Comparison of Effects of Antimicrobial Interventions on Multidrug-Resistant Salmonella, Susceptible Salmonella, and Escherichia coli O157:H7†

2008 ◽  
Vol 71 (11) ◽  
pp. 2177-2181 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
NORASAK KALCHAYANAND ◽  
JOSEPH M. BOSILEVAC ◽  
DAYNA M. BRICHTA-HARHAY ◽  
STEVEN D. SHACKELFORD ◽  
...  

Several strains of Salmonella have been identified as resistant to multiple antibiotics. What is not known is whether strains possessing multidrug resistance properties also have the ability to resist the killing effects of the antimicrobial interventions used in beef processing. The research project described herein was designed to determine whether antimicrobial interventions currently in place in beef processing facilities are adequate for reducing the foodborne pathogen loads on beef carcass surfaces contaminated with multidrug-resistant (MDR) Salmonella. The data presented here indicate that MDR Salmonella is reduced at least as effectively as are Escherichia coli O157:H7 and susceptible Salmonella when treated with antimicrobial interventions currently in use at most U.S. beef processing plants. The E. coli O157:H7 strains used in this study were divided into two groups, strains that have a genetic polymorphism associated with human disease and strains not typically found to cause human disease. No differences were detected in the abilities of these two strain types to survive antimicrobial interventions. These results indicate that neither the drug resistance status of a particular Salmonella strain nor the likelihood that a particular E. coli O157:H7 strain will cause human illness influences the antimicrobial efficacy of the interventions utilized by the modern beef processing plants.

2003 ◽  
Vol 66 (11) ◽  
pp. 1978-1986 ◽  
Author(s):  
GENEVIEVE A. BARKOCY-GALLAGHER ◽  
TERRANCE M. ARTHUR ◽  
MILDRED RIVERA-BETANCOURT ◽  
XIANGWU NOU ◽  
STEVEN D. SHACKELFORD ◽  
...  

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.


2004 ◽  
Vol 67 (4) ◽  
pp. 658-665 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
XIANGWU NOU ◽  
STEVEN D. SHACKELFORD ◽  
TOMMY L. WHEELER ◽  
...  

The effectiveness of current antimicrobial interventions used in reducing the prevalence or load of Escherichia coli O157 and indicator organisms on cattle hides and carcasses at two commercial beef processing plants was evaluated. Sponge sampling of beef cattle was performed at five locations from the initial entry of the animals to the slaughter floor to the exit of carcasses from the “hotbox” cooler. For each sample, E. coli O157 prevalence was determined and total aerobic bacteria, Enterobacteriaceae, and E. coli O157 were enumerated. E. coli O157 was found on 76% of animal hides coming into the plants, but no carcasses leaving the cooler were identified as contaminated with E. coli O157. A positive relationship was seen between the incidence of E. coli O157 in hide samples and that in preevisceration samples. Aerobic plate counts and Enterobacteriaceae counts averaged 7.8 and 6.2 log CFU/100 cm2, respectively, on hides, and 1.4 and 0.4 log CFU/100 cm2, respectively, on chilled carcasses. Aerobic plate counts and Enterobacteriaceae counts on preevisceration carcasses were significantly related to the respective levels on the corresponding hides; the carcasses of animals whose hides carried higher numbers of bacteria were more likely to carry higher numbers of bacteria. Implementation of the sampling protocol described here would allow processors to evaluate the efficacy of on-line antimicrobial interventions and allow industrywide benchmarking of hygienic practices.


2002 ◽  
Vol 68 (10) ◽  
pp. 4847-4852 ◽  
Author(s):  
Terrance M. Arthur ◽  
Genevieve A. Barkocy-Gallagher ◽  
Mildred Rivera-Betancourt ◽  
Mohammad Koohmaraie

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.


2001 ◽  
Vol 67 (9) ◽  
pp. 3810-3818 ◽  
Author(s):  
Genevieve A. Barkocy-Gallagher ◽  
Terrance M. Arthur ◽  
Gregory R. Siragusa ◽  
James E. Keen ◽  
Robert O. Elder ◽  
...  

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.


2012 ◽  
Vol 75 (12) ◽  
pp. 2213-2218 ◽  
Author(s):  
JOHN W. SCHMIDT ◽  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
NORASAK KALCHAYANAND ◽  
TOMMY L. WHEELER

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.


2004 ◽  
Vol 67 (11) ◽  
pp. 2603-2607 ◽  
Author(s):  
T. R. CALLAWAY ◽  
C. H. STAHL ◽  
T. S. EDRINGTON ◽  
K. J. GENOVESE ◽  
L. M. LINCOLN ◽  
...  

Escherichia coli O157:H7 is a virulent foodborne pathogen that causes severe human illness and inhabits the intestinal tract of food animals. Colicins are antimicrobial proteins produced by E. coli strains that inhibit or kill other E. coli. In the present study, the efficacy of three pore-forming colicins (E1, N, and A) were quantified in vitro against E. coli O157:H7 strains 86-24 and 933. Colicins E1 and N reduced the growth of E. coli O157:H7 strains, but the efficacy of each colicin varied among strains. Colicin E1 was more effective against both strains of E. coli O157:H7 than colicins A and N and reduced (P < 0.05) populations of E. coli O157:H7 at concentrations <0.1 μg/ml. These potent antimicrobial proteins may potentially provide an effective and environmentally sound preharvest strategy to reduce E. coli O157:H7 in food animals.


2007 ◽  
Vol 70 (5) ◽  
pp. 1076-1079 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
DAYNA M. BRICHTA-HARHAY ◽  
NORASAK KALCHAYANAND ◽  
STEVEN D. SHACKELFORD ◽  
...  

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.


2008 ◽  
Vol 71 (9) ◽  
pp. 1752-1760 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
DAYNA M. BRICHTA-HARHAY ◽  
NORASAK KALCHAYANAND ◽  
DAVID A. KING ◽  
...  

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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Zhanqiang Su ◽  
Panpan Tong ◽  
Ling Zhang ◽  
Mengmeng Zhang ◽  
Dong Wang ◽  
...  

The bovine Escherichia coli O157:H7 is a major foodborne pathogen causing severe bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome in humans. Cattle are recognized major reservoir and source of E. coli O157:H7. We investigated the antibiotic resistance, molecular profiles, and intrinsic relationship between 21 isolates of E. coli O157:H7 from cattle farms and slaughtering houses in Xinjiang. Using pulsed-field gel electrophoresis (PFGE) molecular typing, two types of PFGE were revealed through cluster analysis, including clusters I and II, with 66 and 100% similarity of PFGE spectra between 21 isolates. We also detected that 18 isolates (86%) carried at least one virulence gene, 16 isolates (76%) carried the eae gene, and 7 (33%) carried the stx1 + stx2 + eae + hly + tccp genes. Eighteen isolates were susceptible to antibiotics. Three isolates were resistant to antibiotics, and two were multidrug resistant. One of the two multidrug-resistant isolates detectably carried the blaCTX−M−121 gene. This is the first finding of the blaCTX−M−121 gene detected in E. coli O157:H7 isolated from cattle in Xinjiang. The blaCTX−M−121 gene is transferable between the bacterial strains via plasmid transmission. The results indicated that E. coli O157:H7 may have undergone clonal propagation in cattle population and cross-regional transmission in Xinjiang, China.


2009 ◽  
Vol 72 (6) ◽  
pp. 1272-1278 ◽  
Author(s):  
JOSEPH M. BOSILEVAC ◽  
TERRANCE M. ARTHUR ◽  
JAMES L. BONO ◽  
DAYNA M. BRICHTA-HARHAY ◽  
NORASAK KALCHAYANAND ◽  
...  

A significant portion (15 to 20%) of beef in the United States is produced in small beef processing plants that harvest fewer than 1,000 cattle per day. However, there are little data on the prevalence and levels of Escherichia coli O157:H7 and Salmonella in these processing plants. To address this lack of data, hides (n = 1,995) and carcasses (n = 1,995) of cattle at seven small processing plants located across the United States were analyzed for E. coli O157:H7 and Salmonella. Across all plants, hide prevalence of E. coli O157:H7 and Salmonella was 71 and 91%, respectively. Twelve percent of hides had E. coli O157:H7 at enumerable levels (≥40 CFU/100 cm2), while 36% of hides had Salmonella at enumerable levels. Across all plants, the prevalence of E. coli O157:H7 on preevisceration carcasses was 33%, with 2% at an enumerable level (≥0.8 CFU/100 cm2). Across all plants, Salmonella prevalence on preevisceration carcasses was 58%, with 8% at an enumerable level. Significant plant-to-plant variations in levels and prevalence of pathogens on carcasses were detected. Reduced levels of pathogens on carcasses were noted among small processors that had incorporated a hide-directed intervention. The results obtained are comparable to those observed previously for larger processors, showing that smaller beef processors face and address the same challenges as do larger beef processors.


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