Effects of Simulated Dry and Wet Chilling and Aging of Beef Fat and Lean Tissues on the Reduction of Escherichia coli O157:H7 and Salmonella

2011 ◽  
Vol 74 (2) ◽  
pp. 289-293 ◽  
Author(s):  
A. W. TITTOR ◽  
M. G. TITTOR ◽  
M. M. BRASHEARS ◽  
J. C. BROOKS ◽  
A. J. GARMYN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Control Point ◽  
Tissue Type ◽  
Escherichia Coli O157 ◽  
Air Velocity ◽  
E Coli ◽  
Critical Control Point ◽  
Initial Reduction ◽  
Plate Counts ◽  
Antimicrobial Interventions

The efficacy of dry and wet chilling and aging of beef as methods for the reduction of Escherichia coli O157:H7 and Salmonella on lean and fat tissues was studied. Samples were obtained from a harvest facility prior to antimicrobial interventions and were inoculated with a cocktail mixture of E. coli O157:H7 or Salmonella to achieve a target inoculation of 6 log CFU/cm2. Wet chilled and aged samples were then suspended, sprayed (10°C) continuously for 15 min and then sprayed for 1 min every 17 min for 17 h, and vacuum packed after 48 h. Dry chilled and aged samples were suspended in refrigeration (3°C) with an air velocity of 0.25 m/s and a relative humidity of 80%. A large initial reduction of E. coli O157:H7 and Salmonella was observed, regardless of tissue type and chilling method. Fewer E. coli O157:H7 microorganisms were detected on wet chilled samples at 24 and 36 h; however, plate counts were higher from wet aged samples excised at 7 through 28 days. The final plate counts were 1.03 and 3.67 log CFU/cm2 for dry and wet aged samples, respectively. Fewer E. coli O157:H7 microorganisms were detected on fat samples from each sampling time, with the exception of 28 days, compared with lean samples. Similar trends were observed in the reduction of Salmonella for chilling or aging method and tissue type, resulting in final plate counts of 1.25 and 3.67 log CFU/cm2 for dry and wet aged samples, respectively. The findings reaffirmed wet or dry chilling and aging as potential interventions for small plants as a critical control point.

Validation of Time and Temperature Values as Critical Limits for the Control of Escherichia coli O157:H7 during the Production of Fresh Ground Beef

2006 ◽  
Vol 69 (8) ◽  
pp. 1978-1982 ◽  
Author(s):  
J. E. MANN ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Room Temperature ◽  
Hazard Analysis ◽  
Control Point ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Meat Processing ◽  
E Coli ◽  
Critical Control Point ◽  
Critical Limits

In order to provide beef processors with valuable data to validate critical limits set for temperature during grinding, a study was conducted to determine Escherichia coli O157:H7 growth at various temperatures in raw ground beef. Fresh ground beef samples were inoculated with a cocktail mixture of streptomycin-resistant E. coli O157:H7 to facilitate recovery in the presence of background flora. Samples were held at 4.4, 7.2, and 10°C, and at room temperature (22.2 to 23.3°C) to mimic typical processing and holding temperatures observed in meat processing environments. E. coli O157:H7 counts were determined by direct plating onto tryptic soy agar with streptomycin (1,000 μg/ml), at 2-h intervals over 12 h for samples held at room temperature. Samples held under refrigeration temperatures were sampled at 4, 8, 12, 24, 48, and 72 h. Less than one log of E. coli O157:H7 growth was observed at 48 h for samples held at 10°C. Samples held at 4.4 and 7.2°C showed less than one log of E. coli O157:H7 growth at 72 h. Samples held at room temperature showed no significant increase in E. coli O157:H7 counts for the first 6 h, but increased significantly afterwards. These results illustrate that meat processors can utilize a variety of time and temperature combinations as critical limits in their hazard analysis critical control point plans to minimize E. coli O157:H7 growth during the production and storage of ground beef.

Escherichia coli O157:H7 Prevalence in Fecal Samples of Cattle from a Southeastern Beef Cow-Calf Herd

2003 ◽  
Vol 66 (10) ◽  
pp. 1778-1782 ◽  
Author(s):  
D. G. RILEY ◽  
J. T. GRAY ◽  
G. H. LONERAGAN ◽  
K. S. BARLING ◽  
C. C. CHASE
Keyword(s):  
Escherichia Coli ◽  
Control Point ◽  
Foodborne Pathogen ◽  
Beef Cows ◽  
Escherichia Coli O157 ◽  
Fecal Samples ◽  
E Coli ◽  
Critical Control Point ◽  
Cow Calf ◽  
Culture Positive

The proportion of fecal samples culture-positive for Escherichia coli O157:H7 was determined for samples collected from 296 beef cows on pasture in a single Florida herd in October, November, and December 2001. The overall proportion of samples that cultured positive was 0.03. The proportion of cows that were culture-positive on at least one occasion was 0.091. No effect of pregnancy status or nutritional regimen on the proportion of culture-positive samples for E. coli O157:H7 was detected. We detected a breed effect on the shedding of E. coli O157, with Romosinuano cows having a lower (P < 0.01) proportion of samples culture-positive than Angus or Brahman cows. This difference might have resulted from the presence of confounding variables; however, it also might represent evidence of breed-to-breed genetic variation in E. coli O157 shedding. Further research is warranted to evaluate breed as a possible risk factor for shedding of this important foodborne pathogen. Further substantiated findings could indicate that breed is a cow-calf–level critical control point of E. coli O157:H7.

Evaluation of Lactic Acid as an Initial and Secondary Subprimal Intervention for Escherichia coli O157:H7, Non-O157 Shiga Toxin–Producing E. coli, and a Nonpathogenic E. coli Surrogate for E. coli O157:H7

2012 ◽  
Vol 75 (9) ◽  
pp. 1701-1708 ◽  
Author(s):  
C. I. PITTMAN ◽  
I. GEORNARAS ◽  
D. R. WOERNER ◽  
K. K. NIGHTINGALE ◽  
J. N. SOFOS ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Shiga Toxin ◽  
Hazard Analysis ◽  
Control Point ◽  
Escherichia Coli O157 ◽  
Meat Industry ◽  
Bacterial Reduction ◽  
E Coli ◽  
Critical Control Point

Lactic acid can reduce microbial contamination on beef carcass surfaces when used as a food safety intervention, but effectiveness when applied to the surface of chilled beef subprimal sections is not well documented. Studies characterizing bacterial reduction on subprimals after lactic acid treatment would be useful for validations of hazard analysis critical control point (HACCP) systems. The objective of this study was to validate initial use of lactic acid as a subprimal intervention during beef fabrication followed by a secondary application to vacuum-packaged product that was applied at industry operating parameters. Chilled beef subprimal sections (100 cm2) were either left uninoculated or were inoculated with 6 log CFU/cm2 of a 5-strain mixture of Escherichia coli O157:H7, a 12-strain mixture of non-O157 Shiga toxin–producing E. coli (STEC), or a 5-strain mixture of nonpathogenic (biotype I) E. coli that are considered surrogates for E. coli O157:H7. Uninoculated and inoculated subprimal sections received only an initial or an initial and a second “rework” application of lactic acid in a custom-built spray cabinet at 1 of 16 application parameters. After the initial spray, total inoculum counts were reduced from 6.0 log CFU/cm2 to 3.6, 4.4, and 4.4 log CFU/cm2 for the E. coli surrogates, E. coli O157:H7, and non-O157 STEC inoculation groups, respectively. After the second (rework) application, total inoculum counts were 2.6, 3.2, and 3.6 log CFU/cm2 for the E. coli surrogates, E. coli O157:H7, and non-O157 STEC inoculation groups, respectively. Both the initial and secondary lactic acid treatments effectively reduced counts of pathogenic and nonpathogenic strains of E. coli and natural microflora on beef subprimals. These data will be useful to the meat industry as part of the HACCP validation process.

Influence of Lactic Acid Bacteria on Survival of Escherichia coli O157:H7 in Inoculated Minas Cheese during Storage at 8.5°C

2001 ◽  
Vol 64 (8) ◽  
pp. 1151-1155 ◽  
Author(s):  
SUSANA M. I. SAAD ◽  
CÉZAR VANZIN ◽  
MARICÊ N. OLIVEIRA ◽  
BERNADETTE D. G. M. FRANCO
Keyword(s):  
Escherichia Coli ◽  
Hazard Analysis ◽  
Control Point ◽  
Raw Milk ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Critical Control Point ◽  
Plastic Bags ◽  
Test Kit ◽  
Sterile Plastic

Minas cheese is a typical Brazilian fresh cheese, manufactured by addition of rennin and CaCl2 to milk, followed by draining the curd. The intrinsic characteristics of this product make it favorable for growth of pathogens, including Escherichia coli O157:H7. The influence of the addition of a commercial mesophilic type O lactic culture to this product on the growth of this pathogen during storage at 8.5°C was evaluated. Eight different formulations of Minas cheese were manufactured using raw or pasteurized milk and with or without salt and lactic culture. Individual portions of each formulation were transferred to sterile plastic bags and inoculated with E. coli O157:H7 to yield ca. 103 or 106 CFU/g. After blending by hand massaging the bags, samples were stored at 8.5°C for up to 14 days. E. coli O157:H7 was counted after 1, 2, 7, and 14 days of storage using 3M Petrifilm Test Kit-HEC. Counts in samples without added lactic culture showed a 2-log increase in the first 24 h and remained constant during the following 14 days. Counts in samples with added lactic culture showed a 0.5-log increase in the first 24 h, followed by a decrease. These variations were statistically significant (P < 0.05). No significant variations (P > 0.05) were obtained for cheese samples manufactured with pasteurized or raw milk, with or without salt. Results indicate that the addition of type O lactic culture may be an additional safeguard to well-established good manufacturing practices and hazard analysis and critical control point programs in the control of growth of E. coli O157:H7 in Minas cheese.

Validation of Lactic Acid Bacteria, Lactic Acid, and Acidified Sodium Chlorite as Decontaminating Interventions To Control Escherichia coli O157:H7 and Salmonella Typhimurium DT 104 in Mechanically Tenderized and Brine-Enhanced (Nonintact) Beef at the Purveyor

2010 ◽  
Vol 73 (12) ◽  
pp. 2169-2179 ◽  
Author(s):  
ALEJANDRO ECHEVERRY ◽  
J. CHANCE BROOKS ◽  
MARKUS F. MILLER ◽  
JESSE A. COLLINS ◽  
GUY H. LONERAGAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Salmonella Typhimurium ◽  
Control Point ◽  
Meat Products ◽  
Sodium Chlorite ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Critical Control Point

After three different outbreaks were linked to the consumption of nonintact meat products contaminated with Escherichia coli O157:H7, the U.S. Food Safety and Inspection Service published notice requiring establishments producing mechanically tenderized and moisture-enhanced beef products to reassess their respective hazard analysis and critical control point systems, due to potential risk to the consumers. The objective of this study was to validate the use of lactic acid bacteria (LAB), acidified sodium chlorite (ASC), and lactic acid (LA) sprays when applied under a simulated purveyor setting as effective interventions to control and reduce E. coli O157:H7 and Salmonella Typhimurium DT 104 in inoculated U.S. Department of Agriculture (USDA) Choice strip loins (longissimus lumborum muscles) pieces intended for either mechanical blade tenderization or injection enhancement with a brine solution after an aging period of 14 or 21 days at 4.4°C under vacuum. After the mechanical process, translocation of E. coli O157:H7 and Salmonella Typhimurium DT 104 from the surface into the internal muscles occurred at levels between 1.00 and 5.72 log CFU/g, compared with controls. LAB and LA reduced internal E. coli O157:H7 loads up to 3.0 log, while ASC reduced the pathogen 1.4 to 2.3 log more than the control (P < 0.05), respectively. Salmonella Typhimurium DT 104 was also reduced internally 1.3 to 2.8, 1.0 to 2.3, and 1.4 to 1.8 log after application of LAB, LA, and ASC, respectively. The application of antimicrobials by purveyors prior to mechanical tenderization or enhancement of steaks should increase the safety of these types of products.

scholarly journals Concentration and Prevalence of Escherichia coli O157 in Cattle Feces at Slaughter

2003 ◽  
Vol 69 (5) ◽  
pp. 2444-2447 ◽  
Author(s):  
F. Omisakin ◽  
M. MacRae ◽  
I. D. Ogden ◽  
N. J. C. Strachan
Keyword(s):  
Escherichia Coli ◽  
Confidence Interval ◽  
Potential Risk ◽  
Prevalence Rate ◽  
Hazard Analysis ◽  
Control Point ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Critical Control Point ◽  
Cattle Feces

ABSTRACT The concentration and prevalence of Escherichia coli O157 in cattle feces at the time of slaughter was studied over a 9-week period from May to July 2002. Fecal samples (n = 589) were collected from the rectums of slaughtered cattle, and the animal-level prevalence rate was estimated to be 7.5% (95% confidence interval [CI], 5.4 to 9.6%) while the group prevalence was 40.4% (95% CI, 27.7 to 53.2%). Of the 44 infected animals detected, 9% were high shedders that contained E. coli O157 at concentrations of >104 CFU g−1. These 9% represented >96% of the total E. coli O157 produced by all animals tested. All isolates possessed the vt 2 gene, 39 had the eaeA gene, and a further five had the vt 1 gene also. The presence of high-shedding animals at the abattoir increases the potential risk of meat contamination during the slaughtering process and stresses the need for correctly implemented hazard analysis and critical control point procedures.

scholarly journals Escherichia coli O157 Prevalence and Enumeration of Aerobic Bacteria, Enterobacteriaceae, and Escherichia coli O157 at Various Steps in Commercial Beef Processing Plants†

2004 ◽  
Vol 67 (4) ◽  
pp. 658-665 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
XIANGWU NOU ◽  
STEVEN D. SHACKELFORD ◽  
TOMMY L. WHEELER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Aerobic Bacteria ◽  
Escherichia Coli O157 ◽  
Indicator Organisms ◽  
E Coli ◽  
Beef Processing ◽  
Processing Plants ◽  
Plate Counts ◽  
On Line ◽  
Antimicrobial Interventions

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.

Hazard Analysis of Escherichia coli O157:H7 Contamination during Beef Slaughtering in Calvados, France

2001 ◽  
Vol 64 (9) ◽  
pp. 1341-1345 ◽  
Author(s):  
R. GUYON ◽  
F. DOREY ◽  
J. P. MALAS ◽  
A. LECLERCQ
Keyword(s):  
Escherichia Coli ◽  
Critical Points ◽  
Hazard Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Control Point ◽  
Point System ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Critical Control Point ◽  
Beef Carcasses

To identify hazard points and critical points during beef slaughtering, which is a necessary first step toward developing a hazard analysis and critical control point system to control meat contamination by Escherichia coli O157:H7, samples (n = 192) from surfaces, work tops, worker's hands, and beef carcasses were collected from a slaughterhouse in Calvados, France. Five strains of E. coli O157:H7 were isolated from a footbridge and a worker's apron at the preevisceration post and from a worker's hand at the defatting post. Three isolates carried stx2c, eae, and EHEC-hlyA genes and showed similar molecular types by random amplified polymorphic DNA, polymerase chain reaction IS3, and XbaI pulsed-field gel electrophoresis. Thus, this study has shown that preevisceration and defatting post and associated worker's materials are critical points for carcasses contamination by E. coli O157:H7 during beef slaughtering.

Decontamination of Beef Subprimal Cuts Intended for Blade Tenderization or Moisture Enhancement

2007 ◽  
Vol 70 (5) ◽  
pp. 1174-1180 ◽  
Author(s):  
C. E. HELLER ◽  
J. A. SCANGA ◽  
J. N. SOFOS ◽  
K. E. BELK ◽  
W. WARREN-SERNA ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Hot Water ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Low Concentrations ◽  
Blade Tenderization ◽  
Antimicrobial Interventions

The prevalence of Escherichia coli O157:H7 on beef subprimal cuts intended for mechanical tenderization was evaluated. This evaluation was followed by the assessment of five antimicrobial interventions at minimizing the risk of transferring E. coli O157:H7 to the interior of inoculated subprimal cuts during blade tenderization (BT) or moisture enhancement (ME). Prevalence of E. coli O157:H7 on 1,014 uninoculated beef subprimals collected from six packing facilities was 0.2%. Outside round pieces inoculated with E. coli O157:H7 at 104 CFU/100 cm2 were treated with (i) no intervention, (ii) surface trimming, (iii) hot water (82°C), (iv) warm 2.5% lactic acid (55°C), (v) warm 5.0% lactic acid (55°C), or (vi) 2% activated lactoferrin followed by warm 5.0% lactic acid (55°C) and then submitted to BT or ME. Prevalence (n = 196) of internalized (BT and ME) E. coli O157:H7 was 99%. Enumeration of E. coli O157:H7 (n = 192) revealed mean surface reductions of 0.93 to 1.10 log CFU/100 cm2 for all antimicrobial interventions. E. coli O157:H7 was detected on 3 of the 76 internal BT samples and 73 of the 76 internal ME samples. Internal ME samples with no intervention had significantly higher mean E. coli O157:H7 populations than did those internal samples treated with an intervention, but there were no significant differences in E. coli O157:H7 populations among internal BT samples. Results of this study demonstrate that the incidence of E. coli O157:H7 on the surface of beef subprimal cuts is low and that interventions applied before mechanical tenderization can effectively reduce the transfer of low concentrations of E. coli O157:H7 to the interior of beef subprimal cuts.

Microbial Contamination of Carcasses, Meat, and Equipment from an Iberian Pork Cutting Plant

2004 ◽  
Vol 67 (8) ◽  
pp. 1624-1629 ◽  
Author(s):  
TERESA RIVAS PALÁ ◽  
ANA SEVILLA
Keyword(s):  
Microbial Contamination ◽  
Hazard Analysis ◽  
Control Point ◽  
E Coli ◽  
Critical Control Point ◽  
Plate Counts ◽  
Intensive Rearing ◽  
Meat Samples ◽  
Type 3 ◽  
Meat Type

An assessment and follow-up of the microbial contamination of an Iberian pork cutting room is presented. Samples were taken from carcasses (n = 76), meat pieces (three types, n = 71), meat for dry-cured sausages (3 types, n = 66), and surfaces of equipment (n = 158). Aerobic plate counts (APC) at 37°C on meat pieces (primal cuts) were lower than on carcasses (3.62 log CFU/10 cm2 against 4.63 log CFU/10 cm2), probably owing to the removal of the skin. However, more than 80% of the meat pieces showed presence of Escherichia coli. For the three types of meat intended for dry-cured sausages, higher counts (P < 0.001) were found for meat type 3—an important cut obtained from the vertebral column—at 2.62 log CFU/g for E. coli; the particular surface used in the handling of meat type 3 also showed high counts (P <0.001) for E. coli. Consequently, attention should be paid to the hazard analysis critical control point plan at this stage. Salmonella was isolated from 3.94% of the carcass surfaces (perianal zone), 4.46% of meat pieces, and 13.58% of meat for dry-cured sausages. Moreover, the percentages for isolation of Salmonella from carcasses of Iberian pigs (extensive rearing) in our study were lower than those generally reported in the literature for “white pigs” (intensive rearing). Coagulase-positive Staphylococcus aureus was isolated in 31.82% of meat samples for dry-cured sausages, in 16.90% of meat pieces, and in 15.50% of the equipment after 4 h of work. Of the coagulase-positive strains isolated, 47.61% were producers of enterotoxin.

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