Comparison of Decontamination Efficacy of Antimicrobial Treatments for Beef Trimmings against <i>Escherichia coli</i> O157:H7 and 6 Non‐O157 Shiga Toxin‐Producing <i>E. coli</i> Serogroups

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.

mentioning

confidence: 99%

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

Kalchayanand

Koohmaraie²,

Wheeler

2016

“…In contrast, when beef trimmings or cheek meat tissues were dipped into 225-or 300-ppm hypobromous acid solution, populations of STEC, including non-0157 STEC and Salmonella, were not reduced (15,36). Methods of applying hypobromous acid solutions, therefore, need more investigation.…”

Section: Resultsmentioning

confidence: 66%

“…The effectiveness of CAB-1 and CAB-2 in reducing Salmonella and non-0157 STEC strains (P < 0.05) was similar to the reduction of E. coli 0157:H7 (Table 1). Several antimicrobial compounds commonly used in the beef industry also were reported to reduce the six non-0157 STEC strains on inoculated fresh beef as effectively as they reduced E. coli 0157:H7 (15,23). The four studied antimicrobial compounds reduced APC by 0.8 to 1.8 log CFU/cm2 and EBC by 1.2 to 2.0 log CFU/cm2 after chilling at 4°C for 48 h. In a preliminary study, water (22 to 25°C) sprayed for 15 s at 20 lb/in2 reduced both APC and EBC by 0.2 log CFU/cm2 (data not shown); also, data from three commercial beef processing plants (4) indicated that water spraying has a minimal effect on reducing bacteria attached on the surface of fresh beef.…”

Section: Resultsmentioning

confidence: 98%

“…CAB-1 is a combination of citric and hydrochloric acids, whereas CAB-2 is a combination of citric, hydrochloric, and phosphoric acids. In the meat industry, lactic and acetic acid solutions are the most commonly used organic acids and have been shown to effectively reduce E. coll 0157:H7 (33) as well as non-0157 STEC on surfaces of fresh beef (15,23). There is limited information on the efficacy of citric acid-based antimicrobial compounds against pathogens on fresh meat.…”

Section: Resultsmentioning

confidence: 99%

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Efficacy of Antimicrobial Compounds on Surface Decontamination of Seven Shiga Toxin-Producing Escherichia coli and Salmonella Inoculated onto Fresh Beef

Kalchayanand

Arthur

Bosilevac

et al. 2015

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.

“…Spontaneous rifampin-resistant mutants of the E. coli O157:H7, non-O157 STEC, and nonpathogenic E. coli strains were used for selection and differentiation of the inocula from natural meat-associated microbial populations. These strains have previously been used in various inoculated challenge studies conducted with beef products in our laboratory (15,28,31). Xylose lysine deoxycholate (XLD; Acumedia, Neogen Corp., Lansing, MI) agar was used for selective enumeration of the Salmonella inoculum.…”

Section: Methodsmentioning

confidence: 99%

Antimicrobial Efficacy of a Lactic Acid and Citric Acid Blend against Shiga Toxin-Producing Escherichia coli, Salmonella, and Nonpathogenic Escherichia coli Biotype I on Inoculated Prerigor Beef Carcass Surface Tissue

Scott

Yang

Geornaras

et al. 2015

Self Cite

Studies were conducted to (i) determine whether inoculants of nonpathogenic Escherichia coli biotype I effectively served as surrogates for E. coli O157:H7, non-O157 Shiga toxin-producing E. coli, and Salmonella when prerigor beef carcass tissue was treated with a commercially available blend of lactic acid and citric acid (LCA) at a range of industry conditions of concentration, temperature, and pressure; (ii) determine the antimicrobial efficacy of LCA; and (iii) investigate the use of surrogates to validate a hot water and LCA sequential treatment as a carcass spray intervention in a commercial beef harvest plant. In an initial laboratory study, beef brisket tissue samples were left uninoculated or were inoculated (∼6 log CFU/cm(2)) on the adipose side with E. coli O157:H7 (5-strain mixture), non-O157 Shiga toxin-producing E. coli (12-strain mixture), Salmonella (6-strain mixture), or nonpathogenic E. coli (5-strain mixture). Samples were left untreated (control) or were treated with LCA, in a spray cabinet, at one of eight combinations of solution concentration (1.9 and 2.5%), solution temperature (43 and 60°C), and application pressure (15 and 30 lb/in(2)). In a second study, the E. coli surrogates were inoculated (∼6 log CFU/cm(2)) on beef carcasses in a commercial facility to validate the use of a hot water treatment (92.2 to 92.8°C, 13 to 15 lb/in(2)) followed by an LCA treatment (1.9%, 50 to 51.7°C, 13 to 15 lb/in(2), 10 s). In the in vitro study, surrogate and pathogen bacteria did not differ in their response to the tested LCA treatments. Treatment with LCA reduced (P < 0.05) inoculated populations by 0.9 to 1.5 log CFU/cm(2), irrespective of inoculum type. The hot water and LCA sequential treatments evaluated in the commercial facility reduced (P < 0.05) the inoculated nonpathogenic E. coli surrogates on carcasses by 3.7 log CFU/cm(2). This study therefore provides the meat industry with data for this sequential multiple hurdle system for the operation parameters described.