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.

Dynamic Effects of Free Chlorine Concentration, Organic Load, and Exposure Time on the Inactivation of Salmonella, Escherichia coli O157:H7, and Non-O157 Shiga Toxin–Producing E. coli†

2013 ◽  
Vol 76 (3) ◽  
pp. 386-393 ◽  
Author(s):  
CANGLIANG SHEN ◽  
YAGUANG LUO ◽  
XIANGWU NOU ◽  
QIN WANG ◽  
PATRICIA MILLNER
Keyword(s):  
Escherichia Coli ◽  
Organic Matter ◽  
Exposure Time ◽  
Shiga Toxin ◽  
Contact Time ◽  
Organic Load ◽  
Escherichia Coli O157 ◽  
Pathogen Inactivation ◽  
Dynamic Effects ◽  
E Coli

This study evaluated the dynamic effects of free-chlorine (FC) concentration, contact time, and organic load on the inactivation of Salmonella, Escherichia coli O157:H7, and non-O157 Shiga toxin–producing E. coli (STEC) in suspension. Bacterial cells from four strains each of Salmonella, E. coli O157:H7, and non-O157 STEC were inoculated separately or as a multistrain cocktail into solutions with varying FC concentrations. Lettuce or tomato extract was used to simulate the organic matter present during commercial fresh and fresh-cut produce wash operations. After exposure to FC for various lengths of time, the bacterial survival and water-quality changes were determined. In the absence of organic matter in a wash solution, pathogen inactivation is primarily a function of initial FC concentration (P < 0.0001), exposure time (P < 0.0001), and pathogen strains (P < 0.0001). In general, an over 4.5-log CFU/ml pathogen reduction was found after exposure to >0.5 mg/liter FC for over 30 s, or to >1.0 mg/liter FC for over 5 s. When the combination of FC concentration and contact time were less than or equal to the above conditions, survival of pathogens was strain dependant and ranked as: Salmonella > E. coli O157:H7 > non-O157 STEC. When organic matter was present in the wash solution, pathogen inactivation efficacy was specifically dependent on the residual FC concentration, which directly relates to both the initial FC concentration and the organic load. Prevention of pathogen survival in chlorinated produce wash solutions can be achieved by maintaining sufficient FC concentration and reducing the accumulation of organic matter.

scholarly journals Efficacy of Antimicrobial Compounds on Surface Decontamination of Seven Shiga Toxin–Producing Escherichia coli and Salmonella Inoculated onto Fresh Beef†

2015 ◽  
Vol 78 (3) ◽  
pp. 503-510 ◽  
Author(s):  
NORASAK KALCHAYANAND ◽  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
JOHN W. SCHMIDT ◽  
RONG WANG ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Sodium Chlorite ◽  
Antimicrobial Compounds ◽  
Beef Processing ◽  
Beef Carcasses ◽  
Processing Plants ◽  
Plate Counts ◽  
Inoculation Study ◽  
Antimicrobial Treatments

Several antimicrobial compounds have been used in commercial meat processing plants for decontamination of pathogens on beef carcasses, but there are many commercially available, novel antimicrobial compounds that may be more effective and suitable for use in beef processing pathogen-reduction programs. Sixty-four prerigor beef flanks (cutaneous trunci) were used in a study to determine whether hypobromous acid, neutral acidified sodium chlorite, and two citric acid–based antimicrobial compounds effectively reduce seven Shiga toxin–producing Escherichia coli (STEC) serogroups and Salmonella on the surface of fresh beef. Two cocktail mixtures were inoculated onto prerigor beef flank surfaces. Cocktail mixture 1 was composed of STEC serogroups O26, O103, O111, O145, and O157; and cocktail mixture 2 was composed of STEC serogroups O45, O121, and O157 and Salmonella. The inoculated fresh beef flanks were subjected to spray treatments with four antimicrobial compounds. Following antimicrobial treatments, both control and treated fresh beef samples were either enumerated immediately or were stored for 48 h at 4°C before enumeration. All four antimicrobial compounds caused 0.7- to 2.0-log reductions of STEC, Salmonella, aerobic plate counts, and Enterobacteriaceae. Results also indicated that the four antimicrobial compounds were as effective at reducing the six non-O157 STEC strains as they were at reducing E. coli O157:H7 on the surfaces of fresh beef. The recovery of all seven STEC strains and Salmonella in a low-inoculation study indicated that none of the four antimicrobial compounds eliminated all of the tested pathogens.

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.

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.

Occurrence and characterization of Shiga toxin-producing Escherichia coli (STEC) isolated from Chinese beef processing plants

Meat Science ◽  
2020 ◽  
Vol 168 ◽  
pp. 108188
Author(s):  
Pengcheng Dong ◽  
Tongtong Xiao ◽  
George-John E. Nychas ◽  
Yimin Zhang ◽  
Lixian Zhu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Beef Processing ◽  
Processing Plants

Validation of a Sequential Hide-On Bob Veal Carcass Antimicrobial Intervention Composed of a Hot Water Wash and Lactic Acid Spray in Combination with Scalding To Control Shiga Toxin–Producing Escherichia coli Surrogates†

2018 ◽  
Vol 81 (5) ◽  
pp. 762-768
Author(s):  
JOSHUA D. HASTY ◽  
JOHN A. HENSON ◽  
GARY R. ACUFF ◽  
DENNIS E. BURSON ◽  
JOHN B. LUCHANSKY ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Ambient Temperature ◽  
Shiga Toxin ◽  
Hot Water ◽  
E Coli ◽  
Chemical Agents ◽  
Antimicrobial Interventions ◽  
Antimicrobial Intervention ◽  
Additional Reduction

ABSTRACT Scalding of hide-on bob veal carcasses with or without standard scalding chemical agents typically used for hogs, followed by an 82.2°C hot water wash and lactic acid spray (applied at ambient temperature) before chilling, was evaluated to determine its effectiveness in reducing Shiga toxin–producing Escherichia coli surrogate populations. A five-strain cocktail of rifampin-resistant, nonpathogenic E. coli surrogates was used to inoculate hides of veal carcasses immediately after exsanguination (target inoculation level of 7.0 log CFU/100 cm2). For carcasses receiving no scalding treatments, spraying with 82.2°C water as a final wash resulted in a 4.5-log CFU/100 cm2 surrogate reduction, and an additional 1.2-log CFU/100 cm2 reduction was achieved by spraying with 4.5% lactic acid before chilling. Scalding hide-on carcasses in 60°C water (no chemicals added) for 4 min in a traditional hog scalding tank resulted in a 2.1-log CFU/100 cm2 reduction in surrogate levels, and a subsequent preevisceration 82.2°C water wash provided an additional 2.9-log CFU/100 cm2 reduction. Spraying a 4.5% solution of lactic acid onto scalded, hide-on carcasses (after the 82.2°C water wash) resulted in a minimal additional reduction of 0.4 log CFU/100 cm2. Incorporation of scalding chemicals into the scald water resulted in a 4.1-log CFU/100 cm2 reduction (1.9 log CFU/100 cm2 greater than scalding without chemicals) in the surrogate population, and the first 82.2°C wash provided an additional 2.5-log CFU/100 cm2 reduction. Application of antimicrobial interventions did not affect the carcass temperature decline during chilling, the pH decline, or the color characteristics of the ribeye or the flank of the bob veal carcasses.

Reductions of Shiga Toxin–Producing Escherichia coli and Salmonella Typhimurium on Beef Trim by Lactic Acid, Levulinic Acid, and Sodium Dodecyl Sulfate Treatments

2014 ◽  
Vol 77 (4) ◽  
pp. 528-537 ◽  
Author(s):  
TONG ZHAO ◽  
PING ZHAO ◽  
DONG CHEN ◽  
RAVIRAJSINH JADEJA ◽  
YEN-CON HUNG ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Sodium Dodecyl Sulfate ◽  
Salmonella Typhimurium ◽  
Bactericidal Activity ◽  
Shiga Toxin ◽  
Levulinic Acid ◽  
Sodium Dodecyl ◽  
E Coli ◽  
Dodecyl Sulfate

Studies were done at 21°C to determine the bactericidal activity of lactic acid, levulinic acid, and sodium dodecyl sulfate (SDS) applied individually and in combination on Shiga toxin–producing Escherichia coli (STEC) in pure culture and to compare the efficacy of lactic acid and levulinic acid plus SDS treatments applied by spray or immersion to inactivate STEC and Salmonella (107 CFU/cm2) on beef trim pieces (10 by 10 by 7.5 cm). Application of 3% lactic acid for 2 min to pure cultures was shown to reduce E. coli O26:H11, O45:H2, O111:H8, O103:H2, O121:H2, O145:NM, and O157:H7 populations by 2.1, 0.4, 0.3, 1.4, 0.3, 2.1, and 1.7 log CFU/ml, respectively. Treatment with 0.5% levulinic acid plus 0.05% SDS for <1 min reduced the populations of all STEC strains to undetectable levels (>6 log/ml reduction). Beef surface temperature was found to affect the bactericidal activity of treatment with 3% levulinic acid plus 2% SDS (LV-SDS). Treating cold (4°C) beef trim with LV-SDS at 21, 62, or 81°C for 30 s reduced E. coli O157:H7 by 1.0, 1.1, or 1.4 log CFU/cm2, respectively, whereas treating beef trim at 8°C with LV-SDS at 12°C for 0.1, 1, 3, or 5 min reduced E. coli O157:H7 by 1.4, 2.4, 2.5, or 3.3 log CFU/cm2, respectively. Spray treatment of beef trim at 4°C with 5% lactic acid only reduced the E. coli O157:H7 population by 1.3 log CFU/cm2. Treating beef trim at 8°C with LV-SDS for 1, 2, or 3 min reduced Salmonella Typhimurium by 2.1, 2.6, and >5.0 log CFU/cm2, respectively. Hand massaging the treated beef trim substantially reduced contamination of both pathogens, with no detectable E. coli O157:H7 or Salmonella Typhimurium (<5 CFU/cm2) on beef trim pieces treated with LV-SDS. Reduction of E. coli O157:H7 and Salmonella Typhimurium populations was enhanced, but bactericidal activity was affected by the meat temperature.

Sign in / Sign up

Export Citation Format

Share Document