Advanced
Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas
Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas
Food Science of Animal Resources. 2016. Feb, 36(1): 100-108
Copyright © 2016, Korean Society for Food Science of Animal Resources
This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licences/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • Received : November 18, 2015
  • Accepted : January 07, 2016
  • Published : February 28, 2016
Download
PDF
e-PUB
PubReader
PPT
Export by style
Article
Author
Metrics
Cited by
TagCloud
About the Authors
Hyobi, Kim
Bora, Yum
Division of Biological Science and Technology, Yonsei University, Wonju 26493, Korea
Sung-Sik, Yoon
Division of Biological Science and Technology, Yonsei University, Wonju 26493, Korea
Kyoung-Ju, Song
Purgofarm, Hwasung 18523, Korea
Jong-Rak, Kim
Purgofarm, Hwasung 18523, Korea
Donghoon, Myeong
Byungjoon, Chang
Nong-Hoon, Choe
nojamaji@hanmail.net

Abstract
Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella . ClO 2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO 2 each at 20 ppm, 40 ppm, and 80 ppm against S . Enteritidis; 40 ppm and 80 ppm against S . Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella , the most prevalent contaminant in the egg industry.
Keywords
Introduction
Microbiological contamination in table eggs is concerning to consumers and thus safety measures are required in the egg industry. In fact, Salmonella is the most common cause of food poisoning in the US. Because poultry is one of the major reservoirs of human Salmonella ( Bae ., 2013 ), control measures in this source become a critical issue in the domestic egg industry. Previous studies showed that the isolation rate of Salmonella spp. from chicken cecal contents was quite high at 21.3% ( Cheong ., 2007 ). Zoonotic bacteria present in the digestive tracts of poultry may contaminate the egg contents or eggshell during egg production. Consumption or handling of the contaminated eggs can then cause human infections.
Salmonellosis is one of the most important and widely distributed foodborne bacterial illness ( CDC, 2008 ; WHO, 2013 ). Salmonella spp., particularly Salmonella Enteritidis ( Salmonella enterica subsp. enterica serovar Enteritidis; SE), have been attributed to many food-borne disease outbreaks in humans, which were traced back to eggshells ( Braden, 2006 ; Chousalkar ., 2010 ; ECDC, 2014 ; Morgan ., 2007 ; Zielicka-Hardy ., 2012 ) The Food and Drug Administration (FDA) estimates that 142,000 illnesses are caused by consuming eggs contaminated with SE each year ( FDA, 2009 ). In the US, multi-state outbreaks of human SE infection associated with shell eggs occurred in 2010, resulting in approximately 1939 illnesses ( CDC, 2010 ). In Europe, multi-country outbreaks of SE infection have been associated with the consumption of eggs produced in Germany. Outbreaks in Austria, France, and Germany were traced to the same egg packaging center in southern Germany ( ECDC, 2014 ).
In the hatching egg industry, hygienic management is directly linked to the hatching rate. Bacterial diseases, such as fowl typhoid (FT) and pullorum disease (PD) result in large costs to the hatching egg industry by lowering the hatchout rate. These diseases are serious problems in the many countries where measures for controlling bacterial diseases are not sufficient.
FT and PD, caused by Salmonella Gallinarum ( Salmonella enterica subsp. enterica serovar Gallinarum; SG) and Salmonella Pullorum ( Salmonella enterica subsp. enterica serovar Pullorum; SP), respectively, are among the most significant diseases in poultry. In chicks and poults, SG and SP cause diarrhea, dehydration, anorexia, weakness, and high mortality. These diseases in mature fowl cause lower egg production and hatchout rates combined as well as anorexia and high mortality. Trans-ovarial infection, leading to infection of the egg and the chick, is one of the most significant infection routes related to these diseases ( Shivaprasad, 2000 ). FT and PD have nearly disappeared from commercial poultry meats in developed nations, including the US, Canada, New Zealand, Australia, Japan, and many European countries. However, these diseases are common in countries in Central and South America, Asia, and Africa ( CFSPH, 2010 ; Shivaprasad, 2000 ).
In Korea, outbreaks of FT and PD have been increasing since the 1990s, inflicting economic damage on domestic poultry farms. Thus, a live attenuated SG vaccine is used in broilers to prevent FT. However, the efficacy of this vaccine remains uncertain, and live vaccines cannot be used in layer hens because of the potential for egg-transmitted infections ( Kim ., 2006 ; Kim ., 2007 ; Kwon ., 2010 ). Therefore, new methods to prevent these two chronic diseases are required.
Chlorine, usually used as disinfectant, produces trihalomethanes and chlorophenols which are reported as a potentially mutagenic compounds or carcinogenic substances ( Dunnick and Melnick, 1993 ; Owusuyaw ., 1990 ). Researchers have focused on chlorine dioxide as chlorine’s alternative sanitizer. Chlorine dioxide (ClO 2 ) produces less substance when it reacts with organic compounds. Furthermore, it is more stable and has 5 times higher sterilizing power than chlorine ( Beuchat ., 2004 ; Kim ., 1998 ; Moore ., 1980 ).
In this study, we chose chlorine dioxide (ClO 2 ) as a disinfecting agent to control microorganism-contaminated eggshells. In addition, the disinfection efficacy of ClO 2 solution in dentistry, for example, with dental materials and instruments and for oral hygiene, has been studied ( Agnihotry ., 2014 ; Drake and Villhauer, 2011 ; Watamoto ., 2013 ).
In 1998, the FDA approved the use of ClO 2 solution for washing fruits and vegetables. In turn, ClO 2 was approved as an alternative sanitizer by the US Environmental Protection Agency and the US FDA for postharvest application to fruits and vegetables in 2006 ( FDA, 1998 ; Sun ., 2014 ). Recently, many studies have reported the advantages of gaseous ClO 2 . ClO 2 gas is more diffusible than aqueous form, making it more efficient for eliminating microorganisms in food or on food processing surfaces ( Du ., 2002 ). Gaseous from has been shown to be more effective than aqueous form at the same concentration against Listeria monocytogenes on the surface of green peppers ( Han ., 2001 ). Additionally, the freshness and quality of food can be reduced through contact with water, and thus, disinfectants in gaseous forms are more appropriate than the aqueous form.
The objective of this study was to evaluate the effects of ClO 2 gas on salmonellae inoculated onto eggshells under laboratory-controlled settings. Choi . (2015) reported that aqueous ClO 2 has an efficacy of reducing Salmonella enterica on the surface of eggshells. This study is analogous to ours, but we used gaseous ClO 2 and controlled environmental factors such as exposure time of wide range, varying concentrations and humidity.
Materials and Methods
- Egg samples
Eggs were collected from a market or an egg-packing center. Very dirty eggs with visible fecal contamination were excluded from the experiment samples.
- ClO2gas-generating system
The ClO 2 gas was generated by a ClO 2 generator (CA- 300, PurgoFarm, Korea). Aqueous NaClO 2 was passed through the patented multi-porous membrane electrode assembly, producing highly pure ClO 2 gas (>98% ClO 2 ). After a sequence of electrochemical reactions, ClO 2 gas was released through a vent into a collecting chamber in the dark. The stream of ClO 2 was controlled by a valve to maintain the desired ClO 2 concentration in the treatment chamber. During treatment, the ClO 2 concentration in the chamber was monitored using a PortaSens II gas leak detector (C-16, Analytic Technology, USA) ( Fig. 1 ).
PPT Slide
Lager Image
ClO2 gas-generating system used in this study.
SE (ATCC 13076) and SG (ATCC9184) were selected as test bacteria. Each strain was incubated in nutrient broth (Oxoid, Hampshire, UK) for 24±2 h at 37℃. The inoculum density was found to be ≥ 0.01 absorbance at 600 nm by using a micro ELISA plate reader (VERSAmax, Molecular Devices, USA).
- Inoculation of egg
SE and SG were inoculated onto the eggshells of clean eggs. The inoculation was performed by spotting 100 μL of the test inoculum (>10 6 CFU/mL of the test organism) with sterilized micropipette tips onto the surface of the eggshell.
The government guidelines on disinfectants efficacy recommends that 5% (w/v) yeast extract is used as substitute for organic matter to determine the bacterial reduction ( QIA, 2013 ). Therefore, to set up the environment containing organic matter, 96 mL of 5% or 10% yeast extract (Sigma, USA) solution and 4 mL of a test inoculum were vortexed together, and then 100 μL of this mixture was spotted onto each eggshell. All eggs used in the experiments were allowed to dry at room temperature for 40-60 min.
- Exposure to ClO2gas
Following inoculation of the bacterial suspensions and drying, two eggs for each bacterial sample were exposed to ClO 2 gas. Two untreated eggs were used as a control. All treatments were performed in triplicate.
Environmental factors, including concentrations (ppm), contact time (min), humidity (% RH), and percentage organic matter, were applied differently during gas exposure. The applications of these environmental factors are summarized in Table 1 .
Application of environmental factors during exposure to ClO2gas
PPT Slide
Lager Image
Application of environmental factors during exposure to ClO2 gas
- Determination of bacterial contamination of eggshells
To measure bacteria on the eggshells, the egg was placed aseptically into a plastic bag containing 50 mL sterile distilled water and shaken for 10 min on an orbital shaker. One milliliter of the resulting water sample was serially diluted by 10-fold.
Xylose lysine deoxycholate agar (Oxoid, UK) for SE and the Salmonella Chromogenic Agar Base with Salmonella Selective Supplement SR0194 (Oxoid, UK) for SG were inoculated with 100 μL of each 10-fold serially diluted sample. Agars were incubated for 24±2 h at 37℃.
- Statistical analysis
Bacterial counts were log10-transformed prior to statistical analysis. Statistical analysis was performed using the SPSS statistical package (version 17.0, SPSS Inc., USA). A value of p <0.05 was considered statistically significant.
Results
- Disinfectant efficacy changes with concentration and exposure time
We evaluated the efficacy of ClO 2 gas against SE under wet conditions (80±5% RH). The change in ClO 2 concentrations (5, 10, 20, 40, 80 ppm) and exposure time (5, 10, 30 min) reduced SE contamination after inoculation ( Fig. 2 ). Exposure to 5 ppm ClO 2 gas reduced SE by <2 log (0.36, 0.51, 1.67 log) after 5, 10, and 30 min. With 10 ppm, 20 ppm, and 40 ppm ClO 2 gas exposure, SE was reduced by <2 log (0.49, 0.90 log-10 ppm/0.92, 1.62 log-20 ppm/1.63, 1.69 log-40 ppm) after 5 and 10 min of exposure. A reduction of 2-4 log occurred at 10 ppm after 30 min (3.22 log), and at 80 ppm after 5 and 10 min (2.45, 2.87 log). A >4 log reduction was achieved by exposure to 20 ppm (4.49 log), 40 ppm (5.3 log), 80 ppm (6.45 log) for 30 min.
PPT Slide
Lager Image
Effect of chlorine dioxide gas at various concentrations and exposure times on the inactivation of Salmonella Enteritidis on eggshells under the wet condition.
PPT Slide
Lager Image
Effects of the concentrations of chlorine dioxide gas against Salmonella Enteritidis on eggshells under dry or wet conditions without organic matter. Samples were exposed to ClO2 gas for 5 min. *, **, ***: significant difference was found (p<0.05, p<0.01, p<0.001, respectively).
We evaluated the efficacy of ClO 2 gas against SG under the wet condition (80±5% RH). The reduction in SG surface contamination changed with varying concentrations (5, 10, 20, 40, 80 ppm) and exposure times (5, 10, 30 min) ( Fig. 6 ). SG contamination on the eggshells was reduced by <2 log at 5 ppm ClO 2 gas exposure for 5, 10, and 30 min (0.33, 0.48, 0.63 log), 10 ppm for 5 and 10 min (0.70, 0.96 log), at 20 ppm for 5 and 10 min (1.02, 1.32 log), 40 ppm for 5 min (1.18 log), and 80 ppm for 5 min (1.97 log). SG was reduced by 2-4 log at 10 ppm and 20 ppm after 30 min (2.10, 2.43 log), and 40 ppm and 80 ppm after 10 min (2.16, 288 log). An exposure time of 30 min was required to achieve a >4 log reduction at 40 ppm (4.83 log) and 80 ppm (6.82 log).
- Disinfectant efficacy changes with humidity and organic matter
ClO 2 gas showed a relatively strong bactericidal effect against SE, regardless of the presence of organic matter (yeast extract, Sigma, USA) under wet as compared to dry conditions.
Exposure to ClO 2 gas resulted in 0.37, 065, 1.16, and 1.47 log reductions at 10, 20, 40, and 80 ppm for 5 min under dry conditions without organic matter (Fig. 3). The reductions in SE were 0.49, 0.91, 1.63, and 2.45 log under wet conditions without organic matter. A significant difference ( p <0.001) in SE reduction was found between dry conditions and wet conditions with exposure to 40 ppm ( p <0.01) and 80 ppm of ClO 2 gas for 5 min without organic matter. The SE contamination on eggshells was reduced by 0.23, 0.27, 1.071, and 1.27 log at 10, 20, 40, and 80 ppm, respectively, for 5 min under dry conditions with organic matter (yeast extract, Sigma, USA) ( Fig. 4 ). The reductions in SE were 0.47, 0.51, 1.27, and 1.71 log at the same ClO 2 exposures under wet conditions with organic matter. A significant difference ( p <0.05) was found between the dry and wet conditions at 80 ppm for 5 min with organic matter.
PPT Slide
Lager Image
Effects of the concentrations of chlorine dioxide gas against Salmonella Enteritidis on eggshells under dry or wet conditions with organic matter (10% yeast extract). Samples were exposed to ClO2 gas for 5 min. *, **, ***: significant difference was found (p<0.05, p<0.01, p<0.001, respectively).
The reduction in SE on the eggshells by an 80 ppm ClO 2 gas treatment for 5 min without organic matter (0% yeast extract) ranged from 2.14 to 2.67 Log CFU/eggshell (25% to 75%) and from 2.03 to 2.99 Log CFU/eggshell (minimum to maximum) ( Fig. 5 ). The median and mean of the log reduction in SE without yeast extract were 2.43 and 2.45, respectively. The reduction in SE on the eggshell by the same gas treatment with 5% yeast extract ranged from 1.48 to 2.34 log CFU/eggshell (25% to 75%) and from 1.37 to 2.43 log CFU/eggshell (minimum to maximum). The median and mean of the log reduction in SE with 5% yeast extract were 1.73 and 1.85, respectively. The reduction in SE on the eggshells by the same treatment with 10% yeast extract ranged from 1.56 to 1.84 Log CFU/eggshell (25% to 75%) and from 1.42 to 2.07 Log CFU/eggshell (minimum to maximum). The median and mean of the log reduction in SE with 10% yeast extract were 1.66 and 1.71, respectively. A significant difference ( p <0.001) was observed between SE reductions with 0% yeast extract and 5-10% yeast extract.
PPT Slide
Lager Image
Effect of chlorine dioxide gas against Salmonella Enteritidis on eggshells in the presence of organic matter (0, 5, and 10% yeast extract). The number of viable cells is shown on a bar graph (A) and in log10 reduction (B). ***: significant difference was found (p<0.001).
Exposure to ClO 2 gas resulted in 0.20, 0.33, 0.66, and 1.54 log reductions in SG at 10, 20, 40, and 80 ppm, respectively, for 5 min under the dry condition without organic matter ( Fig. 7 ). The reductions in SG were 0.70, 1.02, 1.18, and 1.97 log under the wet condition without organic matter. Significant differences were found between the dry condition and wet condition at 10 ppm ( p <0.05), 20 ppm ( p <0.001), 40 ppm ( p <0.01), and 80 ppm ( p <0.05).
PPT Slide
Lager Image
Effect of chlorine dioxide gas at various concentrations and exposure times in inactivating Salmonella Gallinarum on eggshells under wet condition.
PPT Slide
Lager Image
Effects of different concentrations of chlorine dioxide gas against Salmonella Gallinarum on eggshells under dry or wet conditions without organic matter. Samples were exposed to ClO2 gas for 5 min. *, **, ***: significant difference was found (p<0.05, p<0.01, p<0.001, respectively).
The SG contamination on eggshells was reduced by 0.10, 0.26, 0.66, and 0.80 log with exposure to 10, 20, 40, and 80 ppm ClO 2 gas, respectively, for 5 min under the dry condition with organic matter (yeast extract, Sigma, USA) ( Fig. 8 ). The reductions in SG were 0.49, 0.85, 1.03, and 1.38 log under the wet condition with organic matter. Significant differences were obtained between the dry and wet conditions at 20 ppm ( p <0.01) and 80 ppm ( p <0.01) ClO 2 gas exposure for 5 min with organic matter.
PPT Slide
Lager Image
Effects of different concentrations of chlorine dioxide gas against Salmonella Gallinarum on eggshells under dry or wet conditions with organic matter (10% yeast extract). Samples were exposed to ClO2 gas for 5 min. *, **, ***: significant difference was found (p<0.05, p<0.01, p<0.001, respectively).
The reduction in SG on the eggshells by ClO 2 gas treatment of 80 ppm for 5 min without organic matter (0% yeast extract) ranged from 1.66 to 2.28 Log CFU/eggshell (25% to 75%) and from 1.53 to 2.45 Log CFU/eggshell (minimum to maximum) ( Fig. 9 ). The median and mean log reductions in SG with no added yeast extract were 1.96 and 1.97, respectively. The reduction in SG on the eggshells following the same treatment with 5% yeast extract ranged from 1.77 to 2.40 Log CFU/eggshell (25% to 75%) and from 0.54 to 2.45 Log CFU/eggshell (minimum to maximum). The median and mean log reductions in SG with 5% yeast extract were 1.84 and 1.8, respectively. The reductions in SG on the eggshells following the same treatment with 10% yeast extract ranged from 0.93 to 1.55 Log CFU/eggshell (25% to 75%) and from 0.93 to 2.15 Log CFU/eggshell (minimum to maximum). The median and mean log reductions in SG with 10% yeast extract were 1.35 and 1.38, respectively. A significant difference ( p <0.05) in SG was observed between the results with 0% yeast extract and with 10% yeast extract.
PPT Slide
Lager Image
Effect of chlorine dioxide gas against Salmonella Gallinarum on eggshells in the presence of organic matter (0, 5, and 10% yeast extract). The number of viable cells is shown on a bar graph (A) and in log10 reduction (B). *: significant difference was found (p<0.05).
Discussionc
ClO 2 has been known to be a potent sanitizer/disinfectant for more than 40 years ( Benarde ., 1965 ). Recently, ClO 2 in its gaseous form has been used to disinfect space, food, and food-related equipment ( Hsu and Huang, 2013 ; Lee ., 2004 ; Lowe ., 2013 ; Prodduk ., 2014 ; Sun ., 2014 ; Trinetta ., 2012 ; Trinetta ., 2013a ; Trinetta ., 2013b ). The use of ClO 2 gas as an effective disinfectant is promising for the microbial reduction on fruits ( Du ., 2003 ). Sun . (2014) reported that a controlled-release ClO 2 gas fumigation technology showed promise as an effective and practical antimicrobial strategy for the commercial clamshell packaging of blueberries and other fruits. Further, Prodduk . (2014) found that ClO 2 gas treatment was capable of penetrating and inactivating cells attached to inaccessible sites and within biofilms on sprout surface. In this study, the disinfectant efficacy of ClO 2 gas varied with environmental factors such as gas concentrations (ppm), exposure time (min), humidity (% RH), and presence of organic matter.
First, the antimicrobial effects of ClO 2 gas against SE and SG were evaluated according to changes in gas concentrations (5, 10, 20, 40, 80 ppm) and exposure times (5, 10, 30 min) under the wet condition (80±5% RH). We considered a 4-log reduction to be an effective standard based on MFDS Regulations (Surface Tests of Sanitizers and Disinfectants) ( MFDS, 2009 ).
In the case of SE, <4 log reduction was noted when each of the concentration and exposure time of ClO 2 gas was 20, 40, or 80 ppm for 30 min. SE is a major pathogen related to food poisoning by contaminated eggs. Previous studies have reported the efficacy of commercial cleaning or sanitizing solutions on eggshells contaminated with SE. Sodium carbonate, sodium hypochlorite, and potassium hydroxide were evaluated for their bactericidal activity on eggshells contaminated with SE. The results indicated that the three chemicals applied at the concentrations recommended by the manufacturer (sodium carbonate, 36 ppm; other treatments, 200 ppm) could not eliminate 10 4 or 10 6 CFU/mL of SE from eggshells ( Soljour ., 2004 ). Iodine- based disinfectants (approximately 75 ppm) and chorine (200 ppm) spray reduced SE by 1.35 log and 1.45 log on the eggshell in one study ( Knape ., 2001 ). The antimicrobial effects of ClO 2 gas against SE observed in this study were remarkable compared with commercial cleaning or sanitizing solutions. A few recent studies investigated the effects of electrolyzed oxidizing water on eggs. They showed a log reduction of ≥2.1 log in SE using electrolyzed oxidizing water, whereas a log reduction of 1.7 log in SE was observed for typical commercial detergent-sanitizer (100 ppm free chlorine solution) treatments. However, both electrolyzed oxidizing water and commercial detergent-sanitizers significantly affected the cuticle layer in eggs ( Bialka ., 2004 ). The cuticle layer of eggshells plays an important role as a natural barrier ( Gole ., 2014 ). Destruction of the cuticle layer may be a cause of food poisoning, as it is then becomes easy for microorganisms to penetrate the eggshell.
SG is the causative bacteria of FT, a severe systemic disease in chickens. FT has been eradicated from commercial poultry in many developed countries, including the US, Canada, and most countries in Western Europe ( Shivaprasad, 2000 ). However, this disease remains common in some countries in Central and South America, Africa, and Asia, including Korea ( Shivaprasad, 2000 ). It causes serious economic problems in the poultry industry in Korea, although SG has little public health significance because it has highly adapted to the chicken as a host species. Thus, the efficient control of SG in hatching eggs is particularly important. However, fewer studies on the antimicrobial effects of disinfectants against SG have been carried out than for SE. In this study, we achieved >4 log reduction of SG at 40 ppm and 80 ppm ClO 2 gas treatment with a required exposure time of 30 min.
Humidity is one of the crucial factors in reducing microorganisms by ClO 2 gas. Previous studies reported that inactivation of bacterial contaminants by ClO 2 gas was negatively impacted by a low relative humidity ( Lowe ., 2013 ). This study also revealed that disinfection of eggshells by ClO 2 gas was less effective under the dry condition (30±5%) than under the wet condition (RH 80±5%). Regardless of the bacterial species and organic matter present, the reduction in bacteria by ClO 2 gas was greater under high RH conditions. A significant difference was found at a high concentration of ClO 2 gas between dry (RH 30±5%) and wet conditions (RH 80±5%).
Most disinfectants, including chlorine and its derivatives, are inactivated by interactions with organic matter. Eggshell surfaces can be contaminated by organic matter such as feces or rice straws during the production process. Therefore, an agent with high efficacy in the presence of organic matter may be effective for disinfecting eggs. When ClO 2 gas was used to inhibit SG inoculated onto eggshells under wet conditions, no significant difference was observed in the presence of 0% yeast extract vs. 5% yeast extract. However, the reduction in SE with 5% yeast extract was significantly different from the control. The percentage of organic matter had a greater influence on the effect of ClO 2 gas on SE than on SG.
Numerous studies have evaluated the antimicrobial effects of ClO 2 in various fields. ClO 2 has been studied as an agent for water disinfection and various other purposes ( Hsu and Huang, 2015 ). In this study, ClO 2 gas is a considerable sanitizer against Salmonella enterica on eggshells. Like this, industry related with poultry could use ClO 2 gas treatment in order to reduce attached salmonellae on poultry skin. With the application of a proper concentration and exposure time, ClO 2 gas exposure may be an excellent method for egg disinfection as an alternative to current methods used to sanitize eggs. Moreover, although it needs further study, ClO 2 gas could be widely utilized in various food industries.
Acknowledgements
This paper was supported by Konkuk University in 2012.
References
Agnihotry A. , Gill K. S. , Singhal D. , Fedorowicz Z. , Dash S. , Pedrazzi V. (2014) A comparison of the bleaching effectiveness of chlorine dioxide and hydrogen peroxide on dental composite Braz. Dent. J. 25 524 - 527    DOI : 10.1590/0103-6440201300098
Bae D. H. , Dessie H. K. , Baek H. J. , Kim S. G. , Lee H. S. , Lee Y. J. (2013) Prevalence and characteristics of Salmonella spp. isolated from poultry slaughterhouses in Korea J. Vet. Med. Sci. 75 1193 - 1200    DOI : 10.1292/jvms.13-0093
Benarde M. A. , Israel B. M. , Olivieri V. P. , Granstrom M. L. (1965) Efficiency of chlorine dioxide as a bactericide Appl. Microbiol. 13 776 - 780
Beuchat L. R. , Pettigrew C. A. , Tremblay M. E. , Roselle B. J. , Scouten A. J. (2004) Lethality of chlorine, chlorine dioxide, and a commercial fruit and vegetable sanitizer to vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis J. Food Prot. 67 1702 - 1708
Bialka K. L. , Demirci A. , Knabel S. J. , Patterson P. H. , Puri V. M. (2004) Efficacy of electrolyzed oxidizing water for the microbial safety and quality of eggs Poult. Sci. 83 2071 - 2078    DOI : 10.1093/ps/83.12.2071
Braden C. R. (2006) Salmonella enterica serotype Enteritidis and eggs: a national epidemic in the United States Clin. Infect. Dis. 43 512 - 517    DOI : 10.1086/505973
CDC (2008) Salmonellosis: General Information Retrieved from:
CDC (2010) Multistate outbreak of human Salmonella Enteritidis infections associated with shell eggs Available from:
CFSPH (2010) Emerging and exotic diseases of animals textbook Center for food security and public health 169 - 172
Cheong H. J. , Lee Y. J. , Hwang I. S. , Kee S. Y. , Cheong H. W. , Song J. Y. , Kim J. M. , Park Y. H. , Jung J. H. , Kim W. J. (2007) Characteristics of non-typhoidal Salmonella iso-- Korea J. Korean Med. Sci. 22 773 - 778    DOI : 10.3346/jkms.2007.22.5.773
Choi S. , Park S. , Kim Y. , Kim B.-S. , Beuchat L. R. , Hoikyung K. , Ryu J.-H. (2015) Reduction of Salmonella enterica on the surface of eggshells by sequential treatment with aqueous chlorine dioxide and drying Int. J. Food Microbiol. 210 84 - 87    DOI : 10.1016/j.ijfoodmicro.2015.06.009
Chousalkar K. K. , Flynn P. , Sutherland M. , Roberts J. R. , Cheetham B. F. (2010) Recovery of Salmonella and Escherichia coli from commercial egg shells and effect of translucency on bacterial penetration in eggs Int. J. Food Microbiol. 142 207 - 213    DOI : 10.1016/j.ijfoodmicro.2010.06.029
Drake D. , Villhauer A. L. (2011) An in vitro comparative study determining bactericidal activity of stabilized chl- orine dioxide and other oral rinses J. Clin. Dent. 22 1 - 5
Du J. , Han Y. , Linton R. H. (2002) Inactivation by chlorine dioxide gas (ClO2) of Listeria monocytogenes spotted onto different apple surfaces Food Microbiol. 19 481 - 490    DOI : 10.1006/fmic.2002.0501
Du J. , Han Y. , Linton R. H. (2003) Efficacy of chlorine dioxide gas in reducing Escherichia coli O157:H7 on apple surfaces Food Microbiol. 20 583 - 591    DOI : 10.1016/S0740-0020(02)00129-6
Dunnick J. K. , Melnick R. L. (1993) Assessment of the carcinogenic potential of chlorinated water - Experimental studies of chlorine, chloramine, and trihalomethanes J. Natl. Cancer Inst. 85 817 - 822    DOI : 10.1093/jnci/85.10.817
ECDC Multi-country outbreak of Salmonella Enteritidis infections associated with consumption of eggs from Germany Retrieved from: . Accessed2014
FDA FDA improvesfood safety Retrieved from: Accessed Aug. 9, 2009
FDA Guidance for industry - guide to minimize microbial food safety hazards for fresh fruits and vegetables Retrieved from: Accessed 1998
Gole V. C. , Roberts J. R. , Sexton M. , May D. , Kiermeier A. , Chousalkar K. K. (2014) Effect of egg washing and correlation between cuticle and egg penetration by various Salmonella strains Int. J. Food Microbiol. 182-183 18 - 25    DOI : 10.1016/j.ijfoodmicro.2014.04.030
Han Y. , Linton R. H. , Nielsen S. S. , Nelson P. E. (2001) Reduction of Listeria monocytogenes on green peppers (Capsicum annuum L.) by gaseous and aqueous chlorine dioxide and water washing and its growth at 7 degrees C. J. Food Prot. 64 1730 - 1738
Hsu C. S. , Huang D. J. (2013) Disinfection efficiency of chlorine dioxide gas in student cafeterias in Taiwan J. Air Waste Manag. Assoc. 63 796 - 805    DOI : 10.1080/10962247.2012.735212
Hsu C. S. , Huang D. J. (2015) Disinfection of herbal spa pool using combined chlorine dioxide and sodium hypochlorite treatment Environ. Monit. Assess. 187 34 -    DOI : 10.1007/s10661-014-4242-3
Kim A. , Lee Y. J. , Kang M. S. , Kwag S. I. , Cho J. K. (2007) Dissemination and tracking of Salmonella spp. in integrated broiler operation J. Vet. Sci. 8 155 - 161    DOI : 10.4142/jvs.2007.8.2.155
Kim A. R. , Kim J. H. , Lee Y. J. , Cho Y. M. , Kwon J. H. , Kwon Y. K. , Lee Y. J. , Choi J. G. , Joh S. J. , Kim M. C. , Lee E. K. (2006) The prevalence of pullorum disease-fowl typhoid in grand parent stock and parent stock in Korea, 2003 Korean J. Vet. Res. 46 347 - 353
Kim J. , Du W. X. , Otwell W. S. , Marshall M. R. , Wei C. I. (1998) Nutrients in salmon and red grouper fillets as affected by chlorine dioxide (ClO2) treatment J. Food Sci. 63 629 - 633
Knape K. D. , Carey J. B. , Ricke S. C. (2001) Response of foodborne Salmonella spp. marker strains inoculated on egg shell surfaces to disinfectants in a commercial egg washer J. Environ. Sci. Health B 36 219 - 227    DOI : 10.1081/PFC-100103745
Kwon Y. K. , Kim A. , Kang M. S. , Her M. , Jung B. Y. , Lee K. M. , Jeong W. , An B. K. , Kwon J. H. (2010) Prevalence and characterization of Salmonella Gallinarum in the chicken in Korea during 2000 to 2008 Poult. Sci. 89 236 - 242    DOI : 10.3382/ps.2009-00420
Lee S. Y. , Costello M. , Kang D. H. (2004) Efficacy of chlorine dioxide gas as a sanitizer of lettuce leaves J. Food Prot. 67 1371 - 1376
Lowe J. J. , Gibbs S. G. , Iwen P. C. , Smith P. W. , Hewlett A. L. (2013) Decontamination of a hospital room using gaseous chlorine dioxide: Bacillus anthracis, Francisella tularensis, and Yersinia pestis J. Occup. Environ. Hyg. 10 533 - 539    DOI : 10.1080/15459624.2013.818241
MFDS (2009) Notification No. 2009-59 of the Ministry of Food and Drug Safety
Moore G. S. , Calabrese E. J. , Ho S. C. (1980) Groups at potentially high-risk from chlorine dioxide treated water J. Environ. Pathol. Toxicol. 4 465 - 470
Morgan O. , Milne L. , Kumar S. , Murray D. , Man W. , Georgiou M. , Verlander N. Q. , de Pinna E. , McEvoy M. (2007) Outbreak of Salmonella Enteritidis phage type 13a: case-control investigation in Hertsmere, United Kingdom Euro Surveill. 12 E9 - 10
Owusuyaw J. , Toth J. P. , Wheeler W. B. , Wei C. I. (1990) Mutagenicity and identification of the reaction-products of aqueous chlorine or chlorine dioxide with L-tryptophan J. Food Sci. 55 1714 - 1719    DOI : 10.1111/j.1365-2621.1990.tb03607.x
Prodduk V. , Annous B. A. , Liu L. , Yam K. L. (2014) Evaluation of chlorine dioxide gas treatment to inactivate Salmonella enterica on mungbean sprouts J. Food Prot. 77 1876 - 1881    DOI : 10.4315/0362-028X.JFP-13-407
QIA(Animal and Plant Quarantine Agency, Korea) Guidelines on disinfenctants efficacy, Notification No. 2013-34
Shivaprasad H. L. (2000) Fowl typhoid and pullorum disease Rev. Sci .Tech. 19 405 - 424
Soljour G. , Assanta M. A. , Messier S. , Boulianne M. (2004) Efficacy of egg cleaning compounds on eggshells contaminated with Salmonella enterica serovar Enteritidis J. Food Prot. 67 706 - 712
Sun X. , Bai J. , Ference C. , Wang Z. , Zhang Y. , Narciso J. , Zhou K. (2014) Antimicrobial activity of controlled-release chlorine dioxide gas on fresh blueberries J. Food Prot. 77 1127 - 1132    DOI : 10.4315/0362-028X.JFP-13-554
Trinetta V. , Linton R. H. , Morgan M. T. (2013a) The application of high-concentration short-time chlorine dioxide treatment for selected specialty crops including Roma tomatoes (Lycopersicon esculentum), cantaloupes (Cucumis melo ssp. melo var. cantaloupensis) and strawberries (Fragaria x ananassa) Food Microbiol. 34 296 - 302    DOI : 10.1016/j.fm.2012.12.010
Trinetta V. , Linton R. H. , Morgan M. T. (2013b) Use of chlorine dioxide gas for the postharvest control of Alternaria alternata and Stemphylium vesicarium on Roma tomatoes J. Sci. Food Agric. 93 3330 - 3333    DOI : 10.1002/jsfa.6180
Trinetta V. , Vaid R. , Xu Q. , Linton R. , Morgan M. (2012) Inactivation of Listeria monocytogenes on ready-toeat food processing equipment by chlorine dioxide gas Food Control. 26 357 - 362    DOI : 10.1016/j.foodcont.2012.02.008
Watamoto T. , Egusa H. , Sawase T. , Yatani H. (2013) Clinical evaluation of chlorine dioxide for disinfection of dental instruments Int. J. Prosthodont. 26 541 - 544    DOI : 10.11607/ijp.3465
WHO Salmonella (non-typhoidal) Retrieved from: . Accessed 2013
Zielicka-Hardy A. , Zarowna D. , Szych J. , Madajczak G. , Sadkowska-Todys M. (2012) Ensuring safety of homeproduced eggs to control salmonellosis in Poland: lessons from an outbreak in September 2011 Euro Surveill. 17 12 - 19