egg-white and Salmonella-Infections--Animal

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a food-borne bacterial pathogen that can cause human salmonellosis predominately by contamination of eggs and egg products. However, its survival mechanisms in egg white are not fully understood, especially from a proteomic point of view. In this study, the proteomic profiles of S. Enteritidis in Luria-Bertani (LB) broth containing 50% and 80% egg white, and in whole egg white were compared with the profile in LB broth using iTRAQ technology to identify key proteins that were involved in S. Enteritidis survival in egg white. It was found that there were 303, 284 and 273 differentially expressed proteins in S. Enteritidis after 6 h exposure to whole, 80% and 50% egg white, respectively. Most of up-regulated proteins were primarily associated with iron acquisition, cofactor and amino acid biosynthesis, transporter, regulation and stress responses, whereas down-regulated proteins were mainly involved in energy metabolism, virulence as well as motility and chemotaxis. Three stress response-related proteins (YbgC, TolQ, TolA) of the tol-pal system responsible for maintaining cell membrane stability of Gram-negative bacteria were up-regulated in S. Enteritidis in response to whole egg white. Interestingly, deletion of ybgC resulted in a decreased resistance of S. Enteritidis to egg white. Compared with the wild type and complementary strains, a 3-log population reduction was observed in △ybgC mutant strain after incubation in whole egg white for 24 h. Cellular morphology of △ybgC mutant strain was altered from rods to spheres along with cell lysis in whole egg white. Furthermore, deletion of ybgC decreased the expression of tol-pal system-related genes (tolR, tolA). Collectively, these proteomic and mutagenic analysis reveal that YbgC is essential for S. Enteritidis survival in egg white.

Topics: Animals; Chickens; Egg White; Eggs; Genes, Bacterial; Microbial Viability; Proteome; Proteomics; Salmonella enteritidis; Salmonella Infections, Animal

Salmonella Enteritidis has developed the potential to contaminate eggs by surviving in the antimicrobial environment of the hen's egg white. This has led to a worldwide pandemic of foodborne salmonellosis infections in humans due to the consumption of contaminated eggs and egg-derived products. The molecular mechanisms of Salmonella Enteritidis egg white survival are not fully clear. Using in vivo expression technology and promoter-reporter fusions we showed that the promoter of the tolC gene, encoding the TolC outer membrane channel that is used by multidrug efflux pumps to export harmful molecules and to secrete bacterial products, is activated by egg white at the chicken body temperature. Using a Salmonella Enteritidis tolC deletion mutant we showed that TolC has an important role in egg white survival. Chromatographic separation techniques and subsequent testing of antimicrobial activities of separated egg white fractions led to the identification of ovotransferrin as the egg white antimicrobial factor which is capable of inhibiting growth of a tolC deletion strain but not the wild type strain. We provide evidence that TolC protects Salmonella Enteritidis against ovotransferrin-mediated growth inhibition in egg white.

Topics: Animals; Bacterial Outer Membrane Proteins; Base Sequence; Chickens; Egg White; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Sequence Deletion

Salmonella enterica serovar Oranienburg (SO) was linked to a human salmonellosis outbreak in the Midwest in 2015 and 2016 from consumption of eggs. However, unlike Salmonella enterica serovar Enteritidis (SE), little is known regarding the potential of SO to colonize in laying hens and contaminate eggs. We used in vivo and in vitro models to evaluate tissue colonization and survival capacity of SO. Twenty eight-week-old laying hens were each challenged with an oral dose of approximately 107 (n = 92) or 109 (n = 96) colony-forming units (CFU) in 1 mL saline and evaluated after 1, 2, and 4 wk. Standard microbiological methods with pre-enrichment and enrichment in selective media were used for detection of SO in tissues, egg shell wash, internal egg contents, and excreta. Peak colonization of spleen (86.9%), ovaries (31.6%), upper oviduct (15.8%), and lower oviduct (34.3%) was detected between 1 and 2 wk post-infection (pi), while at 4 wk SO was only recovered from spleens (25%). Salmonella enterica serovar Oranienburg was not recovered from internal egg contents. However, the presence of SO on egg shells was seen when there were traces of excreta. Shedding in excreta was found in 92 and 100% birds gavaged with 107 and 109 CFU at 2 wk pi, respectively. The invasion and proliferation of SO in ovarian granulosa cells (GC) was compared to that of SE, and while the invasion of SO into GC was comparable to SE, proliferation of SO was significantly lower (P < 0.05). The infective potential of SO was also assessed by enumerating survival in egg white over 4 wk under refrigerated conditions, resulting in 65% survival at 4 wk. Overall, our data suggested that SO infection in layers did not result in egg contamination via vertical transmission, and colonization of egg-forming tissues was limited to 2 wk pi. Survival within GC and egg white demonstrates the ability of SO to withstand antibacterial factors and the potential of SO to penetrate the yolk.

Topics: Administration, Oral; Animals; Chickens; Colony Count, Microbial; Egg White; Female; Granulosa Cells; Ovum; Poultry Diseases; Salmonella enterica; Salmonella Infections, Animal

Salmonella enterica serovars Enteritidis (S. Enteritidis) is one of the most common causes of food borne illness. Bacterial growth environment plays an important role in regulating gene expression thereby affecting the virulence profile of the bacteria. Different foods present diverse growth conditions which may affect the pathogenic potential of the bacteria. In the present study, the effect of food environments on the pathogenic potential of S. Enteritidis has been evaluated. S. Enteritidis was grown in different foods e.g. egg white, peanut butter and milk, and virulent phenotypes were compared to those grown in Luria Bertani broth. In-vivo experiments in C57BL/6 mice revealed S. Enteritidis grown in egg white did not induce significant (p<0.001) production of proinflammatory cytokines in mice and were unable to cause colitis despite efficient colonization in cecum, mesenteric lymph node, spleen and liver. Further studies revealed that bacteria grown in LB activated MAP Kinase and NFκB pathways efficiently, while those grown in egg white poorly activated the above pathways which can account for the decreased production of proinflammatory cytokines. qRT PCR analysis revealed SPI-1 effectors were downregulated in bacteria grown in egg white. Interestingly, bacteria grown in egg white showed reversal of phenotype upon change in growth media to LB. Additionally, bacteria grown in milk and peanut butter showed different degrees of virulence in mice as compared to those grown in LB media. Thus, the present study demonstrates that, S. Enteritidis grown in egg white colonizes systemic sites without causing colitis in a mouse model, while bacteria grown in milk and peanut butter show different pathogenicity profiles suggesting that food environments significantly affect the pathogenicity of S. Enteritidis.

Topics: Animals; Arachis; Cecum; Chickens; Colitis; Egg White; Foodborne Diseases; Immunomodulation; Intercellular Signaling Peptides and Proteins; Mice; Mice, Inbred C57BL; Milk; Peptides; Salmonella enteritidis; Salmonella Infections, Animal; Virulence; Virulence Factors

Eggs contaminated with Salmonella Enteritidis are an important source of human foodborne Salmonella infections. Salmonella Enteritidis is able to contaminate egg white during formation of the egg within the chicken oviduct, and it has developed strategies to withstand the antimicrobial properties of egg white to survive in this hostile environment. The mechanisms involved in the persistence of Salmonella Enteritidis in egg white are likely to be complex. To address this issue, a microarray-based transposon library screen was performed to identify genes necessary for survival of Salmonella Enteritidis in egg white at chicken body temperature. The majority of identified genes belonged to the lipopolysaccharide biosynthesis pathway. Additionally, we provide evidence that the serine protease/heat shock protein (HtrA) appears essential for the survival of Salmonella Enteritidis in egg white at chicken body temperature.

Topics: Animals; Bacterial Proteins; Body Temperature; Chickens; Egg White; Genome-Wide Association Study; Heat-Shock Proteins; Lipopolysaccharides; Periplasmic Proteins; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Serine Endopeptidases

Salmonella enterica subspecies enterica serovar Enteritidis has caused a worldwide egg-associated pandemic since the mid 1980s. The exact mechanisms causing this egg tropism are still largely unknown, and only a few Salmonella genes have been implicated in the interaction with the oviduct or eggs. A in vivo expression technology screening performed previously, identified the uspA and uspB genes as being highly expressed in the chicken oviduct and in eggs. Here, we demonstrate that uspA and uspB gene expression is indeed induced after contact with egg white. Intra-oviduct inoculation of Salmonella Enteritidis uspB and uspBA mutant strains showed that the mutants had a decreased ability to colonize the magnum and isthmus of the oviduct, the organs that produce the egg white and eggshell membranes, respectively, at 7 days post-inoculation. Intravenous challenge showed that a Salmonella Enteritidis uspBA mutant strain had a decreased ability to contaminate eggs. Analogous to the function of universal stress proteins A and B in other bacterial species, we hypothesize that the Salmonella uspA and uspB genes are involved in long term persistence of Salmonella Enteritidis in harmful environments, such as in the oviduct and eggs, by conferring resistance against compounds that damage the bacterial cell membrane and DNA.

Topics: Animals; Bacterial Proteins; Chickens; Egg White; Eggs; Fallopian Tubes; Female; Gene Expression; Heat-Shock Proteins; Humans; Oviducts; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal

Serological tests applied in poultry flocks can be a valuable tool in assessing health of hens. One obstacle in making this assessment is that results of serological tests in a given flock are not always correlated with results of bacteriological tests. The aim of this study was to determine dependencies between the level of antibodies in egg yolk and the contamination of egg contents (whites and yolks) with Salmonella Enteritidis bacilli. Infected birds were also treated with selected antibiotics. It was determined that Salmonella Enteritidis was not found in experimentally infected laying hens until day 12 post-inoculation. The results of the study also suggest the existence of relation between the level of anti-Salmonella antibodies in egg yolks and the frequency of isolation of Salmonella from eggs. It was also found that the lowest level of yolk antibodies was found in the group of birds treated with enrofloxacin.

Topics: Animals; Anti-Bacterial Agents; Chickens; Egg White; Egg Yolk; Female; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal

Topics: Animals; Bacteriophage Typing; Belgium; Chickens; Commerce; Drug Resistance, Bacterial; Egg Shell; Egg White; Egg Yolk; Eggs; England; Feces; Female; Food Contamination; Food Microbiology; France; Germany; Ireland; Netherlands; Poland; Portugal; Poultry Diseases; Salmonella; Salmonella enteritidis; Salmonella Infections, Animal; Salmonella Vaccines; Spain; Species Specificity; Vaccination

The preventive effect of partially hydrolyzed guar gum (PHGG) on the colonization of Salmonella enteritidis (SE) in young and laying hens was investigated. The effects of feed supplemented with 0.025, 0.05, and 0.1% PHGG was examined on young hens orally infected with SE. The incidence of SE in organs was decreased, the excretion of SE into feces was increased, and the agglutinating antibody titer to SE in serum was decreased by the administration of PHGG to young hens. In particular, feed supplemented with 0.025% PHGG was the most effective. It was also shown that feed supplemented with 0.025% PHGG increased the number of Bifidobacterium spp. and Lactobacillus spp., the most numerous intestinal bacteria in the cecum of young hen. The effect of the excretion of SE via feces was also observed in an experiment using laying hens. The incidence of SE on the surface of the eggshell and in egg white and egg yolk was also decreased when the feed of laying hens was supplemented with 0.025% PHGG. These results show that the administration of feed supplemented with PHGG can prevent the colonization of SE in young and laying hens, which, in turn, could be related to improvement in the balance of intestinal microflora.

Topics: Agglutination Tests; Animal Feed; Animals; Antibodies, Bacterial; Bifidobacterium; Chickens; Colony Count, Microbial; Egg Shell; Egg White; Egg Yolk; Eggs; Feces; Female; Galactans; Hydrolysis; Intestines; Lactobacillus; Mannans; O Antigens; Oviposition; Plant Gums; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal

To investigate prevalence of Salmonella enteritidis-positive eggs, excretion of the organism in fecal droppings, and infection of internal organs after oral inoculation of White Leghorn hens with S enteritidis phage type 8.. 30 White Leghorn laying hens.. At 25 weeks of age, hens were each inoculated orally with 10(10) colony-forming units of S enteritidis, then were observed for 8 weeks.. Salmonella enteritidis Y-BP2 did not cause any clinical signs of disease or decrease in egg production. However, at 1 week after inoculation, 63.9% of the eggs collected from inoculated hens were culture positive for S enteritidis. The organism was isolated from the shell washings, egg shells, yolk, and albumen. A total of 592 eggs from S enteritidis-inoculated hens were examined. Of these eggs, 157 (26.5%) were positive for S enteritidis on external shell washings alone, 17 (2.9%) were positive for S enteritidis internally, and 44 (7.4%) were positive for S enteritidis externally and internally. The percentage of culture-positive eggs gradually decreased between postinoculation weeks 2 and 5, then gradually increased to a high of 76% at week B. At 3, 7, and 10 days after S enteritidis inoculation, cloacal swab specimens from 3 hens were positive for S enteritidis. Salmonella enteritidis was recovered from ovary, oviduct, liver, and cecal junction from S enteritidis-inoculated hens.. Our results indicated that birds infected with this isolate produced S enteritidis-positive eggs at high frequencies initially, that decreased over time. When S enteritidis antibody began to decrease, reaching geometric mean titer < or = 40, the frequency of S enteritidis-positive eggs increased.

Topics: Analysis of Variance; Animal Feed; Animals; Chickens; Cloaca; Egg Shell; Egg White; Egg Yolk; Eggs; Feces; Female; Liver; Ovary; Oviducts; Oviposition; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Spleen; Time Factors

A total of 105 specific pathogen-free (SPF) laying hens and eight cocks were orally infected with strains of Salmonella enteritidis. The organs of these animals were examined bacteriologically for up to 6 weeks post infectionem (p.i.). One-half of the eggs laid on a single day were examined 1 day after laying, and the other half 28 days after laying. The siderophore, ferrioxamine E, was added to the pre-enrichment medium. A high correlation was found to exist between colonization of the caecum by salmonellas and the level of contamination of the egg shell. No correlation was found between the contamination of the egg shell and that of the egg content. The strains used for infection were not recovered from any yolk out of a total of 938 eggs. S. enteritidis was isolated from the albumen in four cases (0.4%). Storage of the eggs for 28 days after laying resulted in a decrease in the frequency of salmonella detection on the egg shell and in the egg content. The strains used for infection could be isolated from various sections of the sexual organs for up to 2 weeks p.i. S. enteritidis was most frequently found in the ovary and rarely in the oviduct, but never in the pre-ovulatory mature follicles. In the groups that included salmonella-infected cocks, the salmonella detection frequency did not increase either for the egg content or for the organs of the laying hens. It seems that primary vertical transmission of salmonellas occurs, in rare cases, as a result of an infection of the albumen but not of the yolk.

Topics: Animals; Chickens; Egg Shell; Egg White; Female; Infectious Disease Transmission, Vertical; Male; Ovary; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Specific Pathogen-Free Organisms

A total of six different strains of Salmonella enteritidis (phage type 4) were used for the artificial infection of the egg yolk and albumen of SPF hatching eggs. An artificial yolk infection with low infection doses of S. enteritidis resulted in a considerable multiplication of salmonellas in the egg after a short time and a rapid embryonic death. After inoculation of 10(3) cfu of different S. enteritidis strains into the albumen, living day-old chicks infected with salmonellas were hatched. This model corresponds to a primary vertical transmission of salmonellas and permits the investigation of problems concerning the pathogen/host relationship.

Topics: Animals; Chickens; Disease Models, Animal; Egg White; Egg Yolk; Infectious Disease Transmission, Vertical; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Specific Pathogen-Free Organisms

Topics: Animals; Chick Embryo; Chickens; Egg White; Female; Fertilization; Genotype; Globulins; Mucins; Salmonella Infections, Animal