Comparison of the virucidal efficacy of peracetic acid, potassium monopersulphate and sodium hypochlorite on bacteriophages P001 and MS2

AimsThe phagicidal activity of peroxy products against the virulent bacteriophage P001 infecting lactic acid bacteria and bacteriophage MS2 used as a surrogate of enteric viruses (EVs) was evaluated and compared to sodium hypochlorite using the EN 13610 European suspension test and a surface test developed in our laboratories. Methods and ResultsInfectivity tests were adapted and/or developed to determine the activity of disinfectants against reference P001 phage of Lactoccocus lactis and F-specific RNA phage MS2 of Escherichia coli in conditions simulating practical use. Similar concentrations of sodium hypochlorite were phagicidal against both bacteriophages, either at 005-0125% of active chlorine using the suspension test or at 012-05% using the surface test. For Potassium monopersulphate (MPS), phagicidal concentrations varied from 0006 to 0012% whatever the type of test and phages. However, for peracetic acid products (PAP) used in suspension, concentrations 55 times higher were necessary against MS2 (0271%) than against P001 (0005%). With the surface test, 0089-0178% concentrations of PAP were effective against MS2, but these concentrations were 16-32 times greater than needed against P001. ConclusionsSodium hypochlorite and MPS had similar phagicidal activities against P001 and MS2, but PAP did not. Significance and Impact of the StudyThis is the first comparative study to investigate through suspension and surface tests the difference in resistance to peroxy compounds between a reference bacteriophage (P001) used to evaluate phagicidal concentrations in European standards and a surrogate of EVs (MS2). Results underline the importance of validation tests on pertinent surrogates of viruses or bacteriophages to adjust the concentration of disinfectants for use in the food and water industries.