scholarly journals Inactivation of Shiga Toxin-Producing Escherichia coli in Refrigerated and Frozen Meatballs Using High Pressure Processing

2020 ◽  
Vol 8 (3) ◽  
pp. 360
Author(s):  
Anna C. S. Porto-Fett ◽  
Armitra Jackson-Davis ◽  
Lamin S. Kassama ◽  
Marciauna Daniel ◽  
Michelle Oliver ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Shiga Toxin ◽  
Ground Beef ◽  
High Pressure Processing ◽  
Ground Meat ◽  
Pathogen Reduction ◽  
G Prior

High pressure processing (HPP) was evaluated to inactivate Shiga toxin-producing Escherichia coli (STEC) in raw meatballs. Ground meat (>90% lean) was inoculated (ca. 7.0 log CFU/g) with a rifampicin-resistant cocktail of eight STEC strains (O26:H11, O45:H2, O103:H2, O104:H4, O111:H-, O121:H19, O145:NM, and O157:H7). Inoculated ground beef, ground veal, or a mixture of ground beef, pork, and veal were separately mixed with liquid whole eggs and seasonings, shaped by hand into meatballs (40 g each), and stored at −20 or at 4 °C for at least 18 h. Samples were then exposed to 400 or 600 MPa for 0 to 18 min. There were no differences (p > 0.05) in pathogen reduction related to the species of meat used or for meatballs that were refrigerated (0.9 to 2.9 log CFU/g) compared to otherwise similar meatballs that were stored frozen (1.0 to 3.0 log CFU/g) prior to HPP treatment. However, less time was needed to achieve a ≥ 2.0 log CFU/g reduction at 600 MPa (1 to 3 min) compared to 400 MPa (at least 9 min). This work provides new and practically useful information on the use of HPP to inactivate STEC in raw meatballs.

Inactivation of Shiga Toxin–Producing Escherichia coli and Listeria monocytogenes within Plant versus Beef Burgers in Response to High Pressure Processing

2020 ◽  
Vol 83 (5) ◽  
pp. 865-873
Author(s):  
ANNA C. S. PORTO-FETT ◽  
LAURA E. SHANE ◽  
BRADLEY A. SHOYER ◽  
MANUELA OSORIA ◽  
YANGJIN JUNG ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Listeria Monocytogenes ◽  
Shiga Toxin ◽  
Ground Beef ◽  
High Pressure Processing ◽  
Empirical Observation ◽  
Beef Burger ◽  
Beef Burgers

ABSTRACT We evaluated high pressure processing to lower levels of Shiga toxin–producing Escherichia coli (STEC) and Listeria monocytogenes inoculated into samples of plant or beef burgers. Multistrain cocktails of STEC and L. monocytogenes were separately inoculated (∼7.0 log CFU/g) into plant burgers or ground beef. Refrigerated (i.e., 4°C) or frozen (i.e., −20°C) samples (25 g each) were subsequently exposed to 350 MPa for up to 9 or 18 min or 600 MPa for up to 4.5 or 12 min. When refrigerated plant or beef burger samples were treated at 350 MPa for up to 9 min, levels of STEC were reduced by ca. 0.7 to 1.3 log CFU/g. However, when refrigerated plant or beef burger samples were treated at 350 MPa for up to 9 min, levels of L. monocytogenes remained relatively unchanged (ca. ≤0.3-log CFU/g decrease) in plant burger samples but were reduced by ca. 0.3 to 2.0 log CFU/g in ground beef. When refrigerated plant or beef burger samples were treated at 600 MPa for up to 4.5 min, levels of STEC and L. monocytogenes were reduced by ca. 0.7 to 4.1 and ca. 0.3 to 5.6 log CFU/g, respectively. Similarly, when frozen plant and beef burger samples were treated at 350 MPa up to 18 min, reductions of ca. 1.7 to 3.6 and ca. 0.6 to 3.6 log CFU/g in STEC and L. monocytogenes numbers, respectively, were observed. Exposure of frozen plant or beef burger samples to 600 MPa for up to 12 min resulted in reductions of ca. 2.4 to 4.4 and ca. 1.8 to 3.4 log CFU/g in levels of STEC and L. monocytogenes, respectively. Via empirical observation, pressurization did not adversely affect the color of plant burger samples, whereas appreciable changes in color were observed in pressurized ground beef. These data confirm that time and pressure levels already validated for control of STEC and L. monocytogenes in ground beef will likely be equally effective toward these same pathogens in plant burgers without causing untoward effects on product color. HIGHLIGHTS

Inactivation of a diverse set of shiga toxin-producing Escherichia coli in ground beef by high pressure processing

2015 ◽  
Vol 52 ◽  
pp. 84-87 ◽  
Author(s):  
Shiowshuh Sheen ◽  
Jennifer Cassidy ◽  
Butch Scullen ◽  
Christopher Sommers
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Shiga Toxin ◽  
Ground Beef ◽  
High Pressure Processing

Use of Nonpathogenic Escherichia coli Surrogates as Predictors of the Survival of Nontyphoidal Salmonella, non-O157 Shiga Toxin–Producing Escherichia coli, and Escherichia coli O157 Populations after High Hydrostatic Pressure Processing

2018 ◽  
Vol 81 (7) ◽  
pp. 1068-1072 ◽  
Author(s):  
DALE R. WOERNER ◽  
IFIGENIA GEORNARAS ◽  
JENNIFER N. MARTIN ◽  
KEITH E. BELK ◽  
GARY R. ACUFF ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Shiga Toxin ◽  
Pathogenic Bacteria ◽  
Ground Beef ◽  
High Pressure Processing ◽  
Escherichia Coli O157 ◽  
Specific Level ◽  
E Coli ◽  
Pathogen Populations

ABSTRACT Validated surrogates are a useful tool for studying the response of pathogens to food safety interventions, but better surrogates are needed for studies using high pressure processing. Ground beef (85% lean, 15% fat) was inoculated separately with mixed cultures of Escherichia coli O157, non-O157 Shiga toxin–producing E. coli, nontyphoidal Salmonella, and nonpathogenic E. coli surrogate bacteria. The inoculated ground beef was subjected to high hydrostatic pressures of 200, 400, and 600 MPa for 4, 6, and 8 min at each pressure. High pressure processing at 200 MPa reduced the inoculated populations of the pathogenic bacteria by 0.9 to 1.8 log CFU/g, 400 MPa reduced the inoculated populations by 2.5 to 3.6 log CFU/g, and 600 MPa reduced the inoculated populations by 4.5 to 5.6 log CFU/g. The nonpathogenic E. coli surrogates were more resistant to the effects of high pressure processing than were the inoculated pathogen populations. This finding suggests that the nonpathogenic E. coli surrogates could be used as process control indicators for high pressure processing of ground beef to predict a specific level of pathogen reduction. The surviving populations of the potential surrogate bacteria were proportional to the surviving populations of the pathogenic bacteria. The models allow for an estimation of the potential surviving populations of the pathogenic bacteria based on quantitative results of the populations of the surrogate bacteria.

Effect of High Pressure Processing on the survival of Shiga Toxin-Producing Escherichia coli (Big Six vs. O157:H7) in ground beef

2015 ◽  
Vol 48 ◽  
pp. 1-7 ◽  
Author(s):  
HsinYun Hsu ◽  
Shiowshuh Sheen ◽  
Joseph Sites ◽  
Jennifer Cassidy ◽  
Butch Scullen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Shiga Toxin ◽  
Ground Beef ◽  
High Pressure Processing ◽  
Big Six

scholarly journals Optimization of Reverse Transcriptase PCR To Detect Viable Shiga-Toxin-Producing Escherichia coli

2002 ◽  
Vol 68 (2) ◽  
pp. 799-806 ◽  
Author(s):  
S. C. McIngvale ◽  
D. Elhanafi ◽  
M. A. Drake
Keyword(s):  
Escherichia Coli ◽  
Reverse Transcriptase ◽  
Shiga Toxin ◽  
Incubation Temperature ◽  
Ground Beef ◽  
Ground Meat ◽  
Rt Pcr ◽  
Initial Inoculum ◽  
Reverse Transcriptase Pcr ◽  
Mrna Targets

ABSTRACT The ability of reverse transcriptase PCR (RT-PCR) to detect viable Shiga-toxin-producing Escherichia coli (STEC) was investigated. Four primer sets, each targeting a specific region in the slt-II operon, were evaluated for their stringency and specificity for slt-II mRNA. STEC were evaluated for toxin expression under various conditions, including cell growth phase, growth medium, incubation temperature, and aeration. Following primer optimization, STEC were inoculated into Trypticase soy broth and cooked ground beef enrichments. Cells were harvested and RNA or DNA was extracted at 4, 8, 12, and 24 h. RT-PCR or PCR was conducted, and the products were visualized by gel electrophoresis and by Southern blots. mRNA targets were detected in 12-h cooked ground meat enrichments with an initial inoculum of 1 CFU/g. These results indicate that RT-PCR of E. coli slt-II mRNA is useful for detection of viable STEC in ground beef.

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