The COVID-19 pandemic has deeply influenced everyone’s cleaning and sanitisation procedures. High-level disinfection has been extensively used to prevent the spread of SARS-CoV-2, but it has most certainly come with potential negative impacts on our environment and contributes to the serious threat posed by antimicrobial resistance (AMR). The researchers leading this latest study (published in November 2021), aimed to identify how effective sanitisation and cleaning activity could be preserved while also using probiotics which in their past studies have been proven time and time again to be an effective eco-friendly and more sustainable. In previous research within healthcare settings – the team had identified probiotic detergents were able to consistently abate pathogen contamination over sustained periods and reduce the risks associated with AMR. Their previous results were very positive: probiotic cleaning agents stably reduced resistant pathogens by 80% probiotics reduced associated hospital infections by 52% and; probiotics for cleaning had a relevant positive impact on antimicrobial resistance (60% decrease) leading to a 75% reduction in healthcare-associated infection costs
The results showed that the probiotic cleaning solutions were able to inactivate 99.99% of all tested viruses within 1–2 hours of contact, both in a suspension and on surfaces.
Notably, while control disinfectants became inactive within 2 hours after application, the probiotic antiviral action persisted up to 24 hours post application. This suggests that its use may effectively allow a continuous prevention of virus spread, without worsening environmental pollution or the likelihood of AMR.
- The tests performed with probiotics on Coronaviruses and the most highly resistant MVA viruses, evidenced a high inactivation activity both in decontamination and in prevention.
- Notably, probiotic-treated surfaces completely inactivated viruses, even 24 hours after treatment. By comparison the surfaces treated with disinfectants did not maintain their inactivating ability over time (up to 2 hours only).
- 2 hours after application, one of the disinfectants used actually had its effectiveness drop below the minimum threshold needed for it to be considered as a ‘virucidal’ agent. Beyond 2 hours from application, the antiviral activity of both the chemical disinfectants tested had disappeared completely.
- The results showed that probiotics were active on all enveloped viruses at all dilutions in a time-dependent manner. In particular, the 1:100 dilution completely inactivated within 1 h all tested viruses except for MVA, which was inactivated in 2 h.
- It is proposed that the presence of enzymes in probiotics that are capable of processing lipids, proteins, and sugars, support the hypothesis that such cleaning agents could chemically degrade the outer components of enveloped viruses, achieving successful virus inactivation.
- To manage the varying infectious activity times for more resistant viruses, the study indicated higher concentrations of probiotic detergents were beneficial. Higher concentrations can be also used to obtain inactivation in shorter periods (e.g. after an confirmed case).
- The surfactants contained in detergent are known to disrupt and damage the envelope of viruses and may thus account at least in part for the probiotics’ antiviral action. It is however the active enzymes in the Bacilli strain of probiotics that is likely to contribute to the continuous cleaning action witnessed.