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ABSTRACT: Objectives: Salmonella enterica serovar Entritidis is an important pathogen in foodborne diseases and causes gastroenteritis. Several studies have investigated the genetic diversity of the strains of this bacterium. However, our knowledge of the discriminatory power of the molecular methods is limited. Methods: In total, 34 strains of S. enteritidis were isolated from food related to animals. Antibiotic resistance of the strains, antibiotic resistance genes, and biofilm formation capacity of the strains were evaluated. For the genetic analysis of the strains, PFGE was performed using AvrII restriction enzyme. Results: Among the tested antibiotics, cefuroxime, nalidixic acid, and ciprofloxacin showed the highest resistance rates (79.4%, 47%, and 44.2%, respectively). Only three antibiotic-resistance genes were identified in these strains (blaTEM: 67.6%, tetA: 9%, and sul2: 3%). In total, 91% of the strains were biofilm producers. Clustering of strains using AvrII for 26 samples with the same XbaI PFGE profile showed that these strains were in one clone and had high homogeneity. Conclusions: In conclusion, it is better to use a combination of several typing methods for typing strains that are genetically very close so that the results are reliable.

Background: After years of significant decline, the incidence of Salmonella enterica serotype Enteritidis (SE) human infections in Europe has started stagnating in recent years. The reasons for this stagnation remain largely unclear and are possibly multifactorial and interconnected in nature. We assessed and ranked several potential determinants of the stagnating SE trend in Europe, as well as different options for intervention at the level of poultry health and production, public health (infra)structure, and pathogen biology. Methods: A Multi-Criteria Decision-Analysis (MCDA) approach based on the Analytical Hierarchy Process was used. Through two separate surveys, a European panel of Salmonella experts first provided weights for several pre-defined criteria and subsequently scored different potential determinants and options for intervention (i.e. alternatives) against the criteria, during 2020–21. The weighting and scoring were based on Saaty's pairwise comparisons. The final ranking of the alternatives was derived from the summation of the products of each criterion weight with the score of the corresponding alternative. Sensitivity analyses were performed to assess the impact of different methodological choices, including European regions, and domains of expertise on the ranking of the determinants and options for intervention. Results: The first and second-ranked determinants of the stagnated trend in human SE infections were related to poultry health and production, namely “inadequacies of sampling programmes” and “premature relaxation of control measures”. This ranking agreed with the ranking of the options for intervention, which were also those at the poultry health and production level, specifically “stricter biosecurity”, “improving sampling”, and “better/increased vaccination”. Differences in rankings were observed among European regions and domains of expertise. Conclusions: The rankings of potential determinants and options for intervention for the stagnating SE trend in Europe pointed to the level of poultry health and production. Salmonella-control activities in poultry in Europe are harmonized across countries since many years, but the results of this study suggest that further improvements may be necessary for some countries. A multidisciplinary collaboration among veterinarians, public health professionals, and microbiologists is needed to further understand the origins of the stagnating SE trend and to identify effective interventions in order to reverse the trend, contextually in a given country, following a One Health approach.

Abstract Salmonella enterica serotype Enteritidis (SE) is a zoonotic pathogen which causes foodborne diseases in humans as well as severe disease symptoms in young chickens. More insight in innate and adaptive immune responses of chickens to SE infection is needed to understand elimination of SE. Seven-day-old broiler chickens were experimentally challenged with SE and numbers and responsiveness of innate and adaptive immune cells as well as antibody titers were assessed. SE was observed in the ileum and spleen of SE-infected chickens at 7 days post-infection (dpi). At 1 dpi numbers of intraepithelial cytotoxic CD8+ T cells were significantly increased alongside numerically increased intraepithelial IL-2Rα+ and 20E5+ natural killer (NK) cells at 1 and 3 dpi. At both time points, activation of intraepithelial and splenic NK cells was significantly enhanced. At 7 dpi in the spleen, presence of macrophages and expression of activation markers on dendritic cells were significantly increased. At 21 dpi, SE-induced proliferation of splenic CD4+ and CD8+ T cells was observed and SE-specific antibodies were detected in sera of all SE-infected chickens. In conclusion, SE results in enhanced numbers and activation of innate cells and we hypothesized that in concert with subsequent specific T cell and antibody responses, reduction of SE is achieved. A better understanding of innate and adaptive immune responses important in the elimination of SE will aid in developing immune-modulation strategies, which may increase resistance to SE in young broiler chickens.

Objective(s): This study aimed to evaluate antibiotic resistance profiles and presence of virulence genes among Salmonella enterica serovar Enteritidis (S. Enteritidis) isolated from patients with gastroenteritis in various regions of Iran. Moreover, genetic relatedness among the strains was assessed by pulsed-field gel electrophoresis (PFGE).Materials and Methods: From April through September 2017, 59 Salmonella strains were isolated from 2116 stool samples. Of these strains, 27 S. Enteritidis were recovered. These strains were subjected to disk diffusion tests, polymerase chain reaction (PCR) for detection of virulence genes (invA, hilA, pefA, rck, stn, ssrA, ssaR, sefA, spvC, sipA, sipC, sopB, sopE, and sopE2), and PFGE.Results: High prevalence of resistance towards cefuroxime (n = 20, 74.1%) and ciprofloxacin (n = 13, 48.2%) were demonstrated. All tested strains possessed invA, hilA, sefA, sipA, sopB, and sopE. The least prevalent virulence gene was rck (n = 6; 22.2%). Based on combinations of virulence genes, 12 virulotypes were observed. The most common virulotype was VP2 (n = 12; 44.4%), harboring all of the virulence genes except for rck. PFGE typing showed only two distinct fingerprints among tested strains. Each fingerprint had completely different virulotypes. Notably, VP4 (harboring all genes except for rck and spvC) was only presented in pulsotype A, while VP2 was confined to pulsotype B.Conclusion: S. Enteritidis strains were derived from a limited number of clones, suggesting that it is highly homogenous. Future works should consider combinations of other genotyping methods together with larger sample sizes from more diverse sources.

Salmonella enterica serotype Enteritidis (SE) is a zoonotic pathogen which causes foodborne diseases in humans as well as severe disease symptoms in young chickens. More insight in innate and adaptive immune responses of chickens to SE infection is needed to understand elimination of SE. Seven-day-old broiler chickens were experimentally challenged with SE and numbers and responsiveness of innate and adaptive immune cells as well as antibody titers were assessed. SE was observed in the ileum and spleen of SE-infected chickens at 7 days post-infection (dpi). At 1 dpi numbers of intraepithelial cytotoxic CD8+ T cells were significantly increased alongside numerically increased intraepithelial IL-2Rα+ and 20E5+ natural killer (NK) cells at 1 and 3 dpi. At both time points, activation of intraepithelial and splenic NK cells was significantly enhanced. At 7 dpi in the spleen, presence of macrophages and expression of activation markers on dendritic cells were significantly increased. At 21 dpi, SE-induced proliferation of splenic CD4+ and CD8+ T cells was observed and SE-specific antibodies were detected in sera of all SE-infected chickens. In conclusion, SE results in enhanced numbers and activation of innate cells and we hypothesized that in concert with subsequent specific T cell and antibody responses, reduction of SE is achieved. A better understanding of innate and adaptive immune responses important in the elimination of SE will aid in developing immune-modulation strategies, which may increase resistance to SE in young broiler chickens. [ABSTRACT FROM AUTHOR]

Abstract INTRODUCTION: Salmonella enterica serotype Enteritidis (S. Enteritidis) is a cause of food-borne human illness. Given the prevalence of antibiotic resistance of Salmonella Enteritidis and the lack of antibiotic efficacy in future years, its replacement with other agents is necessary. One of the most useful agents is bacteriophages. METHODS S. Enteritidis was identified using a multiplex polymerase chain reaction assay. The effective bacteriophages were isolated from hospital wastewater samples. The effects of the bacteriophages were evaluated both in vitro and in vivo. RESULTS The phage SE20 belonged to the Podoviridae family, and the genome size was 40 kb. The evaluation of phage SE20 at variable pH ranges showed its susceptibility to pH < 3 and pH > 12. The animal model showed that mice infected with S. Enteritidis developed hepatomegaly and splenomegaly, but did not experience gastrointestinal complications after receiving the bacteriophages. CONCLUSIONS The results of this study suggest that phage SE20 is a promising candidate for controlling salmonellosis caused by Salmonella Enteritidis.

Salmonella enterica serotype Enteritidis is one of the most commonly reported causes of human salmonellosis. Its low genetic diversity, measured by fingerprinting methods, has made subtyping a challenge. We used whole-genome sequencing to characterize 125 S. enterica Enteritidis and 3 S. enterica serotype Nitra strains. Single-nucleotide polymorphisms were filtered to identify 4,887 reliable loci that distinguished all isolates from each other. Our whole-genome single-nucleotide polymorphism typing approach was robust for S. enterica Enteritidis subtyping with combined data for different strains from 2 different sequencing platforms. Five major genetic lineages were recognized, which revealed possible patterns of geographic and epidemiologic distribution. Analyses on the population dynamics and evolutionary history estimated that major lineages emerged during the 17th–18th centuries and diversified during the 1920s and 1950s.

Abstract. The aim of this work was detection of class 1 integrons and their contribution to the antimicrobial resistance phenotypes in strains of subspecies enterica serotype Enteritidis. S. Enteritidis strains (n = 29) were isolated from patients with salmonellosis at “Nork” Clinical Hospital of Infectious Diseases, Yerevan, Republic of Armenia. High prevalence of multi-drug resistance (MDR) phenotypes was revealed and isolates with MDR phenotypes which are rare in the S. Enteritidis serotype were observed. Class 1 integrons were detected in 27,6% of isolates, with the prevalence of a variable region of 1000 bp. Occurrence of the MDR phenotype was more frequent in integron-positive isolates compared to integron-negative isolates of S. Enteritidis. Further studies are necessary to reveal the genetic background of MDR phenotypes and to estimate the genetic kinship among the isolates. Our results suggest a rapid and large-scale penetration of antibiotic resistance genes into populations of S. Enteritidis, which complicates infection control. More rigorous regulations should be imposed on antibiotic use, together with a vigilant epidemiological surveillance, to prevent the emergence and spread of MDR S. Enteritidis.

Salmonella enterica subspecies enterica serotype Enteritidis ( S . Enteritidis) is one of the leading causes of food-borne gastroenteritis associated with the consumption of contaminated food products of animal origin. Little is known about the genetic diversity and virulence content of S . Enteritidis isolated from poultry meats and eggs in Iran. A total of 34 S . Enteritidis strains were collected from different food sources of animal origin in Tehran from May 2015 to July 2016. All of the S . Enteritidis strains were serotyped, antimicrobial susceptibility tested, and characterized for virulence genes. Pulsed-field gel electrophoresis (PFGE) was also applied for comparison of genetic relatedness. All of the strains harbored invA , hilA , ssrA , sefA , spvC , and sipA genes. A high prevalence of resistance against certain antibiotics such as cefuroxime (79.4%), nalidixic acid (47%), and ciprofloxacin (44.2%) was also observed. Regarding PFGE, S . Enteritidis strains from different sources showed considerable overlap, suggesting the lack of diversity among these isolates. Moreover, no correlation between virulence profiles or antibiotypes and PFGE clusters was observed. In conclusion, our study provided valuable information on virulence gene content, antibiotic resistance, and genetic diversity of S . Enteritidis isolated from food sources. [ABSTRACT FROM AUTHOR]

Salmonella enterica serotype Enteritidis (SE) is the most frequent etiological agent of human salmonellosis. The molecular epidemiology and antimicrobial susceptibility of human and chicken isolates of SE were examined. Methods: A total of 27 human and 40 chicken isolates of SE were collected in 2005–2006. We examined these isolates by antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and plasmid analysis. Results: Most isolates were susceptible to the seven antibiotics tested, except chicken isolates in 2005, which showed 70% resistance to streptomycin and 75% to tetracycline. There were six plasmid profiles identified among these isolates. Almost all isolates (97%) harbored the 60-kb serotype-specific virulence plasmid. PFGE using Xba I digestion separated human isolates into eight subtypes (1a–1h) and chicken isolates into four subtypes (1a–1c and 1g). In 2005, 1a and 1c were predominant for human isolates and 1a for chicken isolates. However, in 2006, 1a and 1c remained predominant for human isolates and 1b and 1c for chicken isolates. Most 1b and 1c isolates belonged to plasmid type 2 or 4. Correlation between plasmid patterns and PFGE subtypes was obtained between a 36-kb plasmid and 1b and between another 3.6-kb plasmid and 1a. Conclusion: Plasmid profiling and PFGE were efficient for discriminating SE isolates from different sources. Our data support the notion that SE is transmitted from chickens to humans, presumably through the food chain, but it appears that chickens are not the sole reservoir for human infection with SE in Taiwan. SE remained susceptible to most antimicrobial agents.

Salmonella enterica serotype Enteritidis (S. Enteritidis) is an important causative agent of nontyphoidal salmonellosis in human populations. In this study, we collected 72 S. Enteritidis strains from 2004 to 2014 in Ningbo, mid-east China. Of the 72 strains, we identified a dominant clone of 58 strains recovered from patient's feces (n = 48), blood (n = 1), pleural effusion (n = 1), chickens (n = 3), and dessert cakes (n = 5) by pulsed-field gel electrophoresis (PFGE) and variable-number of tandem repeat analysis (MLVA). The profile arrangements of MLVA were SE1-SE2-SE3-SE5- SE6-SE8-SE9: 4-4-3-11-10-1-3. These dominant strains were susceptible to ampicillin, chloramphenicol, tetracycline, ciprofloxacin, gentamicin, cefotaxime and trimethoprim–sulfamethoxazole, and resistant to nalidixic acid. Additionally, all isolates harboured virulence genes invA, sipA, sopE, and spvB when tested by PCR. Our results reveal that genetically similar S. Enteritidis strains which accounted for several outbreaks as well as blood infection and pleural cavity infection are prevalent in China for a long-term period. This situation calls for further attention in the prevention and control of foodborne disease caused by Salmonella species. [ABSTRACT FROM AUTHOR]

Several countries still permit strains of Salmonella enterica serotype Enteritidis, a leading cause of gastrointestinal illness in humans, to be used in rat baits. To assess the human health risk associated with such rat bait, we first reviewed historic data on health hazards associated with Ratin, a rodenticide that was used in Europe until the early 1960s. Ratin caused outbreaks of human illness, including several deaths. We then compared S. Enteritidis isolated from a current commercial product, Biorat, with S. Enteritidis from Ratin and found that the strains were both phage type 6a. Based on the similarity of the strains, currently available Salmonella-based rodenticides likely are as great a threat to public health as historic strains were. Health officials should be aware that the continued use of Salmonella-based rodenticides is a risk to public health and should take appropriate measures to prevent use in their jurisdictions.

Abstract: Thioridazine (TZ)-induced accumulation of the universal efflux pump substrate ethidium bromide and its subsequent efflux by Salmonella strains with various degrees of overexpressed efflux pumps takes place automatically at pH 7.4, is independent of a metabolic source, is not affected by a proton ionophore and is precluded by palmitic acid. Salmonella enterica serotype Enteritidis cultured in medium containing increasing concentrations of TZ does not grow during the first 6–8h, after which time its growth is similar to unexposed controls. At the end of a 16-h exposure period, the organism is resistant to >250mg/L TZ. Parallel assessment by real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) of the activity of genes that regulate and code for the AcrB transporter of the main efflux pump (AcrAB) of the organism at periodic intervals suggests a sequence of activation beginning with the stress gene soxS, followed by the global regulator ramA, then by the local regulator marA and then by the transporter acrB. These activations take place during the period of no growth. By the end of a 16-h culture period, only the acrB transporter gene is still highly overexpressed. Assessment of the activity of genes of the two-component regulon PmrA/B indicates that TZ also activates this regulon. Because activation of pmrA/B also activates acrB, development of high resistance to TZ during a 16-h culture period is in part due to activation of the two-component regulon. [Copyright &y& Elsevier]

Abstract: Several compounds isolated from the plant Carpobrotus edulis were evaluated for their activity against multidrug-resistant (MDR) bacteria and their efflux pump systems. Amongst the compounds isolated, six compounds were tested, namely uvaol, β-amyrin, oleanolic acid, catechin, epicatechin and monogalactosyldiacylglycerol. Oleanolic acid presented high antibacterial activity against a large number of bacterial strains. The triterpene uvaol was the most active compound for modulation of efflux activity by MDR Gram-positive strains. [Copyright &y& Elsevier]

Background/purpose: Salmonella enterica serotype Enteritidis (SE) is the most frequent etiological agent of human salmonellosis. The molecular epidemiology and antimicrobial susceptibility of human and chicken isolates of SE were examined.Methods: A total of 27 human and 40 chicken isolates of SE were collected in 2005-2006. We examined these isolates by antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and plasmid analysis.Results: Most isolates were susceptible to the seven antibiotics tested, except chicken isolates in 2005, which showed 70% resistance to streptomycin and 75% to tetracycline. There were six plasmid profiles identified among these isolates. Almost all isolates (97%) harbored the 60-kb serotype-specific virulence plasmid. PFGE using XbaI digestion separated human isolates into eight subtypes (1a-1h) and chicken isolates into four subtypes (1a-1c and 1g). In 2005, 1a and 1c were predominant for human isolates and 1a for chicken isolates. However, in 2006, 1a and 1c remained predominant for human isolates and 1b and 1c for chicken isolates. Most 1b and 1c isolates belonged to plasmid type 2 or 4. Correlation between plasmid patterns and PFGE subtypes was obtained between a 36-kb plasmid and 1b and between another 3.6-kb plasmid and 1a.Conclusion: Plasmid profiling and PFGE were efficient for discriminating SE isolates from different sources. Our data support the notion that SE is transmitted from chickens to humans, presumably through the food chain, but it appears that chickens are not the sole reservoir for human infection with SE in Taiwan SE remained susceptible to most antimicrobial agents. [ABSTRACT FROM AUTHOR]

Abstract: Carvacrol is known to inhibit a number of food borne pathogens. The activity of carvacrol vapour was evaluated against S. enterica serotype Enteritidis on tryptone soya agar and on pieces of raw chicken. On agar, the size of the inhibition zone increased with decreasing volume of agar, increasing vapour exposure period, increasing temperature, increasing volume of carvacrol used and with decreasing bacterial density. Inhibition was equally effective under aerobic and anaerobic conditions. On chicken pieces (10×10×5 mm, UV-sterilized and inoculated with approx. 5×103 cfu) carvacrol vapour significantly reduced viable numbers of salmonellae at 4, 20 and 37 °C and all viable cells were eliminated by a minimum of 3 h at 37 °C (p <0.05). A minimum concentration of 20% carvacrol v/v in ethanol was required to achieve a significant reduction and from 40% v/v no viable cells were recovered (p <0.05). In conclusion, carvacrol vapour is effective at inhibiting the growth of S. enterica serotype Enteritidis on agar and at inhibiting and eliminating these bacteria on the surface of raw chicken. [Copyright &y& Elsevier]

Abstract: Salmonella enterica subsp. enterica serotype Enteritidis is not readily subtyped beyond the level of phage type (PT). Pulsed field gel electrophoresis (PFGE) is generally acknowledged to be the most discriminating typing method for Salmonella, but only a restricted variety of PFGE types has been described for S. enterica serotype Enteritidis. In the present study, a modification of the SE-AFLP typing method was used to investigate both outbreak and apparently sporadic isolates of S. enterica serotype Enteritidis belonging to different PTs and/or PFGE types. The method proved to be as discriminatory as PFGE when combined with phage typing, and provided subtyping data consistent with epidemiological information. Although the modified SE-AFLP typing method did not prove to achieve a superior discriminatory ability in resolving clusters, it has a high enough throughput for use in outbreak investigations. This method can be used in combination with other typing methods to obtain epidemiologically relevant subtyping data on S. enterica serotype Enteritidis. [Copyright &y& Elsevier]

Aims: To study the reaction patterns of selected antibodies to Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis and Listeria monocytogenes cells exposed to various environmental stresses. Methods and Results: Escherichia coli O157:H7, Salmonella Enteritidis and L. monocytogenes cells subjected to different environmental stress of temperatures (4 and 45°C), NaCl (5·5%), oxidative stress (15 mmol−1 H2O2), acidic pH (5·5) and ethanol (5%) for 3 h (short-term stress) or for 5 days (long-term stress) were analysed by ELISA and Western blotting. The ELISA results indicated that most stresses caused 12–16% reductions in reaction for anti- E. coli O157:H7 and 20–48% reductions for anti- Salmonella polyclonal antibodies during short-term stress, whereas the most stresses exhibited enhanced reaction (44–100% increase) with the anti- L. monocytogenes polyclonal antibody. During long-term stress exposure to combined stress conditions of pH 5·5, 3·5% NaCl at 12°C or at 4°C, antibody reactions to the three pathogens were highly variable with the combined stress at 4°C showing the most reductions (8–40%). Likewise, there were about 18–59% reductions in antibody reactions with pathogens when cultured in hotdog samples with the combined stress conditions. Western blot analyses of crude cell surface antigens from both short- and long-term stressed cells revealed that the changes in antibody reactions observed in ELISA were either because of repression, expression or possible denaturation of antigens on the surface of cells. Conclusions: Overall, the antibody reactions were significantly reduced in pathogens exposed to both short- and long-term environmental stresses in culture medium or in meat sample because of expression, repression or denaturation of specific antigens in cells. Significance and Impact of the Study: In order to ensure the reliable detection of foodborne pathogens using antibody-based methods, the influence of stress on antibody reactions should be thoroughly examined and understood first as the physiological activities in cells are often altered in response to a stress. [ABSTRACT FROM AUTHOR]

A total of 22 Salmonella enterica serotype Enteritidis (S. Enteritidis) strains isolated from human and chicken were subjected to DNA fingerprinting by repetitive sequence PCR using ERIC and BOX primers, antibiotic resistance and plasmid patterns. Both ERIC and BOX PCR amplification data revealed a highly genetic homogeneity between isolates from human and chicken except one isolate, which originated from chicken and showed a different DNA band pattern from others. Eleven of 22 S. Enteritidis isolates (50%) were resistant to more than one antibiotics and characterized by 5 resistance patterns. The most common pattern was penicillin resistant (63.6%). Only one isolate from chicken showed a multiple drug resistance patterns to 4 antibiotics. All 22 S. Enteritidis isolates harbored more than two plasmids with eight different plasmid profiles including two to six plasmids with approximate molecular size ranging from 1.9 to 21 kb. A band of 15 kb size was detected in all isolates tested, however, the band sizes smaller than 15 kb were found only in isolates from chicken. [ABSTRACT FROM AUTHOR]

Cost effective control of avian diseases and food borne pathogens remains a high priority for all sectors of the poultry industry with cleansing and disinfection, vaccination and competitive exclusion approaches being used widely. Previous studies showed that Bacillus subtilis PY79hr was an effective competitive exclusion agent for use in poultry to control avian pathogenic Escherichia coli serotype O78:K80. Here we report experiments that were undertaken to test the efficacy of B. subtilis PY79hr in the control of Salmonella enterica serotype Enteritidis and Clostridium perfringens in young chickens. To do this, 1-day-old and 20-day-old specific pathogen free (SPF) chicks were dosed with a suspension of B. subtilis spores prior to challenge with S. Enteritidis (S1400) and C. perfringens, respectively. For both challenge models, a single oral inoculum of 1×109 spores given 24 h prior to challenge was sufficient to suppress colonisation and persistence of both S. Enteritidis and C. perfringens. In particular, the faecal shedding of S. Enteritidis, as measured by a semi-quantitative cloacal swabbing technique, was reduced significantly for the 36 days duration of the experiment. B. subtilis persisted in the intestine although with decreasing numbers over the same period. These data add further evidence that B. subtilis spores may be effective agents in the control of avian diseases and food borne pathogens. [Copyright &y& Elsevier]

Abstract: Independent studies have demonstrated that flagella are associated with the invasive process of Salmonella enterica serotypes, and aflagellate derivatives of Salmonella enterica serotype Enteritidis are attenuated in murine and avian models of infection. One widely held view is that the motility afforded by flagella, probably aided by chemotactic responses, mediates the initial interaction between bacterium and host cell. The adherence and invasion properties of two S. Enteritidis wild-type strains and isogenic aflagellate mutants were assessed on HEp-2 and Div-1 cells that are of human and avian epithelial origin, respectively. Both aflagellate derivatives showed a significant reduction of invasion compared with wild type over the three hours of the assays. Complementation of the defective fliC allele recovered partially the wild-type phenotype. Examination of the bacterium-host cell interaction by electron and confocal microscopy approaches showed that wild-type bacteria induced ruffle formation and significant cytoskeletal rearrangements on HEp-2 cells within 5 minutes of contact. The aflagellate derivatives induced fewer ruffles than wild type. Ruffle formation on the Div-1 cell line was less pronounced than for HEp-2 cells for wild-type S. Enteritidis. Collectively, these data support the hypothesis that flagella play an active role in the early events of the invasive process. [Copyright &y& Elsevier]

The humoral immunity, spleen and thymus weight indices, lymphocyte count in the thymus cortex, and granuloma diameter at vaccination sites were assessed in four differently immunopotentiated groups of meat chicken breeders. Breeders in the first two groups were given a killed Salmonella enterica serotype Enteritidis (SE) vaccine subcutaneously at 15 and 19 weeks of age. Breeders in the third and fourth groups were left unvaccinated. Breeders in the first group were further immunopotentiated with zinc and thymulin. Each bird in the first group was given the immunopotentiators intraperitoneally in a volume of 0.1 ml at intervals of 3 days for a period of 3 weeks, starting at 15 weeks of age. At each time, each bird in the first group received thymulin (10 ng) and ZnCl2 (1 μmol/L), using a carboxymethyl cellulose carrier, totalling 90 ng thymulin and 9 μmol of ZnCl2 per bird. Each bird in the first three groups was challenged orally with 6.7×106 cfu/ml of highly virulent SE organisms, at an age of 22 weeks. The first group, which had received zinc and thymulin, had the earliest and highest humoral immune response to SE ( p<0.05). This was observed at 2 and 4 weeks after the first vaccination. In addition, the first group had the highest mean thymus weight index, and the highest mean lymphocyte count in the thymus cortex. No significant difference was observed between the first two vaccinated groups in the mean granuloma diameter developed at the two vaccination sites 48 h after administration of the vaccine ( p>0.05). [ABSTRACT FROM AUTHOR]

As an important foodborne pathogen, Salmonella enterica serotype Enteritidis is recognized as one of the most common causes of human salmonellosis globally. Outbreak detection for this highly homogenous serotype, however, has remained challenging. Rapid advances in sequencing technologies have presented whole-genome sequencing (WGS) as a significant advancement for source tracing and molecular typing of foodborne pathogens. A retrospective analysis was conducted using Salmonella Enteritidis isolates ( n  = 65) from 11 epidemiologically confirmed outbreaks and a collection of contemporaneous sporadic isolates ( n  = 258) during 2007-2017 to evaluate the performance of WGS in delineating outbreak-associated isolates. Whole-genome single-nucleotide polymorphism (SNP)-based phylogenetic analysis revealed well-supported clades in concordance with epidemiological evidence and pairwise distances of ≤3 SNPs for all outbreaks. WGS-based framework of outbreak detection was thus proposed and applied prospectively to investigate isolates ( n  = 66) from nine outbreaks during 2018-2019. We further demonstrated the superior discriminatory power and accuracy of WGS to resolve and delineate outbreaks for pragmatic food source tracing. The proposed integrated WGS framework is the first in China for Salmonella Enteritidis and has the potential to serve as a paradigm for outbreak detection and source tracing of Salmonella throughout the stages of food production, as well as expanded to other foodborne pathogens.

Phage typing of 741 isolates of Salmonella enterica serotype Enteritidis from the slovak Republic in 1995 has been carried out using the scheme of Ward and colleagues (1987). 202 strains (51 isolated from food) were from 9 outbreaks, 536 isolates were from sporadic cases and 3 isolates were from nosocomial infections of new-born babies. 704 isolates (95%) from all sources were typeable and belonged to 7 different phage types (PTs). PT8 was the phage type most frequently identified (72.6%). Other epidemiologically relevant phage types were PT2 (8.5%), 4 (7.9%) and 1 (4.2%). With an incidence of 1.3--0.1% isolates of PTs 21, 6, 9 were found. 26 (3.5%) isolates were designated RDNC and 11 (1.5%) were untypeable. [ABSTRACT FROM AUTHOR]

Objectives: Salmonella enterica serotype Enteritidis is a major serotype associated with human salmonellosis. The main objective of this study was to determine the antibiotic susceptibility patterns and the presence of virulence-associated genes among S. Enteritidis strains isolated from patients with gastroenteritis in Tehran, Iran., Methods: Over a period of 14 months (May 2015 to July 2016), 44 S. Enteritidis isolates recovered from clinical sources were characterised for antimicrobial susceptibility and virulence genes. Possible genetic relatedness among the strains was also assessed using pulsed-field gel electrophoresis (PFGE)., Results: Salmonella Enteritidis isolates showed high rates of resistance to ciprofloxacin (90.9%) and nalidixic acid (77.3%). Of the 44 S. Enteritidis isolates, 30 (68.2%) were resistant to three or more antibiotics. Twenty-two different antimicrobial resistance patterns were detected among the isolates. The most frequent resistance type was antibiotype 14 (resistance to ciprofloxacin, cefuroxime and nalidixic acid), occurring in 8 (18.2%) of the isolates. Notably, all of the isolates carried invA, sefA, sipA and sopE2 virulence genes. Furthermore, 17 virulence profiles were observed among the strains. The most common virulence profile was VP1 (n=17; 38.6%), harbouring all of the virulence genes. Two distinct PFGE patterns were observed among 44S. Enteritidis isolates. There was no association between virulence profiles or antibiotypes and PFGE clusters., Conclusions: Overall, this study provides valuable information on the virulence gene content, antibiotic resistance and genetic diversity of S. Enteritidis isolated from human sources in Iran., (Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.)

Abstract: Non typhoidal Salmonella species are thought to be potentially infectious to humans. We isolated Salmonella enteritidis from a 10-year-old boy with fever and thrombocytopenia. We reviewed the literature concerning infections caused by Salmonella but we could not find any such case report from India. [Copyright &y& Elsevier]

Outbreaks of Salmonella enterica serotype Enteritidis infections associated with eggs occurred in French Polynesia during 2008-2013. Molecular analysis of isolates by using clustered regularly interspaced short palindromic repeat polymorphisms and multilocus variable-number tandem-repeat analysis was performed. This subtyping made defining the epidemic strain, finding the source, and decontaminating affected poultry flocks possible.