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PubMedDate not supplied

[Dynamics of amino acid and protein metabolism of laying hens after the administration of 15N-labeled wheat protein. 3. Incorporation of 15N into egg shell, egg white and egg yolk].

12 colostomized laying hybrids received a ration meeting their requirement of 15N labelled wheat with a 15N excess (15N') of 14.37 atom-% over 4 days. The 15N' of the total ration amounted to 4.47 atom-%. Each hen consumed 135 mg 15N' per day. On another 4 days the same rations with non labelled wheat were fed. The 12 hens laid 56 eggs during the 8 days of the experiment. They were divided into egg shell, white and yolk of egg. In addition, the protein of the white and yolk of egg was precipitated with trichloric acetic acid (TCA) and the nitrogen in these fractions was determined. On average of the 56 eggs, the N quota in the egg shell was 5.3%, in the white of egg 49.1% and in the yolk 45.6%. The atom-% 15N' in the shells of the eggs laid on the first day of the experiment was on average 0.21, whereas only 0.03 and 0.02 atom-% 15N' resp. could be detected in the white and yolks of the eggs. On the first day after the last 15N application the atom-% 15N' in the egg shell and the white of egg was highest and amounted to 2.33 and 2.43 atom-% resp. The highest value of 1.83 atom-% 15N' in the yolk was ascertained 3 days after the last 15N intake. The mean quota of TCA-precipitable N in the white of egg is 97.6% and in the yolk 94.4% of the respective total N. The atom-% 15N' in the non-protein N-compounds was higher than in the protein fractions.

Amino Acids↗
PubMed2005

Impact of commercial processing on the microbiology of shell eggs.

Shell egg microbiology has been studied extensively, but little information is available on how modern U.S. processing conditions impact microbial populations. As regulations are being drafted for the industry, such information can be important for determining processing steps critical to product safety. Five different shell egg surface microbial populations (aerobic bacteria, yeasts and molds, Enterobacteriaceae, Escherichia coli, and Salmonella) were monitored at 12 points along the processing line (accumulator, prewash rinse, washer 1, washer 2, sanitizer, dryer, oiler, scales, two packer head lanes, rewash entrance, and rewash exit). Three commercial facilities were each visited three times, a total of 990 eggs were sampled, and 5,220 microbiological samples were subsequently analyzed. Although variations existed in concentrations of microorganisms recovered from each plant, the patterns of fluctuation for each population were similar at each plant. On average, aerobes, yeasts and molds, Enterobacteriaceae, and E. coli prevalence were reduced by 30, 20, 50, and 30%, respectively, by the end of processing. The microbial concentrations (log CFU per milliliter) in the egg rinse collected from packer head lanes were decreased by 3.3, 1.3, 1.3, and 0.5, respectively, when compared with those of rinses collected from eggs at the accumulator. Salmonella was recovered from 0 to 48% of pooled samples in the three repetitions. Higher concentrations of Salmonella were recovered from preprocessed than from in-process or ready-to-pack eggs. These data indicate that current commercial practices decrease microbial contamination of egg shell surfaces.

Animals↗
PubMed2000

Food labeling, safe handling statements, labeling of shell eggs; refrigeration of shell eggs held for retail distribution. Food and Drug Administration, HHS. Final rule.

The Food and Drug Administration (FDA) is revising its food labeling regulations to require a safe handling statement on cartons of shell eggs that have not been treated to destroy Salmonella microorganisms. The agency also is requiring that, when held at retail establishments, shell eggs be stored and displayed under refrigeration at a temperature of 7.2 degrees C (45 degrees F) or less. FDA is taking these actions because of the number of outbreaks of foodborne illnesses and deaths caused by Salmonella Enteritidis (SE) that are associated with the consumption of shell eggs. These actions also respond, in part, to petitions from Rose Acres Farm, Inc., and the Center for Science in the Public Interest (CSPI). Safe handling statements will help consumers take measures to protect themselves from illness or deaths associated with consumption of shell eggs that have not been treated to destroy Salmonella (all serotypes). Refrigeration of shell eggs that have not been treated to destroy Salmonella will help prevent the growth of SE in shell eggs.

Consumer Product Safety↗
PubMed2005

Recovery of Salmonella from commercial shell eggs by shell rinse and shell crush methodologies.

Salmonella is the most important human pathogen associated with shell eggs. Salmonella Enteritidis is the serotype most often implicated in outbreaks, although other serotypes have been recovered from eggs and from the commercial shell egg washing environment. Many sample methods are used to recover microorganisms from eggshells and membranes. A shell rinse and modified shell-and-membrane crush method for recovery of Salmonella were compared. Eggs were collected from 3 commercial shell-washing facilities (X, Y, and Z) during 3 visits. Twelve eggs were collected from each of 10 to 12 locations along the egg processing chain. After being transported back to the laboratory, each egg was sampled first by a shell rinse method and then by a shell crush method. For each technique (rinse or crush), 2 pools of 5 eggs per location sampled were selectively enriched for the recovery of Salmonella. Presumptive samples positive for Salmonella were confirmed serologically. Overall, there were 10.1% (40/396) Salmonella-positive pooled samples. Salmonella were recovered by the shell rinse and shell crush techniques (4.8 vs. 5.3%, respectively). Plant X yielded 21.5% Salmonella positives, whereas less than 5% of samples from plants Y and Z were found to be contaminated with the organism (4.2 and 4.5%, respectively). Salmonella was recovered more often from unwashed eggs (15.8%) than from washed eggs (8.3%). For some eggs, Salmonella was only recovered by one of the methods. Use of both approaches in the same experiment increased sampling sensitivity, although in most cases, crushing provided more sensitive Salmonella recovery.

Animals↗
PubMed2005

Correlation of eggshell strength and Salmonella enteritidis contamination of commercial shell eggs.

Shell quality has been identified as a heritable trait that can be manipulated by genetic selection. Previous research has concluded that many methods of determining shell quality produce variable results. With the development of newer, more precise measuring technologies, shell strength can now be assessed in a consistent, objective fashion. A research project was conducted to determine what role shell strength might play in affecting external Salmonella Enteritidis contamination of egg contents. Visibly clean eggs were collected from an in-line shell egg-processing facility at the accumulator. Eggs were inoculated by dipping in a concentrated suspension of nalidixic acid-resistant Salmonella Enteritidis. After storage, eggs were assessed for shell strength and both external and internal Salmonella Enteritidis contamination. In the first study, there was a significant difference (P < 0.05) in shell strength among the three replicates. No differences between treatments were found for shell strength or Salmonella Enteritidis contamination of contents. In the second study, there were no replicate differences for any of the monitored factors. When rinsate and content samples were enriched, 100% of the rinsates were positive for Salmonella Enteritidis. No content samples were shown to be contaminated with Salmonella Enteritidis during direct plating, but 3 to 5% of the samples from each replicate were positive after enrichment. Correlation analysis of the results from each study found only weak correlations between shell strength and Salmonella Enteritidis contamination on eggshell surface or contents. Within the range of shell strengths recorded in this study, the correlation analysis suggests that shell strength does not play a major role in Salmonella Enteritidis contamination. Further work with eggs that represent a greater range of shell strengths could provide a clearer indication of the interaction of shell strength and Salmonella Enteritidis contamination.

Animals↗
PubMed1990

Effect of 1 alpha,25-dihydroxycholecalciferol on egg shell quality and egg production.

1. The effect of replacing dietary cholecalciferol (D3) by 1 alpha,25-dihydroxycholecalciferol (1,25-(OH)2D3) on egg shell quality and egg production was tested on 32-week-old White Leghorn laying hens over 9 weeks. 2. Hens fed on a diet supplemented with 5 micrograms 1,25-(OH)2D3/kg diet, tended to lay more eggs, and the eggs had significantly higher specific gravity and percentage shell than eggs from control hens fed on a diet supplemented with 27.5 micrograms D3/kg diet. 3. The effect became apparent after about 4 weeks of treatment and persisted until the end of the test. 4. Hens fed on a diet without D3 supplement started to lay very thin or soft shelled eggs within 4 weeks, suggesting that the birds' reserves of D3 or its metabolites were depleted within this period. 5. The results suggest that 1,25-(OH)2D3 can be substituted for D3 in layer diets to improve egg shell quality.

Animals↗
PubMed1994

Contamination of egg shell and contents with Salmonella enteritidis: a review.

Salmonella enteritidis can contaminate the contents of clean, intact shell eggs as a result of infections of the reproductive tissue of laying hens. The principal site of infection would appear to be the upper oviduct. In egg contents the most important sites of contamination are either the outside of the vitelline membrane or the albumen surrounding it. In fresh eggs, only few salmonellas are present and as albumen is an iron-restricted environment, growth will only occur once storage-related changes to vitelline membrane permeability, which allow salmonellas to invade yolk contents, have taken place. When this happens high populations are achieved in both yolk contents and albumen. Some eggs from naturally infected hens have been found to contain large numbers of S. enteritidis. The rate of change in membrane permeability is temperature-dependent. In eggs stored at 20 degrees C, yolk invasion is uncommon until eggs have been stored for 3 weeks. In stimulated kitchen conditions where temperatures reached 30 degrees C, salmonellas could grow rapidly after a few days.

Animals↗
PubMed1978

Influence of hen dietary calcium and phosphorus on the integrity of the egg shell as it would influence hatching success and the consequences of preincubation 2, 4, 5-T spraying with and without a high TCDD level.

Commercial strain laying hens were fed practical rations deficient in calcium and/or phosphorus to affect weak shelled eggs. Spraying these eggs prior to incubation with 2, 4, 5-T preparations having extremes in TCDD contamination at 10x recommendation was without effect on all parameters used to evaluate embryological development and subsequent early performance of resultant chicks. Analyses for 2, 4, 5-T residues indicated that the shell though weakened was unaffected as a barrier to herbicide contamination.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1993

An outbreak of infection with Salmonella enteritidis phage type 4 associated with the use of raw shell eggs.

A community outbreak of Salmonella enteritidis phage type (PT) 4 infection, associated with eating food from a sandwich bar in Colchester, occurred in July 1991. One hundred and forty-four people were reported with food poisoning, of whom 132 met the clinical case definition. Three cohort studies of 92 people showed that illness was associated with the consumption of food containing mayonnaise. S. enteritidis PT4, indistinguishable by plasmid profile analysis, was isolated from stool samples from 83 people, food items including egg shells from the sandwich bar, and birds taken from the egg producing farm which supplied the eggs. This was the largest recorded outbreak of S. enteritidis PT4 infection in recent years associated with eggs produced in the United Kingdom. Existing advice on avoiding the use of raw eggs in uncooked dishes had not been followed. This outbreak highlights the importance of training in the implementation of this advice.

Adolescent↗
PubMed1981

Lysine-derived cross-links in the egg shell membrane.

Egg shell membrane protein contains significant quantities of the lysine-derived aldehyde, allysine, and its aldol condensation product. NaB3H4 reduction followed by alkaline hydrolysis of purified protein revealed that there were six residues/1000 of both allysine and the reduced aldol while only traces of desmosine and isodesmosine were detected. The amino acid composition of the membrane protein did not resemble that of mammalian elastin.

2-Aminoadipic Acid↗
PubMed1997

Pathogenesis of reduced egg production and soft-shelled eggs in laying hens associated with Leucocytozoon caulleryi infection.

The pathogenesis of reduced egg production with soft-shelled eggs in laying hens naturally infected with Leucocytozoon caulleryi was investigated. Many large schizonts of L. caulleryi schizonts were seen in the ovary and oviducts of chickens. Granulomatous and lymphocytic inflammation, edema, and pressure atrophy were associated with these schizonts. The uterine region that secretes the egg shell exhibited the most severe damage. These lesions in the reproductive organs may explain the mechanism for causing the reduced egg production and soft-shelled eggs in laying hens infected with L. caulleryi.

Animals↗
PubMed1975

Effect of chlorinated hydrocarbons on shell gland carbonic anhydrase and egg shell thickness in Japanese quail.

Japanese quail (Coturnix japonica) were fed different levels of pesticide in their diets for 15 weeks. The levels of pesticide used were 25, 50, 100, 200 p.p.m. DDE 25, 50, 100, 200 p.p.m. DDT and 50 p.p.m. PCB. Carbonic anhydrase activities were analyzed in the shell glands and blood; pesticide concentration in the eggs of the first experiment was measured; egg weight, shell weight and shell thickness were also measured. No depression in growth was observed at any levels of pesticides used. Quail fed 200 p.p.m. DDE showed a high mortality rate after 10--12 weeks on the diet, while other levels produced no increase in death rate. Lower levels of DDT and DDE (25 and 50 p.p.m.) had no significant effect on egg shell weight or thickness. Higher levels (100 and 200 p.p.m) of DDT and DDE produced a small increase in shell weight and a 5 per cent decrease in shell thickness and were associated with increased shell breakage. At levels of 25 p.p.m. and 50 p.p.m. DDE, the activity of carbonic anhydrase in the shell gland was significantly increased. At levels of 200 p.p.m. DDE and 100 p.p.m. DDT in the diet, the activity of carbonic anhydrase was decreased by 12--15 per cent. A 50 per cent reduction in carbonic anhydrase activity in the shell gland seemed to be necessary for an increased production of soft shelled eggs when it was induces by sulfanilamide. Pesticide residues in the eggs of Japanes quail up to about 300 p.p.m. DDE and 150 p.p.m. DDT were not associated with any change in egg shell thickness. At about 600 p.p.m. DDE and 500 p.p.m. DDT in the eggs, corresponding to 100 and 200 p.p.m. in the diet, the egg shell thickness was reduced by 5 per cent. PCB at 50 p.p.m. produced a small decrease (4.5 per cent) in shell thickness and an increase in the percentage of cracked eggs.

Animals↗
PubMed2005

Shell rinse and shell crush methods for the recovery of aerobic microorganisms and enterobacteriaceae from shell eggs.

Recovery of bacteria from shell eggs is important for evaluating the efficacy of processing and the quality and safety of the final product. Shell rinse (SR) techniques are easy to perform and widely used. An alternative sampling method involves crushing and rubbing the shell (CR). To determine the most appropriate method for recovering microorganisms from shell eggs, 358 shell eggs were collected from a commercial egg processor and sampled by SR and CR techniques. Total aerobic mesophiles and Enterobacteriaceae were enumerated on plate count and violet red bile glucose agar plates, respectively. Unwashed, in process, and postprocess eggs were evaluated in the study. Aerobic microorganism prevalence for eggshells sampled was similar for both methods (approximately 100%), but the log CFU per milliliter values were higher in the SR than the CR samples (3.2 and 2.2, respectively). Average Enterobacteriaceae recovery was similar for both methods (45 versus 40% for the SR and CR methods, respectively) when all eggs were considered together. This population was detected more often by SR when unwashed eggs were sampled (90 versus 56% for the SR and CR methods, respectively), equally by SR and CR for in-process eggs (30 versus 29.3% for the SR and CR methods, respectively), but more often by CR for postprocess eggs (10 versus 36% for the SR and CR methods, respectively). The SR technique was easier to perform and recovered larger numbers of aerobic organisms, particularly for unwashed eggs. However, the CR technique was more efficient for recovery of Enterobacteriaceae from postprocess eggs. Stage of shell egg processing may be an important consideration when choosing egg sampling methods.

Animals↗
PubMed1989

Characterization of shell gland lipids from chickens (Gallus domesticus) producing strong or weak egg shells.

1. The reduction in egg shell strength in hens at the end of the first reproductive cycle was not associated with abnormal uterine or body fat accumulation. 2. The phosphatidylcholine concentration was greater in the shell glands of hens producing strong egg shells compared to that of producing weak egg shells. 3. Differences were not detected in the total lipid or cholesterol concentrations or the fatty acid profiles of phosphatidylcholine or phosphatidylethanolamine fractions. 4. Following an induced molt, the fatty acid profile of the total lipid fraction of the shell gland was altered with a decrease in stearic acid and an increase in oleic acid. 5. The results demonstrate that alterations in egg shell strength are mainly associated with changes in shell gland phospholipid polar head group composition and not with changes in phospholipid fatty acid profile or cholesterol concentration.

Animals↗
PubMed1993

Calbindin D28K regulation in precociously matured chick egg shell gland in vitro.

Egg shell calcification in the hen uterus (egg shell gland, ESG) depends primarily on intestinal absorption of dietary Ca2+ as well as ESG Ca2+ transport into the shell. Intestinal Ca2+ absorption is linked to vitamin D-induced calbindin D28K (D28K) concentration. The ESG also contains D28K, and Ca2+ transport into the shell appears to be linked to D28K gene expression, but until this report, there was no direct proof that ESG D28K was or was not vitamin D-dependent. To address this issue, highly developed ESG from estradiol (E2)-injected, severely vitamin D-depleted chicks were cultured in serum-free medium with excellent viability. Addition of the vitamin D-hormone, 1,25(OH)2 vitamin D3 (1,25), to the culture medium increased ESG D28K levels as much as 70%. E2 alone had no effect, but E2 plus 1,25 further increased ESG D28K levels up to 160%. By contrast, progesterone (P4) prevented the 1,25-stimulated increase in D28K, while having no effect on basal D28K level. Of considerable interest, thapsigargin (THAPS), which increases intracellular Ca2+ concentration ([Ca2+]i) in many cell types, stimulated D28K synthesis in a concentration-dependent manner in the complete absence of 1,25 and independent of the [Ca2+] of the medium. These results are the first direct evidence that ESG D28K is under direct control of 1,25 and that both gonadal steroid hormones, E2 and P4, may be coregulators. Further, the effects of THAPS suggest that [Ca2+]i itself may also regulate D28K. This new in vitro model clearly represents a unique opportunity to study the regulation of the ESG calcium transport mechanism under stringently defined conditions.

Animals↗
PubMed2006

Improved physical and biochemical features of a collagen membrane by conjugating with soluble egg shell membrane protein.

Soluble egg shell membrane protein (SEP) prepared from the egg shell membrane by performic acid oxidation and pepsin digestion was applied to prepare a membrane conjugated with pepsin-solubilized collagen (PSC) by cross-linking with water-soluble carbodiimide. SEP enabled a conjugated membrane to be constructed with a well-developed network structure having thicker collagen fibrils and higher stability than the PSC membrane alone, as indicated by reduced solubility and collagenase-digestion, increased denaturation temperature, and superior flexibility. The SEP-PSC membrane (SEP:PSC of 1:1, w/w) had lower sweatiness than the PSC membrane. Fibroblasts and keratinocytes adhered to the SEP-PSC-coated wells (SEP:PSC of 1:10, w/w) as a fundamental model of an artificial skin similar to that to the PSC-coated wells due to similar expression level of several cell-adhesion proteins. An SEP-PSC coating accelerated the cell growth of fibroblasts, whereas the cell growth of keratinocytes did not change, or decreased slightly due to more rapid differentiation indicated by a more substantial expression of differentiation marker proteins than a PSC-coating without SEP.

Animals↗