Lethality of Chlorine, Chlorine Dioxide, and a Commercial Produce Sanitizer to Bacillus cereus and Pseudomonas in a Liquid Detergent, on Stainless Steel, and in Biofilm

2006 ◽  
Vol 69 (11) ◽  
pp. 2621-2634 ◽  
Author(s):  
AUDREY C. KRESKE ◽  
JEE-HOON RYU ◽  
CHARLES A. PETTIGREW ◽  
LARRY R. BEUCHAT
Keyword(s):  
Stainless Steel ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Total Population ◽  
Horse Serum ◽  
Effective Strategies ◽  
Food Contact Surfaces ◽  
Dishwashing Detergent ◽  
Contact Surfaces ◽  
Spoilage Microorganisms

Many factors that are not fully understood may influence the effectiveness of sanitizer treatments for eliminating pathogens and spoilage microorganisms in food or detergent residues or in biofilms on food contact surfaces. This study was done to determine the sensitivities of Pseudomonas cells and Bacillus cereus cells and spores suspended in a liquid dishwashing detergent and inoculated onto the surface of stainless steel to treatment with chlorine, chlorine dioxide, and a commercial produce sanitizer (Fit). Cells and spores were incubated in a liquid dishwashing detergent for 16 to 18 h before treatment with sanitizers. At 50 μg/ml, chlorine dioxide killed a significantly higher number of Pseudomonas cells (3.82 log CFU/ml) than did chlorine (a reduction of 1.34 log CFU/ml). Stainless steel coupons were spot inoculated with Pseudomonas cells and B. cereus cells and spores, with water and 5% horse serum as carriers. Chlorine was more effective than chlorine dioxide in killing cells and spores of B. cereus suspended in horse serum. B. cereus biofilm on stainless steel coupons that were treated with chlorine dioxide or chlorine at 200 μg/ml had total population reductions (vegetative cells plus spores) of ≥4.42 log CFU per coupon; the number of spores was reduced by ≥3.80 log CFU per coupon. Fit (0.5%) was ineffective for killing spot-inoculated B. cereus and B. cereus in biofilm, but treatment with mixtures of Fit and chlorine dioxide caused greater reductions than did treatment with chlorine dioxide alone. In contrast, when chlorine was combined with Fit, the lethality of chlorine was completely lost. This study provides information on the survival and sanitizer sensitivity of Pseudomonas and B. cereus in a liquid dishwashing detergent, on the surface of stainless steel, and in a biofilm. This information will be useful for developing more effective strategies for cleaning and sanitizing contact surfaces in food preparation and processing environments.

scholarly journals Inactivation Kinetics and Mechanism of a Human Norovirus Surrogate on Stainless Steel Coupons via Chlorine Dioxide Gas

2015 ◽  
Vol 82 (1) ◽  
pp. 116-123 ◽  
Author(s):  
Jia Wei Yeap ◽  
Simran Kaur ◽  
Fangfei Lou ◽  
Erin DiCaprio ◽  
Mark Morgan ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Chlorine Dioxide ◽  
Plaque Assay ◽  
Kinetics And Mechanism ◽  
Inactivation Kinetics ◽  
Human Norovirus ◽  
Effective Measure ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces

ABSTRACTAcute gastroenteritis caused by human norovirus is a significant public health issue. Fresh produce and seafood are examples of high-risk foods associated with norovirus outbreaks. Food contact surfaces also have the potential to harbor noroviruses if exposed to fecal contamination, aerosolized vomitus, or infected food handlers. Currently, there is no effective measure to decontaminate norovirus on food contact surfaces. Chlorine dioxide (ClO2) gas is a strong oxidizer and is used as a decontaminating agent in food processing plants. The objective of this study was to determine the kinetics and mechanism of ClO2gas inactivation of a norovirus surrogate, murine norovirus 1 (MNV-1), on stainless steel (SS) coupons. MNV-1 was inoculated on SS coupons at the concentration of 107PFU/coupon. The samples were treated with ClO2gas at 1, 1.5, 2, 2.5, and 4 mg/liter for up to 5 min at 25°C and a relative humidity of 85%, and virus survival was determined by plaque assay. Treatment of the SS coupons with ClO2gas at 2 mg/liter for 5 min and 2.5 mg/liter for 2 min resulted in at least a 3-log reduction in MNV-1, while no infectious virus was recovered at a concentration of 4 mg/liter even within 1 min of treatment. Furthermore, it was found that the mechanism of ClO2gas inactivation included degradation of viral protein, disruption of viral structure, and degradation of viral genomic RNA. In conclusion, treatment with ClO2gas can serve as an effective method to inactivate a human norovirus surrogate on SS contact surfaces.

Evaluation of Chlorine, Chlorine Dioxide, and a Peroxyacetic Acid–Based Sanitizer for Effectiveness in Killing Bacillus cereus and Bacillus thuringiensis Spores in Suspensions, on the Surface of Stainless Steel, and on Apples

2006 ◽  
Vol 69 (8) ◽  
pp. 1892-1903 ◽  
Author(s):  
AUDREY C. KRESKE ◽  
JEE-HOON RYU ◽  
LARRY R. BEUCHAT
Keyword(s):  
Stainless Steel ◽  
Bacillus Thuringiensis ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Food Processing ◽  
Horse Serum ◽  
Peroxyacetic Acid ◽  
Food Processing Industry ◽  
Bacillus Spores ◽  
Food Contact Surface

Chlorine (10 to 200 μg/ml), chlorine dioxide (10 to 200 μg/ml), and a peroxyacetic acid–based sanitizer (40 and 80 μg/ml) were evaluated for effectiveness in killing spores of Bacillus cereus and Bacillus thuringiensis in suspensions and on the surface of stainless steel and apples. Water and 5% horse serum were used as carriers for spore inoculum applied to the surface of stainless steel coupons, and 5% horse serum was used as a carrier for inoculum applied to apples. Inocula were dried on stainless steel for 5 h and on apples for 22 to 24 h before treating with sanitizers. At the concentrations of sanitizers tested, sensitivities of planktonic B. cereus and B. thuringiensis spores were similar. A portion of the spores surviving treatment with chlorine and, more markedly, chlorine dioxide had decreased tolerance to heat. Planktonic spores of both species were more sensitive to sanitizers than were spores on the surface of stainless steel or apples. At the same concentrations, chlorine was more effective than chlorine dioxide in killing spores in suspension and on stainless steel. The lethality of chlorine dioxide was markedly reduced when inoculum on stainless steel coupons was suspended in 5% horse serum as a carrier rather than water. Chlorine and chlorine dioxide at concentrations of 10 to 100 μg/ml were equally effective in killing spores on apples. Significant reductions of ≥3.8 to 4.5 log CFU per apple were achieved by treatment with 100 μg/ml of either of the two sanitizers. The peroxyacetic acid sanitizer (40 and 80 μg/ml) was ineffective in killing Bacillus spores in the test systems investigated. Results provide information on the effectiveness of sanitizers commonly used in the food processing industry in killing Bacillus spores in suspension, on a food-contact surface, and on a ready-to-eat food.

Inactivation of Bacillus cereus Spores on Stainless Steel by Combined Superheated Steam and UV-C Irradiation Treatment

2019 ◽  
Vol 83 (1) ◽  
pp. 13-16 ◽  
Author(s):  
SANG-SOON KIM ◽  
SOO-HWAN KIM ◽  
SANG-HYUN PARK ◽  
DONG-HYUN KANG
Keyword(s):  
Stainless Steel ◽  
Bacillus Cereus ◽  
Superheated Steam ◽  
Dipicolinic Acid ◽  
Combined Treatment ◽  
Bactericidal Effect ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Uv C

ABSTRACT Bacillus cereus spore contamination on food contact surfaces is of great concern in the food industry. Thus, in the present study, superheated steam (SHS) was used alone or combined with UV-C irradiation for inactivation of B. cereus spores inoculated on stainless steel coupons. Temperatures higher than 250°C were needed to effectively inactivate B. cereus spores by SHS treatment alone, while a synergistic bactericidal effect resulted from the sequential treatment of SHS before or after UV-C irradiation. The increased dipicolinic acid ratio obtained by the combined treatment had a significant role in the synergistic bactericidal effect. Therefore, the combined treatment of SHS and UV-C could be used effectively to inactivate B. cereus on stainless steel. It is recommended to use hurdle technology with reduced energy consumption to ensure microbiological safety on food contact surfaces. HIGHLIGHTS

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

2004 ◽  
Vol 67 (8) ◽  
pp. 1702-1708 ◽  
Author(s):  
LARRY R. BEUCHAT ◽  
CHARLES A. PETTIGREW ◽  
MARIO E. TREMBLAY ◽  
BRIAN J. ROSELLE ◽  
ALAN J. SCOUTEN
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Alkaline Ph ◽  
Fruit And Vegetable ◽  
Vegetative Cells ◽  
Inorganic Solids ◽  
Powder Product ◽  
Food Contact Surfaces ◽  
Contact Surfaces

Chlorine, ClO2, and a commercial raw fruit and vegetable sanitizer were evaluated for their effectiveness in killing vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis. The ultimate goal was to use one or both species as a potential surrogate(s) for Bacillus anthracis in studies that focus on determining the efficacy of sanitizers in killing the pathogen on food contact surfaces and foods. Treatment with alkaline (pH 10.5 to 11.0) ClO2 (200 μg/ml) produced by electrochemical technologies reduced populations of a five-strain mixture of vegetative cells and a five-strain mixture of spores of B. cereus by more than 5.4 and more than 6.4 log CFU/ml respectively, within 5 min. This finding compares with respective reductions of 4.5 and 1.8 log CFU/ml resulting from treatment with 200 μg/ml of chlorine. Treatment with a 1.5% acidified (pH 3.0) solution of Fit powder product was less effective, causing 2.5- and 0.4-log CFU/ml reductions in the number of B. cereus cells and spores, respectively. Treatment with alkaline ClO2 (85 μg/ml), acidified (pH 3.4) ClO2 (85 μg/ml), and a mixture of ClO2 (85 μg/ml) and Fit powder product (0.5%) (pH 3.5) caused reductions in vegetative cell/spore populations of more than 5.3/5.6, 5.3/5.7, and 5.3/6.0 log CFU/ml, respectively. Treatment of B. cereus and B. thuringiensis spores in a medium (3.4 mg/ml of organic and inorganic solids) in which cells had grown and produced spores with an equal volume of alkaline (pH 12.1) ClO2 (400 μg/ml) for 30 min reduced populations by 4.6 and 5.2 log CFU/ml, respectively, indicating high lethality in the presence of materials other than spores that would potentially react with and neutralize the sporicidal activity of ClO2

Biofilm Formation and Sporulation by Bacillus cereus on a Stainless Steel Surface and Subsequent Resistance of Vegetative Cells and Spores to Chlorine, Chlorine Dioxide, and a Peroxyacetic Acid–Based Sanitizer

2005 ◽  
Vol 68 (12) ◽  
pp. 2614-2622 ◽  
Author(s):  
JEE-HOON RYU ◽  
LARRY R. BEUCHAT
Keyword(s):  
Stainless Steel ◽  
Relative Humidity ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Biofilm Formation ◽  
Total Cell ◽  
Stainless Steel Surface ◽  
Peroxyacetic Acid ◽  
Vegetative Cells ◽  
Cell Counts

Biofilm formation by Bacillus cereus 038-2 on stainless steel coupons, sporulation in the biofilm as affected by nutrient availability, temperature, and relative humidity, and the resistance of vegetative cells and spores in biofilm to sanitizers were investigated. Total counts in biofilm formed on coupons immersed in tryptic soy broth (TSB) at 12 and 22°C consisted of 99.94% of vegetative cells and 0.06% of spores. Coupons on which biofilm had formed were immersed in TSB or exposed to air with 100, 97, 93, or 85% relative humidity. Biofilm on coupons immersed in TSB at 12°C for an additional 6 days or 22°C for an additional 4 days contained 0.30 and 0.02% of spores, respectively, whereas biofilm exposed to air with 100 or 97% relative humidity at 22°C for 4 days contained 10 and 2.5% of spores, respectively. Sporulation did not occur in biofilm exposed to 93 or 85% relative humidity at 22°C. Treatment of biofilm on coupons that had been immersed in TSB at 22°C with chlorine (50 μg/ml), chlorine dioxide (50 μg/ml), and a peroxyacetic acid–based sanitizer (Tsunami 200, 40 μg/ml) for 5 min reduced total cell counts (vegetative cells plus spores) by 4.7, 3.0, and 3.8 log CFU per coupon, respectively; total cell counts in biofilm exposed to air with 100% relative humidity were reduced by 1.5, 2.4, and 1.1 log CFU per coupon, respectively, reflecting the presence of lower numbers of vegetative cells. Spores that survived treatment with chlorine dioxide had reduced resistance to heat. It is concluded that exposure of biofilm formed by B. cereus exposed to air at high relative humidity (≥97%) promotes the production of spores. Spores and, to a lesser extent, vegetative cells embedded in biofilm are protected against inactivation by sanitizers. Results provide new insights to developing strategies to achieve more effective sanitation programs to minimize risks associated with B. cereus in biofilm formed on food contact surfaces and on foods.

Control of Listeria innocua Biofilms on Food Contact Surfaces with Slightly Acidic Electrolyzed Water and the Risk of Biofilm Cells Transfer to Duck Meat

2018 ◽  
Vol 81 (4) ◽  
pp. 582-592 ◽  
Author(s):  
HYE RI JEON ◽  
MI JIN KWON ◽  
KI SUN YOON
Keyword(s):  
Stainless Steel ◽  
Food Processing ◽  
Biofilm Formation ◽  
Listeria Innocua ◽  
Potential Hazard ◽  
Processing Efficiency ◽  
Electrolyzed Water ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces

ABSTRACT Biofilm formation on food contact surfaces is a potential hazard leading to cross-contamination during food processing. We investigated Listeria innocua biofilm formation on various food contact surfaces and compared the washing effect of slightly acidic electrolyzed water (SAEW) at 30, 50, 70, and 120 ppm with that of 200 ppm of sodium hypochlorite (NaClO) on biofilm cells. The risk of L. innocua biofilm transfer and growth on food at retail markets was also investigated. The viability of biofilms that formed on food contact surfaces and then transferred cells to duck meat was confirmed by fluorescence microscopy. L. innocua biofilm formation was greatest on rubber, followed by polypropylene, glass, and stainless steel. Regardless of sanitizer type, washing removed biofilms from polypropylene and stainless steel better than from rubber and glass. Among the various SAEW concentrations, washing with 70 ppm of SAEW for 5 min significantly reduced L. innocua biofilms on food contact surfaces during food processing. Efficiency of transfer of L. innocua biofilm cells was the highest on polypropylene and lowest on stainless steel. The transferred biofilm cells grew to the maximum population density, and the lag time of transferred biofilm cells was longer than that of planktonic cells. The biofilm cells that transferred to duck meat coexisted with live, injured, and dead cells, which indicates that effective washing is essential to remove biofilm on food contact surfaces during food processing to reduce the risk of foodborne disease outbreaks.

Concentration and Detection of Caliciviruses from Food Contact Surfaces

2002 ◽  
Vol 65 (6) ◽  
pp. 999-1004 ◽  
Author(s):  
ANIL TAKU ◽  
BALDEV R. GULATI ◽  
PAUL B. ALLWOOD ◽  
KERRIN PALAZZI ◽  
CRAIG W. HEDBERG ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Food Service ◽  
Contact Period ◽  
Norwalk Virus ◽  
Buffer Solution ◽  
Simple Method ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Elution Method

Outbreaks of human Norwalk virus (NV) and Norwalk-like viruses often originate in food service establishments. No reliable method is available for the detection of these human caliciviruses on food contact surfaces. We describe a simple method for the detection of NV from stainless steel work surfaces using cultivable feline calicivirus (FCV) as a model. Stainless steel surfaces were artificially contaminated with known amounts of FCV, followed by its elution in a buffer solution. Three methods of virus elution were compared. In the first method, moistened cotton swabs or pieces of nylon filter (1MDS) were used to elute the contaminating virus. The second method consisted of flooding the contaminated surface with eluting buffer, allowing it to stay in contact for 15 min, followed by aspiration of the buffer (aspiration method) after a contact period of 15 min. The third method, the scraping-aspiration method, was similar to the aspiration method, except that the surfaces were scraped with a cell scraper before buffer aspiration. Maximum virus recovery (32 to 71%) was obtained with the scraping-aspiration method using 0.05 M glycine buffer at pH 6.5. Two methods (organic flocculation and filter adsorption elution) were compared to reduce the volume of the eluate recovered from larger surfaces. The organic flocculation method gave an average overall recovery of 55% compared to the filter-adsorption-elution method, which yielded an average recovery of only 8%. The newly developed method was validated for the detection of NV by artificial contamination of 929-cm2 stainless steel sheets with NV-positive stool samples and for the detection of the recovered virus by reverse transcription–polymerase chain reaction.

Inhibition of Initial Attachment of Injured Salmonella Typhimurium onto Abiotic Surfaces

2017 ◽  
Vol 81 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Woo-Ju Kim ◽  
Ki-Ok Jeong ◽  
Dong-Hyun Kang
Keyword(s):  
Hydrogen Peroxide ◽  
Stainless Steel ◽  
Lactic Acid ◽  
Salmonella Typhimurium ◽  
Food Processing ◽  
Food Contact ◽  
Abiotic Surfaces ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Biofilm Development

ABSTRACT Following sanitation interventions in food processing facilities, sublethally injured bacterial cells can remain on food contact surfaces. We investigated whether injured Salmonella Typhimurium cells can attach onto abiotic surfaces, which is the initial stage for further biofilm development. We utilized heat, UV, hydrogen peroxide, and lactic acid treatments, which are widely utilized by the food industry. Our results showed that heat, UV, and hydrogen peroxide did not effectively change populations of attached Salmonella Typhimurium. Cells treated with hydrogen peroxide had a slightly higher tendency to adhere to abiotic surfaces, although there was no significant difference between the populations of control and hydrogen peroxide–treated cells. However, lactic acid effectively reduced the number of Salmonella Typhimurium cells attached to stainless steel. We also compared physicochemical changes of Salmonella Typhimurium after application of lactic acid and used hydrogen peroxide as a positive control because only lactic acid showed a decreased tendency for attachment and hydrogen peroxide induced slightly higher numbers of attached bacteria cells. Extracellular polymeric substance produced by Salmonella Typhimurium was not detected in any treatment. Significant differences in hydrophobicity were not observed. Surface charges of cell membranes did not show relevant correlation with numbers of attached cells, whereas autoaggregation showed a positive correlation with attachment to stainless steel. Our results highlight that when lactic acid is applied in a food processing facility, it can effectively interfere with adhesion of injured Salmonella Typhimurium cells onto food contact surfaces.

Simple, Accurate Method for Evaluating the Amount of Fat and Protein Residue on a Food Contact Surface1,2

1984 ◽  
Vol 47 (10) ◽  
pp. 762-764
Author(s):  
H. E. HUFF ◽  
M. E. ANDERSON ◽  
R. T. MARSHALL
Keyword(s):  
Stainless Steel ◽  
Recovery Rate ◽  
Gravimetric Method ◽  
Accurate Method ◽  
Food Grade ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Different Types ◽  
Contact Surfaces ◽  
Pork Fat

The objective of this research was to evaluate a method for quantitatively removing pork fat and blood plasma from different food contact surfaces - glass, stainless steel, plastic and food grade belting. Two studies were conducted. In the first study, a mass balance procedure was used to determine whether the developed method could remove virtually all the fat or protein placed on stainless steel and glass. In the second study, a gravimetric method was used to verify that the amount of fat on test strips could be harvested and quantified as residue. A recovery rate of from 98% or 100% was achieved for the different types of food contact surfaces.

scholarly journals Controlling Bacillus cereus adherence to stainless steel with different cleaning and sanitizing procedures used in dairy plants

2010 ◽  
Vol 62 (6) ◽  
pp. 1478-1483 ◽  
Author(s):  
V.C Salustiano ◽  
N.J Andrade ◽  
J.I Ribeiro Junior ◽  
P.E Fernandes ◽  
J.P Lopes ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Physicochemical Properties ◽  
Bacillus Cereus ◽  
Lower Number ◽  
Thermodynamic Aspect ◽  
Contact Surfaces

Bacillus cereus adherence to stainless steel used to milk contact surfaces was observed, depending on the cleaning and sanitizing procedures applied and the physicochemical properties of the surfaces. Numbers of surviving B. cereus after hygiene procedures were affected by temperature, the concentrations of both alkaline and acid washes, and the pH of the chlorine solution. The adhesion of B. cereus to the stainless steel was not thermodynamically favorable, and the adherence of this microorganism occurred in lower number, in accordance to the thermodynamic aspect of adhesion.

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