Validation of post-harvest antimicrobial interventions to control Shiga toxin-producing Escherichia coli (STEC) on market hog carcass surfaces

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.

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Validation of commonly used antimicrobial interventions on bob veal carcasses for reducing Shiga toxin producing Escherichia coli surrogate populations

Journal of Food Protection ◽

10.4315/jfp-20-458 ◽

2021 ◽

Author(s):

Chevise L. Thomas ◽

Harshavardhan Thippareddi ◽

Sanjay Kumar ◽

Macc Rigdon ◽

Robert W. Mckee ◽

...

Keyword(s):

Escherichia Coli ◽

Lactic Acid ◽

Shiga Toxin ◽

Hot Water ◽

Peroxyacetic Acid ◽

E Coli ◽

Translocation Experiment ◽

Low Levels ◽

Antimicrobial Interventions ◽

Antimicrobial Treatments

Ruminants are natural reservoirs of Shiga toxin producing Escherichia coli (STEC), and the STEC can be easily transferred to carcasses during the conversion of animals to meat. Three experiments were conducted to validate the efficacy of lactic acid (4%; LA), peroxyacetic acid (300 ppm; PAA), and hot water (80˚C; HW) for their individual or combined abilities to reduce STEC surrogates on bob veal carcasses pre- and post-chill and through fabrication. In experiment 1, hot carcasses (n=9) were inoculated with a 5-strain cocktail (ca. 8 log CFU/mL) containing rifampicin-resistant surrogate Escherichia coli ( E. coli ; BAA-1427, BAA-1428, BAA-1429, BAA-1430, and BAA-1431) and then treated with HW, LA, or PAA. Carcasses were then chilled (0±1°C; 24 h), split in half, and each side was treated with either LA or PAA. In experiment 2, hot carcasses (n=3) were inoculated and chilled (24 h). After 24 h, the carcasses were split, and each side was treated with either LA or PAA. For experiment 3, carcasses (n=3) were chilled for 24 h, split, inoculated, and treated with either LA or PAA. After chilling, carcasses from all three experiments were fabricated to subprimals and the cut surfaces were sampled to determine the translocation. Experiment 1 showed that LA+LA was the most effective ( P ≤ 0.05) treatment for reducing surrogate E. coli on veal. In experiments 2 and 3, LA and PAA were similar ( P > 0.05) in their abilities to reduce E. coli on chilled veal carcasses. In experiments 1 and 2, all antimicrobial treatments resulted in undetectable levels (< 0.2 log CFU/cm 2 ) of surrogate E. coli on cut surfaces after fabrication, while low levels (1.7 and 1.0 log CFU/cm 2 for LA and PAA, respectively) were observed in experiment 3. Of the antimicrobial interventions utilized, lactic acid was more effective for reducing STEC surrogate populations on veal carcasses, pre- and/or post-chill.

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Evaluation of decontamination efficacy of commonly used antimicrobial interventions for beef carcasses against Shiga toxin-producing Escherichia coli

Meat Science ◽

10.1016/j.meatsci.2018.04.009 ◽

2018 ◽

Vol 142 ◽

pp. 44-51 ◽

Cited By ~ 10

Author(s):

Marcelo Signorini ◽

Magdalena Costa ◽

David Teitelbaum ◽

Viviana Restovich ◽

Hebe Brasesco ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Beef Carcasses ◽

Antimicrobial Interventions

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Seasonal Prevalence of Shiga Toxin–Producing Escherichia coli, Including O157:H7 and Non-O157 Serotypes, and Salmonella in Commercial Beef Processing Plants†

Journal of Food Protection ◽

10.4315/0362-028x-66.11.1978 ◽

2003 ◽

Vol 66 (11) ◽

pp. 1978-1986 ◽

Cited By ~ 314

Author(s):

GENEVIEVE A. BARKOCY-GALLAGHER ◽

TERRANCE M. ARTHUR ◽

MILDRED RIVERA-BETANCOURT ◽

XIANGWU NOU ◽

STEVEN D. SHACKELFORD ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Escherichia Coli O157 ◽

Seasonal Prevalence ◽

Fecal Samples ◽

E Coli ◽

Beef Processing ◽

Beef Carcasses ◽

Processing Plants ◽

Antimicrobial Interventions

The seasonal prevalence of Escherichia coli O157:H7, Salmonella, non-O157 E. coli (STEC), and stx-harboring cells was monitored at three Midwestern fed-beef processing plants. Overall, E. coli O157:H7 was recovered from 5.9% of fecal samples, 60.6% of hide samples, and 26.7% of carcasses sampled before the preevisceration wash. This pathogen also was recovered from 1.2% (15 of 1,232) of carcasses sampled at chilling (postintervention) at approximate levels of <3.0 cells per 100 cm2. In one case, the E. coli O157:H7 concentration dropped from ca. 1,100 cells per 320 cm2 at the preevisceration stage to a level that was undetectable on ca. 2,500 cm2 at the postintervention stage. The prevalence of E. coli O157:H7 in feces peaked in the summer, whereas its prevalence on hide was high from the spring through the fall. Overall, Salmonella was recovered from 4.4, 71.0, and 12.7% of fecal, hide, and preevisceration carcass samples, respectively. Salmonella was recovered from one postintervention carcass (of 1,016 sampled). Salmonella prevalence peaked in feces in the summer and was highest on hide and preevisceration carcasses in the summer and the fall. Non-O157 STEC prevalence also appeared to vary by season, but the efficiency in the recovery of isolates from stx-positive samples ranged from 37.5 to 83.8% and could have influenced these results. Cells harboring stx genes were detected by PCR in 34.3, 92.0, 96.6, and 16.2% of fecal, hide, preevisceration carcass, and postintervention carcass samples, respectively. The approximate level of non-O157 STEC and stx-harboring cells on postintervention carcasses was ≥3.0 cells per 100 cm2 for only 8 of 199 carcasses (4.0%). Overall, the prevalence of E. coli O157:H7, Salmonella, and non-O157 STEC varied by season, was higher on hides than in feces, and decreased dramatically, along with pathogen levels, during processing and during the application of antimicrobial interventions. These results demonstrate the effectiveness of the current interventions used by the industry and highlight the significance of hides as a major source of pathogens on beef carcasses.

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Evaluation of Commonly Used Antimicrobial Interventions for Fresh Beef Inoculated with Shiga Toxin–Producing Escherichia coli Serotypes O26, O45, O103, O111, O121, O145, and O157:H7†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-11-531 ◽

2012 ◽

Vol 75 (7) ◽

pp. 1207-1212 ◽

Cited By ~ 48

Author(s):

NORASAK KALCHAYANAND ◽

TERRANCE M. ARTHUR ◽

JOSEPH M. BOSILEVAC ◽

JOHN W. SCHMIDT ◽

RONG WANG ◽

...

Keyword(s):

Escherichia Coli ◽

Lactic Acid ◽

Shiga Toxin ◽

Hot Water ◽

Sodium Chlorite ◽

Meat Industry ◽

Peroxyacetic Acid ◽

E Coli ◽

Low Level ◽

Antimicrobial Interventions

Although numerous antimicrobial interventions targeting Escherichia coli O157:H7 have been developed and implemented to decontaminate meat and meat products during the harvesting process, the information on efficacy of these interventions against the so-called Big Six non-O157 Shiga toxin–producing E. coli (STEC) strains is limited. Prerigor beef flanks (160) were inoculated to determine if antimicrobial interventions currently used by the meat industry have a similar effect in reducing non-O157 STEC serogroups O26, O45, O103, O111, O121, and O145 compared with E. coli O157:H7. A high (104 CFU/cm2) or a low (101 CFU/cm2) inoculation of two cocktail mixtures was applied to surfaces of fresh beef. Cocktail mixture 1 was composed of O26, O103, O111, O145, and O157, while cocktail mixture 2 was composed of O45, O121, and O157. The inoculated fresh beef flanks were subjected to spray treatments by the following four antimicrobial compounds: acidified sodium chlorite, peroxyacetic acid, lactic acid, and hot water. High-level inoculation samples were enumerated for the remaining bacteria populations after each treatment and compared with the untreated controls, while low-level inoculation samples were chilled for 48 h at 4°C before enrichment, immunomagnetic separation, and isolation. Spray treatments with hot water were the most effective, resulting in mean pathogen reductions of 3.2 to 4.2 log CFU/cm2, followed by lactic acid. Hot water and lactic acid also were the most effective interventions with the low-level inoculation on surfaces of fresh beef flanks after chilling. Peroxyacetic acid had an intermediate effect, while acidified sodium chlorite was the least effective in reducing STEC levels immediately after treatment. Results indicate that the reduction of non-O157 STEC by antimicrobial interventions on fresh beef surfaces were at least as great as for E. coli O157:H7. However, the recovery of these low inoculation levels of pathogens indicated that there is no single intervention to eliminate them.

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Antimicrobial Interventions for O157:H7 and Non-O157 Shiga Toxin–Producing Escherichia coli on Beef Subprimal and Mechanically Tenderized Steaks

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-178 ◽

2015 ◽

Vol 78 (3) ◽

pp. 511-517 ◽

Cited By ~ 9

Author(s):

YEN-TE LIAO ◽

J. CHANCE BROOKS ◽

JENNIFER N. MARTIN ◽

ALEJANDRO ECHEVERRY ◽

GUY H. LONERAGAN ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

E Coli ◽

Intervention Treatment ◽

Hypobromous Acid ◽

Emerging Risk ◽

Antimicrobial Interventions ◽

High Level ◽

Antimicrobial Treatments ◽

Vacuum Storage

Non-O157 Shiga toxin–producing Escherichia coli (STEC) is an emerging risk for food safety. Although numerous postharvest antimicrobial interventions have been effectively used to control E. coli O157:H7 during beef harvesting, research regarding their effectiveness against non-O157 STEC is scarce. The objectives of this study were (i) to evaluate effects of the spray treatments—ambient water, 5% lactic acid (LA), 200 ppm of hypobromous acid (HA), and 200 ppm of peroxyacetic acid (PA)—on the reduction of O157:H7 or non-O157 STEC (O26, O103, O111, and O145) with high (106 log CFU/50 cm2) or low (102 log CFU/50 cm2) levels on beef subprimals after vacuum storage for 14 days and (ii) to evaluate the association of the antimicrobial treatments and cooking (50 or 70°C) on the reduction of the pathogens in blade-tenderized steaks. The treatment effects were only observed (P = 0.012) on samples taken immediately after spray intervention treatment following inoculation with a high level of O157:H7. The LA and PA treatments significantly reduced low-inoculated non-O157 STEC after spray intervention; further, the LA and HA treatments resulted in significant reductions of non-O157 STEC on the low-inoculated samples after storage. Although cooking effectively reduced the detection of pathogens in internal steak samples, internalized E. coli O157:H7 and non-O157 STEC were able to survive in steaks cooked to a medium degree of doneness (70°C). This study indicated that the reduction on surface populations was not sufficient enough to eliminate the pathogen's detection following vacuum storage, mechanical tenderization, and cooking. Nevertheless, the findings of this study emphasize the necessity for a multihurdle approach and further investigations of factors that may influence thermal tolerance of internalized pathogenic STEC.

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The efficacy of antimicrobial interventions on Shiga toxin producing Escherichia coli (STEC) surrogate populations inoculated on beef striploins prior to blade tenderization

LWT ◽

10.1016/j.lwt.2019.108689 ◽

2020 ◽

Vol 117 ◽

pp. 108689

Author(s):

Chevise L. Thomas ◽

Harshavardhan Thippareddi ◽

Macc Rigdon ◽

Sanjay Kumar ◽

Robert W. McKee ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Blade Tenderization ◽

Antimicrobial Interventions

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Prevalence and Characterization of Non-O157 Shiga Toxin-Producing Escherichia coli on Carcasses in Commercial Beef Cattle Processing Plants

Applied and Environmental Microbiology ◽

10.1128/aem.68.10.4847-4852.2002 ◽

2002 ◽

Vol 68 (10) ◽

pp. 4847-4852 ◽

Cited By ~ 87

Author(s):

Terrance M. Arthur ◽

Genevieve A. Barkocy-Gallagher ◽

Mildred Rivera-Betancourt ◽

Mohammad Koohmaraie

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Human Disease ◽

The United States ◽

E Coli ◽

Beef Processing ◽

Processing Plants ◽

Antimicrobial Interventions ◽

Reported Data ◽

Beef Carcass

ABSTRACT Beef carcass sponge samples collected from July to August 1999 at four large processing plants in the United States were surveyed for the presence of non-O157 Shiga toxin-producing Escherichia coli (STEC). Twenty-eight (93%) of 30 single-source lots surveyed included at least one sample containing non-O157 STEC. Of 334 carcasses sampled prior to evisceration, 180 (54%) were found to harbor non-O157 STEC. Non-O157 STEC isolates were also recovered from 27 (8%) of 326 carcasses sampled after the application of antimicrobial interventions. Altogether, 361 non-O157 STEC isolates, comprising 41 different O serogroups, were recovered. O serogroups that previously have been associated with human disease accounted for 178 (49%) of 361 isolates. Although 40 isolates (11%) carried a combination of virulence factor genes (enterohemorrhagic E. coli hlyA, eae, and at least one stx gene) frequently associated with STEC strains causing severe human disease, only 12 of these isolates also belonged to an O serogroup previously associated with human disease. Combining previously reported data on O157-positive samples (R. O. Elder, J. E. Keen, G. R. Siragusa, G. A. Barkocy-Gallagher, M. Koohmaraie, and W. W. Laegreid, Proc. Natl. Acad. Sci. USA 97:2999-3003, 2000) with these data regarding non-O157-positive samples indicated total STEC prevalences of 72 and 10% in preevisceration and postprocessing beef carcass samples, respectively, showing that the interventions used by the beef-processing industry effected a sevenfold reduction in carcass contamination by STEC.

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