Viability of and Escherichia coli O157:H7 and Listeria monocytogenes in a delicatessen appetizer (yogurt-based) salad as affected by citrus extract (Citrox©) and storage temperature

2018 ◽  
Vol 69 ◽  
pp. 11-17 ◽  
Author(s):  
Maria I. Tsiraki ◽  
Hany M. Yehia ◽  
Tahra Elobeid ◽  
Tareq Osaili ◽  
Hercules Sakkas ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Storage Temperature ◽  
Escherichia Coli O157 ◽  
Citrus Extract ◽  
And Storage

Death of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in Garlic Butter as Affected by Storage Temperature

2002 ◽  
Vol 65 (12) ◽  
pp. 1976-1980 ◽  
Author(s):  
BARBARA B. ADLER ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Storage Time ◽  
Storage Temperature ◽  
Rapid Decline ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Pathogen Populations ◽  
And Storage

Garlic is known to have antimicrobial activity against several spoilage and pathogenic bacteria. However, the fate of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in garlic butter has not been reported. This study was undertaken to determine the viability of these organisms in garlic butter as affected by the type of raw minced garlic added to the butter, storage temperature, and storage time. Unsalted butter at 40°C was combined with raw minced jumbo, elephant, or small-cloved garlic at a 4:1 butter/garlic ratio (wt/wt), inoculated with mixed-strain suspensions of Salmonella, E. coli O157:H7, or L. monocytogenes, and stored at 4.4, 21, or 37°C for up to 48 h. All pathogens retained their viability at 4.4°C, regardless of the presence of garlic. The addition of garlic to butter enhanced the rates of inactivation of all three pathogens at 21 and 37°C. The most rapid decline in pathogen populations was observed at 37°C. The inactivation of L. monocytogenes occurred more slowly than did that of Salmonella or E. coli O157:H7. The inactivation of Salmonella and L. monocytogenes was more rapid in jumbo garlic butter than in elephant or small-cloved garlic butter. It is concluded that Salmonella, E. coli O157:H7, and L. monocytogenes did not grow in unsalted butter, with or without garlic added (20%, wt/wt), when inoculated products were stored at 4.4, 21, and 37°C for up to 48 h.

Inhibitory Activity of Colicin E1 against Listeria monocytogenes

2007 ◽  
Vol 70 (5) ◽  
pp. 1256-1262 ◽  
Author(s):  
BRENDA S. PATTON ◽  
JAMES S. DICKSON ◽  
STEVEN M. LONERGAN ◽  
SARA A. CUTLER ◽  
CHAD H. STAHL
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Inhibitory Activity ◽  
Storage Temperature ◽  
Strain Differences ◽  
Inoculum Concentration ◽  
Gram Negative ◽  
Initial Inoculum ◽  
Colicin E1 ◽  
And Storage

Colicins are gram-negative bacteriocins produced by and effective against Escherichia coli and related species. Colicin E1 (ColE1) is composed of three functional domains, which collectively have a pore-forming effect on targeted bacteria. ColE1 binding and translocation domains are highly specific in contrast to the pore-forming domain, implying that ColE1 could be broadly effective. In this study, the activity of ColE1 against Listeria monocytogenes was evaluated in broth and on surfaces of ready-to-eat products. Individual strains of L. monocytogenes were examined in broth containing ColE1 at 0, 0.1, 1, or 10 μg/ml. Although strain differences in sensitivity to ColE1 existed, growth was significantly reduced in all strains at doses as low as 0.1 μg/ml. Sterilized ham slices were submerged in a five-strain L. monocytogenes cocktail (either 7 or 4 log CFU/ml) and placed in vacuum packages containing 0, 1, 5, 10, 25, or 50 μg of ColE1. Ham slices were then stored at 4 or 10°C, and samples were removed and examined for L. monocytogenes after 1, 3, 7, and 14 days. Reduction of L. monocytogenes by ColE1 was dependent on initial inoculum concentration and storage temperature. For slices stored at 4°C, treatment with 25 μg reduced Listeria growth below detection limits for the slices inoculated with 4 log CFU/ml for the entire 14 days, whereas for the 7-log CFU/ml slices, growth was detected at 7 days postinoculation. For slices stored at 10°C, 10 μg/ml ColE1 significantly inhibited growth of L. monocytogenes for up to 3 days for both inoculation groups. These data indicate that ColE1 is highly effective against Listeria.

Fate of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella typhimurium during Preparation and Storage of Beef Jerky

1996 ◽  
Vol 59 (12) ◽  
pp. 1336-1338 ◽  
Author(s):  
JUDY A. HARRISON ◽  
MARK A. HARRISON
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Microbial Populations ◽  
Escherichia Coli O157 ◽  
Beef Jerky ◽  
Drying Up ◽  
Moisture Conditions ◽  
And Storage

The fate of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella typhimurium during preparation and storage of beef jerky was determined. Control strips and one-half of the inoculated beef loin strips were marinated at 4°C overnight and dried at 60°C (140°F) for 10h. The remaining half of the inoculated samples were heated in marinade to 71.1°C (160°F). Strips were dried at 60°C (140°F) for 10 h. Microbial populations were determined at intervals during drying up to 10 h and also from samples stored at 25°C for 8 weeks at various moisture levels. In general, L. monocytogenes was more resistant to the treatments. After 3 h of drying, populations on the unheated, inoculated samples were reduced by 3.3, 1.8 and 3.1 log units, respectively, and all three were reduced by 5.5 to 6.0 log units after 10h. Reduction of the three populations on strips that were cooked prior to drying was 4.5 to 5.5 log units immediately after cooking. The populations decreased to undetectable levels after 10 h of drying. None of the three pathogens were detected on the controls. After 8 weeks of storage none of the pathogens were detected, indicating that they were unable to recover under the moisture conditions during storage.

Viability of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in Yellow Fat Spreads as Affected by Storage Temperature

2003 ◽  
Vol 66 (4) ◽  
pp. 549-558 ◽  
Author(s):  
SARAH L. HOLLIDAY ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Storage Temperature ◽  
Salt Content ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Inhibition Of Growth ◽  
Time Required ◽  
Kinetics Of

A study was conducted to characterize the survival and inactivation kinetics of a five-serotype mixture of Salmonella (6.23 to 6.55 log10 CFU per 3.5-ml or 4-g sample), a five-strain mixture of Escherichia coli O157:H7 (5.36 to 6.14 log10 CFU per 3.5-ml or 4-g sample), and a six-strain mixture of Listeria monocytogenes (5.91 to 6.18 log10 CFU per 3.5-ml or 4-g sample) inoculated into seven yellow fat spreads (one margarine, one butter-margarine blend, and five dairy and nondairy spreads and toppings) after formulation and processing and stored at 4.4, 10, and 21°C for up to 94 days. Neither Salmonella nor E. coli O157:H7 grew in any of the test products. The time required for the elimination of each pathogen depended on the product and the storage temperature. Death was more rapid at 21°C than at 4.4 or 10°C. Depending on the product, the time required for the elimination of viable cells at 21°C ranged from 5 to 7 days to >94 days for Salmonella, from 3 to 5 days to 28 to 42 days for E. coli O157:H7, and from 10 to 14 days to >94 days for L. monocytogenes. Death was most rapid in a water-continuous spray product (pH 3.66, 4.12% salt) and least rapid in a butter-margarine blend (pH 6.66, 1.88% salt). E. coli O157:H7 died more rapidly than did Salmonella or L. monocytogenes regardless of storage temperature. Salmonella survived longer in high-fat (≥61%) products than in products with lower fat contents. The inhibition of growth is attributed to factors such as acidic pH, salt content, the presence of preservatives, emulsion characteristics, and nutrient deprivation. L. monocytogenes did not grow in six of the test products, but its population increased between 42 and 63 days in a butter-margarine blend stored at 10°C and between 3 and 7 days when the blend was stored at 21°C. On the basis of the experimental parameters examined in this study, traditional margarine and spreads not containing butter are not “potentially hazardous foods” in that they do not support the growth of Salmonella, E. coli O157:H7, or L. monocytogenes.

Reduction of Listeria monocytogenes and Escherichia coli O157:H7 Numbers on Vacuum-Packaged Fresh Beef Treated with Nisin or Nisin Combined with EDTA†

1999 ◽  
Vol 62 (10) ◽  
pp. 1123-1127 ◽  
Author(s):  
SHANSHAN ZHANG ◽  
AZLIN MUSTAPHA
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Bacterial Growth ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Key Factor ◽  
Vacuum Package ◽  
And Storage

Nisin or nisin combined with EDTA was used to treat fresh beef. Beef cubes (2.5 by 2.5 by 2.5 cm) that were inoculated with approximately 7 log CFU/ml of Listeria monocytogenes Scott A or Escherichia coli O157:H7 505 B were dipped in the following solutions: (i) H2O, (ii) HCl, (iii) nisin, (iv) EDTA, or (v) nisin combined with EDTA, respectively, for 10 min each, with an exception of one set of control beef samples without treatment. Beef samples were then drip-dried for 15 min, vacuum packaged, and stored at 4°C for up to 30 days. The pH on beef after different treatments was not a key factor in preventing bacterial growth. Treatment with nisin or with nisin combined with EDTA reduced the population of L. monocytogenes by 2.01 and 0.99 log CFU/cm2 as compared to the control, respectively, under the conditions of vacuum package and storage at 4°C for up to 30 days. However, the effect of nisin and nisin combined with EDTA against E. coli O157:H7 505 B was marginal at 1.02 log CFU/cm2 and 0.8 log CFU/cm2 reductions, respectively.

scholarly journals Behavior of Escherichia coli O157:H7 and Listeria monocytogenes during fermentation and storage of camel yogurt

2016 ◽  
Vol 99 (3) ◽  
pp. 1802-1811 ◽  
Author(s):  
Anas A. Al-Nabulsi ◽  
Amin N. Olaimat ◽  
Tareq M. Osaili ◽  
Mutamed M. Ayyash ◽  
Aisha Abushelaibi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Escherichia Coli O157 ◽  
And Storage

Effects of Acetic-Lactic Acid Treatments Applied to Beef Trim on Populations of Escherichia coli O157:H7 and Listeria monocytogenes in Ground Beef†

1997 ◽  
Vol 60 (12) ◽  
pp. 1560-1563 ◽  
Author(s):  
D. E. CONNER ◽  
J. S. KOTROLA ◽  
W. B. MIKEL ◽  
K. C. TAMBLYN
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Beef Production ◽  
E Coli ◽  
Production Scheme ◽  
And Storage ◽  
Lactic Acids ◽  
Acid Treatments

The efficacy of organic acid sprays for eliminating Escherichia coli O157:H7 and Listeria monocytogenes from beef trim used in a model ground beef production scheme was determined. Beef trim pieces with ca. 20% fat inoculated with E. coli O157:H7 or L. monocytogenes (ca. 3 log10 CFU/g) were utilized as controls or treated by spraying with 2 or 4% acetic and lactic acids. Propylene glycol (20%) was the carrier for each treatment. Following acid treatment, intact pieces were stored at 4°C for 12 or 24 h, ground, divided into 4 100-g retail packages and stored at 4°C for 0, 1, 2, or 4 days, at which time surviving populations of E. coli O157:H7 or L. monocytogenes were enumerated. High populations (>2.6 log10 CFU/g) of the pathogens persisted in all treatments. The 2% acid spray reduced (P < 0.01) the E. coli O157:H7 population by only 0.1 log10 CFU/g. The 2 and 4% acid sprays reduced (P < 0.001) the L. monocytogenes populations by 0.36 and 0.44 log10 CFU/g, respectively. Storing beef trim intact prior to grinding resulted in lower populations of E. coli O157:H7, and storage following grinding did not affect populations of either pathogen. The acid treatments tested were only slightly effective as sanitizers for beef trim destined for ground beef production.

Viability of Escherichia coli O157:H7 in Salami Following Conditioning of Batter, Fermentation and Drying of Sticks, and Storage of Slices

1998 ◽  
Vol 61 (4) ◽  
pp. 377-382 ◽  
Author(s):  
NANCY G. FAITH ◽  
NELLY PARNIERE ◽  
TRINA LARSON ◽  
TIMOTHY D. LORANG ◽  
CHARLES W. KASPAR ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Storage Temperature ◽  
Starter Culture ◽  
Escherichia Coli O157 ◽  
Protein Ratio ◽  
E Coli ◽  
Log10 Unit ◽  
Storage Atmosphere ◽  
Unit Reduction ◽  
And Storage

The fate of Escherichia coli O157:H7 was monitored in salami during conditioning of batter, fermentation and drying of sticks, and storage of slices. The raw batter (75% pork:25% beef, wt/wt, fat content about 20%) was inoculated with a pediococcal starter culture (about 108 CFU/g) and a five-strain cocktail of E. coli O157:H7 (≥2 × 107 CFU/g) and stuffed into 104-mm diameter fibrous casings. After being refrigerated at 4°C or being tempered at 13°C, frozen at −20°C, and thawed at 4°C, or being frozen at −20°C, and thawed at 4°C, the inoculated batter was fermented at 24°C and 90% relative humidity (RH) to pH ≤4.8, dried at 13°C and 65% RH to a moisture/protein ratio of ≤1.9:1, and then stored at 4 or 21°C under air or vacuum. For salami sticks sampled immediately after drying, appreciable differences were evident among the various batter-conditioning treatments; pathogen numbers were reduced from original levels by 2.1, 1.6, or 1.1 log10 units when batter was tempered, frozen, and thawed, frozen and thawed, or refrigerated, respectively. Similarly, regardless of storage temperature or atmosphere, within 7 days salami slices cut from sticks prepared from batter that was tempered, frozen, and thawed (2.7- to 4.9-log10-unit reduction) or frozen and thawed (2.3- to 4.8-log10-unit reduction) displayed a greater impact on pathogen numbers than slices cut from sticks prepared from batter that was refrigerated (1.6- to 3.1-log10-unit reduction). The effects of batter conditioning notwithstanding, a greater reduction in levels of E. coli O157:H7 was observed when slices were stored at 21°C compared to otherwise similar slices stored at 4°C. After storage for 60 days the pathogen was only detected by enrichment in slices stored at 21°C, whereas pathogen levels ranged from 1.4 to 4.5 log10 CFU/g in slices stored at 4°C. Differences related to storage atmosphere were first observed after slices were stored for 21 days. Such differences were more readily demonstrable after 60 and 90 days, with pathogen numbers for treatments that were statistically different ranging from 0.6- to 1.5-log10 units higher on slices stored under vacuum than in air. These data emphasize the need to implement multiple barriers to appreciably reduce numbers of E. coli O157:H7 in salami.

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