Radiosensitization of Escherichia coli and Salmonella Typhi in Ground Beef

2004 ◽  
Vol 67 (6) ◽  
pp. 1157-1162 ◽  
Author(s):  
F. CHIASSON ◽  
J. BORSA ◽  
B. OUATTARA ◽  
M. LACROIX
Keyword(s):  
Escherichia Coli ◽  
Ascorbic Acid ◽  
Pathogenic Bacteria ◽  
Ground Beef ◽  
Relative Sensitivity ◽  
Salmonella Typhi ◽  
Modified Atmosphere ◽  
Tetrasodium Pyrophosphate ◽  
E Coli

The radiosensitization of two pathogenic bacteria, Escherichia coli and Salmonella Typhi, was evaluated in the presence of thyme and its principal essential oil constituents (carvacrol and thymol) in ground beef. Ground beef was inoculated with E. coli or Salmonella Typhi (105 CFU/g), and each compound was added separately at various concentrations (0 to 3.5%, wt/wt). The antimicrobial potential of carvacrol, thymol, and thyme was evaluated in unirradiated meat by determining the MIC in percentage (wt/wt) after 24 h of storage at 4 ± 1°C. Results showed a MIC of 0.88 ± 0.12%, 1.14 ± 0.05%, and 2.33 ± 0.32% for E. coli in the presence of carvacrol, thymol, and thyme, respectively. MICs of 1.15 ± 0.02%, 1.60 ± 0.01%, and 2.75 ± 0.17% were observed for Salmonella Typhi in the presence of the same compounds, respectively. The best antimicrobial compound (i.e., carvacrol) was selected and added to the sterilized ground beef along with ascorbic acid (0.5%, wt/wt) and tetrasodium pyrophosphate (0.1%, wt/wt). Meat samples (10 g) were packed in air and then irradiated in a 60Co irradiator at doses of 0 to 0.7 kGy for the determination of E. coli radiation D10 and 0 to 2.25 kGy for the determination of Salmonella Typhi radiation D10. Addition of carvacrol increased the relative sensitivity of both bacteria 2.2 times. The radiation D10 was reduced from 0.126 ± 0.0039 to 0.057 ± 0.0015 kGy for E. coli and from 0.519 ± 0.0308 to 0.235 ± 0.0158 kGy for Salmonella Typhi. The addition of tetrasodium pyrophosphate did not affect significantly (P > 0.05) the radiosensitization of either bacterium. However, the presence of ascorbic acid in the media reduced significantly (P ≤ 0.05) the radiosensitivity of both bacteria. An additive effect of carvacrol addition and packaging under modified atmosphere conditions (60% O2–30% CO2–10% N2) was also observed on bacterial radiosensitization at 4°C. Compared with the control packed under air, modified atmosphere packaging conditions in the presence of carvacrol and tetrasodium pyrophosphate improved the relative sensitivity of E. coli by 2.7 times and Salmonella Typhi by 9.9 times.

Effect of Selected Plant Essential Oils or Their Constituents and Modified Atmosphere Packaging on the Radiosensitivity of Escherichia coli O157:H7 and Salmonella Typhi in Ground Beef

2008 ◽  
Vol 71 (3) ◽  
pp. 516-521 ◽  
Author(s):  
M. TURGIS ◽  
J. BORSA ◽  
M. MILLETTE ◽  
S. SALMIERI ◽  
M. LACROIX
Keyword(s):  
Escherichia Coli ◽  
Essential Oils ◽  
Modified Atmosphere Packaging ◽  
Ground Beef ◽  
Radiation Sensitivity ◽  
Salmonella Typhi ◽  
Modified Atmosphere ◽  
Plant Essential Oils ◽  
E Coli

Twenty-six different essential oils were tested for their efficiency to increase the relative radiosensitivity of Escherichia coli and Salmonella Typhi in medium-fat ground beef (23% fat). Ground beef was inoculated with E. coli O157:H7 or Salmonella (106 CFU/g), and each essential oil or one of their main constituents was added separately at a concentration of 0.5% (wt/wt). Meat samples (10 g) were packed under air or under modified atmosphere and irradiated at doses from 0 to 1 kGy for the determination of the D10-value of E. coli O157:H7, and from 0 to 1.75 kGy for the determination of the D10-value of Salmonella Typhi. Depending on the compound tested, the relative radiation sensitivity increased from 1 to 3.57 for E. coli O157:H7 and from 1 to 3.26 for Salmonella Typhi. Addition of essential oils or their constituents before irradiation also reduced the irradiation dose needed to eliminate both pathogens. In the presence of Chinese cinnamon or Spanish oregano essential oils, the minimum doses required to eliminate the bacteria were reduced from 1.2 to 0.35 and from 1.4 to 0.5 for E. coli O157:H7 and Salmonella Typhi, respectively. Cinnamon, oregano, and mustard essential oils were the most effective radiosensitizers.

Combined Effect of Carvacrol and Packaging Conditions on Radiosensitivity of Escherichia coli and Salmonella Typhi in Ground Beef

2005 ◽  
Vol 68 (12) ◽  
pp. 2567-2570 ◽  
Author(s):  
F. CHIASSON ◽  
J. BORSA ◽  
M. LACROIX
Keyword(s):  
Escherichia Coli ◽  
Modified Atmosphere Packaging ◽  
Ground Beef ◽  
Salmonella Typhi ◽  
Combined Effect ◽  
Modified Atmosphere ◽  
Tetrasodium Pyrophosphate ◽  
E Coli

This study was undertaken to evaluate the effect of 1.0% carvacrol and 0.1% tetrasodium pyrophosphate on the radiation D10 of Escherichia coli and Salmonella Typhi added to ground beef at a concentration of 105 CFU/g. The ground beef was then packaged under four different atmosphere conditions: air (78.1% N2, 20.9% O2, 0.036% CO2), 100% CO2, modified atmosphere (60% O2, 30% CO2, 10% N2) and vacuum. Samples were irradiated at doses of 0.1 to 0.6 kGy for E. coli and 0.5 to 2.0 kGy for Salmonella Typhi. Radiation D10-values of 0.126 and 0.526 kGy were observed for E. coli and Salmonella Typhi, respectively, when meat was packed under air. When meat was packed under modified atmosphere conditions, the radiation D10-values for E. coli and Salmonella Typhi were 0.086 and 0.221 kGy, respectively. The addition of carvacrol and tetrasodium pyrophosphate and the use of modified atmosphere packaging reduced the radiation D10-value from 0.126 to 0.046 kGy for E. coli and from 0.526 to 0.053 kGy for Salmonella Typhi. Under vacuum and 100% CO2 conditions, the radiation D10 reduction was not as great as that for the modified atmosphere regardless of the presence or absence of carvacrol and tetrasodium pyrophosphate.

scholarly journals Antibacterial Activity of Liverworts of Dumortiera hirsute (Sw.) Nees Ethyl Acetate Extract Against Pathogenic Bacteria

2021 ◽  
Vol 9 (2) ◽  
pp. 75
Author(s):  
Luthfiah Luthfiah ◽  
Dwi Setyati ◽  
Sattya Arimurti
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Ethyl Acetate ◽  
Pathogenic Bacteria ◽  
Ethyl Acetate Extract ◽  
Antibacterial Properties ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
E Coli ◽  
Agar Well Diffusion Method

Dumortiera hirsuta is one of the liverworts that can be used as a medicinal to prevent infection by pathogenic bacteria. The content of secondary metabolites of D. hirsuta has potential as antibacterial properties includes flavonoids, alkaloids and steroids. This research is to analyze the antibacterial activity of moss D. hirsuta against pathogenic bacteria that will be beneficial to humans. Liverworts of D. hirsuta were extracted using ethyl acetate solvent and tested against three types of pathogenic bacteria using the agar well-diffusion method. The results of this study indicated that the ethyl acetate extract of D. hirsuta at 100% concentration could inhibit the growth of Escherichia coli, Staphylococcus aureus, and Salmonella typhi bacteria. The range of antibacterial activity categories of the ethyl acetate extract of D. hirsuta to E. coli, S. aureus, and S. typhi between weak to moderate.

scholarly journals Characterization and Antimicrobial-Resistance Profile of Escherichia coli O157 and O157: H7 Isolated from Modified Atmosphere Packaged Meat Samples

2017 ◽  
Vol 5 (10) ◽  
pp. 1142
Author(s):  
Özgür Çadırcı ◽  
Ali Gücükoğlu ◽  
Göknur Terzi Güzel ◽  
Tolga Uyanık ◽  
Abdulaziz Abdulahi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Modified Atmosphere Packaging ◽  
Meat Products ◽  
Ground Beef ◽  
Inhibitory Effect ◽  
Modified Atmosphere ◽  
O157 Strain ◽  
E Coli ◽  
O157 Isolate ◽  
Meat Samples

Shiga-like toxin producing Escherichia coli is still an important public issue which causes extremely dangerous health problems. This study was planned in order to examine the inhibitory effect of Modified Atmosphere Packaging application on E. coli O157 and O157: H7. The purposes of the present study were to detect E. coli O157 and O157: H7 strains from ground and cubed beef. A total of 100 MAP cattle meat products (50 minced meat, 50 meat cubes) were collected from the markets and butchers in Samsun province between May and October 2013. According to results, 1(1/50-2%) E. coli O157 and 1(1/50-2%) E. coli O157: H7 strains isolated from 50 ground beef samples, while 1 (1/50-2%) E. coli O157 strain was identified from 50 cubed beef samples. It was determined that E. coli O157 isolate obtained from the MAP ground beef carried stx1, stx2 genes; E. coli O157: H7 isolate carried stx1, stx2, eaeA and hylA genes while E. coli O157 isolate obtained from the MAP cubed meat only carried the stx2 gene. In antibiogram test, both E. coli O157 isolates were resistant to streptomycin and one E. coli O157: H7 isolate was resistant to streptomycin, cephalothin and tetracycline. As a consequence; in order to protect public health, products should be kept in proper hygienic and technical conditions during sale and storage and use of uncontrolled antibiotics should be avoided.

Thermal Inactivation of Escherichia coli O157:H7 Isolated from Ground Beef and Bovine Feces, and Suitability of Media for Enumeration

1998 ◽  
Vol 61 (3) ◽  
pp. 285-289 ◽  
Author(s):  
M. ROCELLE S. CLAVERO ◽  
LARRY R. BEUCHAT ◽  
MICHAEL P. DOYLE
Keyword(s):  
Escherichia Coli ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Treatment Temperature ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Polyethylene Bags ◽  
D Values ◽  
Bovine Feces

Rates of thermal inactivation of five strains of Escherichia coli O157:H7 isolated from ground beef implicated in outbreaks of hemorrhagic colitis and five strains isolated from bovine feces were determined. Ground beef (22% fat, 10 g), inoculated with individual test strains at populations ranging from 6.85 to 7.40 log10 CFU g−1 of beef, was formed into patties (0.3 cm thick and 8.0 cm in diameter) and sealed in polyethylene bags. For each strain and treatment temperature (54.4, 58.9, 62.8, 65.6, or 68.3°C), 6 bags were simultaneously immersed into a recirculating water bath. Viable cells in patties heated for various lengths of time were enumerated by plating diluted samples on sorbitol MacConkey agar supplemented with 4-methylumbelliferyl-β-d-glucuronide (MSMA) and modified eosin methylene blue (MEMB) agar. Regardless of strain or treatment temperature, higher numbers of E. coli O157:H7 cells were generally recovered on MEMB agar than on MSMA, indicating the inferiority of MSMA as a recovery medium for quantitative determination of E. coli O157:H7 cells in heat-processed ground beef. Significantly (P ≤ 0.05) higher D values when enumeration was done using MEMB agar compared with MSMA. Mean D values for combined strain data at 54.4, 58.9, 62.8, and 65.6°C from cultures on MEMB agar were 123.90, 6.47, 0.62, and 0.20 min, respectively, whereas D values of 25.5, 5.21, 0.57, and 0.18 min were obtained at the same temperatures from cultures on MSMA. Results suggest that cooking ground beef patties to an internal temperature of 68.3°C for 40 s will inactivate at least 99.99% of E. coli O157:H7 cells; z values of 4.0 and 5.1°C were calculated from mean D values obtained from MEMB agar and MSMA, respectively, as recovery media. Differences in D values and z values existed among strains but rates of thermal inactivation do not appear to be correlated with the sources of the isolates.

Escherichia coli O157 in Ground Beef from Local Retail Markets in Pachuca, Mexico

2013 ◽  
Vol 76 (4) ◽  
pp. 680-684 ◽  
Author(s):  
CARLOS A. GÓMEZ-ALDAPA ◽  
CLAUDIO A. DÍZ-CRUZ ◽  
JORGE F. CERNA-CORTES ◽  
M. del REFUGIO TORRES-VITELA ◽  
ANGELICA VILLARRUEL-LÓPEZ ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Ground Beef ◽  
Culture Method ◽  
Escherichia Coli O157 ◽  
Simultaneous Application ◽  
Retail Markets ◽  
First Report ◽  
E Coli ◽  
Commercial Kits

Escherichia coli O157 strains have been recognized as pathogenic bacteria, of which raw beef is a known vehicle. An evaluation was done of the presence of E. coli O157 in ground beef from local retail markets in Pachuca, Hidalgo State, Mexico. A total of 120 ground beef samples (500 g) were tested for E. coli O157 by simultaneous application of the U.S. Department of Agriculture, Food Safety and Inspection Service (FSIS)'s Microbiology Laboratory Guidebook culture procedure 5.05, and two commercial kits, Reveal for E. coli O157:H7 and Visual Immunoprecipitate Assay (VIP) Gold for enterohemorrhagic E. coli. Two incubation times (8 and 20 h) were used with the commercial kits. Presence of stx1, stx2, and eaeA loci was determined by multiplex PCR. Of 360 subsamples (120 per procedure), 12 samples were found to be E. coli O157 positive by the FSIS culture method. With VIP, 73 subsamples were presumptive positive after 8 h of enrichment, and 60 were presumptive positive after 20 h of enrichment. Of these, only 6 (8 h) and 8 (20 h) subsamples were confirmed true positives with the FSIS method. With Reveal, 60 subsamples were presumptive positive after 8 h of enrichment and 50 were presumptive positive after 20 h of enrichment. Of these, only 6 (8 h) and 8 (20 h) subsamples were confirmed as true positives with the FSIS method. A total of 57 E. coli O157:H7 and 21 E. coli O157 strains were isolated. None of the O157 or O157:H7 strains had stx1 or stx2 loci, and only one had the eaeA locus. To our knowledge, this is the first report of the presence of E. coli O157 in commercial ground beef from Mexico, and the first report of isolation of a large number of stx-negative E. coli O157 and E. coli O157:H7 strains in Mexico.

scholarly journals Antibiotics, Acid and Heat Tolerance of Honey adapted Escherichia coli, Salmonella Typhi and Klebsiella pneumoniae

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 311 ◽  
Author(s):  
Rabia Ayub ◽  
Muhammad Umer ◽  
Abid Aslam Maan ◽  
Bilal Rasool ◽  
Muhammad Kashif Iqbal Khan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Pathogenic Bacteria ◽  
Salmonella Typhi ◽  
Low Ph ◽  
Cross Resistance ◽  
Ziziphus Mauritiana ◽  
Continuous Exposure ◽  
E Coli ◽  
The Impact

The medicinal importance of honey has been known for many decades due to its antimicrobial properties against life-threatening bacteria. However, previous studies revealed that microorganisms are able to develop adaptations after continuous exposure to antimicrobial compounds. The present study was conducted to explore the impact of subinhibitory concentrations of branded honey (Marhaba) and unbranded honey (extracted from Ziziphus mauritiana plant) locally available in Pakistan on Escherichia coli ATCC 10536, Salmonella Typhi and Klebsiella pneumoniae by investigating the development of self- or cross-resistance to antibiotics (gentamicin, kanamycin and imipenem). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of autoclaved honeys were determined. The bacterial cells of E. coli ATCC 10536, S. Typhi and K. pneumoniae were subjected to honey adaptation by exposing to ¼ × MIC (4 passages) and ½ × MIC (4 passages) of both honeys. Moreover, tolerance to low pH and high temperature was also studied in adapted and unadapted cells. The decreasing trend in growth pattern (OD600nm) of E. coli ATCC 10536, S. Typhi and K. pneumoniae was observed with increases in the concentration of honeys (6.25–50% v/v) respectively. Our results showed that continuous exposure of both honeys did not lead to the development of any self- or cross-resistance in tested bacteria. However, percent survival to low pH was found to be significantly higher in adapted cells as compared to unadapted cells. The results indicate that both branded honey (Marhaba) and unbranded honey (extracted from Ziziphus mauritiana plant) were effective in controlling the growth of tested pathogenic bacteria. However, the emergence of tolerance to adverse conditions (pH 2.5, temperature 60 °C) deserves further investigation before proposing honey as a better antibacterial agent in food fabrication/processing, where low pH and high temperatures are usually implemented.

Effects of Vacuum or Modified Atmosphere Packaging in Combination with Irradiation for Control of Escherichia coli O157:H7 in Ground Beef Patties

2011 ◽  
Vol 74 (12) ◽  
pp. 2018-2023 ◽  
Author(s):  
LI L. KUDRA ◽  
JOSEPH G. SEBRANEK ◽  
JAMES S. DICKSON ◽  
AUBREY F. MENDONCA ◽  
ELAINE M. LARSON ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Modified Atmosphere Packaging ◽  
Ground Beef ◽  
Vacuum Packaging ◽  
Modified Atmosphere ◽  
Escherichia Coli O157 ◽  
Refrigerated Storage ◽  
High Co2 ◽  
E Coli ◽  
Beef Patties

The efficacy of controlling Escherichia coli O157:H7 in ground beef patties by combining irradiation with vacuum packaging or modified atmosphere packaging (MAP) was investigated. Fresh ground beef patties were inoculated with a five-strain cocktail of E. coli O157:H7 at 5 log CFU/g. Single patties, packaged with vacuum or high-CO2 MAP (99.6% CO2 plus 0.4% CO), were irradiated at 0 (control), 0.5, 1.0, or 1.5 kGy. The D10-value for this pathogen was 0.47 ± 0.02 kGy in vacuum and 0.50 ± 0.02 kGy in MAP packaging. Irradiation with 1.5 kGy reduced E. coli O157:H7 by 3.0 to 3.3 log, while 0.5 and 1.0 kGy achieved reductions of 0.7 to 1.0, and 2.0 to 2.2 log, respectively. After irradiation, the numbers of survivors of this pathogen on beef patties in refrigerated storage (4°C) did not change significantly for 6 weeks. Temperature abuse (at 25°C) resulted in growth in vacuum-packaged patties treated with 0.5 and 1.5 kGy, but no growth in MAP packages. This study demonstrated that combining irradiation with MAP was similar in effectiveness to irradiation with vacuum packaging for control of E. coli O157:H7 in ground beef patties during refrigerated storage. However, high-CO2 MAP appeared to be more effective after temperature abuse.

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 >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 >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 >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.

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