Effect of Thermoultrasonication on Salmonella enterica Serovar Enteritidis in Distilled Water and Intact Shell Eggs

The combined effects of simultaneous application of ultrasonic waves and heat treatment (thermoultrasonication) on the survival of a strain of Salmonella enterica Enteritidis was studied in both distilled water and intentionally contaminated intact eggs immersed in water. Although minor differences were observed between parameters obtained for thermoultrasonic treatment of bacteria suspended in water and those attached to the shell egg, the thermoultrasonication effects were considered to be of the same level in the range of temperatures assayed (52 to 58°C). This combined process presented a clearly higher killing effect than the heat treatment alone. It decreased the decimal reduction times (D-values) by 80 to 55%, respectively, in the range of temperatures for heat treatment when the organism was suspended in water, which means a 99.5% reduction (5D to >2D) of the original bacterial load versus a 90% reduction for the heat treatment alone. The practical implications of the phenomenon are discussed.

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Destruction of Salmonella Senftenberg on the Shells of Intact Eggs by Thermoultrasonication

Journal of Food Protection ◽

10.4315/0362-028x-68.4.841 ◽

2005 ◽

Vol 68 (4) ◽

pp. 841-844 ◽

Cited By ~ 9

Author(s):

M. C. CABEZA ◽

M. L. GARCÍA ◽

L. de la HOZ ◽

I. CAMBERO ◽

J. A. ORDÓÑEZ

Keyword(s):

Heat Treatment ◽

Ultrasonic Treatment ◽

Salmonella Enteritidis ◽

Ultrasonic Waves ◽

Combined Effect ◽

Salmonella Enterica Serovar Enteritidis ◽

Combined Process ◽

Killing Effect ◽

D Values ◽

Salmonella Senftenberg

The combined effect of ultrasonic waves and heat treatment applied simultaneously was evaluated on the survival of strains of Salmonella Senftenberg on shells of intact eggs. This combined process has a higher killing effect than heat treatment alone. The decimal reduction times (D-values) were decreased by 65.2 to 11.1% in the temperature range studied (57.8 to 67°C). In contrast to the effect on Salmonella enterica serovar Enteritidis in a previous study, thermoultrasonication had no important advantage for elimination of Salmonella Senftenberg. However, because 52°C is a nonlethal temperature for Salmonella Senftenberg, the conditions used for the elimination of Salmonella Enteritidis (52°C for 12 min) in the previous study would be equivalent to ultrasonic treatment alone in the present study. This thermoultrasonication treatment may result in a 100-fold greater reduction of Salmonella Senftenberg than that achieved by common in-shell egg pasteurization (60°C for 3.5 min).

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Factors Affecting Thermal Resistance of Salmonella enterica Serovar Enteritidis ODA 99-30581-13 in Shell Egg Contents and Use of Heat-Ozone Combinations for Egg Pasteurization

Journal of Food Protection ◽

10.4315/0362-028x.jfp-12-324 ◽

2013 ◽

Vol 76 (2) ◽

pp. 213-219 ◽

Cited By ~ 7

Author(s):

JENNIFER J. PERRY ◽

AHMED E. YOUSEF

Keyword(s):

Heat Treatment ◽

Thermal Resistance ◽

Salmonella Enterica ◽

Salmonella Enteritidis ◽

Egg Quality ◽

Heating Time ◽

Heating Process ◽

Salmonella Enterica Serovar Enteritidis ◽

Factors Affecting ◽

Shell Eggs

Infection of laying hens with Salmonella enterica serovar Enteritidis leads to deposition of the pathogen into the albumen or yolk of forming eggs. Heat treatment can inactivate internalized Salmonella Enteritidis in shell eggs, but factors such as the nature and location of contamination may influence the efficacy of thermal treatments. In the current research, natural contamination was mimicked by introducing small inocula of Salmonella Enteritidis into different locations of shell eggs and incubating inoculated eggs. These pathogen-containing eggs were heated at 57°C for 40 min, and temperature within eggs was monitored at the locations of inocula. Comparison of inactivation at equivalent internal temperatures revealed similar levels of lethality regardless of inoculum location. Refrigeration between incubation and heat treatment did not increase thermal resistance of cells in albumen but decreased cell inactivation in yolk. Sequential application of heat and gaseous ozone allows for the development of a process capable of decontaminating shell eggs with minimal thermal treatment and impact on egg quality. Inoculated eggs were subjected to (i) an immersion heating process similar to that used in commercial pasteurization or (ii) immersion heating, at reduced duration, followed by vacuum (50.8 kPa) and treatment with ozone gas (maximum 160 g/m3) under pressure (~ 187.5 kPa). All treatments tested produced greater than 5-log inactivation, which is required for “pasteurization” processes. Differences were observed in the visual quality of eggs depending on treatment parameters. Application of ozone subsequent to heating allows for a significant reduction in heating time without decreasing process lethality.

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Effect of fixed or changing temperatures during prolonged storage on the growth of Salmonella enterica serovar Enteritidis inoculated artificially into shell eggs

Epidemiology and Infection ◽

10.1017/s0950268807009612 ◽

2007 ◽

Vol 136 (9) ◽

pp. 1210-1216 ◽

Cited By ~ 5

Author(s):

M. OKAMURA ◽

S. KIKUCHI ◽

A. SUZUKI ◽

H. TACHIZAKI ◽

K. TAKEHARA ◽

...

Keyword(s):

Bacterial Growth ◽

Salmonella Enterica ◽

Prolonged Storage ◽

Salmonella Enterica Serovar Enteritidis ◽

Shell Eggs ◽

Egg Storage

SUMMARYThe fate of Salmonella enterica serovar Enteritidis (SE) in whole, unbroken eggs was monitored during storage at fixed or changing temperatures after inoculation with 20–47 c.f.u. of SE. Eggs stored at 10°C and 20°C showed little or no bacterial growth over 6 weeks, while egg storage at 30°C increased the percentage of the eggs that contained >106 c.f.u. after 3 weeks. Egg storage at 20°C for 5 days followed by 10°C caused only a few eggs with >106 c.f.u. after 2 weeks, whereas storage at 22–30°C or 27–35°C for 5 days followed by 25°C induced a rapid increase of eggs that contained >106 c.f.u. after 1 or 2 weeks, respectively. Therefore, egg storage at 10°C and 20°C can control SE growth, although the temperature during egg storage and transportation from farm to table should also be taken into consideration.

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Thermal Injury and Recovery of Salmonella enterica Serovar Enteritidis in Ground Chicken with Temperature, pH, and Sodium Chloride as Controlling Factors†

Journal of Food Protection ◽

10.4315/0362-028x-69.9.2058 ◽

2006 ◽

Vol 69 (9) ◽

pp. 2058-2065 ◽

Cited By ~ 21

Author(s):

L. SHERRE CHAMBLISS ◽

NEELAM NARANG ◽

VIJAY K. JUNEJA ◽

MARK A. HARRISON

Keyword(s):

Salmonella Enterica ◽

Salmonella Enteritidis ◽

Thermal Injury ◽

Heating Temperature ◽

Inhibitory Effect ◽

Salmonella Enterica Serovar Enteritidis ◽

Randomized Design ◽

Nacl Concentration ◽

Ph Range ◽

D Values

Cells of Salmonella enterica serovar Enteritidis were grown at 25 and 35°C, heat injured (55, 60, and 62.5°C), and recovered in tryptic soy broth (TSB) at various NaCl concentrations (2.0 and 3.5%) and pH levels (5.5 and 6.5). To assess the interactions of growth temperature, heating temperature, NaCl concentration and pH on the thermal injury and recovery of Salmonella Enteritidis in ground chicken, a randomized design with each experimental combination was used. When a logistic equation for nonlinear survival curves was used, D-values of cells of Salmonella Enteritidis grown at 25°C were 7.60, 5.73, and 4.81 min at 55, 60, and 62.5°C, respectively. For cells grown at 35°C, the D-values were 12.38, 7.45, and 5.70 min at 55, 60, and 62.5°C. The influence of tryptic soy agar and double modified lysine agar (DMLIA) on the recovery of heat-injured cells was determined. Recovery was significantly reduced on DMLIA at increased pH levels and NaCl concentrations. Higher numbers of cells were recovered in TSB with 2.0% NaCl than in TSB with 3.5% NaCl. It was observed that the rate of recovery of heat-injured cells was similar at each pH. Therefore, a pH range of 5.5 to 6.5 does not have a major inhibitory effect on the recovery of Salmonella Enteritidis.

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Inactivation of Salmonella enterica Serovar Enteritidis on Shell Eggs by Ozone and UV Radiation

Journal of Food Protection ◽

10.4315/0362-028x-68.4.711 ◽

2005 ◽

Vol 68 (4) ◽

pp. 711-717 ◽

Cited By ~ 70

Author(s):

LUIS A. RODRIGUEZ-ROMO ◽

AHMED E. YOUSEF

Keyword(s):

Uv Radiation ◽

Salmonella Enterica ◽

Treatment Time ◽

Ozone Treatment ◽

Salmonella Enterica Serovar Enteritidis ◽

Time Saving ◽

Shell Eggs ◽

Total Treatment Time ◽

Total Treatment ◽

Short Time

The presence of Salmonella enterica serovar Enteritidis in shell eggs has serious public health implications. Several treatments have been developed to control Salmonella on eggs with mixed results. Currently, there is a need for time-saving, economical, and effective egg sanitization treatments. In this study, shell eggs externally contaminated with Salmonella (8.0 × 105 to 4.0 × 106 CFU/g of eggshell) were treated with gaseous ozone (O3) at 0 to 15 lb/in2 gauge for 0 to 20 min. In other experiments, contaminated shell eggs were exposed to UV radiation at 100 to 2,500 μW/cm2 for 0 to 5 min. Treatment combination included exposing contaminated eggs to UV (1,500 to 2,500 μW/cm2) for 1 min, followed by ozone at 5 lb/in2 gauge for 1 min. Eggs that were (i) noncontaminated and untreated, (ii) contaminated and untreated, and (iii) contaminated and treated with air were used as controls. Results indicated that treating shell eggs with ozone or UV, separately or in combination, significantly (P < 0.05) reduced Salmonella on shell eggs. For example, contaminated eggs treated with ozone at 4 to 8°C and 15 lb/in2 gauge for 10 min or with UV (1,500 to 2,500 μW/cm2) at 22 to 25°C for 5 min produced 5.9- or 4.3-log microbial reductions or more, respectively, when compared with contaminated untreated controls. Combinations including UV followed by ozone treatment resulted in synergistic inactivation of Salmonella by 4.6 log units or more in about 2 min of total treatment time. Salmonella was effectively inactivated on shell eggs in a short time and at low temperature with the use of a combination of UV radiation and ozone.

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Genome Sequences of Two Strains of Salmonella enterica Serovar Enteritidis Isolated from Shell Eggs

Genome Announcements ◽

10.1128/genomea.00954-15 ◽

2015 ◽

Vol 3 (5) ◽

Cited By ~ 1

Author(s):

Matthew R. Moreau ◽

Dona Saumya S. Wijetunge ◽

Eranda Mangala K. Kurundu Hewage ◽

Bhushan M. Jayarao ◽

Subhashinie Kariyawasam

Keyword(s):

Gel Electrophoresis ◽

Salmonella Enterica ◽

Complete Genome ◽

Pulsed Field Gel Electrophoresis ◽

Genome Sequences ◽

Salmonella Enterica Serovar Enteritidis ◽

Pulsed Field ◽

Shell Eggs

This report presents the complete genome sequences of two Salmonella enterica serovar Enteritidis strains bearing the pulsed-field gel electrophoresis profile JEGX01.0004, which were isolated from the internal contents of eggs.

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Inactivation of Salmonella enterica Serovar Enteritidis by Ultrasonic Waves under Pressure at Different Water Activities

Applied and Environmental Microbiology ◽

10.1128/aem.69.1.668-672.2003 ◽

2003 ◽

Vol 69 (1) ◽

pp. 668-672 ◽

Cited By ~ 49

Author(s):

I. Álvarez ◽

P. Mañas ◽

F. J. Sala ◽

S. Condón

Keyword(s):

Synergistic Effect ◽

Water Activity ◽

Salmonella Enterica ◽

Lethal Effect ◽

Ultrasonic Waves ◽

Microbial Inactivation ◽

Salmonella Enterica Serovar Enteritidis ◽

Decimal Reduction Time ◽

Lethal Temperatures ◽

Reduced Water

ABSTRACT The inactivation of Salmonella enterica serovar Enteritidis by ultrasonic waves (20 kHz; 117-μm wavelength) under pressure (175 kPa) at nonlethal temperatures (manosonication [MS]) and lethal temperatures (manothermosonication [MTS]) in media of different water activities has been investigated. Heat decimal reduction time values increased 30 times when the water activity was decreased from nearly 1 to 0.96, but the MS resistance was increased only twofold. The inactivation of Salmonella serovar Enteritidis by ultrasound under pressure at low water activities was a phenomenon of the “all-or-nothing” type. A synergistic lethal effect was observed between heat and ultrasound in media with reduced water activity; the lower the water activity, the greater the synergistic effect. This work could be useful for improving sanitation and preservation treatments of foods, especially those which are sensitive to temperature and those in which components protect microorganisms to heat. It also contributes to our knowledge of microbial inactivation mechanisms by MS and MTS treatments.

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