Microbicidal effects of weakly acidified chlorous acid water against feline calicivirus and Clostridium difficile spores under protein-rich conditions.

Hisataka Goda,Hitoshi Yamaoka,Yatsuka Fujita,Isanori Horiuchi,Atsushi Terada,Hiroyuki Kawata,Tamiko Nagao,Ayano Tada,Haruyuki Nakayama-Imaohji,Tomomi Kuwahara,Vijai Gupta

doi:10.1371/journal.pone.0176718

Hisataka Goda, Hitoshi Yamaoka + Show 9 more

Open Access

https://doi.org/10.1371/journal.pone.0176718

Copy DOI

Journal: PloS one	Publication Date: May 4, 2017
Citations: 19	License type: CC BY 4.0

Affiliation: Nihon University, Shikoku University, Kagawa University

Abstract

Sanitation of environmental surfaces with chlorine based-disinfectants is a principal measure to control outbreaks of norovirus or Clostridium difficile. The microbicidal activity of chlorine-based disinfectants depends on the free available chlorine (FAC), but their oxidative potential is rapidly eliminated by organic matter. In this study, the microbicidal activities of weakly acidified chlorous acid water (WACAW) and sodium hypochlorite solution (NaClO) against feline calcivirus (FCV) and C. difficile spores were compared in protein-rich conditions. WACAW inactivated FCV and C. difficile spores better than NaClO under all experimental conditions used in this study. WACAW above 100 ppm FAC decreased FCV >4 log10 within 30 sec in the presence of 0.5% each of bovine serum albumin (BSA), polypeptone or meat extract. Even in the presence of 5% BSA, WACAW at 600 ppm FAC reduced FCV >4 log10 within 30 sec. Polypeptone inhibited the virucidal activity of WACAW against FCV more so than BSA or meat extract. WACAW at 200 ppm FAC decreased C. difficile spores >3 log10 within 1 min in the presence of 0.5% polypeptone. The microbicidal activity of NaClO was extensively diminished in the presence of organic matter. WACAW recovered its FAC to the initial level after partial neutralization by sodium thiosulfate, while no restoration of the FAC was observed in NaClO. These results indicate that WACAW is relatively stable under organic matter-rich conditions and therefore may be useful for treating environmental surfaces contaminated by human excretions.

Highlights

Excretions from symptomatic or asymptomatic carriers of pathogens are the major sources of infectious diseases [1, 2]
The combined chlorine (CMC) levels were markedly increased in NaClO after contact with bovine serum albumin (BSA) while no increase in CMC was observed in weakly acidified chlorous acid water (WACAW). These results indicate that WACAW does not chlorinate the target substances while NaClO produces a large amount of chlorinated substances after contact with organic matters
WACAW (4,000 ppm total chlorine (TC)) retained 9.0% of the initial free available chlorine (FAC) after 10-min contact with 0.5% BSA while the FAC of NaClO (4,000 ppm TC) decreased to 0.05% (Table 1). These results indicate that WACAW is more stable than NaClO under organic matter-rich condition

Summary

Introduction

Excretions from symptomatic or asymptomatic carriers of pathogens are the major sources of infectious diseases [1, 2]. Environmental surfaces contaminated by these excretions are often involved in outbreaks of norovirus and multi-drug resistant microorganisms [3,4,5].

Methods

Results

Conclusion