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Journal of Food Protection Oct 2010Prompt refrigeration to restrict bacterial growth is important for reducing eggborne transmission of Salmonella enterica serovar Enteritidis (SE). The nutrient-rich yolk...
Prompt refrigeration to restrict bacterial growth is important for reducing eggborne transmission of Salmonella enterica serovar Enteritidis (SE). The nutrient-rich yolk interior is a relatively infrequent location for initial SE deposition in eggs, but migration across the vitelline membrane can result in rapid bacterial multiplication during storage at warm temperatures. The objective of the present study was to measure the multiplication of SE in yolks after introduction at three different locations and subsequent storage at a range of temperatures. Using an in vitro egg contamination model, approximately 100 CFU of SE was inoculated either inside yolks, onto the exterior surface of vitelline membranes, or into the adjacent albumen. After storage of samples from each inoculation group at 10, 15, 20, and 25°C for 24 h, SE was enumerated in yolks. For all three inoculation locations, the final SE levels in yolks increased significantly with increasing storage temperatures. At all storage temperatures, significant differences in SE multiplication were observed between inoculation sites (yolk inoculation>vitelline membrane inoculation>albumen inoculation). At 25°C, final log concentrations of 7.759 CFU of SE per ml (yolk inoculation), 2.014 CFU/ml (vitelline membrane inoculation), and 0.757 CFU/ml (albumen inoculation) were attained in yolks after storage. These results demonstrate that, even when the initial site of SE deposition is outside the egg yolk, substantial multiplication supported by yolk nutrients can occur during the first day of storage and the risk of bacterial growth increases at higher ambient storage temperatures.
Topics: Animals; Chickens; Colony Count, Microbial; Consumer Product Safety; Egg Yolk; Food Contamination; Food Microbiology; Food Preservation; Humans; Refrigeration; Salmonella Food Poisoning; Salmonella enteritidis; Temperature; Time Factors; Vitelline Membrane
PubMed: 21067679
DOI: 10.4315/0362-028x-73.10.1902 -
Biochemical and Biophysical Research... Nov 2004We have developed an efficient method for removing the vitelline membrane of Xenopus oocytes for patch clamp recording. Functional studies using oocytes as models...
We have developed an efficient method for removing the vitelline membrane of Xenopus oocytes for patch clamp recording. Functional studies using oocytes as models provide insights into the biological profiles and physiological properties of ion channels. A methodological modification is described in this paper. The important feature of this modification is that protease treatment is used to remove the oocyte's vitelline membrane. This method is simple and the oocytes produced remain in a healthy state during the recording process.
Topics: Animals; Oocytes; Patch-Clamp Techniques; Peptide Hydrolases; Vitelline Membrane; Xenopus
PubMed: 15485648
DOI: 10.1016/j.bbrc.2004.09.162 -
Poultry Science Sep 2006Salmonella enteritidis and Salmonella typhimurium definitive type 104 (DT104) have been detected in the chicken oviduct, and their survival in egg albumen at the chicken...
Salmonella enteritidis and Salmonella typhimurium definitive type 104 (DT104) have been detected in the chicken oviduct, and their survival in egg albumen at the chicken body temperature of 42 degrees C may be important in oviductal and transovarian contamination of intact shell eggs. Eight S. enteritidis and 24 S. typhimurium DT104 strains were tested for their in vitro survival in egg albumen. The concentration of the organisms declined more rapidly when incubated at 42 degrees C than at 37 degrees C and dropped to nondetectable levels within 96 h at the higher, but not at the lower, temperature. In another experiment, 3 S. enteritidis and 3 S. typhimurium DT104 strains were randomly selected, and dosages of 20 and 200 cells of each strain were inoculated onto the vitelline membranes of egg yolks, which were then submerged in the original albumen and incubated for 24 h at 42 degrees C. Under these conditions, the organisms survived in albumen but did not penetrate the vitelline membrane. However, in a similar experiment, penetration did occur when the specimens were incubated at 30 degrees C for 72 h. The results suggest that low numbers of S. enteritidis and S. typhimurium DT104 can be expected to survive in egg albumen during the 24-h period of egg formation in the oviduct but would be unlikely to invade the yolk.before oviposition. However, depending on storage conditions following oviposition, S. enteritidis, as well as S. typhimurium DT104, could survive longer and may eventually invade the egg yolks.
Topics: Albumins; Animals; Chickens; Female; Oviposition; Salmonella enteritidis; Salmonella typhimurium; Temperature; Time Factors; Vitelline Membrane
PubMed: 16977857
DOI: 10.1093/ps/85.9.1678 -
Poultry Science Aug 2000The TA-XT21 texture analyzer (TA) was used to evaluate vitelline membrane strength (VMS). Fresh and aged (1 wk at 25 C) eggs (n = 48 eggs x 2 replications) were...
The TA-XT21 texture analyzer (TA) was used to evaluate vitelline membrane strength (VMS). Fresh and aged (1 wk at 25 C) eggs (n = 48 eggs x 2 replications) were evaluated. Fresh and aged eggs were further divided into two groups of yolk only or whole egg (with intact albumen). Yolk index, Haugh units, pH, broken-out egg weights, VMS, yolk viscosity, and scanning electron microscopy (SEM) images were evaluated. Results from the TA indicated a decrease in VMS in aged eggs compared to fresh eggs and in yolk-only eggs compared to whole eggs. The SEM images indicated a loss of structural integrity in aged eggs as compared to fresh eggs. As expected, aged eggs also had higher albumen and yolk pH, lower Haugh units, lower yolk index, and decreased viscosity compared to fresh eggs. There were no differences in broken-out egg weights or whole egg pH between fresh and aged eggs. As the yolk membrane strength increased, yolk index (r = 0.59) and Haugh units (r = 0.56) decreased, and yolk pH (r = -0.64) and albumen pH (r = -0.57) increased. The study suggests that the TA combined with the modified extrusion cell may be effective in determining VMS. In addition, yolk index, Haugh units, and yolk and albumen pH may be used to predict changes in VMS.
Topics: Animals; Biomechanical Phenomena; Chickens; Egg Yolk; Eggs; Hydrogen-Ion Concentration; Microscopy, Electron, Scanning; Quality Control; Time Factors; Viscosity; Vitelline Membrane
PubMed: 10947190
DOI: 10.1093/ps/79.8.1189 -
Developmental Biology Jan 2000The dorsoventral axis of the Drosophila embryo is defined by a ventral signal that arises within the perivitelline space, an extracellular compartment between the embryo...
The dorsoventral axis of the Drosophila embryo is defined by a ventral signal that arises within the perivitelline space, an extracellular compartment between the embryo plasma membrane and the vitelline membrane layer of the eggshell. Production of the ventral signal requires four members of the serine protease family, including a large modular protein with a protease domain encoded by the nudel gene. Here we provide evidence that the Nudel protease has an integral role in eggshell biogenesis. Mutations in nudel that disrupt Nudel protease function produce eggs having vitelline membranes that are abnormally permeable to the dye neutral red. Permeability varies among mutant nudel alleles but correlates with levels of Nudel protease catalytic activity and function in embryonic dorsoventral patterning. These mutations also block cross-linking of vitelline membrane proteins that normally occurs upon egg activation, just prior to fertilization. In addition, Nudel protease autoactivation temporally coincides with vitelline membrane cross-linking and can be triggered in mature eggs in vitro by conditions that lead to egg activation. We discuss how the Nudel protease might be involved in both eggshell biogenesis and embryonic patterning.
Topics: Animals; Body Patterning; Cell Membrane Permeability; Cross-Linking Reagents; Drosophila; Drosophila Proteins; Enzyme Activation; Serine Endopeptidases; Signal Transduction; Vitelline Membrane
PubMed: 10625559
DOI: 10.1006/dbio.1999.9562 -
Cell Differentiation and Development :... Sep 1988In sabellid polychaetes the vitelline envelopes, in which microvilli with glycocalyx structures at the tips are invested, change in structure during oogenesis. Vitelline...
In sabellid polychaetes the vitelline envelopes, in which microvilli with glycocalyx structures at the tips are invested, change in structure during oogenesis. Vitelline envelopes isolated from Schizobranchia oocytes 25-100 micron and 160-185 micron in diameter, were analyzed in protein components by iodination, electrophoresis, Western blotting and radioactive labeling technique. The observations demonstrate that the membrane proteins of the vitelline envelopes are not consistent but variable in components during oogenesis. Most of these proteins, particularly the high molecular weight proteins, are PAS-positive glycoproteins, which may have specific carbohydrate residues binding to wheat germ agglutinin. The proteins could be labeled with [3H]valine within 36 h by incubating the whole oocytes in sea water to a high level, indicating that the proteins are actively synthesized by the growing oocytes. Synthetic rates of the proteins differ from each other at one stage and are higher in the small than in the large oocytes in general, suggesting that the membrane proteins are involved in the function of the vitelline envelopes during oogenesis.
Topics: Animals; Glycoproteins; Membrane Proteins; Oogenesis; Polychaeta; Vitelline Membrane
PubMed: 3196931
DOI: 10.1016/0922-3371(88)90052-4 -
Journal of Clinical Pathology Dec 1979Eleven lung samples positive for Legionnaires' disease, 12 strains of Legionella pneumophila cultured on various bacteriological media, and one strain growth in the yolk...
Eleven lung samples positive for Legionnaires' disease, 12 strains of Legionella pneumophila cultured on various bacteriological media, and one strain growth in the yolk sac of fertile hens' eggs were examined by negative staining, thin sectioning, and scanning electron microscopy. All organisms studied were ultrastructurally similar irrespective of strain, source, or method of cultivation, presenting mainly as short rods, 0.6 x 1.5 micrometer, with tapered ends, though long forms and filaments were also evident. In this they resembled typical Gram-negative organisms. Division was by non-septate binary fission, and the cell wall was composed of two triple-unit membranes with morphological evidence of a peptidoglycan layer. The bacterial cytoplasm was rich in ribosomes and nuclear elements and often contained vacuoles. No acid polysaccharides or bacterial appendages were detected surrounding the organisms. In lung tissue and yolk sac membranes, the organisms replicated within the cytoplasm of infected cells and in the intercellular spaces and were specifically identified in thin sections by immunoferritin techniques.
Topics: Bacteria; Culture Media; Female; Humans; Legionnaires' Disease; Lung; Microscopy, Electron, Scanning; Staining and Labeling; Vitelline Membrane
PubMed: 94059
DOI: 10.1136/jcp.32.12.1195 -
Symposia of the Society For... 1974
Review
Topics: Animals; Biological Transport; Cattle; Female; Humans; Lysosomes; Microscopy, Electron; Models, Biological; Molecular Weight; Placenta; Pregnancy; Proteins; Rabbits; Uterus; Vitelline Membrane; gamma-Globulins
PubMed: 4141803
DOI: No ID Found -
The EMBO Journal Jan 1985cDNA clones for two Drosophila vitelline membrane genes have been identified on the basis of: (i) stage and tissue specificity of transcription and (ii) size and amino...
cDNA clones for two Drosophila vitelline membrane genes have been identified on the basis of: (i) stage and tissue specificity of transcription and (ii) size and amino acid content of the translation product. Cross-hybridization data suggest that DmcMM99 and DmcMM115 are members of a multi-gene family which includes at least three members, all of which reside on the left arm of the second chromosome. DmcMM99 and DmcMM115 originate from polytene band positions 34C and 26A, respectively. A third, cross-hybridizing gene resides at position 32EF. Southern analysis of a genomic clone, lambda LS1, homologous to DmcMM115, indicates that two vitelline membrane genes may be clustered at the 26A site.
Topics: Animals; Base Sequence; Chromosome Mapping; Cloning, Molecular; DNA; Drosophila melanogaster; Egg Proteins; Female; Genes; Protein Biosynthesis; Transcription, Genetic; Vitelline Membrane
PubMed: 3926479
DOI: 10.1002/j.1460-2075.1985.tb02329.x -
Molecular Reproduction and Development Aug 2008The oocyte vitelline envelope (VE) of gilthead seabream is composed of four known zona pellucida (ZP) proteins, ZPBa, ZPBb, ZPC, and ZPX. We have previously shown that... (Comparative Study)
Comparative Study
The oocyte vitelline envelope (VE) of gilthead seabream is composed of four known zona pellucida (ZP) proteins, ZPBa, ZPBb, ZPC, and ZPX. We have previously shown that the gilthead seabream ZP proteins are differentially transcribed in liver and ovary, with the expression in liver being under estrogenic control. However, although mRNA was found in both liver and ovary, only low ZPBa protein levels were detected in liver and plasma. Using isoform-specific ZP antibodies we show that ZPBa and ZPX translation products are present in the cytosol of stage I and II oocytes. In addition, the zpBa and zpX mRNAs were detected in early developing oocytes. During oocyte growth (vitellogenesis), the VE increased in thickness (>10 microm), and we show that the four ZP isoforms are present in different regions of the VE. ZPX was detected closest to the oocyte plasma membrane while the intermediate region was composed of ZPBa, ZPBb, and ZPC. At the outer layer, only ZPC was detected. When oocytes reach the fully grown stage they resume meiosis and hydration. As the oocyte expands, thinning to 4 microm, the VE acquire a striped and compact appearance at the electron microscopy level. This study provides further evidence for the oocyte origin of some ZP proteins in the gilthead seabream and suggests that the ZP proteins are differentially distributed within the VE.
Topics: Amino Acid Sequence; Animals; Blotting, Western; Egg Proteins; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Immunohistochemistry; Liver; Membrane Glycoproteins; Microscopy, Electron; Molecular Sequence Data; Oocytes; Protein Isoforms; RNA, Messenger; Receptors, Cell Surface; Sea Bream; Vitelline Membrane; Vitellogenesis; Zona Pellucida Glycoproteins
PubMed: 18247334
DOI: 10.1002/mrd.20876