Sub-lethal doses of photodynamic therapy affect biofilm formation ability and metabolic activity of Enterococcus faecalis

Pourhajibagher, Maryam; Chiniforush, Nasim; Shahabi, Sima; Ghorbanzadeh, Roghayeh; Bahador, Abbas

doi:10.1016/j.pdpdt.2016.06.003

Cited by 69 publications

(21 citation statements)

References 40 publications

(44 reference statements)

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“…ICG-APDI showed a stronger inhibitory effect on biofilm formation in E. faecalis than MB- and TBO-APDI at sub-lethal levels. Interestingly, a gradual increase in metabolic activity and biofilm formation were observed upon exposure to a lower dose of sAPDI [69]. …”

Section: Can Resistance Develop After Sub-lethal Apdi?mentioning

confidence: 99%

Can microbial cells develop resistance to oxidative stress in antimicrobial photodynamic inactivation?

Kashef

Hamblin

2017

Drug Resistance Updates

228

163

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Infections have been a major cause of disease throughout the history of humans on earth. With the introduction of antibiotics, it was thought that infections had been conquered. However, bacteria have been able to develop resistance to antibiotics at an exponentially increasing rate. The growing threat from multi-drug resistant organisms calls for intensive action to prevent the emergence of totally resistant and untreatable infections. Novel, non-invasive, non-antibiotic strategies are needed that act more efficiently and faster than current antibiotics. One promising alternative is antimicrobial photodynamic inactivation (APDI), an approach that produces reactive oxygen species when dyes and light are combined. So far, it has been questionable if bacteria can develop resistance against APDI. This review paper gives an overview of recent studies concerning the susceptibility of bacteria towards oxidative stress, and suggests possible mechanisms of the development of APDI-resistance that should at least be addressed. Some ways to potentiate APDI and also to overcome future resistance are suggested.

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Section: Can Resistance Develop After Sub-lethal Apdi?mentioning

confidence: 99%

Can microbial cells develop resistance to oxidative stress in antimicrobial photodynamic inactivation?

Kashef

Hamblin

2017

Drug Resistance Updates

228

163

View full text Add to dashboard Cite

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“…The findings showed that PDT-ICG and PDT-MB and TBO-PDT sub-lethal reduces 42.8%, 22.6%, and 19.5% of biofilms, the sub-lethal dose of PDT-ICG and PDT-MB and TBO PDT reduced 98%, 94%, 82% of metabolic activity, in Enterococcus faecal, respectively. 33 In another study, Pourhajibagher et al investigated the effect of sub-lethal photodynamic therapy on Porphyromongus gingivalis isolated from endodontic infections using diode laser light. The findings of this study showed that MB-sPAD (25 μg/ml-117.18 J/cm 2 ) and (50-100 μg/mL-117.18 J/cm 2 ) significantly inhibited the growth of P. gingivalis than the control group.…”

Section: Application Of Photodynamic Therapy In Vitromentioning

confidence: 99%

Antimicrobial Photodynamic Therapy: An Effective Alternative Approach to Control Bacterial Infections

et al. 2018

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Introduction: The purpose of this review was to evaluate the available literature for in vitro and in vivo effectiveness of antimicrobial Photodynamic therapy (aPDT) in the field of bacteriology. Methods: A review of the relevant articles carried out in PubMed and Scopus to determine the efficiency of aPDT used in the reduction of microbial infection. Thirty-one relevant documents retrieved from PubMed, Scopus by inserting "antimicrobial photodynamic therapy" and "bacterial infection" and "photodynamic therapy" keywords. Results: According to different results, aPDT can be used as an adjuvant for the treatment of infectious diseases. The use of photosensitizer methylene blue, toluidine blue O (TBO), indocyanine green with light diode laser centered at (630±10 nm) and (650±10 nm) wavelengths have been shown to have significant results for the treatment of infectious diseases and bactericidal properties Conclusion: These findings suggest that, aPDT can be an efficient method in the treatment of localized and superficial infections.

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“…To examine the eradication effects of GH12 against 1‐day‐old E. faecalis biofilm, 1 mL of E. faecalis suspension was dispensed into a 24‐well plate and grown at 37 °C for 24 h for biofilm formation (Pourhajibagher et al 2016). After incubation, the supernatant and unattached bacteria were removed.…”

Section: Methodsmentioning

confidence: 99%

Antimicrobial peptide GH12 as root canal irrigant inhibits biofilm and virulence of Enterococcus faecalis

Wang

Chen

et al. 2020

Int Endodontic J

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Aim The objectives of this laboratory‐based study were to investigate the effects of GH12 on Enterococcus faecalis biofilm and virulence. Methodology Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of GH12 against E. faecalis were first determined. A time‐kill assay was further conducted. The effects of GH12 on the expression of virulence and stress genes in E. faecalis were evaluated by RT‐qPCR. Crystal violet stain was used to investigate the effects of GH12 on E. faecalis biofilm formation and 1‐day‐old biofilm. Finally, an ex vivo tooth model contaminated with E. faecalis was used to evaluate the antimicrobial activity of GH12 as an irrigant by CFU counting, SEM and CLSM. One‐way anova and Tukey’s multiple comparisons test were used to compare the differences amongst groups (α = 0.05). Results The MICs and MBCs of GH12 against E. faecalis were 8.0 ± 0.0 and 16.0 ± 0.0 mg L−1, respectively, and GH12 at 32.0 mg L−1 reduced the bacterial numbers by more than 99.9% within 1 min. Various virulence genes (efaA, esp and gelE) and stress genes (dnaK, groEL, ctsR and clpPBCEX) in E. faecalis were significantly downregulated by GH12 at sub‐MIC levels (P < 0.05). Additionally, both E. faecalis biofilm formation and the biomass of 1‐day‐old E. faecalis biofilm were significantly reduced by GH12 (P < 0.05). Elimination of E. faecalis in biofilms from root canal walls was achieved through irrigation with 64.0 mg L−1 GH12 for 30 min. CLSM analysis revealed that GH12 at 64.0 mg L−1 was most effective in eliminating bacteria within dentinal tubules (P < 0.05). Conclusion In a laboratory setting, and when used as an irrigant, GH12 suppressed E. faecalis, downregulated specific virulence and stress‐associated genes, eliminated intracanal E. faecalis protected by biofilms and killed bacteria in dentinal tubules. These results emphasize the need for preclinical and clinical studies to explore the potential of GH12 as an antimicrobial agent during root canal treatment.

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Sub-lethal doses of photodynamic therapy affect biofilm formation ability and metabolic activity of Enterococcus faecalis

Cited by 69 publications

References 40 publications

Can microbial cells develop resistance to oxidative stress in antimicrobial photodynamic inactivation?

Can microbial cells develop resistance to oxidative stress in antimicrobial photodynamic inactivation?

Antimicrobial Photodynamic Therapy: An Effective Alternative Approach to Control Bacterial Infections

Antimicrobial peptide GH12 as root canal irrigant inhibits biofilm and virulence of Enterococcus faecalis

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