Implication of a gene deletion on a Salmonella Enteritidis phage growth parameters

2021 ◽  
pp. 198654
Author(s):  
C Milho ◽  
S Sillankorva
Keyword(s):  
Salmonella Enteritidis ◽  
Gene Deletion ◽  
Growth Parameters ◽  
Phage Growth

scholarly journals Escherichia coli and Salmonella Enteritidis dual-species biofilms: interspecies interactions and antibiofilm efficacy of phages

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Catarina Milho ◽  
Maria Daniela Silva ◽  
Diana Alves ◽  
Hugo Oliveira ◽  
Clara Sousa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Spatial Organization ◽  
Growth Parameters ◽  
Single Species ◽  
Matrix Composition ◽  
Interspecies Interactions ◽  
Host Interactions ◽  
Phage Growth

AbstractEscherichia coli and Salmonella Enteritidis are foodborne pathogens forming challenging biofilms that contribute to their virulence, antimicrobial resistance, and survival on surfaces. Interspecies interactions occur between species in mixed biofilms promoting different outcomes to each species. Here we describe the interactions between E. coli and S. Enteritidis strains, and their control using specific phages. Single-species biofilms presented more cells compared to dual-species biofilms. The spatial organization of strains, observed by confocal microscopy, revealed similar arrangements in both single- and dual-species biofilms. The EPS matrix composition, assessed by Fourier-transform infrared spectroscopy, disclosed that the spectra extracted from the different dual-species biofilms can either be a combination of both species EPS matrix components or that the EPS matrix of one species predominates. Phages damaged more the single-species biofilms than the mixed biofilms, showing also that the killing efficacy was greatly dependent on the phage growth characteristics, bacterial growth parameters, and bacterial spatial distribution in biofilms. This combination of methodologies provides new knowledge of species-species and phage-host interactions in biofilms of these two major foodborne pathogens.

scholarly journals Influence of the Initial Cell Number on the Growth Fitness of Salmonella Enteritidis in Raw and Pasteurized Liquid Whole Egg, Egg White, and Egg Yolk

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1621
Author(s):  
Silvia Guillén ◽  
María Marcén ◽  
Ignacio Álvarez ◽  
Pilar Mañas ◽  
Guillermo Cebrián
Keyword(s):  
Salmonella Enteritidis ◽  
Growth Parameters ◽  
Egg Yolk ◽  
Egg White ◽  
Cell Number ◽  
Initial Number ◽  
Initial Cell ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
Whole Egg

Salmonella growth in egg and egg products has been widely studied, but there are still some aspects that are not fully known. The objective of this work was to study the influence of the initial cell number on the growth fitness of Salmonella Enteritidis in raw and pasteurized egg products. Growth curves of five Salmonella Enteritidis strains in raw and pasteurized egg products, starting from different initial numbers, were obtained and fitted to the Baranyi and Roberts model. The results revealed that lower initial numbers led to longer lag phases (λ) and lower maximum specific growth rates (μmax) in raw liquid whole egg. Similar results were observed in raw egg white (except for one strain). Conversely, no influence (p > 0.05) of the initial concentration on Salmonella growth parameters in raw egg yolk was observed. On the other hand, no influence of the initial number of cells on Salmonella growth fitness in commercial pasteurized liquid whole egg was observed. The results obtained demonstrate that the disappearance of this initial-dose dependency phenomenon was dependent on the intensity of the thermal treatment applied. Finally, the influence of the initial number was, in general, lower in pasteurized than in raw egg white, but large differences among strains were observed.

scholarly journals Ghrelin Gene Deletion Alters Pulsatile Growth Hormone Secretion in Adult Female Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Rim Hassouna ◽  
Gimena Fernandez ◽  
Nicolas Lebrun ◽  
Oriane Fiquet ◽  
Ferdinand Roelfsema ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Food Intake ◽  
Gene Deletion ◽  
Growth Parameters ◽  
Ex Vivo ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Metabolic Parameters ◽  
Female Mice ◽  
Gh Secretion

Using preproghrelin-deficient mice (Ghrl-/-), we previously observed that preproghrelin modulates pulsatile growth hormone (GH) secretion in post-pubertal male mice. However, the role of ghrelin and its derived peptides in the regulation of growth parameters or feeding in females is unknown. We measured pulsatile GH secretion, growth, metabolic parameters and feeding behavior in adult Ghrl-/- and Ghrl+/+ male and female mice. We also assessed GH release from pituitary explants and hypothalamic growth hormone-releasing hormone (GHRH) expression and immunoreactivity. Body weight and body fat mass, linear growth, spontaneous food intake and food intake following a 48-h fast, GH pituitary contents and GH release from pituitary explants ex vivo, fasting glucose and glucose tolerance were not different among adult Ghrl-/- and Ghrl+/+ male or female mice. In vivo, pulsatile GH secretion was decreased, while approximate entropy, that quantified orderliness of secretion, was increased in adult Ghrl-/- females only, defining more irregular GH pattern. The number of neurons immunoreactive for GHRH visualized in the hypothalamic arcuate nucleus was increased in adult Ghrl-/- females, as compared to Ghrl+/+ females, whereas the expression of GHRH was not different amongst groups. Thus, these results point to sex-specific effects of preproghrelin gene deletion on pulsatile GH secretion, but not feeding, growth or metabolic parameters, in adult mice.

Activation of isolated heterophils from chicks stimulated in vivo with salmonella enteritidis-immune lymphokines

1996 ◽  
Vol 54 ◽  
pp. 760-761
Author(s):  
R. B. Moyes ◽  
R. E. Droleskey ◽  
M. H. Kogut ◽  
J. R. DeLoach
Keyword(s):  
Lamina Propria ◽  
Intestinal Mucosa ◽  
Salmonella Enteritidis ◽  
Intestinal Tract ◽  
Polymorphonuclear Cells ◽  
Subclinical Infection ◽  
Egg Products ◽  
Immune Lymphokines ◽  
Organ Invasion

Salmonella enteritidis (SE) is of great concern to the poultry industry due to the organism's ability to penetrate the intestinal mucosa of the laying hen and subsequently colonize the ovaries and yolk membrane. The resultant subclinical infection can lead to SE infection of raw eggs and egg products. Interference with the ability of the organism to invade has been linked to the activation and recruitment of inflammatory polymorphonuclear cells, heterophils, to the lamina propria of the intestinal tract.Recently it has been established that heterophil activation and increased resistance to SE organ invasion can be accomplished by the administration of SE-immune lymphokines (SE-ILK) obtained from supernatants of concanavalin-A stimulated SE immune T lymphocytes from SE hyperimmunized hens. Invasion of SE into the lamina propria provides a secondary signal for directing activated heterophils to the site of SE invasion.

Studies of Ge/Si(100) and Observation of Atomic Steps on Si(100) using Biassed Secondary Electron Imaging in a UHV STEM

1990 ◽  
Vol 48 (1) ◽  
pp. 308-309
Author(s):  
Mohan Krishnamurthy ◽  
Jeff S. Drucker ◽  
John A. Venablest
Keyword(s):  
Secondary Electron ◽  
Critical Thickness ◽  
Surface Defects ◽  
Film Growth ◽  
Growth Parameters ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Surface Steps ◽  
Epitaxial Crystal Growth ◽  
Electron Imaging

Secondary Electron Imaging (SEI) has become a useful mode of studying surfaces in SEM[1] and STEM[2,3] instruments. Samples have been biassed (b-SEI) to provide increased sensitivity to topographic and thin film deposits in ultra high vacuum (UHV)-SEM[1,4]; but this has not generally been done in previous STEM studies. The recently developed UHV-STEM ( codenamed MIDAS) at ASU has efficient collection of secondary electrons using a 'parallelizer' and full sample preparation system[5]. Here we report in-situ deposition and annealing studies on the Ge/Si(100) epitaxial system, and the observation of surface steps on vicinal Si(100) using b-SEI under UHV conditions in MIDAS.Epitaxial crystal growth has previously been studied using SEM and SAM based experiments [4]. The influence of surface defects such as steps on epitaxial growth requires study with high spatial resolution, which we report for the Ge/Si(100) system. Ge grows on Si(100) in the Stranski-Krastonov growth mode wherein it forms pseudomorphic layers for the first 3-4 ML (critical thickness) and beyond which it clusters into islands[6]. In the present experiment, Ge was deposited onto clean Si(100) substrates misoriented 1° and 5° toward <110>. This was done using a mini MBE Knudsen cell at base pressure ~ 5×10-11 mbar and at typical rates of 0.1ML/min (1ML =0.14nm). Depositions just above the critical thickness were done for substrates kept at room temperature, 375°C and 525°C. The R T deposits were annealed at 375°C and 525°C for various times. Detailed studies were done of the initial stages of clustering into very fine (∼1nm) Ge islands and their subsequent coarsening and facetting with longer anneals. From the particle size distributions as a function of time and temperature, useful film growth parameters have been obtained. Fig. 1 shows a b-SE image of Ge island size distribution for a R T deposit and anneal at 525°C. Fig.2(a) shows the distribution for a deposition at 375°C and Fig.2(b) shows at a higher magnification a large facetted island of Ge. Fig.3 shows a distribution of very fine islands from a 525°C deposition. A strong contrast is obtained from these islands which are at most a few ML thick and mottled structure can be seen in the background between the islands, especially in Fig.2(a) and Fig.3.

Sweet's syndrome associated with Salmonella enteritidis infection

1999 ◽  
Vol 24 (3) ◽  
pp. 239-240 ◽  
Author(s):  
Flórez ◽  
Sánchez-Aguilar ◽  
Rosón ◽  
Prieto ◽  
Van den Eyden ◽  
...  
Keyword(s):  
Salmonella Enteritidis ◽  
Sweet’S Syndrome ◽  
Sweet's Syndrome

Evaluation of Azadirachtin on Arthrospira plantensis Gomont growth parameters and antioxidant enzymes

2020 ◽  
Vol 56 ◽  
pp. 8
Author(s):  
Hatice Tunca ◽  
Ali Doğru ◽  
Feray Köçkar ◽  
Burçin Önem ◽  
Tuğba Ongun Sevindik
Keyword(s):  
Enzyme Activity ◽  
Growth Parameters ◽  
Arthrospira Platensis ◽  
Proline Content ◽  
Enzyme Analysis ◽  
Free Proline ◽  
Sod Activity ◽  
Pesticide Pollution ◽  
Antioxidant Parameters ◽  
Mda Content

Azadirachtin (Aza) used as insecticide due to inhibiting growth of insects and preventing them from feeding on plants. To understand the effects of contamination of this insecticide on phototrophs, and to determine the responses of these organisms against these insecticides are extremely important in understanding how the ecosystem is affected. In this study, chlorophyll-a amount, OD 560 and antioxidant parameters (total SOD, APX, GR, Proline, MDA and H2O2) were determined in order to understand the effect of Aza on Arthrospira platensis Gomont. Aza was applied between 0–20 μg mL−1 concentrations for 7 days in the study. Enzyme analysis was conducted at the end of the 7th day. There was a statistically significant decrease in the absorbance of OD560 and the chlorophyll-a content in A. platensis cultures exposed to the Aza (0–20 μg mL−1) during 7 days due to the increase in pesticide levels. SOD activity decreased at 8, 16 and 20 μg mL−1 concentrations; GR enzyme activity showed a significant decrease compared to the control at a concentration of 20 μg mL−1. APX activity did not change significantly compared to control. The MDA content increased significantly at 16 and 20 μg mL−1 concentrations. The H2O2 content significantly increased at 12, 16 and 20 μg mL−1 concentrations (p < 0.05) while the free proline content decreased at 4 μg mL−1 concentration (p < 0.05). As a result, regarding the Aza concentrations used in this study may be a step to prevent pesticide pollution in the environment.

FMR2 gene deletion as a cause of non-specific mental retardation and autistic behavior in two brothers

2010 ◽  
Vol 41 (02) ◽  
Author(s):  
GM Stettner ◽  
B Auber ◽  
M Shoukier ◽  
C Höger ◽  
K Brockmann
Keyword(s):  
Mental Retardation ◽  
Gene Deletion ◽  
Autistic Behavior
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