scholarly journals Determination of the Optimum Time for Preparation of Half-Boiled Eggs Free from Salmonella Enterica Enteritidis

2018 ◽  
Vol 3 (1) ◽  
pp. 16
Author(s):  
Mohamad Fithri Akmar Omar ◽  
Nurdiyana Syahirah Abdul Manaf ◽  
Siti Nurnajwa Nadhirah Mohd Sufian ◽  
Norsuhaida Zakaria ◽  
Nur Farhah Najwa Ayub ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Hot Water ◽  
Average Weight ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Optimum Time ◽  
Colony Forming Units ◽  
Time Required ◽  
Chicken Eggs ◽  
Boiled Water

Introduction: Consuming half-boiled eggs during breakfast is popular among Malaysians. The eggs are usually prepared by submerging them in freshly boiled water for about 20 minutes duration. As chickens have the likelihood of harbouring Salmonella enterica Serovar Enteritidis in their eggs, it is feared that consumption of half-boiled eggs contaminated with S. Enteritidis could lead to gastroenteritis. Hence, this study was carried out to determine the optimum time required for boiled water to kill S. Enteritidis in half-boiled eggs. Methods: Grade C chicken eggs (average weight 54.5 g) were obtained from a local sundry shop and were confirmed to be Salmonella-free prior to the experiment. Fifteen eggs that were previously spiked with 106 colony-forming units (CFU) of S. Enteritidis were completely submerged into freshly-boiled water (≈100ºC) for a maximum of 20 min. Positive controls consisted of eggs that were inoculated but were not treated. At every 5 min interval, three eggs were taken out and checked for presence of viable S. Enteritidis on MacConkey agar, and the respective water temperature was recorded. Results: Results of two independent trials showed that after 10 min of submerging the eggs in the hot water, there were an average of 3 log reductions in the CFU of S. Enteritidis but after 15 min, no viable S. Enteritidis was detected. Conclusion: A half-boiled egg should be prepared by submerging it in freshly boiled water for at least 15 min to ensure that it is safe to be consumed.

scholarly journals Identification of Genes Associated with Survival of Salmonella enterica Serovar Enteritidis in Chicken Egg Albumen

2006 ◽  
Vol 72 (2) ◽  
pp. 1055-1064 ◽  
Author(s):  
Raul I. Clavijo ◽  
Cindy Loui ◽  
Gary L. Andersen ◽  
Lee W. Riley ◽  
Sangwei Lu
Keyword(s):  
Salmonella Enterica ◽  
Human Population ◽  
Acid Metabolism ◽  
Clinical Manifestations ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Serovar Typhimurium ◽  
Contaminated Food ◽  
Egg Albumen ◽  
Chicken Eggs ◽  
Epidemiological Characteristics

ABSTRACT Salmonella enterica consists of over 2,000 serovars that are major causes of morbidity and mortality associated with contaminated food. Despite similarities among serovars of Salmonella enterica, many demonstrate unique host specificities, epidemiological characteristics, and clinical manifestations. One of the unique epidemiological characteristics of the serovar Enteritidis is that it is the only bacterium routinely transmitted to humans through intact chicken eggs. Therefore, Salmonella enterica serovar Enteritidis must be able to persist inside chicken eggs to be transmitted to humans, and its survival in egg is important for its transmission to the human population. The ability of Salmonella enterica serovar Enteritidis to survive in and transmit through eggs may have contributed to its drastically increased prevalence in the 1980s and 1990s. In the present study, using transposon-mediated mutagenesis, we have identified genes important for the association of Salmonella enterica serovar Enteritidis with chicken eggs. Our results indicate that genes involved in cell wall structural and functional integrity, and nucleic acid and amino acid metabolism are important for Salmonella enterica serovar Enteritidis to persist in egg albumen. Two regions unique to Salmonella enterica serovar Enteritidis were also identified, one of which enhanced the survival of a Salmonella enterica serovar Typhimurium isolate in egg albumen. The implication of our results to the serovar specificity of Salmonella enterica is also explored in the present study.

Evaluation of Whole Genome Sequencing for outbreak detection of Salmonella enterica serovar Enteritidis

2020 ◽  
Author(s):  
Ainhoa Arrieta-Gisasola ◽  
Aitor Atxaerandio Landa ◽  
Javier Garaizar ◽  
Joseba Bikandi ◽  
José Karkamo ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Salmonella Enterica ◽  
Outbreak Detection ◽  
Whole Genome ◽  
Salmonella Enterica Serovar Enteritidis

Mercury-204 Determination by Emission Spectroscopy

1965 ◽  
Vol 19 (3) ◽  
pp. 87-89 ◽  
Author(s):  
F. M. Smith
Keyword(s):  
Coefficient Of Variation ◽  
Isotope Shift ◽  
Emission Spectroscopy ◽  
Electrodeless Discharge ◽  
Discharge Lamp ◽  
Isotope Concentration ◽  
Single Determination ◽  
Time Required

The determination of mercury-204 was made by using the isotope shift of the 3984 A mercury line excited by electrodeless discharge. Densitometric traces were made from film recordings of the 3984 A line and the areas under the component peaks were determined. Ratios of each of these areas to the sum of the areas from all the line components are plotted against the isotope concentration to produce a working curve. The coefficient of variation for this method is approximately 11 percent The time required for a single determination (after fabrication of the discharge lamp) is about two hours.

Identification of in vivo-induced genes during infection of chickens with Salmonella enterica serovar Enteritidis

2015 ◽  
Vol 100 ◽  
pp. 1-7 ◽  
Author(s):  
Shizhong Geng ◽  
Zhicheng Liu ◽  
Zhijie Lin ◽  
Paul Barrow ◽  
Zhiming Pan ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Induced Genes

scholarly journals THE EFFECTS ON BIOLOGICAL MATERIALS OF FREEZING AND DRYING BY VACUUM SUBLIMATION

1954 ◽  
Vol 100 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Donald Greiff ◽  
Henry Pinkerton
Keyword(s):  
Influenza Virus ◽  
Biological Materials ◽  
Continuous Operation ◽  
Virus Suspension ◽  
Vacuum Sublimation ◽  
End Point ◽  
Different Temperatures ◽  
Time Required

A vacuum sublimation apparatus is described which will permit, (a) the removal of water from virus suspensions at temperatures ranging down to –80°C., (b) continuous operation with a minimum of attention from the investigator, (c) sealing off of samples at operating pressures (10–5 mm. Hg), (d) simultaneous lyophilization of aliquot samples at different temperatures, (e) isolation of a portion of the apparatus without disturbing the remainder of the system, and (f) determination of the end-point of sublimation without disturbing the samples. The time required for drying 0.1 ml. of influenza virus suspension was shown to increase markedly with decrease of temperature, 8 days being required for dehydration at –80°C. in contrast to 2 days at –30°C. and 1 day at 0°C.

scholarly journals Naturally Occurring Motility-Defective Mutants of Salmonella enterica Serovar Enteritidis Isolated Preferentially from Nonhuman Rather than Human Sources

2011 ◽  
Vol 77 (21) ◽  
pp. 7740-7748 ◽  
Author(s):  
Lucía Yim ◽  
Laura Betancor ◽  
Arací Martínez ◽  
Clare Bryant ◽  
Duncan Maskell ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Intestinal Epithelial ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Transcriptional Responses ◽  
Content Type ◽  
Field Isolates ◽  
Specific Pcr ◽  
Human Intestinal Epithelial Cells ◽  
Natural Isolates ◽  
Cell Invasiveness

ABSTRACTSalmonellosis represents a worldwide health problem because it is one of the major causes of food-borne disease. Although motility is postulated as an importantSalmonellavirulence attribute, there is little information about variation in motility in natural isolates. Here we report the identification of a point mutation (T551 → G) inmotA, a gene essential for flagellar rotation, in severalSalmonella entericaserovar Enteritidis field isolates. This mutation results in bacteria that can biosynthesize structurally normal but paralyzed flagella and are impaired in their capacity to invade human intestinal epithelial cells. Introduction of a wild-type copy ofmotAinto one of these isolates restored both motility and cell invasiveness. ThemotAmutant triggered higher proinflammatory transcriptional responses than an aflagellate isolate in differentiated Caco-2 cells, suggesting that the paralyzed flagella are able to signal through pattern recognition receptors. A specific PCR was designed to screen for the T551 → G mutation in a collection of 266S. Enteritidis field isolates from a nationwide epidemic, comprising 194 from humans and 72 from other sources. We found that 72 of the 266 (27%) isolates were nonmotile, including 24.7% (48/194) of human and 33.3% (24/72) of food isolates. Among nonmotile isolates, 15 carried the T551 → G mutation and, significantly, 13 were recovered from food, including 7 from eggs, but only 2 were from human sources. These results suggest that the presence of paralyzed flagella may impair the ability ofS. Enteritidis to cause disease in the human host but does not prevent its ability to colonize chickens and infect eggs.

scholarly journals Survival characteristics of Salmonella enterica serovar Enteritidis in chicken egg albumen

2006 ◽  
Vol 134 (5) ◽  
pp. 967-976 ◽  
Author(s):  
H. KANG ◽  
C. LOUI ◽  
R. I. CLAVIJO ◽  
L. W. RILEY ◽  
S. LU
Keyword(s):  
Salmonella Enterica ◽  
Iron Acquisition ◽  
Foodborne Pathogen ◽  
Human Infection ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Factors Affecting ◽  
Chicken Egg ◽  
Egg Albumen ◽  
High Concentrations ◽  
Incubation Temperatures

Salmonella enterica serovar Enteritidis (SE) is a major foodborne pathogen primarily causing human infection through contaminated chicken eggs. To understand how SE survives in chicken egg albumen, we systematically and quantitatively analysed the survival properties of SE in egg albumen and identified factors affecting its survival. Survival assays of SE in egg indicate that egg albumen restricted the growth of SE. A major factor that controlled SE's growth in egg albumen was iron restriction, since egg albumen supplemented with iron allowed SE to grow, and iron acquisition mutants of SE showed decreased survival in egg albumen. In addition, low pH of albumen, high concentrations of bacteria and low incubation temperatures of bacteria with albumen facilitates the survival of SE. Our results suggest that egg albumen uses multiple mechanisms to control SE including iron limitation, surface interaction and possible enzymatic activities.

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