scholarly journals Microbial Validation of Dry Aged Beef Trim for Incorporation into Premium Ground Beef

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
K. Philipps ◽  
T. Langford ◽  
B. Harsh ◽  
S. Williams ◽  
J. M. Scheffler
Keyword(s):  
Listeria Monocytogenes ◽  
Risk Mitigation ◽  
Ground Beef ◽  
Aging Treatment ◽  
Main Concern ◽  
Post Inoculation ◽  
Time Data ◽  
E Coli ◽  
Aging Period ◽  
Side Interaction

ObjectivesDry aging treatments impart unique flavors desirable by a segment of the population. Ground beef offers flexibility of use at a lower price point. There is potential to add value to lower priced beef cuts by dry aging them and incorporating them into premium grinds. However, the long dry aging period could allow growth of key pathogens. To determine the risk, the prevalence and potential for growth must be assessed. The effect of a dry aging treatment on the population of Salmonella and Listeria monocytogenes was studied.Materials and MethodsAn in-plant assessment of E. coli O157:H7, Salmonella, and Listeria monocytogenes was conducted by swabbing both the fat and lean sides of 25 ribeye rolls or striploins before direct plating and finally enriching samples. Beef shoulder clods were purchased and used to simulate dry aging. The product was cut into 10 cm × 10 cm blocks before inoculating both fat and lean surfaces with a cocktail mixture containing two strains of Listeria monocytogenes and five strains of Salmonella at a rate of 103 CFU/cm2. Blocks were allowed to dry for 15 min between inoculation of sides and before suspension in a refrigerator (4°C) with a circulating fan and 70–80% humidity. Surfaces were removed at a depth < 5mm for collection and plating on selective media at 0, 1, 7, 14, 21, and 28 d post inoculation. Two sides of six blocks were used at each time point; the experiment was replicated a second time. Data were analyzed to test the effect of time, side, and their interaction for each pathogen; replication was a random variable.ResultsSamples collected in a commercial facility showed no occurrence of E. coli O157:H7 or Salmonella, but three presumptive Listeria monocytogenes colonies were found in the quantitative analysis. The plant does not process ready-to-eat products, the main concern with Listeria monocytogenes. Since all product will be trimmed and cooked prior to consumption, and with the low amount of Listeria monocytogenes, the risk associated with Listeria monocytogenes is relatively low. To validate use of the dry aging treatment on sub-primals to be used for ground beef, the microbial population of the key pathogens used during inoculation must not increase over the treatment period. Salmonella levels on d 1 and 14 were similar (P = 0.53), but numerically less than d 0, and lower (P = 0.0028) on d 1, 21, and 28. There was an effect of side of inoculation; the fat side had significantly higher (P = 0.046) Salmonella levels over the duration of the study. This suggests that Salmonella may have had slightly better attachment to fat at inoculation, but it had no bearing on growth dynamics thereafter. There was no day by side interaction detected (P = 0.51). Listeria monocytogenes showed a similar overall trend; counts were similar on d 7, 14, and 21 (P = 0.079), and numerically less than d 0, whereas counts were lower (P = 0.014) on d 1 and 28. No effect of side (P = 0.21) or a day by side interaction (P = 0.66) were observed.ConclusionOverall, Salmonella and Listeria monocytogenes did not increase during the 28d aging period, indicating that dry-aged beef trim is not higher risk than fresh beef trim. Thus, additional risk mitigation steps may not be necessary during processing of dry aged versus fresh ground beef.

scholarly journals The Relative Efficacy of Thermal and Acidification Stresses on the Survival of E. coli O157:H7, Salmonella, and Listeria Monocytogenes in Ground Beef

2016 ◽  
Vol 6 (3) ◽  
pp. 74
Author(s):  
Sagor Biswas ◽  
Pramod Pandey
Keyword(s):  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Low Ph ◽  
Relative Efficacy ◽  
E Coli ◽  
Log Reduction ◽  
Pathogen Survival ◽  
Level 3 ◽  
Improved Methods ◽  
Biosafety Level

To provide additional insights on pathogen survival, we evaluated the relative efficacy of acidification (pH 2.7), thermophilic treatment (55 °C), and low temperature pasteurization (68 °C) on the inactivation of E. coli O157:H7, Salmonella, and Listeria monocytogenes in ground beef. A series of experiment was conducted under biosafety level 3 environments for assessing the impacts of heat and low pH on pathogen survival. Results showed that 5-log reductions of E. coli O157:H7 could take more than 2640 min at 55 °C, 134 min at 68 °C and 120 min under pH 2.7. Compared to E. coli O157:H7, the 5-log reduction of Salmonella was obtained in 4836, 126, 86 min at 55 °C, 68 °C, and pH 2.7, respectively. The 5-log reduction of Listeria was achieved in 4704, 200, and 115 min under 55 °C, 68 °C, and pH 2.7, respectively. The results of this study will provide additional insights for developing improved methods for controlling pathogens in ground beef.

Effects of Acetic-Lactic Acid Treatments Applied to Beef Trim on Populations of Escherichia coli O157:H7 and Listeria monocytogenes in Ground Beef†

1997 ◽  
Vol 60 (12) ◽  
pp. 1560-1563 ◽  
Author(s):  
D. E. CONNER ◽  
J. S. KOTROLA ◽  
W. B. MIKEL ◽  
K. C. TAMBLYN
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Beef Production ◽  
E Coli ◽  
Production Scheme ◽  
And Storage ◽  
Lactic Acids ◽  
Acid Treatments

The efficacy of organic acid sprays for eliminating Escherichia coli O157:H7 and Listeria monocytogenes from beef trim used in a model ground beef production scheme was determined. Beef trim pieces with ca. 20% fat inoculated with E. coli O157:H7 or L. monocytogenes (ca. 3 log10 CFU/g) were utilized as controls or treated by spraying with 2 or 4% acetic and lactic acids. Propylene glycol (20%) was the carrier for each treatment. Following acid treatment, intact pieces were stored at 4°C for 12 or 24 h, ground, divided into 4 100-g retail packages and stored at 4°C for 0, 1, 2, or 4 days, at which time surviving populations of E. coli O157:H7 or L. monocytogenes were enumerated. High populations (&gt;2.6 log10 CFU/g) of the pathogens persisted in all treatments. The 2% acid spray reduced (P &lt; 0.01) the E. coli O157:H7 population by only 0.1 log10 CFU/g. The 2 and 4% acid sprays reduced (P &lt; 0.001) the L. monocytogenes populations by 0.36 and 0.44 log10 CFU/g, respectively. Storing beef trim intact prior to grinding resulted in lower populations of E. coli O157:H7, and storage following grinding did not affect populations of either pathogen. The acid treatments tested were only slightly effective as sanitizers for beef trim destined for ground beef production.

Incidence of Enterohemorrhagic Escherichia coli, Escherichia coli O157, Salmonella, and Listeria monocytogenes in Retail Fresh Ground Beef, Sprouts, and Mushrooms

2006 ◽  
Vol 69 (2) ◽  
pp. 441-443 ◽  
Author(s):  
M. SAMADPOUR ◽  
M. W. BARBOUR ◽  
T. NGUYEN ◽  
T.-M. CAO ◽  
F. BUCK ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Food Samples ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Pcr Assays ◽  
Retail Food

The objective of this study was to determine the prevalence of enterohemorrhagic Escherichia coli (EHEC), E. coli O157, Salmonella, and Listeria monocytogenes in retail food samples from Seattle, Wash. A total of 2,050 samples of ground beef (1,750 samples), mushrooms (100 samples), and sprouts (200 samples) were collected over a 12-month period and analyzed for the presence of these pathogens. PCR assays, followed by culture confirmation were used to determine the presence or absence of each organism. Of the 1,750 ground beef samples analyzed, 61 (3.5%) were positive for EHEC, and 20 (1.1%) of these were positive for E. coli O157. Salmonella was present in 67 (3.8%) of the 1,750 ground beef samples. Of 512 ground beef samples analyzed, 18 (3.5%) were positive for L. monocytogenes. EHEC was found in 12 (6.0%) of the 200 sprout samples, and 3 (1.5%) of these yielded E. coli O157. Of the 200 total sprout samples, 14 (7.0%) were positive for Salmonella and none were positive for L. monocytogenes. Among the 100 mushroom samples, 4 (4.0%) were positive for EHEC but none of these 4 samples were positive for E. coli O157. Salmonella was detected in 5 (5.0%) of the mushroom samples, and L. monocytogenes was found in 1 (1.0%) of the samples.

Impact of pH Enhancement on Populations of Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7 in Boneless Lean Beef Trimmings†

2003 ◽  
Vol 66 (5) ◽  
pp. 874-877 ◽  
Author(s):  
STEVEN E. NIEBUHR ◽  
J. S. DICKSON
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Final Concentration ◽  
Escherichia Coli O157 ◽  
Ammonia Gas ◽  
E Coli ◽  
Lean Beef ◽  
Pathogen Populations ◽  
Multiple Strains

Boneless lean beef trimmings were inoculated with multiple strains of salmonellae, Listeria monocytogenes, and Escherichia coli O157:H7 at levels of ca. 6 log10 CFU/g. pH enhancement with ammonia gas was then used to increase the pH of the trimmings to ca. 9.6. The product was then frozen, chipped, and compressed into blocks. pH enhancement reduced the populations of salmonellae, L. monocytogenes, and E. coli O157:H7 by approximately 4, 3, and 1 log10 cycles, respectively. After the product had been frozen and compressed into blocks, no salmonellae or E. coli O157:H7 were detectable by enumeration or after enrichment and isolation. The final populations of L. monocytogenes were reduced by ca. 3 log10 cycles relative to the initial populations. When uninoculated pH-enhanced lean boneless trimmings were blended with inoculated ground beef to a final concentration of 15% (wt/wt), pathogen populations in the ground beef were reduced by approximately 0.2 log10 cycles.

Growth of Escherichia coli O157:H7, Salmonella Typhimurium DT104, and Listeria monocytogenes in Dark Cutting Beef at 10 or 22° C†

2002 ◽  
Vol 65 (1) ◽  
pp. 196-198 ◽  
Author(s):  
C. A. HOOPER-KINDER ◽  
P. M. DAVIDSON ◽  
S. K. DUCKETT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Foodborne Pathogens ◽  
Ground Beef ◽  
Growth Characteristics ◽  
Escherichia Coli O157 ◽  
E Coli

An experiment was conducted to determine the effects of the dark, firm, and dry (DFD) condition of beef on growth of the foodborne pathogens Escherichia coli O157:H7, Salmonella Typhimurium DT104, and Listeria monocytogenes Scott A in ground beef. Longissimus muscles from a DFD carcass (pH = 6.45) and normal carcass (N; pH = 5.64) were ground and samples obtained (100 and 0% DFD, respectively). Equal amounts of the 0 and 100% DFD ground samples were mixed to obtain 50% DFD samples. Inoculated 0, 50, and 100% DFD samples were packaged into oxygen-permeable overwrap and stored at 10°C for E. coli O157:H7, Salmonella Typhimurium DT104, and L. monocytogenes Scott A or at 22°C for E. coli O157:H7. Growth characteristics of E. coli O157:H7, Salmonella Typhimurium DT104, and L. monocytogenes Scott A did not differ (P &gt; 0.05) between 0 and 100% DFD. Results indicated that the DFD beef used in this study was no more susceptible to growth of E. coli O157:H7, Salmonella Typhimurium, or L. monocytogenes Scott A than N beef.

Effectiveness of Two Cooking Systems in Destroying Escherichia coli O157:H7 and Listeria monocytogenes in Ground Beef Patties

2000 ◽  
Vol 63 (7) ◽  
pp. 894-899 ◽  
Author(s):  
ELAINE M. D'SA ◽  
MARK A. HARRISON ◽  
SCOTT E. WILLIAMS ◽  
MARC H. BROCCOLI
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Target Temperature ◽  
Internal Temperature ◽  
E Coli ◽  
Beef Patties ◽  
Textural Quality ◽  
Rapid Temperature

A rapid, high-temperature double-sided grilling–broiling (DGB) system was compared to a single-sided broiling (SSB) system for cooking of foodservice ground beef patties to reduce microbial numbers and maintain textural quality. Patties (110g) containing either Escherichia coli O157:H7 or Listeria monocytogenes (106–7 CFU/g) were cooked to target internal temperatures of 60 or 68°C on each cooking system and immediately removed from the grills without the additional holding time at 60 or 68°C that is recommended for foodservice cooking of ground beef patties. Actual final internal temperature attained, position on the grill, degree of doneness, cooking time, after-cook weight, texture characteristics, and bacterial counts of the patties were monitored. The DGB reduced E. coli O157:H7 and L. monocytogenes populations in ground beef patties by 5.7 log10 and 5.4 log10 CFU/g, respectively, when cooked to a target temperature of 60°C (actual final internal temperature of 71.2°C) and by 6.1 log10 and 5.6 log10 CFU/g, respectively, when cooked to a target temperature of 68°C (actual final internal temperature of 75.8°C). The SSB reduced E. coli O157:H7 and L. monocytogenes populations by 1.3 log10 and 1.8 log10 CFU/g, respectively, when cooked to a target temperature of 60°C (actual final internal temperature of 62.7°C) and by 2.9 log10 and 3.6 log10 CFU/g, respectively, when cooked to a target temperature of 68°C (actual final internal temperature of 69.3°C). The DGB system effected a higher, more rapid temperature increase in patties cooked to either target temperature compared to the SSB system. This higher temperature was more effective in destroying pathogens in beef patties. Texture analyses determined that patties cooked on the DGB system had significantly higher values for springiness, adhesiveness, and product height as compared to the SSB system, and patties cooked on either system had significantly higher hardness, gumminess, chewiness, and product height values at the target temperature of 68°C as compared to 60°C.

Thermal Process Validation for Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in Ground Turkey and Beef Products

2004 ◽  
Vol 67 (7) ◽  
pp. 1394-1402 ◽  
Author(s):  
R. Y. MURPHY ◽  
E. M. MARTIN ◽  
L. K. DUNCAN ◽  
B. L. BEARD ◽  
J. A. MARCY
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Process Validation ◽  
E Coli ◽  
Beef Products ◽  
Air Impingement ◽  
D Values

At 55 to 70°C, thermal inactivation D-values for Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes were 19.05 to 0.038, 43.10 to 0.096, and 33.11 to 0.12 min, respectively, in ground turkey and 21.55 to 0.055, 37.04 to 0.066, and 36.90 to 0.063 min, respectively, in ground beef. The z-values were 5.73, 5.54, and 6.13°C, respectively, in ground turkey and 5.43, 5.74, and 6.01°C, respectively, in ground beef. In both ground turkey and beef, significant (P &lt; 0.05) differences were found in the D-values between E. coli O157:H7 and Salmonella or between E. coli O157:H7 and L. monocytogenes. At 65 to 70°C, D-values for E. coli O157:H7, Salmonella, and L. monocytogenes were also significantly (P &lt; 0.05) different between turkey and beef. The obtained D- and z-values were used in predicting process lethality of the pathogens in ground turkey and beef patties cooked in an air impingement oven and confirmed by inoculation studies for a 7-log (CFU/g) reduction of E. coli O157:H7, Salmonella, and L. monocytogenes.

Antimicrobial Effect of Herb Extracts against Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium Associated with Beef†

2000 ◽  
Vol 63 (5) ◽  
pp. 601-607 ◽  
Author(s):  
CATHERINE N. CUTTER
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Pathogenic Bacteria ◽  
Ground Beef ◽  
Antimicrobial Effect ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Herb Extracts

The effects of plant extracts against pathogenic bacteria in vitro are well known, yet few studies have addressed the effects of these compounds against pathogens associated with muscle foods. A series of experiments was conducted to determine the effectiveness of a commercially available, generally recognized as safe, herb extract dispersed in sodium citrate (Protecta One) or sodium chloride (Protecta Two) against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes associated with beef. In the first experiment, E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes inoculated onto beef and subjected to surface spray treatments with 2.5% solutions of Protecta One or Protecta Two were not affected by immediate application (day 0) of the herbal extracts. However, after 7 days of storage at 4°C, E. coli O157:H7 was reduced by &gt;1.3 log10 CFU/cm2 by Protecta Two; L. monocytogenes was reduced by 1.8 and 1.9 log10 CFU/cm2 by Protecta One and Protecta Two, respectively; Salmonella Typhimurium was not reduced &gt;0.3 log10 CFU/cm2 by either extract by day 7. In the second experiment, 2.5% Protecta Two (wt/vol or wt/wt) added to inoculated lean and adipose beef trim, processed, and packaged as ground beef chubs (80% lean, 20% adipose), did not reduce pathogen populations &gt;0.5 log10 CFU/g up to 14 days at 4°C. In the third experiment, surface spray treatments of beef with 2.5% lactic acid or 2.5% solutions of Protecta One or Protecta Two, vacuum packaged, and stored up to 35 days at 4°C did reduce E. coli O157:H7, L. monocytogenes, and Salmonella Typhimurium slightly. These studies suggest that the use of herb extracts may afford some reductions of pathogens on beef surfaces; however, the antimicrobial activity may be diminished in ground beef by adipose components.

scholarly journals PSIV-11 Effects of very low-dose antibiotics on gene expression profiles in ileal mucosa of weaned pigs infected with a pathogenic E. coli

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 286-286
Author(s):  
Kwangwook Kim ◽  
Sungbong Jang ◽  
Yanhong Liu
Keyword(s):  
Gene Expression ◽  
Systemic Inflammation ◽  
Low Dose ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Post Inoculation ◽  
Growth Promoter ◽  
Weaned Pigs ◽  
Ileal Mucosa ◽  
E Coli

Abstract Our previous studies have shown that supplementation of low-dose antibiotic growth promoter (AGP) exacerbated growth performance and systemic inflammation of weaned pigs infected with pathogenic Escherichia coli (E. coli). The objective of this experiment, which is extension of our previous report, was to investigate the effect of low-dose AGP on gene expression in ileal mucosa of weaned pigs experimentally infected with F18 E. coli. Thirty-four pigs (6.88 ± 1.03 kg BW) were individually housed in disease containment rooms and randomly allotted to one of three treatments (9 to 13 pigs/treatment). The three dietary treatments were control diet (control), and 2 additional diets supplemented with 0.5 or 50 mg/kg of AGP (carbadox), respectively. The experiment lasted 18 d [7 d before and 11 d after first inoculation (d 0)]. The F18 E. coli inoculum was orally provided to all pigs with the dose of 1010 cfu/3 mL for 3 consecutive days. Total RNA [4 to 6 pigs/treatment on d 5; 5 to 7 pigs/treatment on 11 post-inoculation (PI)] was extracted from ileal mucosa to analyze gene expression profiles by Batch-Tag-Seq. The modulated differential gene expression were defined by 1.5-fold difference and a cutoff of P &lt; 0.05 using limma-voom package. All processed data were statistically analyzed and evaluated by PANTHER classification system to determine the biological process function of genes in these lists. Compared to control, supplementation of recommended-dose AGP down-regulated genes related to inflammatory responses on d 5 and 11 PI; whereas, feeding low-dose AGP up-regulated genes associated with negative regulation of metabolic process on d 5, but down-regulated the genes related to immune responses on d 11 PI. The present observations support adverse effects of low-dose AGP in our previous study, indicated by exacerbated the detrimental effects of E. coli infection on pigs’ growth rate, diarrhea and systemic inflammation.

scholarly journals Lessons from a large outbreak of Escherichia coli O157[ratio ]H7 infections: insights into the infectious dose and method of widespread contamination of hamburger patties

1999 ◽  
Vol 122 (2) ◽  
pp. 185-192 ◽  
Author(s):  
J. TUTTLE ◽  
T. GOMEZ ◽  
M. P. DOYLE ◽  
J. G. WELLS ◽  
T. ZHAO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ground Beef ◽  
Most Probable Number ◽  
Strong Argument ◽  
Probable Number ◽  
Infectious Dose ◽  
E Coli ◽  
Beef Patties ◽  
Large Outbreak ◽  
Microbiological Testing

Between November 1992 and February 1993, a large outbreak of Escherichia coli O157[ratio ]H7 infections occurred in the western USA and was associated with eating ground beef patties at restaurants of one fast-food chain. Restaurants that were epidemiologically linked with cases served patties produced on two consecutive dates; cultures of recalled ground beef patties produced on those dates yielded E. coli O157[ratio ]H7 strains indistinguishable from those isolated from patients, confirming the vehicle of illness. Seventy-six ground beef patty samples were cultured quantitatively for E. coli O157[ratio ]H7. The median most probable number of organisms was 1·5 per gram (range, <0·3–15) or 67·5 organisms per patty (range, <13·5–675). Correlation of the presence of E. coli O157[ratio ]H7 with other bacterial indicators yielded a significant association between coliform count and the presence of E. coli O157[ratio ]H7 (P=0·04). A meat traceback to investigate possible sources of contamination revealed cattle were probably initially colonized with E. coli O157[ratio ]H7, and that their slaughter caused surface contamination of meat, which once combined with meat from other sources, resulted in a large number of contaminated ground beef patties. Microbiological testing of meat from lots consumed by persons who became ill was suggestive of an infectious dose for E. coli O157[ratio ]H7 of fewer than 700 organisms. These findings present a strong argument for enforcing zero tolerance for this organism in processed food and for markedly decreasing contamination of raw ground beef. Process controls that incorporate microbiological testing of meat may assist these efforts.

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