The acid tolerance responses of the Salmonella strains isolated from beef processing plants

ABSTRACT Escherichia coli O157:H7 and O157 nonmotile isolates (E. coli O157) previously were recovered from feces, hides, and carcasses at four large Midwestern beef processing plants (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). The study implied relationships between cattle infection and carcass contamination within single-source lots as well as between preevisceration and postprocessing carcass contamination, based on prevalence. These relationships now have been verified based on identification of isolates by genomic fingerprinting.E. coli O157 isolates from all positive samples were analyzed by pulsed-field gel electrophoresis of genomic DNA after digestion with XbaI. Seventy-seven individual subtypes (fingerprint patterns) grouping into 47 types were discerned among 343 isolates. Comparison of the fingerprint patterns revealed three clusters of isolates, two of which were closely related to each other. Remarkably, isolates carrying both Shiga toxin genes and nonmotile isolates largely fell into specific clusters. Within lots analyzed, 68.2% of the postharvest (carcass) isolates matched preharvest (animal) isolates. For individual carcasses, 65.3 and 66.7% of the isolates recovered postevisceration and in the cooler, respectively, matched those recovered preevisceration. Multiple isolates were analyzed from some carcass samples and were found to include strains with different genotypes. This study suggests that mostE. coli O157 carcass contamination originates from animals within the same lot and not from cross-contamination between lots. In addition, the data demonstrate that most carcass contamination occurs very early during processing.

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Prevalence and Serotypes of Listeria monocytogenes Contamination in Chinese Beef Processing Plants

Foodborne Pathogens and Disease ◽

10.1089/fpd.2011.1088 ◽

2012 ◽

Vol 9 (6) ◽

pp. 556-560 ◽

Cited By ~ 9

Author(s):

Lixian Zhu ◽

Xiaohui Feng ◽

Lihua Zhang ◽

Ruiliang Zhu ◽

Xin Luo

Keyword(s):

Listeria Monocytogenes ◽

Beef Processing ◽

Processing Plants

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In-Plant Validation Study of Harvest Process Controls in Two Beef Processing Plants in Honduras

Journal of Food Protection ◽

10.4315/0362-028x.jfp-18-395 ◽

2019 ◽

Vol 82 (4) ◽

pp. 677-683

Author(s):

DIEGO CASAS ◽

MINDY M. BRASHEARS ◽

MARK F. MILLER ◽

BRENDA INESTROZA ◽

MARIA BUESO-PONCE ◽

...

Keyword(s):

United States ◽

Food Safety ◽

Lymph Nodes ◽

Hazard Analysis ◽

The United States ◽

Control Points ◽

Beef Processing ◽

Critical Control Points ◽

Processing Plants ◽

Safety Programs

ABSTRACT Imported meat in the United States can become a food safety hazard if proper food safety programs are not fully implemented in foreign meat processing plants. Thus, exporting countries' food safety inspection systems must be equivalent to the U.S. federal inspection system to become eligible to export meat to the United States. The objective of this study was to validate the beef harvest Hazard Analysis and Critical Control Points and food safety programs of two beef processing plants in Honduras operating under U.S. equivalency standards by evaluating the presence of Salmonella (plant A) and Shiga toxin–producing Escherichia coli (STEC; plant B) on hides. Additionally, evaluating pathogen transfer from hides to carcasses, as detected by preevisceration sampling, and the mitigation of transferred pathogens, by application of carcass spray interventions and determination of Salmonella presence in lymph nodes, was also conducted. In plant A, the presence of Salmonella on hides (n = 30 of 687; 4.4%) was significantly greater (P < 0.10) than on carcasses swabbed at preevisceration (n = 7 of 687; 1.0%), after intervention (n = 13 of 678; 1.9%), and in lymph nodes (n = 14 of 691; 2.0%). In plant B, Salmonella was not detected on hide samples; therefore, data could not be used for validation of the harvest Hazard Analysis and Critical Control Points program. Alternatively, STEC presence on hides (n = 21 of 85; 24.7%) was greater (P < 0.10) than on carcasses at preevisceration (n = 3 of 85; 3.5%) and after intervention (n = 1 of 85; 1.2%). Pathogen presence in plant B did not differ (P = 0.306) between carcasses in preevisceration and postintervention stages; both, however, were substantially low. Both plants' controls effectively reduced Salmonella and STEC presence in postintervention carcasses.

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

Meat Science ◽

10.1016/j.meatsci.2020.108188 ◽

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

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Detection of Escherichia coli O157:H7 and Salmonella enterica in Air and Droplets at Three U.S. Commercial Beef Processing Plants†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-12-206 ◽

2012 ◽

Vol 75 (12) ◽

pp. 2213-2218 ◽

Cited By ~ 18

Author(s):

JOHN W. SCHMIDT ◽

TERRANCE M. ARTHUR ◽

JOSEPH M. BOSILEVAC ◽

NORASAK KALCHAYANAND ◽

TOMMY L. WHEELER

Keyword(s):

Escherichia Coli ◽

Salmonella Enterica ◽

Published Data ◽

Escherichia Coli O157 ◽

Liquid Droplets ◽

Air Samples ◽

E Coli ◽

Beef Processing ◽

Processing Plants ◽

Plate Counts

Bacteria are known to be present in the air at beef processing plants, but published data regarding the prevalences of airborne Escherichia coli O157:H7 and Salmonella enterica are very limited. To determine if airborne pathogens were present in beef processing facilities, we placed sedimentation sponges at various locations in three commercial beef plants that processed cattle from slaughter through fabrication. For the 291 slaughter area air samples, E. coli O157:H7 was isolated from 15.8% and S. enterica from 16.5%. Of the 113 evisceration area air samples, E. coli O157:H7 was isolated from only one sample and S. enterica was not isolated from any sample. Pathogens were not isolated from any of the 87 air samples from fabrication areas. Pathogen prevalences, aerobic plate counts, and Enterobacteriaceae counts were highest for air samples obtained from locations near hide removal operations. The process of hide removal disperses liquid droplets, which may contact neighboring carcasses. Samples were obtained both from hide removal locations that were close enough to hide pullers to be contacted by droplets and from locations that were not contacted by droplets. Higher pathogen prevalences, aerobic plate counts, and Enterobacteriaceae counts were observed at locations with samples contacted by the hide removal droplets. We conclude that the hide removal processes likely introduce pathogens into the air via a dispersion of liquid droplets and that these droplets may be an underappreciated source of hide-to-carcass contamination.

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Impact of Sampling Area and Location on Measurement of Indicator Organisms during Beef Carcass Interventions†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-13-134 ◽

2013 ◽

Vol 76 (12) ◽

pp. 2069-2073 ◽

Cited By ~ 2

Author(s):

RONG WANG ◽

DAVID A. KING ◽

MOHAMMAD KOOHMARAIE ◽

JOSEPH M. BOSILEVAC

Keyword(s):

Sampling Method ◽

Sampling Site ◽

Hot Water ◽

The Other ◽

Indicator Organisms ◽

Sample Collection ◽

Beef Processing ◽

Processing Plants ◽

Multiple Indicator ◽

Beef Carcass

The effect of the sponge sample collection site on the recovery of multiple indicator organisms from beef carcass surfaces was evaluated to simplify and validate our previous sampling method for ease of implementation as a general protocol. Sponge samples were collected at three beef processing plants using hot water or acidic antimicrobials as interventions. Two 4,000-cm2 samples were collected from preevisceration carcasses (n = 248), one from the inside and outside round area (top site) and one from the navel-plate-brisket-foreshank area (bottom site). One-half of the samples (n = 124) were collected before a wash cabinet intervention and the other half after the intervention. The numbers of total aerobic bacteria, Enterobacteriaceae, coliforms, and Escherichia coli were determined for one-half of each individual sponge sample. The other halves of the sponges were combined to represent a top plus bottom 8,000-cm2 sample. For the preintervention carcasses, 4,000-cm2 samples collected from the top or bottom sites of the carcasses were not significantly different (P > 0.05) from each other or from the 8,000-cm2 combined sample in recovery of the indicator organisms. Significant reductions of indicator organisms were observed in all three types of sponge samples after intervention; however, samples collected from the bottom site recovered less organisms (P < 0.05) compared with samples of the other types. These results suggested that samples collected from either the top or the bottom site of the carcasses with this method are suitable for monitoring indicator organisms as long as the same sampling site is consistently used.

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Listeria Prevalence and Listeria monocytogenes Serovar Diversity at Cull Cow and Bull Processing Plants in the United States†

Journal of Food Protection ◽

10.4315/0362-028x-70.11.2578 ◽

2007 ◽

Vol 70 (11) ◽

pp. 2578-2582 ◽

Cited By ~ 33

Author(s):

MICHAEL N. GUERINI ◽

DAYNA M. BRICHTA-HARHAY ◽

STEVEN D. SHACKELFORD ◽

TERRANCE M. ARTHUR ◽

JOSEPH M. BOSILEVAC ◽

...

Keyword(s):

United States ◽

Listeria Monocytogenes ◽

Causative Agent ◽

Warm Season ◽

The United States ◽

Prevalence Data ◽

Beef Processing ◽

Processing Plants ◽

Many Sources ◽

Cull Cow

Listeria monocytogenes, the causative agent of epidemic and sporadic listeriosis, is routinely isolated from many sources, including cattle, yet information on the prevalence of Listeria in beef processing plants in the United States is minimal. From July 2005 through April 2006, four commercial cow and bull processing plants were sampled in the United States to determine the prevalence of Listeria and the serovar diversity of L. monocytogenes. Samples were collected during the summer, fall, winter, and spring. Listeria prevalence on hides was consistently higher during cooler weather (28 to 92% of samples) than during warmer weather (6 and 77% of samples). The Listeria prevalence data collected from preevisceration carcass ranged from undetectable in some warm season samples to as high as 71% during cooler weather. Listeria on postintervention carcasses in the chill cooler was normally undetectable, with the exception of summer and spring samples from one plant where >19% of the carcasses were positive for Listeria. On hides, L. monocytogenes serovar 1/2a was the predominant serovar observed, with serovars 1/2b and 4b present 2.5 times less often and serovar 1/2c not detected on any hides sampled. L. monocytogenes serovars 1/2a, 1/2c, and 4b were found on postintervention carcasses. This prevalence study demonstrates that Listeria species are more prevalent on hides during the winter and spring and that interventions being used in cow and bull processing plants appear to be effective in reducing or eliminating Listeria contamination on carcasses.

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Effects of a Minimal Hide Wash Cabinet on the Levels and Prevalence of Escherichia coli O157:H7 and Salmonella on the Hides of Beef Cattle at Slaughter†

Journal of Food Protection ◽

10.4315/0362-028x-70.5.1076 ◽

2007 ◽

Vol 70 (5) ◽

pp. 1076-1079 ◽

Cited By ~ 47

Author(s):

TERRANCE M. ARTHUR ◽

JOSEPH M. BOSILEVAC ◽

DAYNA M. BRICHTA-HARHAY ◽

NORASAK KALCHAYANAND ◽

STEVEN D. SHACKELFORD ◽

...

Keyword(s):

Escherichia Coli ◽

Beef Cattle ◽

Limit Of Detection ◽

Intervention Strategy ◽

Medium Size ◽

Escherichia Coli O157 ◽

E Coli ◽

Beef Processing ◽

Before And After ◽

Processing Plants

Harborage of Escherichia coli O157:H7 and Salmonella on animal hides at slaughter is the main source of beef carcass contamination during processing. Given this finding, interventions have been designed and implemented to target the hides of cattle following entry into beef processing plants. Previous interventions targeting hides have not been suitable for all beef processing plants because of cost and space restrictions. In this study, a hide wash cabinet was evaluated to determine whether it was more amenable to widespread use in the beef processing industry, especially for small and medium-size plants. Overall, 101 (35.1%) of 288 beef cattle hides sampled before entry into the hide wash cabinet harbored E. coli O157:H7 at or above the limit of detection (40 CFU/100 cm2). After passage through the hide wash cabinet, only 38 (13.2%) of 288 hides had E. coli O157:H7 levels ≥40 CFU/100 cm2. Before the hide wash cabinet, 50 (17%) of 288 hides harbored E. coli O157:H7 at levels above 100 CFU/100 cm2, with one sample as high as 20,000 CFU/100 cm2. In contrast, only 14 (5%) of 288 hides had E. coli O157:H7 levels above 100 CFU/100 cm2 after hide washing, with the highest being 2,000 CFU/100 cm2. These same trends also were found for Salmonella before and after hide washing. These results indicate that the hide wash cabinet described in this study was effective and should provide small and medium-size processing plants with an affordable hide wash intervention strategy.

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Source Tracking of Escherichia coli O157:H7 and Salmonella Contamination in the Lairage Environment at Commercial U.S. Beef Processing Plants and Identification of an Effective Intervention†

Journal of Food Protection ◽

10.4315/0362-028x-71.9.1752 ◽

2008 ◽

Vol 71 (9) ◽

pp. 1752-1760 ◽

Cited By ~ 66

Author(s):

TERRANCE M. ARTHUR ◽

JOSEPH M. BOSILEVAC ◽

DAYNA M. BRICHTA-HARHAY ◽

NORASAK KALCHAYANAND ◽

DAVID A. KING ◽

...

Keyword(s):

Escherichia Coli ◽

Gel Electrophoresis ◽

The United States ◽

Pulsed Field Gel Electrophoresis ◽

Processing Plant ◽

Escherichia Coli O157 ◽

Pulsed Field ◽

E Coli ◽

Beef Processing ◽

Processing Plants

Transportation from the feedlot and lairage at the processing plant have been identified as potential sources of Escherichia coli O157:H7 and Salmonella hide contamination. The objective of this study was to perform a comprehensive tracking analysis of E. coli O157:H7 and Salmonella associated with beef cattle from the feedlot through processing. Cattle (n = 581) were sampled in a feedlot, then transported in multiple lots to three commercial, fed beef processing plants in the United States, where they were sampled again. Samples were collected from the tractor trailers prior to loading cattle and from the lairage environment spaces prior to entry of the study cattle. Pathogen prevalence on cattle hides increased on every lot of cattle between exiting the feedlot and beginning processing. Prior to loading cattle, E. coli O157:H7 was found in 9 (64%) of 14 tractor trailers. E. coli O157:H7 was detected in over 60% of the samples from each lairage environment area, while Salmonella was detected in over 70% of the samples from each lairage environment area. E. coli O157:H7 and Salmonella isolates (n 3,645) were analyzed using pulsed-field gel electrophoresis. The results of the pulsed-field gel electrophoresis tracking indicate that the transfer of bacteria onto cattle hides that occurs in the lairage environments of U.S beef processing plants accounts for a larger proportion of the hide and carcass contamination than does the initial bacterial population found on the cattle exiting the feedlot. Finally, the results of this study indicate that hide wash cabinets are effective in removing contamination derived from the lairage environment.

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