Salmonella Enteritidis is the main cause of foodborne salmonellosis worldwide. The limited effectiveness of current interventions against this pathogen has been the main incentive to develop new methods for the efficient control of this infection. To investigate the use of DNA vaccines against S. Enteritidis in humans, immune responses stimulated by two plasmids containing the genes designated SEN1002, located in the pathogenicity island SPI-19 and encoding a Hcp protein involved in transport mechanisms, and SEN1395, located in the genomic island ΦSE14 and encoding a protein of a new superfamily of lysozymes, were evaluated. Humoral and cellular responses following intranasal immunization of two groups of BALB/c mice with the plasmids pV1002 and pV1395 plus adjuvant were evaluated and it was observed that the IgG2a/IgG1 ratios were sixfold higher than control groups. Both plasmids stimulated specific secretory IgA production. Increased proliferation of lymphocytes and IFN-γ production were detected in both experimental groups. DNA-vaccinated mice developed protective immunity against a virulent strain of S. Enteritidis, with nearly 2 logs of protection level compared to the negative control values in the spleen. Therefore, DNA vaccines are efficient at stimulating cellular and humoral immune responses at systemic and mucosal levels.

Decontamination of egg shells is required to improve the microbiological safety of the fresh hen eggs used for human consumption or for hatching. Conventional chemical decontamination methods involving quaternary ammonium disinfectant, sodium hydroxide, phenol, hydrogen peroxide or formaldehyde, leave residues on egg shells that may damage the cuticle layer. Therefore new techniques of egg shells decontamination, such as ultraviolet (UV) radiation, have been developed. This review aims to evaluate the data from available literature and to provide a general review of UV light treatment application for egg shell decontamination. Data shows that UV treatment was effective for the inactivation of the bacterial population present on clean egg shells and recently contaminated shells. Combined treatments such as UV light with ozone or hydrogen peroxide (H2O2) improved the inactivation of microorganisms. Recent advances in science and engineering indicate that treatment with UV light has a competitive advantage in comparison with traditional egg shell sanitation treatments for decontamination.

Salmonella Enteritidis is a major causative agent of foodborne outbreaks worldwide. Using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and pulsed-field gel electrophoresis (PFGE), this study assessed the genetic relatedness, the pathogenic potential, and antimicrobial resistance in 60 strains isolated from chickens and the farm environment in Brazil between 2004 and 2010. The resulting concatenated dendrogram of the two methodologies distinguished the strains into two clusters. Some strains isolated from the two sources were indistinguishable. All the strains contained the 13 virulence markers investigated. Forty-four strains were resistant to nalidixic acid. Quinolone resistance presented by many strains suggests that quinolones may have been used to treat chickens. The high prevalence of virulence markers highlights the importance of poultry as vehicles of S. Enteritidis strains that have the potential to cause disease.

In Ontario, Canada, the number of Salmonella Enteritidis (SE) cases increased over the years 2005–2010. A population-based case-control study was undertaken from January to August 2011 for the purpose of identifying risk factors for acquiring illness due to SE within Ontario. A total of 199 cases and 241 controls were enrolled. After adjustment for confounders, consuming any poultry meat [adjusted odds ratio (aOR) 2·24, 95% confidence interval (CI) 1·31–3·83], processed chicken (aOR 3·32, 95% CI 1·26–8·76) and not washing hands following handling of raw eggs (OR 2·82, 95% CI 1·48–5·37) were significantly associated with SE infection. The population attributable fraction was 46% for any poultry meat consumption and 10% for processed chicken. Poultry meat continues to be identified as a risk factor for SE illness. Control of SE at source, as well as proper food handling practices, are required to reduce the number of SE cases.

A total of 105 033 eggs were collected across Japan from June 2010 to January 2011 and tested for Salmonella Enteritidis to provide data for the risk profiling of S. Enteritidis in eggs by the Food Safety Commission of Japan. S. Enteritidis isolates were recovered from three samples (20 eggs/sample) and these samples were different in regard to sampling period, grading and packaging centre and farm. The prevalence of S. Enteritidis in commercial eggs in Japan is estimated at ∼0·003% which was a tenfold decrease in prevalence compared to similar surveillance in the mid 1990s. The decrease in the contamination in commercial eggs is considered a contributory factor in the decrease of foodborne diseases associated with S. Enteritidis in this period.

Salmonella Enteritidis has emerged as the most prevalent cause of human salmonellosis in Canada. Recent trends of S. Enteritidis subtypes and their potential sources were described by integrating Salmonella data from several Canadian surveillance and monitoring programmes. A threefold increase in S. Enteritidis cases from 2003 to 2009 was identified to be primarily associated with phage types 13, 8 and 13a. Other common phage types (4, 1, 6a) showed winter seasonality and were more likely to be associated with cases linked to international travel. Conversely, phage types 13, 8 and 13a had summer seasonal peaks and were associated with cases of domestically acquired infections. During agri-food surveillance, S. Enteritidis was detected in various commodities, most frequently in chicken (with PT13, PT8 and PT13a predominating). Antimicrobial resistance was low in human and non-human isolates. Continued integrated surveillance and collaborative prevention and control efforts are required to mitigate future illness.

The aim was to determine the effect of orally administered ovine serum immunoglobulin (Ig) on growth performance, organ weight, gut morphology and mucin production in the Salmonella enteritidis – gavaged growing rat. Four groups consisted of non-gavaged rats fed a casein-based control basal diet (BD) and three groups of rats gavaged with 1 × 107 CFU S. enteritidis and fed a casein-based diet, a diet containing freeze-dried ovine Ig (FDOI) or a casein-based diet containing inactivated ovine Ig (IOI). The rats were randomly allocated to one of the four groups (n = 15/group) and received their respective diets for an 18-day experimental study. Gavaging took place on day 15. Average daily gain and body gain : feed ratio (post-gavage, 3 days) were significantly (P < 0.05) higher for the Salmonella-challenged rats fed the FDOI diet compared to those fed the BD and IOI diets. At the end of the study, the small intestine and colon were significantly (P < 0.05) heavier for the gavaged rats fed the FDOI diet compared to the gavaged rats fed either the BD or IOI diet. Moreover, the relative weights of the caecum, liver and spleen of the gavaged rats fed the BD or IOI diet were significantly (P < 0.05) heavier compared to the gavaged rats fed the FDOI diet. Generally, the gavaged rats fed the FDOI diet had significantly (P < 0.05) higher goblet cell counts and luminal mucin protein contents than the gavaged rats fed either the BD or IOI diet and had a more functional gut morphology. Overall, the FDOI fraction prevented the acute effects of S. enteritidis.

In March 2002, an outbreak of Salmonella Enteritidis (SE) infections occurred at a convention centre in Dallas, Texas and continued for 6 weeks. We conducted epidemiological studies, obtained clinical and environmental cultures, and interviewed employees to identify risk factors for infection. From 17 March–25 April 2002, the implicated hotel kitchen catered 41 multi-day conferences attended by 9790 persons. We received 617 illness reports from residents of 46 states. Sauces or items served with sauces were implicated in three cohort studies. SE phage-type 8 was identified as the agent. Eleven food service employees, including one who prepared sauces and salsa, had stool cultures that yielded SE. Although the original source was not determined, prolonged transmission resulted in the largest food handler-associated outbreak reported to date, affecting persons from 46 US states. Transmission ended with implementation of policies to screen food handlers and exclude those whose stool cultures yielded salmonellas.