Vancomycin-Resistant Enterococcus faecium Sterilization and Conductivity Change by Impulse Voltage

Area of Science:

• Environmental microbiology
• Water treatment technologies
• Antimicrobial resistance

Background:

• Antibiotic resistance, particularly vancomycin resistance, is a growing global health concern.
• Conventional chlorine-based sewage sterilization may be insufficient to eliminate resistant bacteria.
• There is a need for effective methods to inactivate drug-resistant bacteria in wastewater.

Purpose of the Study:

• To investigate the efficacy of impulse voltage as a sterilization method for drug-resistant bacteria.
• To determine the optimal conditions for impulse-voltage-mediated bacterial inactivation.
• To explore the correlation between sterilization rate and physical parameters like temperature and conductivity.

Main Methods:

• Application of impulse voltage to bacterial suspensions containing drug-resistant strains.
• Varying applied voltage (above 4.5 kV) and application times.
• Monitoring bacterial inactivation rates (CFU/mL).
• Measuring temperature and electrical conductivity of the bacterial suspension.

Main Results:

• Sterilization of bacteria at concentrations above 10^5 CFU/mL was achieved with impulse voltages above 4.5 kV and sufficient application time.
• Sterilization effectiveness increased with higher temperatures of the bacterial suspension.
• A correlation was observed between the number of sterilized bacteria and electrical conductivity when exceeding 10^5 CFU/mL.

Conclusions:

• Impulse voltage is a viable method for inactivating drug-resistant bacteria in wastewater.
• Sterilization efficiency is influenced by voltage, application time, temperature, and electrical conductivity.
• Electrical conductivity can serve as a rapid indicator for estimating sterilization rates, eliminating the need for traditional culture methods.