Persistent suppression of bacterial growth after exposure to high-frequency alternated current

Abstract number: 1734_65

Cassanelli C., Roveta S., Marchese A., Debbia E.A.

Background: The exposure of a bacterial suspension to the hight frequency alternated current (HFAC) damages the bacterial envelope and delayes cell division. In this study was verified if the HFAC generated by Endox® Endodontic System, an instrument used in endodontic treatment for disinfection of the root canal, produced a phenomenon similar to postantibiotic effect.

Methods:P. aeruginosa and E. faecalis strains employed in this study were clinical isolated belonging to the collection of this Laboratory. A sample of 0.1 ml of a saline bacterial suspension (105 cell/mL) was exposed to HFAC (140 msec, 500 kHz, 1200 kV) for three times and then resuspended in 10 ml of Mueller–Hinton broth. A suspension not treated was employed as control. The suspensions were grown at 37°C for 6–8 hours; plate counts were performed every 60 min. All experiments were repeated for five times.

Results: A persistent suppression of bacterial growth of about 3 hours was observed in the two bacterial species after exposure to HFAC. In the control strains no growth suppression was noted.

Conclusion: The present findings suggest that HFAC generated by Endox® Endodontic System produce a damage in the structure of bacterical cells membrane. This phenomen can be usefull to study the possible variations in the permeability of bacterial membranes and is probaly responsable of bactericidal effect of this instrument.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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