Inactivation of the enveloped virus phi6 with hydrodynamic cavitation

The COVID-19 pandemic reminded us that we need better contingency plans to prevent the spread of infectious agents and the occurrence of epidemics or pandemics. Although the transmissibility of SARS-CoV-2 in water has not been confirmed, there are studies that have reported on the presence of infectious coronaviruses in water and wastewater samples. Since standard water treatments are not designed to eliminate viruses, it is of utmost importance to explore advanced treatment processes that can improve water treatment and help inactivate vi-ruses when needed. This is the first study to investigate the effects of hydrodynamic cavitation on the inacti-vation of bacteriophage phi6, an enveloped virus used as a SARS-CoV-2 surrogate in many studies. In two series of experiments with increasing and constant sample temperature, virus reduction of up to 6.3 logs was achieved. Inactivation of phi6 at temperatures of 10 and 20 degrees C occurs predominantly by the mechanical effect of cavitation and results in a reduction of up to 4.5 logs. At 30 degrees C, the reduction increases to up to 6 logs, where the temperature-induced increased susceptibility of the viral lipid envelope makes the virus more prone to inacti-vation. Furthermore, the control experiments without cavitation showed that the increased temperature alone is not sufficient to cause inactivation, but that additional mechanical stress is still required. The RNA degradation results confirmed that virus inactivation was due to the disrupted lipid bilayer and not to RNA damage. Hy-drodynamic cavitation, therefore, has the potential to inactivate current and potentially emerging enveloped pathogenic viruses in water at lower, environmentally relevant temperatures.

Automated summary

The study investigates the effects of hydrodynamic cavitation on the inactivation of SARS-CoV-2 surrogate bacteriophage phi6. The results show that hydrodynamic cavitation can significantly reduce the virus count at certain temperatures. This suggests that hydrodynamic cavitation has the potential to inactivate current and potential enveloped viruses in water at lower temperatures.