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

2005 ◽  
Vol 32 (7) ◽  
pp. 301-308 ◽  
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 ◽  
Fruit And Vegetable ◽  
Vegetative Cells

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.

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.

Film coating of seeds with Bacillus cereus RS87 spores for early plant growth enhancement

2008 ◽  
Vol 54 (10) ◽  
pp. 861-867 ◽  
Author(s):  
Kanchalee Jetiyanon ◽  
Sakchai Wittaya-Areekul ◽  
Pinyupa Plianbangchang
Keyword(s):  
Plant Growth ◽  
Bacillus Cereus ◽  
Plant Height ◽  
Root Length ◽  
Film Coating ◽  
Field Trials ◽  
Growth Enhancement ◽  
Vegetative Cells ◽  
Plant Growth Promoting ◽  
Growth Promoting

The plant growth-promoting rhizobacterium Bacillus cereus RS87 was previously reported to promote plant growth in various crops in both greenhouse and field trials. To apply as a plant growth promoting agent with practical use, it is essential to ease the burden of routine preparation of a fresh suspension of strain RS87 in laboratory. The objectives of this study were to investigate the feasibility of film-coating seeds with B. cereus RS87 spores for early plant growth enhancement and to reveal the indoleacetic acid (IAA) production released from strain RS87. The experiment consisted of the following 5 treatments: nontreated seeds, water-soaked seeds, film-coated seeds, seeds soaked with vegetative cells of strain RS87, and film-coated seeds with strain RS87 spores. Three experiments were conducted separately to assess seed emergence, root length, and plant height. Results showed that both vegetative cells and spores of strain RS87 significantly promoted (P ≤ 0.05) seed emergence, root length and plant height over the control treatments. The strain RS87 also produced IAA. In conclusion, the film coating of seeds with spores of B. cereus RS87 demonstrated early plant growth enhancement as well as seeds using their vegetative cells. IAA released from strain RS87 would be one of the mechanisms for plant growth enhancement.

Inactivation kinetics of Bacillus cereus vegetative cells and spores from different sources by antimicrobial photodynamic treatment (aPDT)

LWT ◽  
2021 ◽  
Vol 142 ◽  
pp. 111037
Author(s):  
Leonardo do Prado-Silva ◽  
Verônica O. Alvarenga ◽  
Gilberto Ú.L. Braga ◽  
Anderson S. Sant’Ana
Keyword(s):  
Bacillus Cereus ◽  
Inactivation Kinetics ◽  
Photodynamic Treatment ◽  
Vegetative Cells ◽  
Kinetics Of ◽  
Different Sources

scholarly journals Multiple-Locus Sequence Typing Analysis of Bacillus cereus and Bacillus thuringiensis Reveals Separate Clustering and a Distinct Population Structure of Psychrotrophic Strains

2006 ◽  
Vol 72 (2) ◽  
pp. 1569-1578 ◽  
Author(s):  
Alexei Sorokin ◽  
Benjamin Candelon ◽  
Kévin Guilloux ◽  
Nathalie Galleron ◽  
Natalia Wackerow-Kouzova ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacillus Cereus ◽  
Individual Gene ◽  
Mild Winter ◽  
Systematic Testing ◽  
Bacillus Weihenstephanensis ◽  
Paris Area ◽  
Population Structures ◽  
Multiple Strains ◽  
Almost All

ABSTRACT We used multilocus sequence typing (MLST) to characterize phylogenetic relationships for a collection of Bacillus cereus group strains isolated from forest soil in the Paris area during a mild winter. This collection contains multiple strains isolated from the same soil sample and strains isolated from samples from different sites. We characterized 115 strains of this collection and 19 other strains based on the sequences of the clpC, dinB, gdpD, panC, purF, and yhfL loci. The number of alleles ranged from 36 to 53, and a total of 93 allelic profiles or sequence types were distinguished. We identified three major strain clusters—C, T, and W—based on the comparison of individual gene sequences or concatenated sequences. Some less representative clusters and subclusters were also distinguished. Analysis of the MLST data using the concept of clonal complexes led to the identification of two, five, and three such groups in clusters C, T, and W, respectively. Some of the forest isolates were closely related to independently isolated psychrotrophic strains. Systematic testing of the strains of this collection showed that almost all the strains that were able to grow at a low temperature (6°C) belonged to cluster W. Most of these strains, including three independently isolated strains, belong to two clonal complexes and are therefore very closely related genetically. These clonal complexes represent strains corresponding to the previously identified species Bacillus weihenstephanensis. Most of the other strains of our collection, including some from the W cluster, are not psychrotrophic. B. weihenstephanensis (cluster W) strains appear to comprise an effectively sexual population, whereas Bacillus thuringiensis (cluster T) and B. cereus (cluster C) have clonal population structures.

scholarly journals Conjugal transfer between Bacillus thuringiensis and Bacillus cereus strains is not directly correlated with growth of recipient strains

2010 ◽  
Vol 105 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Clelton A. Santos ◽  
Gislayne T. Vilas-Bôas ◽  
Didier Lereclus ◽  
Marise T. Suzuki ◽  
Elisangela A. Angelo ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacillus Cereus ◽  
Conjugal Transfer

Growth, Germination and Toxigenic Activity of Bacillus cereus in Milk Products

1988 ◽  
Vol 51 (9) ◽  
pp. 707-710 ◽  
Author(s):  
H. C. WONG ◽  
Y. L. CHEN ◽  
C. L. F. CHEN
Keyword(s):  
Bacillus Cereus ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Fermented Milk ◽  
Vegetative Cells ◽  
Ovary Cells ◽  
Milk Products ◽  
Pasteurized Milk ◽  
Sterilized Milk ◽  
Reconstituted Milk

Growth, germination and toxigenic activity of Bacillus cereus in pasteurized milk, fruit-flavored reconstituted milk and fermented milk at 30°C were studied. Vegetative cells of B. cereus rapidly increased to 108 CFU/ml in 8 h and 106 CFU/ml in 12 h in pasteurized milk and fruit-flavored reconstituted milk respectively. In fermented milk, vegetative cells of B. cereus were killed or inactivated in 40 min; while about 31% of spores survived the 7 d test period. Spore germination of B. cereus was inhibited by fruit-flavored reconstituted milk and fermented milk. Chinese hamster ovary cells were transformed and/or lysed by pasteurized milk and sterilized milk with B. cereus cultured for 8 h and also by laboratory-prepared fermented milk with B. cereus introduced at the beginning of fermentation an incubated for 12 or 72 h.

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