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1.
Viruses ; 13(3)2021 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-33807081

RESUMEN

The emergent human coronavirus SARS-CoV-2 and its high infectivity rate has highlighted the strong need for new disinfection systems. Evidence has proven that airborne transmission is an important route of spreading for this virus. Therefore, this short communication introduces CLODOS Technology®, a novel strategy to disinfect contaminated surfaces. It is a product based on stable and 99% pure chlorine dioxide, already certified as a bactericide, fungicide and virucide against different pathogens. In this study, CLODOS Technology®, by direct contact or thermonebulization, showed virucidal activity against the human coronavirus HCoV-229E at non-cytotoxic doses. Different conditions such as nebulization, exposure time and product concentration have been tested to standardize and optimize this new feasible method for disinfection.


Asunto(s)
Coronavirus Humano 229E/efectos de los fármacos , Desinfectantes/farmacología , Desinfección/métodos , Línea Celular , Compuestos de Cloro/análisis , Compuestos de Cloro/farmacología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Desinfectantes/análisis , Desinfección/instrumentación , Humanos , Nebulizadores y Vaporizadores , Óxidos/análisis , Óxidos/farmacología
2.
Huan Jing Ke Xue ; 42(4): 1939-1945, 2021 Apr 08.
Artículo en Chino | MEDLINE | ID: mdl-33742829

RESUMEN

In order to study the effects of chlorine dioxide (ClO2) disinfection on the super antibiotic resistance genes (SARGs), the final effluents before and after chlorine dioxide were sampled throughout one year in a wastewater treatment plant (WWTP). The bacteria and extracellular nucleic acid were collected using microporous membrane filtration and nucleic acid adsorption particles, respectively. A total of 9 SARGs was detected through a quantitative real-time polymerase chain reaction (qPCR). The results revealed that both intracellular and extracellular NDM-1, MCR-1, and MEC-A could be positively detected in the samples. Overall, ClO2 disinfection enhanced the relative abundance of the iSARGs (P<0.05), exhibiting a seasonal pattern, and increasing in the spring, summer, and autumn. In spring, it improved the most, up to twice the abundance. No SARGs were detected positive in the winter, either intracellularly or extracellularly. There was no significant variation in the concentrations of eSARGs before and after ClO2 disinfection. Therefore, ClO2 disinfection cannot effectively remove iSARGs and eSARGs in the final effluent from the WWTP.


Asunto(s)
Compuestos de Cloro , Desinfectantes , Purificación del Agua , Antibacterianos/farmacología , Cloro , Compuestos de Cloro/farmacología , Desinfectantes/farmacología , Desinfección , Farmacorresistencia Microbiana/genética , Óxidos/farmacología
3.
Int J Food Microbiol ; 342: 109073, 2021 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-33550154

RESUMEN

Clam jeotgal, called "jogaejeotgal," is a Korean fermented seafood product with, generally, a high amount of added salt to inhibit the growth of pathogenic microorganisms. This study aimed to evaluate the efficacy of chlorine dioxide (ClO2) and sodium hypochlorite (NaOCl) against murine norovirus 1 (MNV-1), a surrogate for human norovirus, in salt-fermented clam, jogaejeotgal. The sequential effect of ClO2 and electron-beam (e-beam) irradiation on the inactivation of MNV-1 was also investigated. Treatments of up to 300 ppm ClO2 and 1000 ppm NaOCl were used to determine the disinfectant concentrations at which more than 1 log (90%) MNV-1 inactivation occurred. The sequential treatment of ClO2 (50-300 ppm) and e-beam (1-5.5 kGy) was performed after storage at 4 °C for 7 days. There was a 1.9-log reduction of the virus in seasoned clams irradiated at 5.5 kGy after ClO2 treatment at 300 ppm. No significant change (p > 0.05) in physicochemical quality was observed after the combined treatment, suggesting the potential for the use of a combined treatment using ClO2 (300 ppm) and e-beam (5.5 kGy) in the jeotgal manufacturing industry for the reduction of norovirus.


Asunto(s)
Bivalvos , Compuestos de Cloro/farmacología , Electrones , Norovirus/fisiología , Óxidos/farmacología , Mariscos/virología , Animales , Desinfectantes/farmacología , Irradiación de Alimentos , Conservación de Alimentos/métodos , Norovirus/efectos de los fármacos , Norovirus/efectos de la radiación , República de Corea , Mariscos/análisis , Hipoclorito de Sodio/farmacología , Inactivación de Virus/efectos de los fármacos , Inactivación de Virus/efectos de la radiación
4.
Int J Food Microbiol ; 337: 108938, 2021 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-33166912

RESUMEN

A packaging system using gaseous chlorine dioxide generating film (CDGF) in a sealed container was developed to extend the shelf life of semi-dry longan pulp (moisture content 38.8 wt%; aw0.8). The antimicrobial properties, formation of chloroxyanion residues and effects of CDGF on the quality of semi-dry longan pulp were investigated. CDGF was triggered by the moisture vapor from semi-dry longan pulp in the sealed container and released gaseous ClO2 into the headspace of the container. The antifungal test showed that CDGF significantly inactivated artificially inoculated molds in semi-dry longan pulp and achieved reductions of over 3 log CFU/g after 28 days storage at room temperature (25 °C). CDGF reduced total aerobic bacterial populations by over 6.4 log CFU/g and maintained these population levels at around 2.0 log CFU/g throughout the 180-day storage period at room temperature. The residual concentrations of chloride, chlorate and perchlorate in longan pulp increased and then decreased during the 180-day storage. Residual chloride levels were maintained at 1.5 mg/g after Day 120 and residual chlorate and perchlorate levels were not detected after Day 120 and Day 180, respectively, in CDGF-treated samples. CDGF treatments reduced total polyphenol content but didn't have any significant impact on the levels of polysaccharides in samples. There were no significant differences between CDGF-treated and control samples in color changes during storage. The content of 5-hydroymethylfurfural (5-HMF) in both samples increased during storage, suggesting that the Maillard reaction occurred. This study demonstrated an effective approach to develop a new antimicrobial packaging system for semi-dry longan pulp.


Asunto(s)
Compuestos de Cloro/farmacología , Microbiología de Alimentos , Almacenamiento de Alimentos/métodos , Óxidos/farmacología , Cloruros/análisis , Recuento de Colonia Microbiana , Desinfectantes/farmacología , Hongos/efectos de los fármacos , Gases/farmacología , Percloratos/análisis , Sapindaceae/microbiología
5.
Food Chem ; 333: 127500, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32693317

RESUMEN

The objectives of this study were to optimize the condition of ultrasonic treatment combined with aqueous chlorine dioxide (ClO2) on nitrate content of spinach by response surface methodology (RSM), and determine the effectiveness of ultrasound (US) and ClO2 alone and in combination, on spinach postharvest quality during 7 days' storage period. The optimal treatment parameters obtained were ultrasonic power (300 W), ClO2 concentration (50 ppm), treatment time (4 min). The combined treatments significantly reduced the nitrate content and maintained better storage quality in terms of total soluble solids (TSS) and ascorbic acid content compared with the individual treatment or untreated. For Chlorophyll content, the combined treatment was significantly higher than the control and ClO2 treatment, but lower than ultrasonic treatment. The results demonstrated that US combined with ClO2 are promising alternatives for the reduction of nitrate content, as well as preserving the quality of stored leafy vegetables.


Asunto(s)
Compuestos de Cloro/farmacología , Conservación de Alimentos/métodos , Conservantes de Alimentos/farmacología , Nitratos/análisis , Óxidos/farmacología , Spinacia oleracea/química , Ultrasonido/métodos , Ácido Ascórbico/análisis , Clorofila/análisis , Conservación de Alimentos/instrumentación , Almacenamiento de Alimentos , Hojas de la Planta/química , Spinacia oleracea/efectos de los fármacos , Verduras/química , Verduras/efectos de los fármacos
6.
Physiol Int ; 107(1): 1-11, 2020 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-32208977

RESUMEN

Motivation: Viruses have caused many epidemics throughout human history. The novel coronavirus [10] is just the latest example. A new viral outbreak can be unpredictable, and development of specific defense tools and countermeasures against the new virus remains time-consuming even in today's era of modern medical science and technology. In the lack of effective and specific medication or vaccination, it would be desirable to have a nonspecific protocol or substance to render the virus inactive, a substance/protocol, which could be applied whenever a new viral outbreak occurs. This is especially important in cases when the emerging new virus is as infectious as SARS-CoV-2 [4]. Aims and structure of the present communication: In this editorial, we propose to consider the possibility of developing and implementing antiviral protocols by applying high purity aqueous chlorine dioxide (ClO2) solutions. The aim of this proposal is to initiate research that could lead to the introduction of practical and effective antiviral protocols. To this end, we first discuss some important properties of the ClO2 molecule, which make it an advantageous antiviral agent, then some earlier results of ClO2 gas application against viruses will be reviewed. Finally, we hypothesize on methods to control the spread of viral infections using aqueous ClO2 solutions.


Asunto(s)
Betacoronavirus , Compuestos de Cloro/farmacología , Enfermedades Transmisibles Emergentes , Infecciones por Coronavirus , Transmisión de Enfermedad Infecciosa/prevención & control , Óxidos/farmacología , Pandemias , Neumonía Viral , Antivirales/farmacología , Betacoronavirus/efectos de los fármacos , Betacoronavirus/patogenicidad , Betacoronavirus/fisiología , Protocolos Clínicos , Enfermedades Transmisibles Emergentes/prevención & control , Enfermedades Transmisibles Emergentes/virología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/virología , Desinfectantes/farmacología , Humanos , Pandemias/prevención & control , Soluciones Farmacéuticas/farmacología , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , Neumonía Viral/virología , Proyectos de Investigación
7.
J Food Prot ; 83(3): 412-417, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32050031

RESUMEN

ABSTRACT: Fresh produce, such as blueberries, continues to be a source of foodborne illness in the United States. Despite new practices and intervention technologies, blueberries and other produce are contaminated with foodborne pathogens, such as Salmonella. The aim of this study was to evaluate the efficacy of chlorine dioxide gas (CDG) against Salmonella enterica serovars Newport, Stanley, Muenchen, and Anatum on artificially contaminated whole fresh blueberries. Blueberries were dip inoculated into a 400-mL bath containing a Salmonella serovar cocktail of either ca. 6 or 9 log CFU/mL. Samples were dried for either 2 or 24 h before treatment with 1.5 or 3 mg of CDG/L of air to a final treatment of 3.55 to 6 ppm/h/g of blueberry. Salmonella cells were recovered by stomaching CDG-treated and nontreated control samples with 0.1% peptone and enumerated on xylose lysine Tergitol 4 agar. CDG treatments achieved up to a 5.63-log CFU/g reduction of the cocktail using 5.5 ppm/h/g, whereas the lowest treatment, 4 ppm/h/g (1.5 mg of CDG/L), was still capable of a 4.45-log CFU/g reduction. Incubation time significantly (P < 0.001) affected CDG efficacy against both inoculation concentrations. Additionally, all serovars responded similarly to CDG treatment when tested individually (P > 0.0691). Finally, the availability of a water reservoir during treatments did not have a significant effect (P = 0.9818) on CDG efficacy in this study. Our results demonstrate that CDG can be an efficacious treatment option for whole blueberry decontamination.


Asunto(s)
Arándanos Azules (Planta)/microbiología , Compuestos de Cloro/farmacología , Desinfectantes , Óxidos/farmacología , Salmonella enterica/efectos de los fármacos , Cloro , Recuento de Colonia Microbiana , Desinfectantes/farmacología , Microbiología de Alimentos , Serogrupo
8.
BMC Res Notes ; 13(1): 69, 2020 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-32051032

RESUMEN

OBJECTIVE: Healthcare-associated infections due to Gram-negative bacteria (GNB) are a major cause of mortality and morbidity throughout the world. The purpose of the research described here was to evaluate the possibility of using an extremely low-concentration gaseous chlorine dioxide (ClO2, 0.01 ppmv, 0.028 mg/m3) as a technique to reduce the risk of environmental infection by GNB. In this study we set up an exposure chamber (1 m3) and used three types of GNB, namely Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii. RESULTS: The extremely low-concentration gaseous ClO2 inactivated E. coli (> 2 log10 reductions, within 2 h), P. aeruginosa (> 4 log10 reductions, within 2 h) and A. baumannii (> 2 log10 reductions, within 3 h) in wet conditions on glass dishes. Treatment of moist environments with extremely low-concentration gaseous ClO2 may help to reduce the risk of environmental infection by GNB without harmful effects.


Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Compuestos de Cloro/farmacología , Desinfectantes/farmacología , Escherichia coli/efectos de los fármacos , Óxidos/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Gases
9.
Food Microbiol ; 87: 103355, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31948612

RESUMEN

Enteric pathogens such as Shiga-toxin producing Escherichia coli (STEC) and Salmonella spp. continue to be a major food safety concern for the beef industry. Currently, no single method is completely effective in controlling these pathogens during carcass processing. Previous research, however, suggested that STEC might become more susceptible to oxidative damage when exposed to carcass chilling (King et al., 2016). We aimed to test that hypothesis by evaluating the antimicrobial effects of an oxidant (chlorine dioxide, ClO2 or peroxyacetic acid, PAA) on beef meat during a simulated spray chilling process (sprayed for 4 s every 15 min for 36 cycles) and/or when applied (sprayed for 144 s) prior to spray chilling with water. In all experiments, the inactivating effects of oxidants were greatest on fat surfaces and much less effective on lean surfaces. ClO2 at 15 ppm, a non-lethal level for E. coli under optimal growth conditions, caused higher log reductions in E. coli numbers (approximately 3-log reduction) when applied during spray chilling than when applied immediately prior to 'normal' spray chilling (approximately 1-log reduction). This confirms the hypothesis that E. coli are more susceptible to oxidative stress during spray chilling. In subsequent studies, both ClO2 and PAA at lethal levels (at ≥20 and ≥ 200 ppm, respectively) applied during spray chilling resulted in pronounced inactivation of both E. coli and Salmonella enterica strains, achieving a ≥4-log reduction at the end of chilling. These results indicate that an oxidant-based application during spray chilling as an antimicrobial intervention could be effective to minimise the problems associated with enteric pathogen contamination on beef meat.


Asunto(s)
Antibacterianos/farmacología , Compuestos de Cloro/farmacología , Conservación de Alimentos/métodos , Óxidos/farmacología , Ácido Peracético/farmacología , Carne Roja/microbiología , Animales , Bovinos , Conservación de Alimentos/instrumentación , Conservantes de Alimentos/farmacología , Carne Roja/análisis , Salmonella enterica/efectos de los fármacos , Salmonella enterica/crecimiento & desarrollo , Escherichia coli Shiga-Toxigénica/efectos de los fármacos , Escherichia coli Shiga-Toxigénica/crecimiento & desarrollo
10.
Chemosphere ; 243: 125453, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31995893

RESUMEN

Fungal contamination in drinking water has been becoming a hot topic. The routine enumeration method of fungal spores is heterotrophic plate counts (HPC). However, this method is time-consuming and labor-intensive and there is also the difficulty of enumerating viable but non-culturable cells. In this study, a rapid, simple and accurate method for quantifying fungal spores and discriminating their viability in water was established using flow cytometry (FCM) combined with fluorescence dyes. The optimal staining conditions are as follows: spores suspensions are sonicated at 495 W for 5 min as pretreatment, and then 10 µL of SYBR Green I (100×) and 30 mM Ethylene diamine tetraacetic acid are added to a 500 µL water sample, which incubate at 35 °C for 20 min in dark. The concentration of fungal spores measured by FCM was highly correlated with HPC results and microscope observations, with correlation coefficient of 0.996 and 0.988, respectively. This staining method can be widely applied to the enumeration and viability evaluation of fungal spores. In addition, chlorine-based inactivation of three genera of fungal spores was assessed by plating and FCM. The result showed that all three genera of fungal spores lost culturability firstly and then membrane integrity decreased, preliminarily revealing the inactivation mechanism. The inactivation rate constants of membrane damage varied in the following order: chlorine dioxide > chlorine > chloramine. This study concluded that FCM is an appropriate and alternative tool to detect fungal spores' viability and can be used for evaluating the fungal inactivation by disinfectants.


Asunto(s)
Desinfección/métodos , Citometría de Flujo/métodos , Esporas Fúngicas/crecimiento & desarrollo , Cloraminas/farmacología , Cloro/farmacología , Compuestos de Cloro/farmacología , Desinfectantes/farmacología , Colorantes Fluorescentes , Hongos/citología , Hongos/efectos de los fármacos , Compuestos Orgánicos , Óxidos/farmacología , Esporas Fúngicas/citología , Coloración y Etiquetado/métodos
11.
Food Microbiol ; 86: 103308, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31703866

RESUMEN

The aim of this study was to use chlorine dioxide (ClO2) gas to inactivate Aspergillus flavus on green coffee beans. Green coffee beans inoculated with A. flavus were exposed to ClO2 gas generated from 0.75, 1, 1.25, or 1.5 mL of ClO2 solution in a sealed container at 25 or 50 °C (100% relative humidity [RH]) for up to 10 h. Numbers of A. flavus on beans treated at 25 °C decreased by 1.1-2.2 log cfu/bean within 1 h of exposure to ClO2 and decreased to below the detection limit (≤1.0 log cfu/bean) at all ClO2 concentrations after 10 h. At 50 °C, the microbial population reached the detection limit within 0.5 h regardless of the ClO2 solution concentration. Beans exposed to gas for 10 h at 25 °C were stored for 14 days under conditions of 43, 75, or 100% RH and 4, 12, or 25 °C. At 4 °C, visible mold growth was not established regardless of RH. After 12 days, mold was observed only at 25 °C. At 100% RH, beans stored under the same conditions without ClO2 gas treatment showed mold formation at 13 and 4 days at 12 and 25 °C, respectively.


Asunto(s)
Aspergillus flavus/efectos de los fármacos , Compuestos de Cloro/farmacología , Cloro/farmacología , Coffea/microbiología , Conservación de Alimentos/métodos , Óxidos/farmacología , Aspergillus flavus/crecimiento & desarrollo , Compuestos de Cloro/química , Recuento de Colonia Microbiana , Óxidos/química , Semillas/microbiología
12.
Artículo en Inglés | MEDLINE | ID: mdl-31752418

RESUMEN

Disinfection and sterilization are needed for guaranteeing that medical and surgical instruments do not spread contagious microorganisms to patients. The aim of this study was to evaluate the efficacy of a simple manual technique of high-level disinfection (HLD) of flexible fiberoptic nasofibroscopes (FFNs) with wipes impregnated with a chlorine dioxide solution (Tristel Trio Wipes System-TTW) against a conventional automated washer machine (Soluscope ENT, Cimrex 12-AW). FFNs used in 62 patients undergoing endoscopy at an ENT clinic were sampled according to an aseptic procedure. For each nasoendoscopy, microbiological samples were taken at two times: (1) after a patient's nasoendoscopy and (2) immediately after high-level disinfection. Ten microliters of each prepared sample were inoculated onto specific culture media for the detection of nasopharyngeal flora microorganisms. The microbiological results obtained from 62 post-disinfection samples revealed bacterial growth on two FFNs disinfected with AW, and five FFNs disinfected with TTW, but this difference is not statistically significant. None of the isolates were pathogenic bacteria. Our results are different than the results obtained by two previously published studies on the TTW system. In both studies, sampling was carried out by swabbing the tip and the handle surface of FFNs. This sampling method was the least effective method means of detecting bacteria on a surface. It can be concluded that the two disinfection systems allow providers to obtain a reduction of the saprophytic and pathogenic microbial load.


Asunto(s)
Bacterias/aislamiento & purificación , Compuestos de Cloro/farmacología , Desinfectantes/farmacología , Desinfección/métodos , Endoscopios/microbiología , Contaminación de Equipos/prevención & control , Óxidos/farmacología , Humanos , Manejo de Especímenes
13.
J Food Prot ; 82(11): 1890-1895, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31622162

RESUMEN

Vibrio parahaemolyticus is a prevalent seafoodborne enteropathogen that has become a global concern since the spread of its pandemic strain in 1996. This study investigates the responses of this pathogen to the oxidative disinfectants hydrogen peroxide, chlorine dioxide, and peracetic acid. Expression of the regulator genes oxyR and rpoS, determined by reverse transcription PCR, in V. parahaemolyticus wild-type, oxyR mutant, and rpoS mutant strains exhibited similar patterns in response to the tested oxidative disinfectants. The transcription of the rpoS gene was markedly enhanced in the oxyR mutant strain in the exponential phase. The expression of catalase KatE1 was tracked by using a LacZ fusion reporter in these strains. The experimental results revealed that KatE1 was a significant scavenger of hydrogen peroxide and peracetic acid in V. parahaemolyticus, and RpoS may partially compensate for the regulatory role of OxyR in the oxyR mutant strain. In contrast to its responses to hydrogen peroxide and paracetic acid, KatE1 was not the primary scavenger of chlorine dioxide in these V. parahaemolyticus strains. This study shows that these disinfectants activated a basic oxidative response in this pathogen with different features.


Asunto(s)
Proteínas Bacterianas , Desinfectantes , Regulación Bacteriana de la Expresión Génica , Vibrio parahaemolyticus , Proteínas Bacterianas/genética , Compuestos de Cloro/farmacología , Desinfectantes/farmacología , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Estrés Oxidativo , Óxidos/farmacología , Ácido Peracético/farmacología , Vibrio parahaemolyticus/efectos de los fármacos
14.
J Food Prot ; 82(10): 1729-1735, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31536419

RESUMEN

The interactive effects of mild heat and gaseous chlorine dioxide (ClO2) on populations of Salmonella on almonds were studied. Almonds, dip inoculated with a two-strain cocktail of attenuated Salmonella Typhimurium, were treated with three concentrations of ClO2 at ambient temperature (ca. 22°C), and at 45, 50, 55, and 60°C for 4 h and with more than 90% relative humidity. Concentrations of ClO2 during treatments were measured, and populations of Salmonella were determined following treatments. Results demonstrated that ClO2 at concentrations of more than 4 mg/L and ambient temperature only reduced populations of Salmonella by 1.46 log CFU/g. With increasing treatment temperature, the efficacy of gaseous ClO2 increased. At 55 and 60°C, >1 mg/L ClO2, and a 4-h treatment time, >4 log CFU/g Salmonella was inactivated. Reductions greater than 4 log of the bacterium by gaseous ClO2 at 55°C were confirmed using a three-strain cocktail of pathogenic Salmonella. Overall, results demonstrated that mild heating is necessary for gaseous ClO2 to achieve more than 4 log CFU/g inactivation of Salmonella on almonds.


Asunto(s)
Compuestos de Cloro , Desinfectantes , Microbiología de Alimentos , Calor , Viabilidad Microbiana , Óxidos , Prunus dulcis , Compuestos de Cloro/química , Compuestos de Cloro/farmacología , Recuento de Colonia Microbiana , Desinfectantes/química , Desinfectantes/farmacología , Microbiología de Alimentos/métodos , Gases , Óxidos/química , Óxidos/farmacología , Prunus dulcis/microbiología
15.
Lett Appl Microbiol ; 69(4): 252-257, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31429475

RESUMEN

Alfalfa sprouts have been implicated in multiple foodborne disease outbreaks. This study evaluated the growth of Listeria monocytogenes during sprouting of alfalfa seeds and the effectiveness of daily chlorine dioxide & ozone rinsing in controlling the growth. Alfalfa seeds inoculated with L. monocytogenes were sprouted for 5 days (25°C) with a daily aqueous ClO2 (3 ppm, 10 min) or ozone water (2 ppm, 5 min) rinse. Neither treatment significantly reduced the growth of L. monocytogenes on sprouting alfalfa seeds. The initial level of L. monocytogenes was 3·44 ± 0·27, which increased to c. 7·0 log CFU per g following 3 days of sprouting. There was no significant difference in the bacterial population between the treatment schemes. Bacterial distribution in roots (7·63 ± 0·511 log CFU per g), stems (7·51 ± 0·511 log CFU per g) and leaves (7·41 ± 0·511 log CFU per g) were similar after 5 days. Spent sanitizers had significantly lower levels of bacterial populations compared to the spent distilled water control. The results indicated that sprouting process provides a favourable condition for the growth of L. monocytogenes and the sanitizer treatment alone may not be able to reduce food safety risks. SIGNIFICANCE AND IMPACT OF THE STUDY: Sprouts are high-risk foods. Consumption of raw sprouts is frequently associated with foodborne disease outbreaks. Optimum sprouting procedure involves soaking seeds in water followed by daily water rinsing to maintain a moist environment that is also favourable for the growth of pathogenic micro-organisms. The present study emphasized the potential food safety risks during sprouting and the effect of applying daily sanitizer rinsing in the place of water rinsing to reduce those risks. The finding of this study may be useful in the development of pre-harvest and post-harvest risk management strategies.


Asunto(s)
Compuestos de Cloro/farmacología , Enfermedades Transmitidas por los Alimentos/prevención & control , Listeria monocytogenes/crecimiento & desarrollo , Medicago sativa/microbiología , Óxidos/farmacología , Agua/farmacología , Recuento de Colonia Microbiana , Microbiología de Alimentos/métodos , Inocuidad de los Alimentos/métodos , Ozono/farmacología , Raíces de Plantas/microbiología , Semillas/microbiología , Verduras/microbiología , Agua/química
16.
J Am Assoc Lab Anim Sci ; 58(5): 569-576, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31466553

RESUMEN

A significant concern in laboratory animal medicine is contamination due to pathogen outbreaks and how to adequately decontaminate small equipment. Many factors play a role in the selection of the decontamination method including cost, efficacy, personnel time and safety. Chlorine dioxide (ClO2) gas is an effective method, but decontamination often requires a ClO2 gas generator with a specialized air-tight exposure chamber. Although this method works well for large-scale decon- tamination, the use of a gas generator may be impractical and too costly for smaller-scale decontamination. The goal of this study was to create and validate an effective, small-scale decontamination method that uses ClO2 gas and which is an affordable, efficient, safe, and reproducible. First, we identified a product that generates ClO2 gas after the combination of 2 dry reagents. To find an affordable exposure chamber, we evaluated the ability of 4 household totes with gasket-seal lid systems to retain ClO2 gas and relative humidity (RH). The efficacy of decontamination was validated by concurrently using 2 different biologic indicators (BI), Bacillus atrophaeus (B.a.) and Geobacillus stearothermophilus (G.s.). All household totes evaluated held sufficient gas and RH for a 15-h cycle, providing adequate contact time to inactivate both BI evaluated. Our results suggest that a total exposure dose of 71 ± 42 ppm-h of ClO2 gas over 15 h at 90% or greater RH is adequate to inactivate both B.a. and G.s. There was no statistical significance between the 2 BI as indicators for decontamination; 65 of 230 (28.3%) B.a. and 75 of 230 (32.6%) G.s spore strips were positive for growth (P = 0.36). In conclusion, we successfully combined a variety of low-cost materials to establish an effective, small-scale method to decontaminate laboratory equipment. Depending on the size of the tote and whether BI are used, the cost of our method is roughly 1% that of large-scale ClO2 gas generators used with specialized air-tight exposure chambers.


Asunto(s)
Compuestos de Cloro/farmacología , Descontaminación/métodos , Desinfectantes/farmacología , Óxidos/farmacología , Animales , Cloro , Contaminación de Equipos , Gases
17.
J Am Assoc Lab Anim Sci ; 58(5): 558-568, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31319899

RESUMEN

Gnotobiotic animal research has expanded markedly over the past decade. Although germ-free animals were first described more than 100 y ago, little evidence-based guidance is available on best operational procedures. A key aspect of gnotobiotic technology is the sterilization of animal enclosures, most commonly flexible vinyl film isolators. The objective of this study was to determine the most effective methods for chemical sterilization of gnotobiotic isolators and associated equipment. As test microbes, we used bacteria from 4 different accidental isolator contaminations that occurred in a gnotobiotic core facility. Identification by 16S ribotyping revealed facultative anaerobic firmicutes, including several Paenibacillus and Bacillus species, and obligate aerobic actinobacteria, namely Micrococcus luteus, among the contaminants. We selected 6 products commonly used for disinfecting hospital rooms, kitchens, and veterinary facilities to represent chlorine-oxide- and peroxide-based disinfectants and tested the hypothesis that these 2 classes are equally effective. However, evaluation of bactericidal and sporicidal activity in liquid cultures revealed that chlorine oxide-based disinfectants were more effective than peroxide-based disinfectants. In both groups, various products effectively sterilized gnotobiotic isolators by fogging in field tests, although bactericidal concentrations were markedly higher than those in suspension cultures, and effectiveness was contact-time-dependent. In addition, in both groups, some disinfectants were excessively corrosive to ferrous metals and acrylic. These results demonstrate that no single disinfectant has all desirable properties and that the different characteristics of disinfectants must be balanced during their selection. However, chlorine oxide-based disinfectants were generally more effective and less corrosive than peroxide-based products.


Asunto(s)
Compuestos de Cloro/farmacología , Desinfección/métodos , Vida Libre de Gérmenes , Vivienda para Animales/normas , Peróxidos/farmacología , Roedores , Animales , Desinfectantes/farmacología , Ciencia de los Animales de Laboratorio , Esterilización
18.
Sci Rep ; 9(1): 10232, 2019 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-31308459

RESUMEN

In vitro cultured seedlings or microtubers are the major starting materials for the production of potato. Currently, seedlings are cultured in media sterilized by autoclaving, which, however, consumes more electricity and takes longer for sterilization, and also requires high temperature-tolerant vessel materials. In order to identify alternative methods of sterilizing culture conditions, the disinfection effects of chlorine dioxide (CD) at 88.0, 29.3, 17.6, 12.6 and 8.8 µM were evaluated in potato medium and vessels. The ≥12.6 µM gaseous CD effectively disinfected vessel through a 30-min fumigation process, and its aqueous solution disinfected potato medium efficiently as well. In presence of 12.6 µM CD in the medium, the potato seedlings had similar morphological features as those grown on autoclaved medium, with some exceptions. The use of 12.6-29.3 µM aqueous CD to sterilize the medium increased antioxidant enzyme activities in potato seedlings, while the use of higher concentration decreased antioxidant enzyme activity levels. SSR analysis did not reveal significant molecular differences in potato seedlings cultured between autoclaved and CD-sterilized medium. In addition to this, CD-sterilized medium induced potato microtuber formation at a similar rate as autoclaved medium. In summary, using CD to sterilize potato medium and vessels did not compromise the growth of seedlings and microtuber induction. This study provides an economical and simplified sterilization method for media used to culture potato plantlets, and this can improve energy use of the large-scale tissue culture industry.


Asunto(s)
Compuestos de Cloro/farmacología , Óxidos/farmacología , Esterilización/métodos , Técnicas de Cultivo de Tejidos/métodos , Compuestos de Cloro/metabolismo , Medios de Cultivo/química , Desinfectantes , Desinfección , Calor , Óxidos/metabolismo , Plantones/efectos de los fármacos , Solanum tuberosum/efectos de los fármacos , Solanum tuberosum/crecimiento & desarrollo , Solanum tuberosum/metabolismo
19.
J Sci Food Agric ; 99(13): 5734-5739, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31163092

RESUMEN

BACKGROUND: Acidovorax citrulli is a plant pathogen causing bacterial fruit blotch in Cucurbitaceae family. Applying high concentration of disinfectants to seeds containing plant pathogen may substantially decrease the germination rate of seeds. Therefore, it is necessary to develop a hurdle technology which can inactivate plant pathogens without decreasing seed viability. This study was conducted to develop a decontamination method to inactivate the plant pathogen Acidovorax citrulli on Cucurbitaceae seeds by sequential treatments with aqueous chlorine dioxide (ClO2 ), drying, and dry heat. RESULTS: The maximum ClO2 concentration that did not lower germination rates of cucumber, honeydew melon, and watermelon seeds was ca. 100 µg mL-1 of ClO2 for 5 min. Optimal incubation conditions for drying seeds that had been treated with aqueous ClO2 were determined as 25 °C and 43% relative humidity (RH) for 48 h. The maximum dry-heat temperature that did not reduce germination rates of seeds, which had been treated with ClO2 and dried at 25 °C, was 60 °C at 43% RH for 24 h. When seeds containing A. citrulli (6.4-7.0 log CFU g-1 ) were treated with aqueous ClO2 (50 µg mL-1 , 5 min), dried (25 °C, 43% RH, 24 h), and dry heated (60 °C, 43% RH, 24 h), the pathogen was inactivated to below the detection limit from all three seed types (<-0.5 log CFU g-1 ). CONCLUSION: The decontamination conditions to inactivate A. citrullii from Cucurbitaceae seeds without decreasing the seed viability were determined (sequential treatment with ClO2 [50 µg mL-1 , 5 min], dried [25 °C, 43% RH, 24 h], and dry heated [60 °C, 43% RH, 24 h]). The results of this study may also be applicable to other plant pathogens on other types of seeds. © 2019 Society of Chemical Industry.


Asunto(s)
Comamonadaceae/efectos de los fármacos , Cucurbitaceae/microbiología , Descontaminación/métodos , Semillas/crecimiento & desarrollo , Compuestos de Cloro/farmacología , Comamonadaceae/crecimiento & desarrollo , Cucurbitaceae/crecimiento & desarrollo , Descontaminación/instrumentación , Desecación , Desinfectantes/farmacología , Germinación , Óxidos/farmacología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Semillas/microbiología
20.
Food Environ Virol ; 11(3): 214-219, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30949936

RESUMEN

The effectiveness of steady-state levels of gaseous chlorine dioxide (ClO2) against Tulane virus (TV), a human norovirus surrogate, on berries was determined. The generated ClO2 was maintained at 1 mg/L inside a 269 L glove box to treat two 50 g batches of blueberries, raspberries, and blackberries, and two 100 g batches of strawberries that were immersion coated with TV. The standardized/normalized treatment concentrations of ClO2 ranging from 0.63 to 4.40 ppm-h/g berry were evaluated. When compared to untreated TV contaminated berries, log reductions of TV were in excess of 2.9 log PFU/g for all berry types and conditions tested, indicating that ClO2 was highly effective. In general, the efficacy of all ClO2 treatments on log reductions of TV on all berries was not significantly different (p < 0.05). The average log reduction with strawberries, raspberries, blueberries, and blackberries, treated with the lowest ClO2 concentration, 0.63 ppm-h/g, were 2.98, 3.40, 3.82, and 4.17 log PFU/g, respectively. Overall results suggest that constant levels of ClO2 could be quite effective against foodborne viruses.


Asunto(s)
Compuestos de Cloro/farmacología , Desinfectantes/farmacología , Conservación de Alimentos/métodos , Frutas/virología , Norovirus/efectos de los fármacos , Óxidos/farmacología , Arándanos Azules (Planta)/virología , Compuestos de Cloro/química , Desinfectantes/química , Contaminación de Alimentos/prevención & control , Fragaria/virología , Gases/química , Gases/farmacología , Norovirus/crecimiento & desarrollo , Norovirus/fisiología , Óxidos/química , Rubus/virología , Inactivación de Virus/efectos de los fármacos
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