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.

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.

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.

Destruction of Alicyclobacillus acidoterrestris Spores in Apple Juice on Stainless Steel Surfaces by Chemical Disinfectants

2009 ◽  
Vol 72 (3) ◽  
pp. 510-514 ◽  
Author(s):  
RICHARD PODOLAK ◽  
PHILIP H. ELLIOTT ◽  
BRADLEY J. TAYLOR ◽  
AAKASH KHURANA ◽  
DARRYL G. BLACK
Keyword(s):  
Stainless Steel ◽  
Chlorine Dioxide ◽  
Apple Juice ◽  
Octanoic Acid ◽  
Stainless Steel Surface ◽  
Peroxyacetic Acid ◽  
Alicyclobacillus Acidoterrestris ◽  
Practical Applications ◽  
Maximum Reduction ◽  
Steel Surfaces

A study was conducted to determine the effects of three commercially available disinfectants on the reduction of Alicyclobacillus acidoterrestris spores in single-strength apple juice applied to stainless steel surfaces. Apple juice was inoculated with A. acidoterrestris spores, spread onto the surface of stainless steel chips (SSC), dried to obtain spore concentrations of approximately 104 CFU/cm2, and treated with disinfectants at temperatures ranging from 40 to 90°C. The concentrations of disinfectants were 200, 500, 1,000, and 2,000 ppm of total chlorine for Clorox (CL) (sodium hypochlorite); 50, 100, and 200 ppm of total chlorine for Carnebon 200 (stabilized chlorine dioxide); and 1,500, 2,000, and 2,600 ppm for Vortexx (VOR) (hydrogen peroxide, peroxyacetic acid, and octanoic acid). For all temperatures tested, VOR at 2,600 ppm (90°C) and CL at 2,000 ppm (90°C) were the most inhibitory against A. acidoterrestris spores, resulting in 2.55- and 2.32-log CFU/cm2 reductions, respectively, after 2 min. All disinfectants and conditions tested resulted in the inactivation of A. acidoterrestris spores, with a maximum reduction of >2 log CFU/cm2. Results from this study indicate that A. acidoterrestris spores, in single-strength apple juice, may be effectively reduced on stainless steel surface by VOR and CL, which may have practical applications in the juice industry.

Considerations about the Organic Acids Effect on Weldings in Food Processing Industry

2020 ◽  
Vol 1157 ◽  
pp. 108-112
Author(s):  
Mihaela Botiş Nistoran ◽  
Gabriela Victoria Mnerie ◽  
Dumitru Mnerie
Keyword(s):  
Stainless Steel ◽  
Organic Acids ◽  
Food Processing ◽  
Design Standards ◽  
Food Processing Industry ◽  
Additional Food ◽  
Processing Industry ◽  
Processing Equipment ◽  
Determining Factor

For food processing equipment, welding uses heat to fuse together the various pipes and pieces of stainless steel. The quality of the weld is a determining factor in whether or not the product meets hygienic design standards for the food processing industry. When fabricating food processing equipment, weld quality is extremely important to maintain the integrity of the products being processed. A weld does not meet hygienic design standards if there is potential for contamination that can result from cracks, crevices, 90-degree angles, corrosion or over-stresses surfaces in the processing equipment. When product is stuck in a crevice it becomes very difficult to remove through regular cleaning leaving the potential for bacteria to build up and contaminate additional food products.

Efficacy of gaseous chlorine dioxide in inactivating Bacillus cereus spores attached to and in a biofilm on stainless steel

2014 ◽  
Vol 188 ◽  
pp. 122-127 ◽  
Author(s):  
Hyegyeong Nam ◽  
Hyun-Sun Seo ◽  
Jihyun Bang ◽  
Hoikyung Kim ◽  
Larry R. Beuchat ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Gaseous Chlorine Dioxide

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

scholarly journals Bacteriophage Intervention Effectively Kills Listeria on Food Contact Surface Materials

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
S. Sirdesai ◽  
B. De Vegt ◽  
R. Peterson ◽  
A. Moncho ◽  
J. Van Mierlo
Keyword(s):  
Stainless Steel ◽  
Food Processing ◽  
P Value ◽  
Bacterial Reduction ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Processing Plants ◽  
Food Contact Surface ◽  
Contact Surfaces ◽  
Phage Treatment

ObjectivesListeria is a pathogenic bacterium that is widespread in nature and can enter food processing plants through many vectors, like raw materials, process waste and personnel. Food processors work hard to keep Listeria out of the environment, but it can at times be found from food contact surfaces to floor drains. The sanitation can be compounded when equipment is pitted or cracked creating a harborage or niche in which Listeria can grow. Many control strategies for cleaning and biofilm removal have been put into place but may not suffice in eliminating Listeria from the food contact surface or environment. Bacteriophages are now being used to tackle these pathogens in food processing environments. Since they only target specific bacteria, they are harmless to humans, animals and plants, while effectively eliminating Listeria.This study determines the efficacy of a commercially available bacteriophage product, PhageGuard Listex, against Listeria on commonly found materials in food processing plants (stainless steel and UHMW polyethylene). Efficacy was determined by applying two phage concentrations, as well as two exposure times.Materials and MethodsOvernight cultures of L. monocytogenes ATCC13832 and L. innocua ATCC51742 were mixed in equal parts to create a Listeria cocktail (2 × 109 CFU/cm2). Sterile coupons (100 cm2) of stainless steel or UHMW polyethylene were artificially inoculated with the cocktail at 2.5ML/cm2 and left to dry at 37°C until completely dry. Subsequently, coupons were treated with 2 × 107 or 1 × 108 Plaque Forming Units (PFU)/cm2 using a spray system and incubated at room temperature for 1 and 3 h, before retrieval and enumeration of bacteria on selective agar plates. Sample size n:3. Results were analyzed using two-way ANOVA, with Dunnett’s multiple comparisons test on the normalized data.ResultsA dose dependent response to the phage treatment was observed, where an increasing phage concentration resulted in an increase in Listeria kill on both surfaces. On stainless steel, a treatment dose of 2 × 107 PFU/cm2 resulted in a statistically significant bacterial reduction of 1.27 log after 1 h (p value < 0.0001), while application of 1 × 108 PFU/cm2 showed a 2.16 log reduction (p value < 0.0001). On UHMW polyethylene, a bacterial reduction of 0.47 log was observed 1 h after applying 2 × 107 PFU/cm2, while the application of 1 × 108 PFU/cm2 led to a reduction of 1.95 log. However, these reductions were not statistically significant (p value > 0.05). After 3 h of treatment, the reductions were slightly higher in both materials (Table 3). After this time, the difference between control and 5% treatment on UHMW polyethylene obtained a p-value < 0.05.ConclusionPhage technology is an easy and safe intervention which can be used as an additional tool to control Listeria in processing environments. The above results indicate that the commercially available phage solution, PhageGuard Listex, can reduce Listeria contamination on food contact surfaces by 0.4 to 3.4 logs after 3 h of treatment.Table 3Log reduction of Listeria cells after applicatio nof two bacteriophage concentrations, measured at 1 and 3 h post phage treatment

Persistent Listeria monocytogenes Strains Show Enhanced Adherence to Food Contact Surface after Short Contact Times

2000 ◽  
Vol 63 (9) ◽  
pp. 1204-1207 ◽  
Author(s):  
JANNE M. LUNDÉN ◽  
MARIA K. MIETTINEN ◽  
TIINA J. AUTIO ◽  
HANNU J. KORKEALA
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Contact Surface ◽  
Food Processing ◽  
Contact Time ◽  
Ice Cream ◽  
Short Contact ◽  
Steel Surfaces ◽  
Food Contact Surface ◽  
Epifluorescence Microscope

Adherence of 3 persistent and 14 nonpersistent Listeria monocytogenes strains to stainless steel surfaces after short and long contact times was investigated. L. monocytogenes strains were obtained from poultry plants and an ice cream plant throughout several years. Adherence tests were performed in tryptic soy broth at 25°C for 1, 2, and 72 h. Test surfaces were rinsed after the contact time, and attached cells were stained with acridine orange and enumerated with an epifluorescence microscope. The persistent poultry plant strains showed adherence 2- to 11-fold higher than the nonpersistent strains following 1- and 2-h contact times. The adherence of the persistent ice cream plant strain after 1- and 2-h contact times was higher than most of the nonpersistent strains. Seven of 12 nonpersistent ice cream strains showed an adherence of less than half that of the persistent strain. After 72 h, the differences in adherence were not as marked, since half the nonpersistent strains had reached adherence levels comparable with the persistent strains. In fact, three nonpersistent strains showed even higher adherence than the persistent strains. Thus, results of this study reveal that persistent L. monocytogenes strains show enhanced adherence at short contact times, promoting their survival in food processing facilities and possibly having an effect on initiation of persistent plant contamination.

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