Inactivation of Escherichia coli JM109, DH5α, and O157:H7 Suspended in Butterfield's Phosphate Buffer by Gamma Irradiation

2008 ◽  
Vol 73 (2) ◽  
pp. M87-M90 ◽  
Author(s):  
C.H. Sommers ◽  
K.T. Rajkowski
Keyword(s):  
Escherichia Coli ◽  
Gamma Irradiation ◽  
Phosphate Buffer ◽  
Escherichia Coli Jm109

Gamma Irradiation and Ozone Treatment for Inactivation of Escherichia coli O157:H7 in Culture Media

1998 ◽  
Vol 61 (6) ◽  
pp. 728-730 ◽  
Author(s):  
MYUNG-WOO BYUN ◽  
OH-JIN KWON ◽  
HONG-SUN YOOK ◽  
KYONG-SU KIM
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Gamma Irradiation ◽  
Phosphate Buffer ◽  
Culture Media ◽  
Ozone Treatment ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
D Values

A study was conducted to investigate the reduction and elimination of Escherichia coli O157:H7 by the effects of gamma irradiation and ozone treatment. Log phase cells were found to be more sensitive to gamma irradiation than stationary phase cells. E. coli O157:H7 was found tobe considerably more resistant to irradiation at −18°C than at 20°C. The D values for this organism for treatment with ozone in tryptic soy agar were higher than those for treatment with ozone in phosphate buffer. Gamma irradiation at a dose of 1.5 kGy or ozone treatment at a concentration of 3 to 18 ppm for 20 to 50 min was required to assure the elimination of E. coli O157:H7.

Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black pepper and red pepper by gamma irradiation

2014 ◽  
Vol 172 ◽  
pp. 125-129 ◽  
Author(s):  
Won-Jae Song ◽  
Hye-Jung Sung ◽  
Sung-Youn Kim ◽  
Kwang-Pyo Kim ◽  
Sangryeol Ryu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Gamma Irradiation ◽  
Black Pepper ◽  
Red Pepper ◽  
Escherichia Coli O157

Reduction of Escherichia coli O157:H7 Counts on Whole Fresh Apples by Treatment with Sanitizers

2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER
Keyword(s):  
Escherichia Coli ◽  
Chlorine Dioxide ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Escherichia Coli O157 ◽  
Peroxyacetic Acid ◽  
Water Control ◽  
Buffer Solution ◽  
E Coli ◽  
Log Reduction

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.

A Comparison of Hand Washing Techniques To Remove Escherichia coli and Caliciviruses under Natural or Artificial Fingernails

2003 ◽  
Vol 66 (12) ◽  
pp. 2296-2301 ◽  
Author(s):  
CHIA-MIN LIN ◽  
FONE-MAO WU ◽  
HOI-KYUNG KIM ◽  
MICHAEL P. DOYLE ◽  
BARRY S. MICHAELS ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tap Water ◽  
Hand Washing ◽  
Microbial Populations ◽  
Liquid Soap ◽  
E Coli ◽  
Hand Sanitizer ◽  
Before And After ◽  
Escherichia Coli Jm109 ◽  
Viral Indicators

Compared with other parts of the hand, the area beneath fingernails harbors the most microorganisms and is most difficult to clean. Artificial fingernails, which are usually long and polished, reportedly harbor higher microbial populations than natural nails. Hence, the efficacy of different hand washing methods for removing microbes from natural and artificial fingernails was evaluated. Strains of nonpathogenic Escherichia coli JM109 and feline calicivirus (FCV) strain F9 were used as bacterial and viral indicators, respectively. Volunteers with artificial or natural nails were artificially contaminated with ground beef containing E. coli JM109 or artificial feces containing FCV. Volunteers washed their hands with tap water, regular liquid soap, antibacterial liquid soap, alcohol-based hand sanitizer gel, regular liquid soap followed by alcohol gel, or regular liquid soap plus a nailbrush. The greatest reduction of inoculated microbial populations was obtained by washing with liquid soap plus a nailbrush, and the least reduction was obtained by rubbing hands with alcohol gel. Lower but not significantly different (P > 0.05) reductions of E. coli and FCV counts were obtained from beneath artificial than from natural fingernails. However, significantly (P ≤ 0.05) higher E. coli and FCV counts were recovered from hands with artificial nails than from natural nails before and after hand washing. In addition, microbial cell numbers were correlated with fingernail length, with greater numbers beneath fingernails with longer nails. These results indicate that best practices for fingernail sanitation of food handlers are to maintain short fingernails and scrub fingernails with soap and a nailbrush when washing hands.

Gamma irradiation triggers a global stress response in Escherichia coli O157:H7 including base and nucleotides excision repair pathways

2020 ◽  
Vol 149 ◽  
pp. 104342
Author(s):  
Ghizlane Gaougaou ◽  
Shiv Shankar ◽  
Quentin Liot ◽  
Philippe Constant ◽  
Eric Déziel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Gamma Irradiation ◽  
Excision Repair ◽  
Escherichia Coli O157 ◽  
Repair Pathways ◽  
Global Stress

Electrochemistry of Escherichia coli JM109: Direct electron transfer and antibiotic resistance

2012 ◽  
Vol 32 (1) ◽  
pp. 219-223 ◽  
Author(s):  
Yaroslava Chalenko ◽  
Victoria Shumyantseva ◽  
Svetlana Ermolaeva ◽  
Alexander Archakov
Keyword(s):  
Escherichia Coli ◽  
Electron Transfer ◽  
Antibiotic Resistance ◽  
Direct Electron Transfer ◽  
Escherichia Coli Jm109

scholarly journals Studies on the Nitrate Reductase of Escherichia Coli in the Cell-Free State

1950 ◽  
Vol 3 (1) ◽  
pp. 28 ◽  
Author(s):  
W Joklik
Keyword(s):  
Escherichia Coli ◽  
Methylene Blue ◽  
Nitrate Reductase ◽  
Phosphate Buffer ◽  
Oxidation Time ◽  
Hydrogen Donor ◽  
Free State ◽  
Ground Glass

A method of purifying the nitrate reductase obtained by crushingEscherichia coli cells in a ground glass mill is described, involving elution atpH 9.5 and precipitation into slightly acidified acetone, followed by treatmentwith phosphate buffer ( pH 8.0) and dialysis. Methods of estimating theactivity of the enzyme without recourse to coupling with other enzymes areoutlined, viz.: (a) the oxidation time method; (b) the use of photochemicallyreduced methylene blue as hydrogen donor.

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