Sublethal injury and recovery of Escherichia coli O157:H7 after freezing and thawing

Food Control ◽  
2021 ◽  
Vol 120 ◽  
pp. 107488
Author(s):  
Ru Zhang ◽  
Linshu Lan ◽  
Hui Shi
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Freezing And Thawing ◽  
Sublethal Injury

scholarly journals Investigating the Effects of Time and Temperature on the Growth of Escherichia coli O157:H7 and Listeria monocytogenes in Raw Cow’s Milk Based on Simulated Consumer Food Handling Practices

2019 ◽  
Vol 16 (15) ◽  
pp. 2691 ◽  
Author(s):  
Roselyn M. Leclair ◽  
Sarah K. McLean ◽  
Louise A. Dunn ◽  
Denny Meyer ◽  
Enzo A. Palombo
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Cow’S Milk ◽  
Escherichia Coli O157 ◽  
Freezing And Thawing ◽  
Food Handling ◽  
E Coli ◽  
Handling Practices ◽  
Food Handling Practices ◽  
Raw Cow’S Milk

Consumption of raw cow’s milk (RCM) is increasing in popularity in developed countries despite the associated foodborne disease risks. While previous research has focused on consumer motivations for drinking RCM, there is limited research on how consumer handling practices may impact the microbiological safety of RCM. In this study, consumer handling practices associated with transport, storage, and freezing and thawing were simulated to investigate the impact of time and temperature variables on the concentrations of either Escherichia coli O157:H7 or Listeria monocytogenes in RCM. We found that the type of storage during simulated transport had a large (η2 = 0.70) and significant (p < 0.001) effect on both pathogens. The refrigeration temperature also had a large (η2 = 0.43) and significant (p < 0.001) effect on both pathogens during refrigerated storage. The interaction between pathogen species and initial pathogen inoculum level had a large (η2 = 0.20) and significant (p = 0.012) effect on the concentration of the pathogens during ambient temperature storage. We found that freezing and thawing practices did not have a significant effect on the pathogens (p > 0.05). However, we were able to recover L. monocytogenes, but not E. coli O157:H7, from RCM after freezing for 365 days. The results from this study highlight that consumer transport and storage practices can have significant effects on the growth of E. coli O157:H7 and L. monocytogenes in RCM. Consumer food handling practices should be considered when developing public health strategies aimed at reducing the risks of RCM consumption.

Evaluating Survival of Escherichia coli O157:H7 in Frozen and Thawed Apple Cider: Potential Use of a Hydrophobic Grid Membrane Filter–SD-39 Agar Method

1998 ◽  
Vol 61 (4) ◽  
pp. 490-494 ◽  
Author(s):  
JAY R. SAGE ◽  
STEVEN C. INGHAM
Keyword(s):  
Escherichia Coli ◽  
Membrane Filter ◽  
Membrane Integrity ◽  
Most Probable Number ◽  
Escherichia Coli O157 ◽  
Freezing And Thawing ◽  
Probable Number ◽  
Cell Membrane Integrity ◽  
Apple Cider ◽  
Agar Method

To determine the susceptibility of Escherichia coli O157:H7 to freezing and thawing in apple cider, methods that recover injured cells are needed for accurate enumeration. This study compared the ISO-GRID™ hydrophobic grid membrane filter (HGMF) SD-39 agar method to two other methods: a reference most probable number (MPN) method, and plating on sorbitol MacConkey agar (SMA). To determine numbers of injured cells, SMA spread plating was also compared to Trypticase soy agar (TSA) spread plating. Two strains of E. coli O157:H7, QA 326 and ATCC 43895, were inoculated into presterilized apple cider (10 ml) which was then frozen (−20°C for 24 h). Samples were thawed at 4°C for 4 h, or at 23°C for 1.5 h, or in a microwave oven (700 W for 10 s). Substantial cell death (0.69- to 6.33-log10 CFU/ml decreases) and injury (0.70- to 2.38-log10 CFU/ml decreases) occurred during freezing and thawing. The extern of death and injury varied with strain and thawing method. The TSA spread plating method recovered the most cells while the HGMF method always recovered more viable cells than the reference MPN method and also either recovered significantly more (P &lt; 0.05) cells or a not significantly different number of cells than SMA spread plating. Some injured cells of both strains were not counted by the HGMF method. Significant numbers of cells injured by freezing and thawing at 4°C in apple cider were enumerated if the cider was diluted 1:2 in Trypticase soy broth immediately before plating. Two epifluorescent microscopic methods showed that injury was not associated with loss of cell membrane integrity.

Effect of Citral on the Thermal Inactivation of Escherichia coli O157:H7 in Citrate Phosphate Buffer and Apple Juice

2010 ◽  
Vol 73 (12) ◽  
pp. 2189-2196 ◽  
Author(s):  
L. ESPINA ◽  
M. SOMOLINOS ◽  
R. PAGÁN ◽  
D. GARCÍA-GONZALO
Keyword(s):  
Escherichia Coli ◽  
Phosphate Buffer ◽  
Apple Juice ◽  
Thermal Inactivation ◽  
Escherichia Coli O157 ◽  
Negative Effects ◽  
E Coli ◽  
Sublethal Injury ◽  
Citrate Phosphate ◽  
Citrate Phosphate Buffer

Inactivation and sublethal injury of Escherichia coli O157:H7 cells induced by heat in citrate phosphate buffer and apple juice (both at pH 3.8) were studied, and the effect of a combined preservation treatment using citral and heat treatments was determined. Heat resistance of E. coli O157:H7 was similar in both treatment media; after 27 min at 54°C, 3 log units of the initial cell population was inactivated in both treatment media. However, under less harsh conditions a protective effect of apple juice was found. Whereas inactivation followed linear kinetics in the citrate phosphate buffer, when cells were treated in apple juice the survival curves were concave downward. Heat treatment caused a great degree of sublethal injury; 4 min at 54°C inactivated less than 0.5 log CFU/ml but sublethally injured more than 3 log CFU/ml. The addition of 18 and 200 ppm of citral to the treatment medium acted synergistically with heat at 54°C to inactivate 3 × 104 and 3 × 107 CFU/ml, respectively. Addition of citral thus reduced the time needed to inactivate 1 log unit of the initial E. coli O157:H7 population from 8.9 to 1.7 min. These results indicate that a combined process of heat and citral can inactivate E. coli O157:H7 cells and reduce their potential negative effects.

Sublethal injury and recovery of Escherichia coli O157:H7 by high pressure carbon dioxide

Food Control ◽  
2015 ◽  
Vol 50 ◽  
pp. 705-713 ◽  
Author(s):  
Xiufang Bi ◽  
Yongtao Wang ◽  
Feng Zhao ◽  
Zhijian Sun ◽  
Xiaosong Hu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Carbon Dioxide ◽  
High Pressure ◽  
Escherichia Coli O157 ◽  
Sublethal Injury

Sublethal injury and recovery of Escherichia coli O157:H7 and K-12 after exposure to lactic acid

Food Control ◽  
2017 ◽  
Vol 82 ◽  
pp. 190-195 ◽  
Author(s):  
Hui Shi ◽  
Zhuozhu Chen ◽  
Dong Chen ◽  
Jianquan Kan
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Escherichia Coli O157 ◽  
Sublethal Injury ◽  
K 12

Sublethal injury and recovery of Escherichia coli O157:H7 after ohmic heating

Food Control ◽  
2018 ◽  
Vol 94 ◽  
pp. 85-92 ◽  
Author(s):  
Xiaojing Tian ◽  
Qianqian Yu ◽  
Lele Shao ◽  
Xingmin Li ◽  
Ruitong Dai
Keyword(s):  
Escherichia Coli ◽  
Ohmic Heating ◽  
Escherichia Coli O157 ◽  
Sublethal Injury

Bedeutung von Escherichia coli O157 beim Schlachtschaf in der Schweiz

2006 ◽  
Vol 148 (6) ◽  
pp. 289-295 ◽  
Author(s):  
C. Zweifel ◽  
M. Kaufmann ◽  
J. Blanco ◽  
R. Stephan
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157

Molecular profiling and antimicrobial susceptibility of Escherichia coli O157:H7 isolated in Bulgaria

2020 ◽  
Vol 23 (3) ◽  
pp. 310-318
Author(s):  
K. Koev ◽  
T. Stoyanchev ◽  
G. Zhelev ◽  
P. Marutsov ◽  
K. Gospodinova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Acid Sensitivity ◽  
Lower Extent ◽  
Phenotype Analysis ◽  
Anal Swab ◽  
Amoxicillin Clavulanic Acid ◽  
Primary Identification ◽  
Stx1 Gene ◽  
Cattle Farms

The purpose of this study was to detect the presence of shiga-toxin producing Escherichia coli (STEC) in faeces of healthy dairy cattle and to determine the sensitivity of isolates to several anti­microbial drugs. A total of 1,104 anal swab samples originating from 28 cattle farms were examined. After the primary identification, 30 strains were found to belong to serogroup О157. By means of conventional multiplex PCR, isolates were screened for presence of resistance genes stx1, stx2 and eaeА. Twenty-nine strains possesses amplicons with a size corresponding to genes stx2 and eaeA, one had amplicons also for the stx1 gene and one lacked amplicons of all three genes. Twenty-eight strains demonstrated amplicons equivalent to gene H7. The results from phenotype analysis of resistance showed preserved sensitivity to ceftriaxone, ceftazidime, cefotaxime, cephalothin, streptomycin, gentamicin, tetracycline, enrofloxacin and combinations sulfamethoxazole/trimethoprim and amoxicillin/clavulanic acid. Sensitivity to ampicillin was relatively preserved, although at a lower extent.

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