Evaluation of the Effects of the Selected Physical and Chemical Effects to Reduce Human Norovirus Surrogate in Cell Culture Lysate

Introduction: Human norovirus (NoV) is a main cause of viral gastroenteritis worldwide. The incidence rate by NoV is steadily increasing in the foodborne diseases.   Chlorine, ethanol, quaternary ammonium and ultrasound have been used to inactivate NoV in foods or tool surface.  Many studies about virus inactivation methods are in progress, but more research needs to be developed.

Purpose: This study was conducted to investigate the effects of selected electrolyzed water, hydrogen peroxide, sodium chloride on the inactivation of MNV-1 as a NoV surrogate in the cell culture lysate.

Methods: The physical and chemical methods such as slightly acidic electrolyzed water (SAEW, chlorine 30 ppm for 0 to 60 min), hydrogen peroxide (H₂O₂, 0 to 50,000 ppm), sodium chloride (NaCl, 0 to 30%) were selected to inactivate MNV-1. The reduction effects of three disinfectants were evaluated by plaque assay.

Results: The total MNV-1 titers were significantly (P < 0.05) decreased with stepwise increase of exposure time of SAEW and concentration of H₂O₂ and NaCl. After MNV-1 cell culture lysate was exposed to SAEW for 5, 10, 20, 30, 60 min, the MNV-1 was reduced up to 2.10 log PFU/ml. After MNV-1 cell culture lysate was treated with 10,000 to 50,000 ppm H₂O₂ within 5 min and the MNV-1 was reduced up to 2.51 log PFU/ml. Compared to reduction of MNV-1 treated with SAEW and H₂O_2, the MNV-1 treated with 5-30 % NaCl was only reduced to less than 1.0 log PFU/ml. According to these results, MNV-1 was most reduced by 50,000 ppm  H₂O₂ and the treatment of NaCl was shown the least reduction.

Significance: SAEW and H₂O₂ could be applied as a good viral sanitizer whereas NaCl was not shown great efficacy against MNV-1. Especially, SAEW can use as an effective treatment against NoV surrogate such as MNV.