Effect of Temperature on the Growth Response of Salmonella Enteritidis Inoculated onto the Vitelline Membranes of Fresh Eggs

2003 ◽  
Vol 66 (8) ◽  
pp. 1368-1373 ◽  
Author(s):  
G. J. FLEISCHMAN ◽  
C. L. NAPIER ◽  
D. STEWART ◽  
S. A. PALUMBO
Keyword(s):  
Salmonella Enteritidis ◽  
Growth Response ◽  
Effect Of Temperature ◽  
Vitelline Membrane ◽  
Growth Responses ◽  
In Ovo ◽  
Maximum Increase ◽  
Comparison Of The Results ◽  
As If

The growth response of Salmonella Enteritidis (SE) on the vitelline membrane in vitro was studied with the use of a special tube devised specifically for the inoculation of SE onto the vitelline membrane and for the sampling of the yolk near the inoculation site. This latter ability allowed the detection of the movement of SE into the yolk. The growth of SE on the membrane was compared with that of SE inoculated into yolk and albumen in vitro and in ovo in fresh in-shell eggs. The incubation time was 2 days, and the incubation temperatures were 4, 8, 15, 27, and 37°C. Comparison of the results obtained for in vitro growth showed that at 4, 8, and 15°C, SE behaved as if it were in the albumen, with its numbers decreasing over time. At 27 and 37°C, SE grew as if it were in yolk, with a maximum increase of 4.5 log CFU after 2 days at 37°C. In no experiments involving growth on the vitelline membrane did SE appear in the yolk. Comparisons between in vitro and in ovo growth responses of SE in yolk and albumen indicate that SE growth on the membrane parallels that in the in-shell egg.

Multiplication and Motility of Salmonella enterica Serovars Enteritidis, Infantis, and Montevideo in In Vitro Contamination Models of Eggs

2006 ◽  
Vol 69 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
TOSHIYUKI MURASE ◽  
KAZUHIKO FUJIMOTO ◽  
RUI NAKAYAMA ◽  
KOICHI OTSUKI
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Egg Yolk ◽  
Vitelline Membrane ◽  
Human Patient ◽  
Polycarbonate Membrane ◽  
Specific Pathogen ◽  
Egg Albumen ◽  
Petri Plate

The invasive ability of Salmonella enterica serovars Enteritidis, Infantis, and Montevideo in eggs was examined. Strains of these serovars originating from egg contents, laying chicken houses, and human patients were experimentally inoculated (0.1-ml dose containing 78 to 178 cells) onto the vitelline membrane of eggs collected from specific-pathogen-free chickens and incubated at 25°C. The test strains were detected in 25 of 138 yolk contents by day 6, indicating the penetration of Salmonella organisms through the vitelline membrane. There were no significant differences in overall rates of penetration between serovars. The organisms were also detected in the albumen from 125 of 138 eggs tested by day 6. Growth to more than 106 CFU/ml was observed in 48 of the 125 albumen samples. An inoculum of 1,000 Salmonella cells was added to 15 ml of albumen at the edge of a petri plate. A 10-mm-diameter cylindrical well, the bottom of which was sealed with a polycarbonate membrane with 3.0-μm pores, was filled with egg yolk and placed into the albumen at the center of the dish, which was maintained at 25°C. Experiments were performed in triplicate with each strain. Salmonella organisms in all the albumen samples were detected by day 11. However, motility of the organisms toward the yolk was observed in only two dishes inoculated with the Salmonella Enteritidis strain from a human patient and in one dish inoculated with the Salmonella Infantis strain from liquid egg. The albumen samples obtained from the dishes inoculated with the Salmonella Enteritidis strain had high numbers of bacteria (>108 CFU/ml). The present study suggests that Salmonella organisms in egg albumen are unlikely to actively move toward the yolk, although deposition on or near the vitelline membrane can be advantageous for proliferation.

Effect of Refrigeration on In Vitro Penetration of Salmonella Enteritidis through the Egg Yolk Membrane

2006 ◽  
Vol 69 (6) ◽  
pp. 1426-1429 ◽  
Author(s):  
RICHARD K. GAST ◽  
PETER S. HOLT ◽  
RUPA GURAYA
Keyword(s):  
Treatment Group ◽  
Salmonella Enteritidis ◽  
Egg Yolk ◽  
Vitelline Membrane

Internally contaminated eggs have been implicated as leading sources of transmission of Salmonella Enteritidis (SE) to humans. Although SE is not often deposited inside the nutrient-rich yolks of naturally contaminated eggs, penetration through the vitelline membrane to reach the yolk contents could result in rapid bacterial multiplication. In previous studies, such penetration has been observed occasionally at warm temperatures during experiments with in vitro egg contamination models. The present study was conducted to determine whether refrigeration affects the frequency of in vitro SE penetration of the egg yolk membrane. After inoculation of small numbers of SE onto the outside of the vitelline membranes of intact yolks, immediate refrigeration of contaminated samples prevented the penetration of SE into the egg yolk contents during 24 h of storage. However, SE penetrated inside the yolk contents in 4% of contaminated egg samples refrigerated after 2 h of storage at 30°C, 15% of samples refrigerated after 6 h of storage at 30°C, and 40% of samples stored at 30°C for 24 h (48 samples per treatment group). These results highlight the value of prompt refrigeration for restricting the opportunities for SE to multiply to high numbers inside the yolks of contaminated eggs.

scholarly journals Phylogenetic Diversity and Effect of Temperature on Pathogenicity of Colletotrichum lupini

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 938-950 ◽  
Author(s):  
Guillaume Dubrulle ◽  
Flora Pensec ◽  
Adeline Picot ◽  
Karim Rigalma ◽  
Audrey Pawtowski ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Early Spring ◽  
Genetic Identification ◽  
Effect Of Temperature ◽  
Colletotrichum Acutatum ◽  
Growth Responses ◽  
In Planta ◽  
Field Samples ◽  
Colletotrichum Lupini

Although lupin anthracnose caused by Colletotrichum lupini is a significant threat for spring and winter lupin crops, it has been poorly studied so far. This study aimed at characterizing the (i) phylogenetic, (ii) morphological, and (iii) physiological diversity of collected isolates from anthracnose-affected lupins. The genetic identification of representative isolates (n = 71) revealed that they were all C. lupini species, further confirming that lupin anthracnose is caused by this species. However, multilocus sequencing on these isolates and 16 additional reference strains of C. lupini revealed a separation into two distinct genetic groups, both of them characterized by a very low genetic diversity. The diversity of morphological characteristics of a selected subset of C. lupini isolates was further evaluated. To the best of our knowledge, microsclerotia production observed for some isolates has never been reported so far within the Colletotrichum acutatum species complex. Finally, the modeling of growth responses of a subset of C. lupini strains revealed the capacity of some strains to grow in vitro at 5°C. This ability was also evidenced in planta, because C. lupini DNA was detectable in plants from 14 days postinoculation at 5°C onward, whereas symptoms began to appear a week later, although at a very low level. Since lupin crops are planted during winter or early spring, growth studies in vitro and in planta demonstrated the capability of the species to grow at temperatures ranging from 5 to 30°C, with an optimum close to 25°C. In this study, C. lupini-specific primers were also designed for real-time quantitative PCR on fungal DNA and allowed the detection of C. lupini in asymptomatic field samples. These results open perspectives to detect earlier and limit the development of this pathogen in lupin crops.

The in-vitro acid-growth response: Relation to in-vivo growth responses and auxin action

Planta ◽  
1972 ◽  
Vol 104 (4) ◽  
pp. 282-296 ◽  
Author(s):  
David L. Rayle ◽  
Robert Cleland
Keyword(s):  
Growth Response ◽  
Growth Responses ◽  
Acid Growth ◽  
Auxin Action ◽  
In Vivo Growth

Effects of L-phenylalanine on somite formation in the early chick embryo

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 175-190
Author(s):  
K. Palén ◽  
L. Thörneby
Keyword(s):  
Chick Embryo ◽  
Regional Differences ◽  
Vitelline Membrane ◽  
Early Developmental Stage ◽  
Yolk Granule ◽  
Chick Embryos ◽  
In Ovo ◽  
Somite Formation ◽  
Early Developmental

Chick embryos were treated in ovo and in vitro with L-phenylalanine from the intermediate streak stage (Hamburger & Hamilton stage 3, 12–13 h of incubation) to the 7-somite stage (H & H stage 9, 29–33 h of incubation). Treatment in ovo resulted in a large number of embryos developing somite blocks, i.e. imperfectly segmented somites. In embryos treated at an early developmental stage (12–21 h of incubation), the blocks of unsegmented somite mesoderm occurred mostly in the somite pairs 1–5, whereas treatment that began at a later stage (24–30 h of incubation) caused blocks in the somite pairs 5–10, i.e. the appearance of blocks of unsegmented somite mesoderm is correlated in time with the onset of the treatment. No difference regarding mitotic indices could be distinguished between normally segmented somites and blocks of unsegmented somite mesoderm. Autoradiography based on tritiated L-phenylalanine showed no regional differences in labelling of the chick embryo body. Electronmicroscopical observations indicate a slightly suppressed formation of microvilli in the cells of the unsegmented mesoderm blocks compared with cells in normally segmented somites. The observed disturbances are probably caused by a suppressed yolk granule decomposition in the developing somite cells. The experiments in vitro support the findings in the in ovo material; at the same time, they reveal an unexpectedly slow diffusion of L-phenylalanine through the vitelline membrane.

Multiplication of Salmonella Enteritidis on the Yolk Membrane and Penetration to the Yolk Contents at 30°C in an In Vitro Egg Contamination Model

2008 ◽  
Vol 71 (9) ◽  
pp. 1905-1909 ◽  
Author(s):  
RICHARD K. GAST ◽  
RUPA GURAYA ◽  
JEAN GUARD-BOULDIN ◽  
PETER S. HOLT
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Vitelline Membrane ◽  
Critical Aspect ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Exterior Surface ◽  
Increased Risk ◽  
The Mean ◽  
Uncommon Location

Refrigeration to limit bacterial multiplication is a critical aspect of efforts to control the transmission of Salmonella enterica serovar Enteritidis (SE) to consumers of contaminated eggs. Although the nutrient-rich yolk interior is an uncommon location for SE contamination in freshly laid, naturally contaminated eggs, migration across the vitelline membrane could lead to rapid bacterial multiplication even when the initial site of deposition is outside the yolk. Multiplication on the yolk membrane (before, or in addition to, multiplication within the yolk contents) could be another source of increased risk to consumers. The present study used an in vitro egg contamination model to compare the abilities of four strains of SE to either multiply in association with the yolk membrane or migrate through that membrane to reach the yolk contents during 36 h of incubation at 30°C. After inoculation onto the exterior surface of intact, whole yolks, all four SE strains penetrated the vitelline membrane to reach the yolk contents (at an overall frequency of 11.5%) after 12 h of incubation. The mean log concentration of SE was significantly higher in whole yolks (including yolk membranes) than in yolk contents at both 12 h (0.818 versus 0.167 CFU/ml) and 36 h (2.767 versus 1.402 CFU/ml) of incubation. These results demonstrate that SE multiplication on the vitelline membrane may both precede and exceed multiplication resulting from penetration into the yolk contents during the first 36 h of unrefrigerated storage, reinforcing the importance of rapid refrigeration for protecting consumers from egg-transmitted illness.

Multiplication of Salmonella Enteritidis in Egg Yolks after Inoculation outside, on, and inside Vitelline Membranes and Storage at Different Temperatures

2010 ◽  
Vol 73 (10) ◽  
pp. 1902-1906 ◽  
Author(s):  
RICHARD K. GAST ◽  
RUPA GURAYA ◽  
JEAN GUARD ◽  
PETER S. HOLT
Keyword(s):  
Bacterial Growth ◽  
Salmonella Enteritidis ◽  
Egg Yolk ◽  
Vitelline Membrane ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Exterior Surface ◽  
Different Temperatures ◽  
Subsequent Storage ◽  
Storage Temperatures

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.

Micropropagation of Three Endemic Begonias Using Various Hormones Concentration and Culture Media Application

2021 ◽  
Vol 6 (2) ◽  
pp. 284-294
Author(s):  
Lily Ismaini ◽  
Intani Quarta Lailaty ◽  
Muhammad Efendi
Keyword(s):  
Analysis Of Variance ◽  
In Vitro Propagation ◽  
Growth Response ◽  
Culture Media ◽  
Ornamental Plant ◽  
Botanic Gardens ◽  
Growth Responses ◽  
Significance Level ◽  
Shoot Number

Three species of Begonias endemic to Java and Sumatra, namely Begonia leuserensis, Begonia atricha and Begonia scottii, were conserved in Cibodas Botanic Gardens as sources of germplasm for ornamental plant and/or medicines. However, the information on efficient hormones concentration and their culture media application through an in vitro propagation effort is still limited. Therefore, this study aimed to explain the growth response of three species of Begonias using various hormones concentrations and culture media through in vitro propagation. The culture media using Murashige & Skoog (MS) media that combinedwith 6-Benzyladenine (BA) dan Thidiazuron (TDZ) hormones in different concentrations i.e. 0.5 mg/L, 1 mg/L, 2 mg/L, and 3 mg/L. Observation parameter included shoot number, plantlets height, and leaves number. The data were analyzed using analysis of variance (ANOVA) with the F test at a 5% significance level. The results showed that three species of Begonias were observed to have different growth responses in the combination of MS+BA and MS+TDZ media. The combination of MS+TDZ media produces more shoots number, while the combination of MS+BA media influenced higher in leaves number. A concentration of 0.5 mg/L of hormone showed a good regeneration, therefore were recommended for in vitro propagation of Begonia species.

Behavioural transformation in chick yolk-sac cells

Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 599-610
Author(s):  
J. Roger Downie
Keyword(s):  
Large Scale ◽  
Culture Conditions ◽  
Yolk Sac ◽  
Vitelline Membrane ◽  
In Ovo ◽  
Epithelial Sheet ◽  
Epithelial Sheets ◽  
Yolk Sac Cells

During the first 3 to 4 days of development in the chick, the extraembryonic part, the yolk-sac, expands to encompass the yolk mass. The yolk-sac, initially a two-layered epithelial sheet, is pulled out by the action of a specialized band of cells at its periphery. These attach to the overlying vitelline membrane and move out over it. However, unincubated blastoderms are not attached to the vitelline membrane, and each comprises a loose assemblage of rounded cells, not an epithelial sheet. The transformation of the unincubated blastoderm into an actively expanding epithelial sheet has been followed in culture, using hanging-drop cultures of fragments to observe large-scale behaviour, and disaggregated blastoderms to observe individual cell behaviour. The timing of events in culture accords well with related events in ovo, and the possibility that in vitro changes are merely a response to culture conditions has been largely excluded. 0−6 h in ovo. No cells attached to the vitelline membrane. All cells loosely attached to one another. 0−6 h in vitro. Cells do not attach to the glass. The cells of disaggregated blastoderms are rounded and stationary. 6−10 h in ovo. Cells at the blastoderm periphery attach to the vitelline membrane inner surface, but expansion does not start. The cells remain loosely attached to one another. 6−10 h in vitro. Cells begin to stick to the glass surface. Cells from disaggregated cultures move around as individuals. They remain rounded with long, narrow filopodia. If two cells collide, the adhesion tends to be brief. 10 + h in ovo. The blastoderm starts to expand rapidly as a cohesive epithelial sheet, pulled by its specialized ‘edge’ cells. All yolk-sac cells become tightly attached to one another. 10 + h in vitro. Blastoderm fragments start to spread rapidly as flattened epithelial sheets. There is no sign of specialized ‘edge’ cells. Cells at the periphery of any fragment take on the role of the edge. Cells from disaggregated cultures flatten out on the glass with wide lamellae all round. When two cells collide, they now tend to stick permanently together. The role of these changes in the mechanics of blastoderm expansion is briefly discussed.

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