Effect of Weak Acid Hypochlorous Solution on Selected Viruses and Bacteria of Laboratory Rodents

Abstract

Weak acid hypochlorous solution (WAHS) is known to have efficacy for inactivating pathogens and to be relatively safe with respect to the live body. Based on these advantages, many animal facilities have recently been introducing WAHS for daily cleaning of animal houses. In this study, we determined the effect of WAHS in inactivating specific pathogens of laboratory rodents and pathogens of opportunistic infection. WAHS with an actual chloride concentration of 60 ppm and a pH value of 6.0 was generated using purpose-built equipment. One volume of mouse hepatitis virus (MHV), Sendai virus, lymphocytic choriomeningitis virus, Bordetella bronchiseptica, Pasteurella pneumotropica, Corynebacterium kutscheri, Staphylococcus aureus, and Pseudomonas aeruginosa was mixed with 9 or 99 volumes of WAHS (×10 and ×100 reaction) for various periods (0.5, 1, and 5 min) at 25°C. After incubation, the remaining infectious viruses and live bacteria were determined by plaque assay or culture. In the ×100 reaction mixture, infectious viruses and live bacteria could not be detected for any of the pathogens examined even with the 0.5-min incubation. However, the effects for MHV, B. bronchiseptica, and P. aeruginosa were variable in the ×10 reaction mixture with the 0.5- and 1-min incubations. Sufficient effects were obtained by elongation of the reaction time to 5 min. In the case of MHV, reducing organic substances in the virus stock resulted in the WAHS being completely effective. WAHS is recommended for daily cleaning in animal facilities but should be used properly in order to obtain a sufficient effect, which includes such things as using a large enough volume to reduce effects of organic substances.

Methods to mitigate infection spread from aerosol‐generating dental procedures

“…Other germicidal agents, such as hypochlorous acid fogs, used at a concentration of 600 ppm for 10 minutes following removal of all organic matter have demonstrated some efficacy in clinical settings 78 …”

Standardization of a Protocol for Quantitative Evaluation of Anti-Aerosolized Influenza Virus Activity by Vapors of a Chemically-Characterized Essential Oil Blend

“…In addition, the increase in reduction of the quantified HA titer in the inoculated embryonated eggs with more elongation of the contact time between the H9N2 virus and the EOB provided evidence on the effectiveness of this blend in reducing the ability of the surviving H9N2 particles to propagate. It is worth noting that other works pointed at sanitizers that injure viruses, thus lowering their ability to multiply in the host cells [49][50][51]. Moreover, the 100% survival of the embryos inoculated by the transport medium, containing only the collected vapor of the EOB, is indicative of the vapor's safety, a data that is in agreement with another work that reported the safety of direct inoculation in chicken embryos of high concentrations of the liquid phase of an equivalent ratio of Eucalyptus and peppermint (1/1 V/V) [52].…”

Effect of hypochlorous acid solution on the eradication and prevention of <i>Pseudomonas aeruginosa</i> infection, serum biochemical variables, and cecum microbiota in rats

“…Environmental cleanup in such facilities is carried out using a chlorhexidine or phenolic disinfectant, and/or by supplying antibiotics, or tap water acidified with hydrochloric acid at pH 2.5 to 3.0. Recently, effectiveness of the weak acid hypochlorous solution in vitro on various microorganisms including P. aeruginosa was reported [ 5 , 7 ]. On the other hand, the solution used as disinfectant for drinking water was ineffective as the effectiveness of HClO in the weak acid hypochlorous solution is possibly decreased by contact with organic materials in the stomach and intestine, and the effect of the weak acid hypochlorous solution on murine Norovirus was limited to the small intestine [ 8 ].…”

“…HClO has been reported to be effective against various microorganisms [ 5 ], while on the other hand, the efficacy of HClO in solution is decreased possibly due to contact with organic material in the stomach and intestine, and therefore when added to drinking water for animals, it has not been proven effective in eliminating pathogens [ 9 ]. Taharaguchi et al have suggested the use of weak acid hypochlorous solution for routine cleaning in animal facilities, but they also point out that the effect could be reduced due to the presence organic material [ 7 ]. The effect of weak acid hypochlorous solution on murine Norovirus in the mouse cecum has been reported to be limited [ 8 ].…”