Mitigating the Antimicrobial Activities of Selected Organic Acids and Commercial Sanitizers with Various Neutralizing Agents

2011 ◽  
Vol 74 (5) ◽  
pp. 820-825 ◽  
Author(s):  
YOEN JU PARK ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Organic Acids ◽  
Shiga Toxin ◽  
Room Temperature ◽  
Sodium Thiosulfate ◽  
Antimicrobial Activities ◽  
Phosphate Buffered Saline ◽  
Lactic Acids

This study was conducted to evaluate the abilities of five neutralizing agents, Dey-Engley (DE) neutralizing broth (single or double strength), morpholinepropanesulfonic acid (MOPS) buffer, phosphate-buffered saline (PBS), and sodium thiosulfate buffer, in mitigating the activities of acetic or lactic acid (2%) and an alkaline or acidic sanitizer (a manufacturer-recommended concentration) againt the cells of Shiga toxin–producing Escherichia coli (STEC; n = 9). To evaluate the possible toxicity of the neutralizing agents to the STEC cells, each STEC strain was exposed to each of the neutralizing agents at room temperature for 10 min. Neutralizing efficacy was evaluated by placing each STEC strain in a mixture of sanitizer and neutralizer under the same conditions. The neutralizing agents had no detectable toxic effect on the STEC strains. PBS was least effective for neutralizing the activity of selected organic acids and sanitizers. Single-strength DE and sodium thiosulfate neutralized the activity of both acetic and lactic acids. MOPS buffer neutralized the activity of acetic acid and lactic acid against six and five STEC strains, respectively. All neutralizing agents, except double-strength DE broth, had a limited neutralizing effect on the activity of the commercial sanitizers used in the study. The double-strength DE broth effectively neutralized the activity of the two commercial sanitizers with no detectable toxic effects on STEC cells.

scholarly journals Inactivation of Shiga Toxin-Producing Escherichia coli (STEC) and Degradation and Removal of Cellulose from STEC Surfaces by Using Selected Enzymatic and Chemical Treatments

2011 ◽  
Vol 77 (24) ◽  
pp. 8532-8537 ◽  
Author(s):  
Yoen Ju Park ◽  
Jinru Chen
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Organic Acids ◽  
Shiga Toxin ◽  
Cell Populations ◽  
Content Type ◽  
Chemical Treatments ◽  
Glycosidic Bonds ◽  
Chemical Agents ◽  
Lactic Acids

ABSTRACTSome Shiga toxin-producingEscherichia coli(STEC) strains produce extracellular cellulose, a long polymer of glucose with β-1-4 glycosidic bonds. This study evaluated the efficacies of selected enzymatic and chemical treatments in inactivating STEC and degrading/removing the cellulose on STEC surfaces. Six cellulose-producing STEC strains were treated with cellulase (0.51 to 3.83 U/15 ml), acetic and lactic acids (2 and 4%), as well as an acidic and alkaline sanitizer (manufacturers' recommended concentrations) under appropriate conditions. Following each treatment, residual amounts of cellulose and surviving populations of STEC were determined. Treatments with acetic and lactic acids significantly (P< 0.05) reduced the populations of STEC, and those with lactic acid also significantly decreased the amounts of cellulose on STEC. The residual amounts of cellulose on STEC positively correlated to the surviving populations of STEC after the treatments with the organic acids (r= 0.64 to 0.94), and the significance of the correlations ranged from 83 to 99%. Treatments with cellulase and the sanitizers both degraded cellulose. However, treatments with cellulase had no influence on the fate of STEC, and those with the sanitizers reduced STEC cell populations to undetectable levels. Thus, the correlations between the residual amounts of cellulose and the surviving populations of STEC caused by these two treatments were not observed. The results suggest that the selected enzymatic and chemical agents degraded and removed the cellulose on STEC surfaces, and the treatments with organic acids and sanitizers also inactivated STEC cells. The amounts of cellulose produced by STEC strains appear to affect their susceptibilities to certain sanitizing treatments.

Control of Escherichia coli O157:H7 with Sodium Metasilicate

2004 ◽  
Vol 67 (7) ◽  
pp. 1501-1506 ◽  
Author(s):  
GEORGE H. WEBER ◽  
JUDY K. O'BRIEN ◽  
FREDRIC G. BENDER
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Room Temperature ◽  
Sodium Metasilicate ◽  
Antimicrobial Activities ◽  
Intervention Strategies ◽  
Trisodium Phosphate ◽  
Escherichia Coli O157 ◽  
E Coli

Three intervention strategies—trisodium phosphate, lactic acid, and sodium metasilicate—were examined for their in vitro antimicrobial activities in water at room temperature against a three-strain cocktail of Escherichia coli O157:H7 and a three-strain cocktail of “generic” E. coli. Both initial inhibition and recovery of injured cells were monitored. When 3.0% (wt/wt) lactic acid, pH 2.4, was inoculated with E. coli O157:H7 (approximately 6 log CFU/ml), viable microorganisms were recovered after a 20-min exposure to the acid. After 20 min in 1.0% (wt/wt) trisodium phosphate, pH 12.0, no viable E. coli O157:H7 microorganisms were detected. Exposure of E. coli O157:H7 to sodium metasilicate (5 to 10 s) at concentrations as low as 0.6%, pH 12.1, resulted in 100% inhibition with no recoverable E. coli O157:H7. No difference in inhibition profiles was detected between the E. coli O157:H7 and generic strains, suggesting that nonpathogenic strains may be used for in-plant sodium metasilicate studies.

Behavior of Acid-Adapted and Unadapted Escherichia coli O157:H7 When Exposed to Reduced pH Achieved with Various Organic Acids

1999 ◽  
Vol 62 (5) ◽  
pp. 451-455 ◽  
Author(s):  
JEE-HOON RYU ◽  
YUN DENG ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Citric Acid ◽  
Organic Acids ◽  
Malic Acid ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Ph Values ◽  
Acid Ph

A study was done to determine if various organic acids differ in their inhibitory or lethal activity against acid-adapted and unadapted Escherichia coli O157:H7 cells. E. coli O157:H7 strain E0139, isolated from venison jerky, was grown in tryptic soy broth (TSB) and in TSB supplemented with 1% glucose (TSBG) for 18 h at 37°C, then plated on tryptic soy agar (TSA) acidified with malic, citric, lactic, or acetic acid at pH 5.4, 5.1, 4.8, 4.5, 4.2, and 3.9. Regardless of whether cells were grown in TSB or TSBG, visible colonies were not formed when plated on TSA acidified with acetic, lactic, malic, or citric acids at pH values of ≤5.4, ≤4.5, ≤4.2, or ≤4.2, respectively. Cells not adapted to reduced pH did not form colonies on TSA acidified with lactic acid (pH 3.9) or acetic acid (pH 3.9 and 4.2); however, a portion of acid-adapted cells remained viable on TSA containing lactic acid (pH 3.9) or acetic acid (pH 4.2) and could be recovered in TSB. Inactivation of acid-adapted cells was less than that of unadapted cells in TSB acidified at pH 3.9 with citric, lactic, or acetic acid and at pH 3.4 with malic acid. Significantly (P ≤ 0.05) higher numbers of acid-adapted cells, compared with unadapted cells, were detected 12 h after inoculation of TSB acidified with acetic acid at pH 3.9; in TSB containing lactic acid (pH 3.9), the number of acid-adapted cells was higher than the number of unadapted cells after 5 h. In TSB acidified at pH 3.9 with citric acid or pH 3.4 with malic acid, significantly higher numbers of acid-adapted cells survived. This study shows that organic acids differ in their inhibitory or lethal activity against acid-adapted and unadapted E. coli O157:H7 cells, and acid-adapted cells are more tolerant than unadapted cells when subsequently exposed to reduced pH caused by these acids.

Survival of Salmonella and Shiga Toxin-producing Escherichia coli and Changes in Indigenous Microbiota During Fermentation of Kombucha Made from Home-brewing Kits

2021 ◽  
Author(s):  
SHERIDAN S. BREWER ◽  
COURTNEY A. LOWE ◽  
LARRY R. BEUCHAT ◽  
Ynes R. Ortega
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Shiga Toxin ◽  
Acetic Acid Bacteria ◽  
The Other ◽  
Clear Correlation ◽  
Initial Population ◽  
Indigenous Microbiota ◽  
Survival And Growth

Survival and growth of Salmonella and Shiga toxin-producing Escherichia coli (STEC) in kombucha prepared from four brands of commercially available kombucha kits intended for use by home brewers were investigated. Changes in microbiota responsible for fermentation were also determined. An initial population of Salmonella (6.77 log CFU/mL) decreased to below the detection limit (0.30 log CFU/mL) within 10 d in kombucha prepared from two of the four test brands. Populations of 1.85 and 1.20 log CFU/mL were detected in two brands fermented for 14 d. An initial population of STEC (7.02 log CFU/mL) decreased to &lt;0.30 log CFU/mL in two of the four brands within 14 d; 0.20 and 0.87 log CFU/mL were detected in kombucha prepared from the other two brands. Salmonella and STEC increased in populations within 1 d in three brands of base tea used to prepare kombucha, and were stable throughout 14 d of incubation. Both pathogens steadily declined in base tea prepared from one brand of kombucha kit. Inactivation of the pathogens occurred as the pH of kombuchas decreased, but a clear correlation between rates of inactivation and decrease in pH was not evident when comparing kombuchas prepared from the four kits. Growth and peak populations of mesophilic aerobic microorganisms, yeasts, lactic acid bacteria, and acetic acid bacteria varied, depending on the kombucha kit brand. There was not strong evidence to correlate the behavior of Salmonella and STEC with any of these groups of indigenous microbiota. Results of this study show that the ability of Salmonella and STEC to survive in kombucha and base tea used to prepare kombucha is dependent on inherent differences in commercially available kombucha kits intended for use in home settings. Strict application of hygienic practices with the goal of preventing contamination with Salmonella or STEC is essential for reducing the risk of illness associated the consumption of kombucha.

scholarly journals Immersion in Antimicrobial Solutions Reduces Salmonella enterica and Shiga Toxin–Producing Escherichia coli on Beef Cheek Meat†

2014 ◽  
Vol 77 (4) ◽  
pp. 538-548 ◽  
Author(s):  
JOHN W. SCHMIDT ◽  
JOSEPH M. BOSILEVAC ◽  
NORASAK KALCHAYANAND ◽  
RONG WANG ◽  
TOMMY L. WHEELER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Shiga Toxin ◽  
Salmonella Enterica ◽  
Room Temperature ◽  
Tap Water ◽  
Sodium Dodecyl ◽  
Effective Intervention ◽  
Peroxyacetic Acid ◽  
Hypobromous Acid

The objective of this study was to determine the effect of immersing beef cheek meat in antimicrobial solutions on the reduction of O157:H7 Shiga toxin–producing Escherichia coli (STEC), non-O157:H7 STEC, and Salmonella enterica. Beef cheek meat was inoculated with O157:H7 STEC, non-O157:H7 STEC, and S. enterica on both the adipose and muscle surfaces. The inoculated cheek meat was then immersed in one of seven antimicrobial solutions for 1, 2.5, or 5 min: (i) 1% Aftec 3000 (AFTEC), (ii) 2.5% Beefxide (BX), (iii) 300 ppm of hypobromous acid (HOBR), (iv) 2.5% lactic acid (LA2.5), (v) 5% lactic acid (LA5), (vi) 0.5% levulinic acid and 0.05% sodium dodecyl sulfate (LEV-SDS), or (vii) 220 ppm of peroxyacetic acid (POA). Inoculated cheek meat was also immersed in 80°C tap water (HW) for 10 s. In general, increasing immersion duration in antimicrobial solutions did not significantly (P ≥ 0.05) increase effectiveness. Immersion in HW for 10 s was the most effective intervention, reducing STEC and S. enterica by 2.2 to 2.3 log CFU/cm2 on the adipose surface and by 1.7 to 1.8 log CFU/cm2 on the muscle surface. Immersion for 1 min in AFTEC, BX, LA2.5, LA5, or POA was also effective as an intervention, reducing STEC and S. enterica by 0.8 to 2.0 log CFU/cm2 on the adipose surface and by 0.6 to 1.4 log CFU/cm2 on the muscle surface. Immersion for 1 min in HOBR or LEV-SDS was not an effective intervention because STEC and S. enterica reductions ranged from 0.1 to 0.4 log CFU/cm2, which were not significantly different (P ≥ 0.05) from the reductions obtained when cheek meat was immersed in room temperature tap water. We conclude that immersion of cheek meat in HW for 10 s and immersion for 1 min in AFTEC, BX, LA2.5, LA5, or POA effectively reduced levels of STEC and S. enterica.

In Vitro Inhibition of the Growth of Salmonella typhimurium and Escherichia coli 0157:H7 by Bacteria Isolated from the Cecal Contents of Adult Chickens

1991 ◽  
Vol 54 (7) ◽  
pp. 496-501 ◽  
Author(s):  
ARTHUR HINTON ◽  
GEORGE E. SPATES ◽  
DONALD E. CORRIER ◽  
MICHAEL E. HUME ◽  
JOHN R. DELOACH ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Salmonella Typhimurium ◽  
Mixed Cultures ◽  
Enterococcus Durans ◽  
E Coli ◽  
Pure Cultures ◽  
In Vitro Inhibition ◽  
Lactic Acids

A Veillonella species and Enterococcus durans were isolated from the cecal contents of adult broilers. Mixed cultures of Veillonella and E. durans inhibited the growth of Salmonella typhimurium and Escherichia coli 0157:H7 on media containing 2.5% lactose (w/v). The growth of S. typhimurium or E. coli 0157:H7 was not inhibited by mixed cultures containing Veillonella and E. durans on media containing only 0.25% lactose or by pure cultures of Veillonella or E. durans on media containing either 0.25% or 2.5% lactose. The mixed cultures of Veillonella and E. durans produced significantly (P&lt;0.05) more acetic, propionic, and lactic acids in media containing 2.5% lactose than in media containing 0.25% lactose. The inhibition of the enteropathogens was related to the production of lactic acid from lactose by the E. durans and the production of acetic and propionic acids from lactic acid by the Veillonella.

scholarly journals Effect of Exposure Time and Organic Matter on Efficacy of Antimicrobial Compounds against Shiga Toxin–Producing Escherichia coli and Salmonella

2016 ◽  
Vol 79 (4) ◽  
pp. 561-568 ◽  
Author(s):  
NORASAK KALCHAYANAND ◽  
MOHAMMAD KOOHMARAIE ◽  
TOMMY L. WHEELER
Keyword(s):  
Escherichia Coli ◽  
Organic Matter ◽  
Lactic Acid ◽  
Exposure Time ◽  
Shiga Toxin ◽  
Peracetic Acid ◽  
Antimicrobial Compounds ◽  
Number Of Factors ◽  
Hypobromous Acid ◽  
Processing Plants

ABSTRACT Several antimicrobial compounds are in commercial meat processing plants for pathogen control on beef carcasses. However, the efficacy of the method used is influenced by a number of factors, such as spray pressure, temperature, type of chemical and concentration, exposure time, method of application, equipment design, and the stage in the process that the method is applied. The objective of this study was to evaluate effectiveness of time of exposure of various antimicrobial compounds against nine strains of Shiga toxin–producing Escherichia coli (STEC) and four strains of Salmonella in aqueous antimicrobial solutions with and without organic matter. Non-O157 STEC, STEC O157:H7, and Salmonella were exposed to the following aqueous antimicrobial solutions with or without beef purge for 15, 30, 60, 120, 300, 600, and 1,800 s: (i) 2.5% lactic acid, (ii) 4.0% lactic acid, (iii) 2.5% Beefxide, (iv) 1% Aftec 3000, (v) 200 ppm of peracetic acid, (vi) 300 ppm of hypobromous acid, and (vii) water as a control. In general, increasing exposure time to antimicrobial compounds significantly (P ≤ 0.05) increased the effectiveness against pathogens tested. In aqueous antimicrobial solutions without organic matter, both peracetic acid and hypobromous acid were the most effective in inactivating populations of STEC and Salmonella, providing at least 5.0-log reductions with exposure for 15 s. However, in antimicrobials containing organic matter, 4.0% lactic acid was the most effective compound in reducing levels of STEC and Salmonella, providing 2- to 3-log reductions with exposure for 15 s. The results of this study indicated that organic matter and exposure time influenced the efficacy of antimicrobial compounds against pathogens, especially with oxidizer compounds. These factors should be considered when choosing an antimicrobial compound for an intervention.

scholarly journals Inactivation of Multi-Drug Resistant Non-Typhoidal Salmonella and Wild-Type Escherichia coli STEC Using Organic Acids: A Potential Alternative to the Food Industry

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 849
Author(s):  
Vinicius Silva Castro ◽  
Yhan da Silva Mutz ◽  
Denes Kaic Alves Rosario ◽  
Adelino Cunha-Neto ◽  
Eduardo Eustáquio de Souza Figueiredo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Organic Acids ◽  
Sodium Hypochlorite ◽  
Bacterial Species ◽  
Disk Diffusion ◽  
Clinical Strains ◽  
Linear Pattern ◽  
E Coli ◽  
Log Reduction

Salmonella and Escherichia coli are the main bacterial species involved in food outbreaks worldwide. Recent reports showed that chemical sanitizers commonly used to control these pathogens could induce antibiotic resistance. Therefore, this study aimed to describe the efficiency of chemical sanitizers and organic acids when inactivating wild and clinical strains of Salmonella and E. coli, targeting a 4-log reduction. To achieve this goal, three methods were applied. (i) Disk-diffusion challenge for organic acids. (ii) Determination of MIC for two acids (acetic and lactic), as well as two sanitizers (quaternary compound and sodium hypochlorite). (iii) The development of inactivation models from the previously defined concentrations. In disk-diffusion, the results indicated that wild strains have higher resistance potential when compared to clinical strains. Regarding the models, quaternary ammonium and lactic acid showed a linear pattern of inactivation, while sodium hypochlorite had a linear pattern with tail dispersion, and acetic acid has Weibull dispersion to E. coli. The concentration to 4-log reduction differed from Salmonella and E. coli in acetic acid and sodium hypochlorite. The use of organic acids is an alternative method for antimicrobial control. Our study indicates the levels of organic acids and sanitizers to be used in the inactivation of emerging foodborne pathogens.

Control of the Biofilms Formed by Curli- and Cellulose-Expressing Shiga Toxin–Producing Escherichia coli Using Treatments with Organic Acids and Commercial Sanitizers

2015 ◽  
Vol 78 (5) ◽  
pp. 990-995 ◽  
Author(s):  
YOEN JU PARK ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Organic Acids ◽  
Shiga Toxin ◽  
Cell Contact ◽  
Bacterial Cells ◽  
Bacterial Surface ◽  
Additional Information ◽  
Steel Surfaces ◽  
Biological Protection

Biofilms are a mixture of bacteria and extracellular products secreted by bacterial cells and are of great concern to the food industry because they offer physical, mechanical, and biological protection to bacterial cells. This study was conducted to quantify biofilms formed by different Shiga toxin–producing Escherichia coli (STEC) strains on polystyrene and stainless steel surfaces and to determine the effectiveness of sanitizing treatments in control of these biofilms. STEC producing various amounts of cellulose (n = 6) or curli (n = 6) were allowed to develop biofilms on polystyrene and stainless steel surfaces at 28°C for 7 days. The biofilms were treated with 2% acetic or lactic acid and manufacturer-recommended concentrations of acidic or alkaline sanitizers, and residual biofilms were quantified. Treatments with the acidic and alkaline sanitizers were more effective than those with the organic acids for removing the biofilms. Compared with their counterparts, cells expressing a greater amount of cellulose or curli formed more biofilm mass and had greater residual mass after sanitizing treatments on polystyrene than on stainless steel. Research suggests that the organic acids and sanitizers used in the present study differed in their ability to control biofilms. Bacterial surface components and cell contact surfaces can influence both biofilm formation and the efficacy of sanitizing treatments. These results provide additional information on control of biofilms formed by STEC.

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