. mutans, thereby demonstrating highly efficient bactericidal activity against biofilms.
SN - 1003-9872
ER -