Comparison of Antimicrobial Efficacy of Multiple Beef Hide Decontamination Strategies To Reduce Levels of Escherichia coli O157:H7 and Salmonella

2008 ◽  
Vol 71 (11) ◽  
pp. 2223-2227 ◽  
Author(s):  
BRANDON A. CARLSON ◽  
JOHN RUBY ◽  
GARY C. SMITH ◽  
JOHN N. SOFOS ◽  
GINA R. BELLINGER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Organic Material ◽  
Sodium Sulfide ◽  
Sodium Metasilicate ◽  
Antimicrobial Efficacy ◽  
Escherichia Coli O157 ◽  
E Coli

This study involved a comparison of the antimicrobial efficacy of several beef hide decontamination interventions to identify those that more effectively reduced levels of Escherichia coli O157:H7 and Salmonella. Whole beef hides were inoculated with E. coli O157:H7 and Salmonella and decontaminated with sprays of solutions of acetic acid (AA; 10%, 55°C), lactic acid (LA; 10%, 55°C), sodium hydroxide (SH; 3%, 23°C), sodium metasilicate (SM; 4%, 23°C), or sodium hydroxide (1.5%), followed by high-pressure washing with chlorinated (0.02%) water (SHC; both applied at 23°C) or water (W; 23°C) or by deluging with solutions of potassium cyanate (PC; 2.4%, 30°C) or sodium sulfide (SS; 6.2%, 30°C). All spraying treatments (AA, LA, SH, SM, and SHC) resulted in removal of visual organic material, whereas the dehairing treatments (PC and SS) successfully removed hair along with visual organic material. The PC, SS, and SHC treatments resulted in the greatest reductions of E. coli O157:H7 (P < 0.05), by 5.1, 4.8, and 5.0 log CFU/cm2, respectively. The SS and SHC treatments decreased Salmonella by 4.2 and 4.4 log CFU/cm2, respectively, compared with the water treatment, which reduced levels by 1.7 log CFU/cm2 (P < 0.05). The SH, AA, and LA treatments also lowered both E. coli O157:H7 and Salmonella by at least 2.0 log CFU/cm2. The treatments that were effective in this study deserve further consideration for commercial implementation as hide decontamination interventions.

Viability of Acid-Adapted Escherichia coli O157:H7 in Ground Beef Treated with Acidic Calcium Sulfate

2004 ◽  
Vol 67 (3) ◽  
pp. 591-595 ◽  
Author(s):  
LARRY R. BEUCHAT ◽  
ALAN J. SCOUTEN
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Calcium Sulfate ◽  
Ground Beef ◽  
Storage Period ◽  
Acid Tolerance ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Acidic Environments ◽  
Subsequent Acid

The effects of lactic acid, acetic acid, and acidic calcium sulfate (ACS) on viability and subsequent acid tolerance of three strains of Escherichia coli O157:H7 were determined. Differences in tolerance to acidic environments were observed among strains, but the level of tolerance was not affected by the acidulant to which cells had been exposed. Cells of E. coli O157:H7 adapted to grow on tryptic soy agar acidified to pH 4.5 with ACS were compared to cells grown at pH 7.2 in the absence of ACS for their ability to survive after inoculation into ground beef treated with ACS, as well as untreated beef. The number of ACS-adapted cells recovered from ACS-treated beef was significantly (α = 0.05) higher than the number of control cells recovered from ACS-treated beef during the first 3 days of a 10-day storage period at 4°C, suggesting that ACS-adapted cells might be initially more tolerant than unadapted cells to reduced pH in ACS-treated beef. Regardless of treatment of ground beef with ACS or adaptation of E. coli O157:H7 to ACS before inoculating ground beef, the pathogen survived in high numbers.

Efficacy of Selected Acidulants in Pureed Green Beans Inoculated with Pathogens (Escherichia coli O157:H7 and Listeria monocytogenes)

2006 ◽  
Vol 69 (8) ◽  
pp. 1865-1869 ◽  
Author(s):  
AAKASH KHURANA ◽  
GEORGE B. AWUAH ◽  
BRADLEY TAYLOR ◽  
ELENA ENACHE
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Titratable Acidity ◽  
Combined Effect ◽  
Escherichia Coli O157 ◽  
Green Beans ◽  
E Coli ◽  
Acid Ph ◽  
D Values

Studies were conducted to evaluate the combined effect of selected acidulants (acetic, citric, malic, and phosphoric acid) and heat on foodborne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes) in pureed green beans. To establish a consistent reference point for comparison, the molar concentrations of the acids remained constant while the acid-to-puree ratio, titratable acidity, and undissociated acid were either measured or calculated for a target acidified green beans at a pH of 3.8, 4.2, and 4.6. The D-values at 149°F were used as the criteria for acid efficacy. Generally, acetic acid (puree, pH 3.8 and 4.2) represented the most effective acid with comparatively low D-values irrespective of the target microorganism. A 10-s heating at 149°F inactivated approximately 106 CFU/ml of E. coli O157:H7 in pureed beans at pH 3.8. The efficacy of acetic acid is likely related to the elevated percent titratable acidity, undissociated acid, and acid-to-puree ratio. The effectiveness (which in this study represents the combined effect of acid and heat) of the remaining acids (citric, malic, and phosphoric) at puree pH values of 3.8 and 4.2 were statistically insignificant (α = 0.05). Surprisingly, acetic acid (puree, pH 4.6) appeared to be the least effective as compared to the other acids tested (citric, malic, and phosphoric) especially on E. coli O157:H7 cells, while L. monocytogenes had a similar resistance to all acids at puree pH 4.6. With the exception of citric acid (pH 3.8), acetic acid (pH 4.6), and malic acid (pH 3.8 and 4.6), which were statistically insignificant (P > 0.05), the D-values for L. monocytogenes were statistically different (P ≤ 0.05) and higher than the D-values for E. coli under similar experimental conditions. A conservative process recommendation (referred to as the “safe harbor” process) was found sufficient and applicable to pureed green beans for the pH range studied.

Efficacy of Chemical Treatments in Eliminating Salmonella and Escherichia coli O157:H7 on Scarified and Polished Alfalfa Seeds

2001 ◽  
Vol 64 (10) ◽  
pp. 1489-1495 ◽  
Author(s):  
SARAH L. HOLLIDAY ◽  
ALAN J. SCOUTEN ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Chemical Treatment ◽  
Organic Material ◽  
Pathogenic Bacteria ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Mechanical Abrasion ◽  
Chemical Treatments ◽  
The Impact ◽  
Alfalfa Seeds

Alfalfa seeds are sometimes subjected to a scarification treatment to enhance water uptake, which results in more rapid and uniform germination during sprout production. It has been hypothesized that this mechanical abrasion treatment diminishes the efficacy of chemical treatments used to kill or remove pathogenic bacteria from seeds. A study was done to compare the effectiveness of chlorine (20,000 ppm), H2O2 (8%), Ca(OH)2 (1%), Ca(OH)2 (1%) plus Tween 80 (1%), and Ca(OH)2 (1%) plus Span 20 (1%) treatments in killing Salmonella and Escherichia coli O157:H7 inoculated onto control, scarified, and polished alfalfa seeds obtained from two suppliers. The influence of the presence of organic material in the inoculum carrier on the efficacy of sanitizers was investigated. Overall, treatment with 1% Ca(OH)2 was the most effective in reducing populations of the pathogens. Reduction in populations of pathogens on seeds obtained from supplier 1 indicate that chemical treatments are less efficacious in eliminating the pathogens on scarified seeds compared to control seeds. However, the effectiveness of chemical treatment in removing Salmonella and E. coli O157:H7 from seeds obtained from supplier 2 was not markedly affected by scarification or polishing. The presence of organic material in the inoculum carrier did not have a marked influence on the efficacy of chemicals in reducing populations of test pathogens. Additional lots of control, scarified, and polished alfalfa seeds of additional varieties need to be tested before conclusions can be drawn concerning the impact of mechanical abrasion on the efficacy of chemical treatment in removing or killing Salmonella and E. coli O157:H7.

Determination of 5-Log Reduction Times for Escherichia coli O157:H7, Salmonella enterica, or Listeria monocytogenes in Acidified Foods with pH 3.5 or 3.8†

2013 ◽  
Vol 76 (7) ◽  
pp. 1245-1249 ◽  
Author(s):  
F. BREIDT ◽  
K. KAY ◽  
J. COOK ◽  
J. OSBORNE ◽  
B. INGHAM ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Benzoic Acid ◽  
Salmonella Enterica ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction ◽  
Acidified Foods

A critical factor in ensuring the safety of acidified foods is the establishment of a thermal process that assures the destruction of acid-resistant vegetative pathogenic and spoilage bacteria. For acidified foods such as dressings and mayonnaises with pH values of 3.5 or higher, the high water phase acidity (acetic acid of 1.5 to 2.5% or higher) can contribute to lethality, but there is a lack of data showing how the use of common ingredients such as acetic acid and preservatives, alone or in combination, can result in a 5-log reduction for strains of Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in the absence of a postpackaging pasteurization step. In this study, we determined the times needed at 10°C to achieve a 5-log reduction of E. coli O157:H7, S. enterica, and L. monocytogenes in pickling brines with a variety of acetic and benzoic acid combinations at pH 3.5 and 3.8. Evaluation of 15 different acid-pH combinations confirmed that strains of E. coli O157:H7 were significantly more acid resistant than strains of S. enterica and L. monocytogenes. Among the acid conditions tested, holding times of 4 days or less could achieve a 5-log reduction for vegetative pathogens at pH 3.5 with 2.5% acetic acid or at pH 3.8 with 2.5% acetic acid containing 0.1% benzoic acid. These data indicate the efficacy of benzoic acid for reducing the time necessary to achieve a 5-log reduction in target pathogens and may be useful for supporting process filings and the determination of critical controls for the manufacture of acidified foods.

Factors Influencing Attachment of Escherichia coli O157:H7 to Beef Tissues and Removal Using Selected Sanitizing Rinses‡

1996 ◽  
Vol 59 (5) ◽  
pp. 453-459 ◽  
Author(s):  
PINA M. FRATAMICO ◽  
FRANKIE J. SCHULTZ ◽  
ROBERT C. BENEDICT ◽  
ROBERT L. BUCHANAN ◽  
PETER H. COOKE
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Surface Structures ◽  
Escherichia Coli O157 ◽  
Adipose Tissues ◽  
E Coli ◽  
Factors Influencing ◽  
Significant Difference ◽  
Phosphate Buffered Saline ◽  
Scanning Electron

Attachment of E. coli O157:H7 and E. coli K12 to beef tenderloin filet, chuck, and adipose tissues was studied. Most attachment occurred within 1 min of incubation; the number of attached organisms depended on the concentration of bacteria in the liquid inoculum. Similar levels of E. coli bound to the three types of beef tissues tested. E. coli O157:H7 was heavily piliated; however, there was no significant difference between levels of bound E. coli O157:H7 and E. coli K12, indicating that these surface structures apparently are not involved in attachment. Scanning electron photomicrographs of meat tissue and of purified collagen suggested that bacteria attached primarily to collagen fibers. Rinsing solutions consisting of 10% trisodium phosphate (TSP), 2% acetic acid (HAc), phosphate-buffered saline (PBS) and combinations of each were tested for effectiveness in reducing the number of attached E. coli. The level of bacteria removed from tenderloin tissue following TSP, HAc, or PBS rinses did not differ considerably. When beef tissues were stored at 4°C for 18 h after the various rinse combinations, TSP rinse treatments reduced the levels of E. coli K12 and O157:H7 attached to adipose tissue up to 3.4 and 2.7 log units, respectively, compared to PBS rinse treatments. Therefore, TSP may be effective for reducing populations of E. coli O157:H7 on beef carcass tissue.

Inactivation of Escherichia coli O157:H7 in Ground Beef by Single-Cycle and Multiple-Cycle High-Pressure Treatments

2008 ◽  
Vol 71 (4) ◽  
pp. 811-815 ◽  
Author(s):  
PILAR MORALES ◽  
JAVIER CALZADA ◽  
MARTA ÁVILA ◽  
MANUEL NUÑEZ
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Shear Force ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Single Cycle ◽  
E Coli ◽  
Beef Patties ◽  
Texture Parameters ◽  
Multiple Cycle

The effect of single- and multiple-cycle high-pressure treatments on the survival of Escherichia coli CECT 4972, a strain belonging to the O157:H7 serotype, in ground beef was investigated. Beef patties were inoculated with 107 CFU/g E. coli O157:H7, and held at 4°C for 20 h before high-pressure treatments. Reduction of the E. coli O157:H7 population by single-cycle treatments at 400 MPa and 12°C ranged from 0.82 log CFU/g for a 1-min cycle to 4.39 log CFU/g for a 20-min cycle. Multiple-cycle treatments were very effective, with four 1-min cycles at 400 MPa and 12°C reducing the E. coli O157:H7 population by 4.38 log CFU/g, and three 5-min cycles by 4.96 log CFU/g. The color parameter L* increased significantly with high-pressure treatments in the interior and the exterior of beef patties, whereas a* decreased in the interior, and b* increased in the exterior—changes that might diminish consumer acceptance of the product. Kramer shear force and energy were generally higher in pressurized than in control ground beef. Maximum values for these texture parameters, which corresponded to tougher patties, were reached after one 10-min cycle in the case of single-cycle treatments or two 5-min cycles in the case of multiple-cycle treatments. High-pressure treatments had no significant effect on Warner-Bratzler shear force.

Escherichia coli O157:H7 Strains Isolated from Environmental Sources Differ Significantly in Acetic Acid Resistance Compared with Human Outbreak Strains†‡

2009 ◽  
Vol 72 (3) ◽  
pp. 503-509 ◽  
Author(s):  
DEOG-HWAN OH ◽  
YOUWEN PAN ◽  
ELAINE BERRY ◽  
MICHAEL COOLEY ◽  
ROBERT MANDRELL ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Acetic Acid Solution ◽  
Acid Resistance ◽  
Escherichia Coli O157 ◽  
Limited Information ◽  
E Coli ◽  
Log Reduction ◽  
Acetic Acid Resistance ◽  
Acidified Foods

A number of studies on the influence of acid on Escherichia coli O157:H7 have shown considerable strain differences, but limited information has been reported to compare the acid resistance based on the different sources of E. coli O157:H7 isolates. The purpose of this study was to determine the survival of E. coli O157:H7 strains isolated from five sources (foods, bovine carcasses, bovine feces, water, and human) in 400 mM acetic acid solutions under conditions that are typical of acidified foods. The isolates from bovine carcasses, feces, and water survived acetic acid treatment at pH 3.3 and 30°C significantly (P ≤ 0.05) better than did any food or human isolates. However, resistance to acetic acid significantly increased as temperature decreased to 15°C for a given pH, with little (P ≥ 0.05) difference among the different isolation sources. All groups of E. coli O157:H7 strains showed more than 1.8- to 4.5-log reduction at pH 3.3 and 30°C after 25 min. Significantly reduced (less than 1-log reduction) lethality for all E. coli O157:H7 strain mixtures was observed when pH increased to 3.7 or 4.3, with little difference in acetic acid resistance among the groups. The addition of glutamate to the acetic acid solution or anaerobic incubation provided the best protection compared with the above conditions for all groups of isolates. These results suggest that temperature, pH, and atmospheric conditions are key factors in establishing strategies for improving the safety of acidified foods.

Combined Effects of Mustard Flour, Acetic Acid, and Salt against Esherichia coli O157:H7 Stored at 5 and 22° C

2002 ◽  
Vol 65 (10) ◽  
pp. 1632-1636 ◽  
Author(s):  
MIN-SUK RHEE ◽  
RICHARD H. DOUGHERTY ◽  
DONG-HYUN KANG
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Sodium Chloride ◽  
Detection Limit ◽  
Additive Effect ◽  
Escherichia Coli O157 ◽  
Combined Effects ◽  
E Coli ◽  
Esherichia Coli

The combined effects of acetic acid and mustard flour were investigated to ascertain their impact on Escherichia coli O157:H7 stored at 5 and 22°C. Samples were prepared with various concentrations of acetic acid (0, 0.25, 0.5, 0.75, and 1% [vol/vol]) combined with 10% (wt/vol) Baltimore or Coleman mustard flour and 2% (fixed; wt/vol) sodium chloride. An acid-adapted mixture of three E. coli O157:H7 strains (106 to 107 CFU/ml) was inoculated into prepared mustard samples that were stored at 5 and 22°C, and samples were assayed periodically for the survival of E. coli O157:H7. The numbers of E. coli O157:H7 were reduced much more rapidly at 22°C than at 5°C. E. coli O157:H7 was rapidly reduced to below the detection limit (<0.3 log10 CFU/ml) after 1 day at 22°C, whereas it survived for up to 5 days at 5°C. There was no synergistic or additive effect with regard to the killing of E. coli O157:H7 with the addition of small amounts of acetic acid to the mustard flour. When stored at 5°C, mustard in combination with 0.25 (M-0.25), 0.5 (M-0.5), and 0.75% (M-0.75) acetic acid exerted less antimicrobial activity than the control (M-0). The order of lethality at 5°C was generally M-0.25 = M-0.5 < M-0.75 = M-0 < M-1. The addition of small amounts of acetic acid (<0.75%) to mustard retards the reduction of E. coli O157:H7. Statistical reduction in populations of E. coli O157:H7 (P < 0.05) was enhanced relative to that of the control (mustard alone) only with the addition of 1% acetic acid. This information may help mustard manufacturers to understand the antimicrobial activity associated with use of mustard flour in combination with acetic acid.

Efficacy of Chemical Interventions against Escherichia coli O157:H7 and Multidrug-Resistant and Antibiotic-Susceptible Salmonella on Inoculated Beef Trimmings

2012 ◽  
Vol 75 (11) ◽  
pp. 1960-1967 ◽  
Author(s):  
IFIGENIA GEORNARAS ◽  
HUA YANG ◽  
GALATIOS MOSCHONAS ◽  
MATTHEW C. NUNNELLY ◽  
KEITH E. BELK ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Chemical Treatment ◽  
Sodium Metasilicate ◽  
Multidrug Resistant ◽  
Antimicrobial Treatment ◽  
Sodium Chlorite ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Salmonella Newport

Studies were conducted to compare the decontamination efficacy of six chemical treatments against Escherichia coli O157:H7 and multidrug-resistant and antibiotic-susceptible Salmonella inoculated on beef trimmings. The inocula, comprising four-strain mixtures of rifampin-resistant E. coli O157:H7 and antibiotic-susceptible or multidrug-resistant (MDR and/or MDR-AmpC) Salmonella Newport and Salmonella Typhimurium, were inoculated (3 log CFU/cm2) separately onto samples (10 by 5 by 1 cm) derived from beef chuck rolls. Samples were left untreated (control), were immersed for 30 s in acidified sodium chlorite (0.1%, pH 2.5), peroxyacetic acid (0.02%, pH 3.8), sodium metasilicate (4%, pH 12.6), Bromitize Plus (0.0225% active bromine, pH 6.6), or AFTEC 3000 (pH 1.2), or were immersed for 5 s in SYNTRx 3300 (pH 1.0). Levels of surviving Salmonella on treated trimmings were not influenced by serotype or antibiotic resistance phenotype and were generally similar (P > 0.05) or lower (P < 0.05) than levels of surviving E. coli O157:H7 regardless of antimicrobial treatment. Overall, depending on chemical treatment (reductions within each chemical treatment were similar among all tested inocula), initial counts of E. coli O157:H7 (2.7 to 3.1 log CFU/cm2) were reduced (P < 0.05) by 0.2 to 1.4 log CFU/cm2. Similarly, initial counts of the tested Salmonella inocula (2.8 to 3.3 log CFU/cm2) were reduced (P < 0.05) by 0.4 to 1.4 (Salmonella Newport, antibiotic susceptible), 0.3 to 1.4 (Salmonella Newport, MDRAmpC), 0.2 to 1.5 (Salmonella Typhimurium, antibiotic susceptible), 0.4 to 1.3 (Salmonella Typhimurium, MDR), and 0.4 to 1.5 (Salmonella Typhimurium, MDR-AmpC) log CFU/cm2, depending on antimicrobial treatment. Reductions obtained with sodium metasilicate were 1.3 to 1.5 log CFU/cm2, regardless of inoculum, and reductions obtained with the five remaining antimicrobial treatments were 0.2 to 0.7 log CFU/cm2 (depending on treatment). Findings of this study should be useful to regulatory authorities and the meat industry as they consider Salmonella contamination on beef trimmings.

Sign in / Sign up

Export Citation Format

Share Document