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The M13 phage carries approximately 5 copies of the pIII protein, each of which is capable of displaying a single-chain variable fragment (scFv) that targets a specific antigen. This feature enables the M13 phage to be widely employed in the construction of scFv libraries, thereby facilitating the identification of antibodies with high specificity and affinity for target antigens. In this study, mice were immunized three times with Salmonella enteritidis (strain C50041) to induce diverse antibodies. The variable region sequences were subsequently amplified by PCR using genome extracted from the mice's splenic cells and fused to the pIII protein to construct the scFv phage display library (C50041-M13-scFv). Through biopanning with the C50041-M13-scFv library, a phage clone (C50041-scFv-4) exhibiting high affinity for the target bacteria was successfully obtained. Moreover, the scFv antibody (scFv-4) derived from C50041-scFv-4 was expressed in a prokaryotic expression system and validated to possess high specificity and affinity for C50041 through in vitro adsorption assays. Additionally, a phage-ELISA method was established: initially, bacteria were immobilized on the bottom surface of a 96-well plate. Next, the positive clone C50041-scFv-4 was introduced to specifically bind to the host cells. Finally, horseradish peroxidase (HRP)-conjugated anti-pVIII antibodies were used to detect the pVIII proteins of the bound phage clones. Owing to the capacity of multiple C50041-scFv-4 probes to simultaneously bind to a single target Salmonella and each phage clone's ability to accommodate hundreds of HRP-labeled antibodies, the proposed phage-ELISA demonstrated remarkable sensitivity (104 CFU mL−1) for detecting Salmonella enteritidis samples. This sensitivity surpasses that of traditional ELISA by one order of magnitude in this study. Our phage-ELISA technology exhibits broad applicability across various biological species and provides an improved and robust platform for pathogen detection including bacteria and viruses. [ABSTRACT FROM AUTHOR]

Introduction: Eggs can mediate foodborne disease resulting in salmonellosis outbreaks that are most commonly caused by Salmonella enterica serovar Enteritidis. Ovotransferrin is a prominent egg-white antimicrobial glycoprotein belonging to the transferrin family, members of which exhibit powerful iron-chelating activity. However, several studies have also described the ability of transferrin proteins to disrupt bacterial membranes. This study aimed to investigate the antimicrobial activity of ovotransferrin toward S. Enteritidis membranes at 30°C under egg-white conditions. Materials and methods: This aim was supported by the deployment of a synthetic medium designed to mimic egg-white (matching the ionic composition and pH). The ability of ovotransferrin to induce bacterial membrane permeabilization in S. Enteritidis was investigated by measuring substrate accessibility to periplasmic β -lactamase and cytosolic β -galactosidase. Results: The depolarization of the inner membrane of S. Enteritidis was measured using a fluorescence probe [DiSC3(5)]. The results show that ovotransferrin induces permeabilization of the outer membrane but not the inner membrane whereas egg white permeabilizes both membranes. In addition, the dissipation of the proton motive force by egg white was found to involve a contribution by ovotransferrin since this protein provoked inner-membrane depolarization. Discussion: It can thus be concluded that ovotransferrin exerts a membranes perturbation activity on S. Enteritidis under egg-white conditions, in addition to its well-known iron-chelation activity. [ABSTRACT FROM AUTHOR]

Microorganisms tend to accumulate on surfaces, forming aggregates such as biofilms, which grant them resistance to various environmental stressors and antimicrobial agents. This ability has hindered the effective treatment of diseases caused by pathogenic microorganisms, including Salmonella, which is responsible for a significant number of deaths worldwide. This study aimed to compare the metabolic profiles of planktonic and sessile cells of Salmonella Enteritidis using a metabolomics approach. The metabolites extracted from the bacterial cells were analyzed by LC/MS approach. Raw data were analyzed using Thermo Xcalibur v 3.1 software. For data processing, XCMS was used for feature detection, retention time, correction and alignment. The data matrix was analyzed by uni- and multivariate statistical methods (PCA, PLS-DA, Heatmap) in MetaboAnalyst software v 6.0. A total of 121 metabolites were presumptively identified as differential metabolic characteristics between the two bacterial states, and they were associated with their corresponding metabolic pathways. Among the metabolites that exhibited positive modulation in planktonic cells were proline, phenylalanine, which act as precursors of essential metabolites and part of the stress adaptation mechanisms. In addition, putrescine and cadaverine, play crucial roles in growth, stress response, and cell stability In contrast, the most representative metabolites in sessile cells included lysine, adenosine, purines, pyrimidines, and citrate, mainly associated with maintaining cellular homeostasis, stress response and metabolic regulation. Finally, pathway enrichment analysis identified metabolic changes in 11 pathways, predominantly involving purine and pyrimidine metabolism, arginine and proline metabolism, and vitamin B6 metabolism. These findings facilitated the identification of potential metabolic pathways associated with biofilm formation in the sessile cells of Salmonella Enteritidis. [ABSTRACT FROM AUTHOR]

RESEARCH HIGHLIGHTSIt was previously reported that utilization of tetrathionate and 1,2-propanediol by Salmonella spp. through the metabolic pathways encoded by ttr and pdu operons are related to overgrowth and out-competing microbiota in an anaerobic environment. However, recent knowledge demonstrated which strains in the absence of ttr and pdu genes provoke both higher intestinal colonization and spreading of bacteria in faeces compared with their respective wild-type strain, and also generate more prominent inflammation. This study evaluated the immune response of different lineages of chicks infected by Salmonella Typhimurium (STM) and Salmonella Enteritidis (SE) with ttrA and pduA gene deletions. Our work was separated into two experiments, one for each strain, utilizing 108 chicks to collect spleen and caecal tonsils for measuring immune response through RT-qPCR. From the immune response analysis, Salmonella Enteritidis mutant and wild-type strains elicited upregulated pro-inflammatory cytokines on the first-day post-infection; the opposite occurred with Salmonella Typhimurium strains (mutant and wild-type). However, the deletions did not impair the immune response produced by mutant strains compared with the respective wild-type in the caecal tonsil and spleen, suggesting that these metabolic pathways are not essential for colonization success. In conclusion, SE and STM, in the absence of ttrA and pduA genes, provoke an immune response with the same intensity as respective wild-type strains.ttrA and pduA double mutants in Salmonella provoke a similar immune response.SE elicited more intense immune responses than STM.The immune response in the broiler was more intense than in other lineages.ttrA and pduA double mutants in Salmonella provoke a similar immune response.SE elicited more intense immune responses than STM.The immune response in the broiler was more intense than in other lineages. [ABSTRACT FROM AUTHOR]

Objective: To establish a rapid detection method for canine brucellosis using recombinase-aided amplification (RAA) technology. Methods: The outer membrane protein 25 gene fragment (Omp25) of Brucella canis was targeted. Primers and fluorescent probes were designed and synthesized, and recombinant plasmids were constructed as standards. The RAA assay was optimized by screening primers and establishing a fluorescent reaction system. Sensitivity was analyzed using plasmid standards with varying copy numbers. Specificity was tested using genomes from Brucella canis, Brucella suis, Brucella melitensis, Brucella abortus, Staphylococcus aureus, pathogenic Escherichia coli, Salmonella enteritidis, Shigella spp. , Proteus mirabilis, and Listeria monocytogenes. Reproducibility was evaluated using plasmid standards from the same and different batches. Results: The optimized RAA system used primers bOmp25-F2/bOmp25-R2 and probe bOmp25-P, with a constant reaction temperature of 39°C for 15 minutes. The detection sensitivity was 1 copy/μL. No cross-reaction was observed with other Brucella species or pathogenic bacteria, indicating high specificity. Intra-batch variability was below 1.00%, and inter-batch variability was below 2.00%. The positive detection coincidence rate of RAA was significantly higher than that of commercial real-time fluorescence quantitative PCR (100% VS 86.96%, P<0.05). Conclusion: The RAA-based rapid detection method for Brucella canis is suitable for clinical rapid testing. It offers advantages such as quick detection, high sensitivity, strong specificity, and good reproducibility. This method provides new insights for the rapid detection of canine brucellosis and the precise diagnosis of other pet diseases, making it suitable for promotion and application. [ABSTRACT FROM AUTHOR]

Background: The transmission of Salmonella spp. to human through the consumption of contaminated food products of animal origin, mainly poultry is a significant global public health concern. The emerging multidrug resistant (MDR) clones of non-typhoidal Salmonella (NTS) serovars, have spread rapidly worldwide both in humans and in the food chain. In this study NTS strains were isolated from diseased laying hens in Iran and were further studied by whole-genome sequencing (WGS) to investigate the prevalent serovars, multilocus sequence types, antimicrobial resistance and virulence genes. Results: Out of eight isolated Salmonella spp. six were identified as S. Enteritidis serovar ST11 (n = 5) or ST5824 (n = 1), and two isolates were recognized as S. Kentucky serotype ST198 lineages. The aminoglycoside resistance gene aac(6′)-Iaa was the most frequently detected gene being present in all serovars, but it did not confer phenotypic resistance to corresponding agents (tobramycin and amikacin). All S. Enteritidis isolates carried a single GyrA D87N/Y substitution. Other identified antimicrobial resistance genes (ARGs) including tetA, floR, sul1, dfrA1, aph(3′)-Ia and double gyrA and parC mutations conferring high-level ciprofloxacin resistance (CIPR) (MIC ≥ 16mg/L) were only found in S. Kentucky isolates. The comparison of phenotypic and genotypic antimicrobial resistance (AMR) profiles revealed inconsistent results for some antibiotics. A total of 11 different Salmonella Pathogenicity Islands (SPIs) including SPIs-1, to 5, 9, 10, 13, 14, C63PI, CS54 and several virulence genes related to type III secretion system, adhesins, iron and magnesium uptake, serum and antimicrobial peptide resistance were detected among the isolates. Conclusions: Our study reports emergence of a highly MDR- CIPRS. Kentucky ST198 clone form poultry associated sources in Iran. The presence of numerous virulence determinants, SPIs and ARGs in the examined NTS isolates poses a significant risk for food safety. The inconsistencies between the genotypic and phenotypic AMR profiles indicate that WGS data alone may not be always sufficient for guiding therapeutic strategies. [ABSTRACT FROM AUTHOR]

Salmonella enteritidis is a major cause of foodborne illness worldwide, and the emergence of ciprofloxacin-resistant strains poses a significant threat to food safety and public health. This study aimed to investigate the prevalence, spread, and mechanisms of ciprofloxacin resistance in S. enteritidis isolates from food and patient samples in Shanghai, China. A total of 1625 S. enteritidis isolates were screened, and 34 (2.1%) exhibited resistance to ciprofloxacin. Pulsed-field gel electrophoresis (PFGE) results suggested that clonal spread might have persisted among these 34 isolates in the local area for several years. Multiple plasmid-mediated quinolone resistance (PMQR) genes, GyrA mutations in the quinolone resistance-determining region (QRDR), and overexpression of RND efflux pumps were identified as potential contributors to ciprofloxacin resistance. PMQR genes oqxAB, qnrA, qnrB, and aac(6')-Ib-cr as well as GyrA mutations S83Y, S83R, D87Y, D87G, D87N, and S83Y-D87Y were identified. The co-transfer of the PMQR gene oqxAB with the ESBL gene blaCTX-M-14/55 on an IncHI2 plasmid with a size of ~245 kbp was observed through conjugation, highlighting the role of horizontal gene transfer in the dissemination of antibiotic resistance. Sequencing of the oqxAB-bearing plasmid p12519A revealed a 248,746 bp sequence with a typical IncHI2 backbone. A 53,104 bp multidrug resistance region (MRR) was identified, containing two key antibiotic resistance determinants: IS26-oqxR-oqxAB-IS26 and IS26-ΔISEcp1-blaCTX-M-14-IS903B. The findings of this study indicate that ciprofloxacin-resistant S. Enteritidis poses a significant threat to food safety and public health. The persistence of clonal spread and the horizontal transfer of resistance genes highlight the need for enhanced surveillance and control measures to prevent the further spread of antibiotic resistance. [ABSTRACT FROM AUTHOR]

The Enterobacteriaceae family poses health risks due to its role in gastrointestinal diseases like acute diarrhea. With rising antibiotic resistance, plants offer promising antibacterial compounds with low toxicity. This study evaluated the antibacterial activity, minimum inhibitory concentration (MIC), and toxicity of ethanolic (EE) and aqueous (AE) extracts from five Mexican medicinal plants traditionally used in Chiapas for treating acute diarrheal diseases (ADD). Antibacterial activity was assessed using disk diffusion assays and MIC determined by macrodilution. Toxicity tests were performed using Artemia salina. As a result, EE extracts exhibited higher antibacterial activity than AE extracts. Byrsonima crassifolia effectively inhibited Salmonella enteritidis (78.26%, MIC 50 mg/mL) and Shigella dysenteriae (76.19%, MIC 25 mg/mL). Solanum torvum showed efficacy against Escherichia coli (55.55%, MIC 12.5 mg/mL) and Salmonella enteritidis (73.91%, MIC 25 mg/mL). Euphorbia maculata inhibited Shigella dysenteriae (104.76%, MIC 25 mg/mL), while Guazuma ulmifolia and Bursera simaruba exhibited no antibacterial effects. All extracts were non-toxic (LD50 > 1000 μg/mL), indicating potential as natural alternatives for ADD treatment. [ABSTRACT FROM AUTHOR]

Salmonella enteritidis is one of the most common pathogens that cause foodborne disease outbreaks and food spoilage, which seriously threatens human health. Bacteriophages have shown broad application prospects in controlling harmful microorganisms during food processing and preservation due to their ability to specifically infect bacteria. In this study, Salmonella enteritidis bacteriophage Salmp-p7 was isolated and characterized from slaughterhouse wastewater. Transmission electron microscopy (TEM) analysis showed that Salmp-p7 belonged to the Siphoviridae family and was active against Salmonella enteritidis and Escherichia coli. Whole genome sequence analysis showed that Salmp-p7 was a lytic bacteriophage with a total length of 60,066 bp of sequence. Salmp-p7 has a short incubation period and a long burst duration, with a burst volume of 55 PFU/cell and a good lysis effect. It can maintain a stable state within the temperature range of 30–60℃ and pH range of 4–12 and has the potential for application in food. In vitro, antimicrobial curves and inhibition of biofilm removal experiments showed that Salmp-p7 could effectively inhibit and eliminate Salmonella enteritidis. The application of Salmp-p7 to the whole liquid of infected eggs resulted in a significant reduction of viable bacteria. And Salmp-p7 has high stability and lytic activity and has the potential to become a new biological control agent for Salmonella enteritidis in eggs. [ABSTRACT FROM AUTHOR]

The European hedgehog (Erinaceus europaeus), common in rural and suburban environments, is perceived as declining within its native range, prompting conservation concerns. This study of hedgehogs admitted to a French rehabilitation center aimed to identify causes of death, detect potential emerging diseases, and systematically screen dead hedgehogs for toxicants and hemopathogens. Using clinical information, necropsy examination, and ancillary testing in 159 dead hedgehogs, we identified the primary cause of death of 92% of them. The leading causes of death were impaired general condition (30%); bacterial infections (26%), frequently caused by Salmonella Enteritidis; and trauma (20%). Additional factors contributing to death were identified in 78%, including a high proportion with significant parasite infestations. Toxicologic screening revealed that 42% of hedgehogs had been exposed to anticoagulant rodenticides, including 6.4% hedgehogs with levels compatible with acute intoxication. These hedgehogs were also exposed to trace metals, especially lead, but no pesticides residues were detected. Hemopathogen screening revealed a low diversity and prevalence of blood pathogens with 3.6, 2.9, and 2.9% individuals infected with Anaplasma phagocytophilum, Mycoplasma turicensis, and Mycoplasma wenyonii, respectively. The variety of diagnoses suggests that there is no unique prominent or emerging disease responsible for the mortality of these hedgehogs. This study also highlighted the high exposure of hedgehogs to various toxicants. To further investigate the extent and causes of population declines, health information issued from several centers should be combined with demographic data as well as ecologic assessments on the availability and quality of natural resources. [ABSTRACT FROM AUTHOR]

As an excellent variety of Camphora glanduliferum, Honganzhang has high essential oil content and can be used as industrial and pharmaceutical raw materials to extract essential oil, which has high development value. In this study, fresh branches and leaves of C. glanduliferum 'Honganzhang' were used as materials. After extracting C. glanduliferum 'Honganzhang' essential oils (CGHEO) by steam distillation, gas chromatography-mass spectrometry (GC-MS) was used to analyze its chemical components. On this basis, the antibacterial effect of CGHEO and its potential physiological mechanism were further explored. The results showed that the main components of CGHEO were Cineole (46.57%), α-terpineol (9.93%), Sabinene (8.02%), β-terpinene (6.04%), and α-pinene (4.49%), these compounds can be used in medicine, food and other industries. In terms of antibacterial effect, CGHEO has significant antibacterial effects on three Gram-negative bacteria (Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa), and two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus). CGHEO can reduce Na+K+-ATPase activity and SDH activity and further interfere with the operation of the bacterial respiratory chain, thereby achieving the effect of inhibiting bacterial reproduction. Based on the main chemical components contained in C. glanduliferum 'Honganzhang' and its remarkable antibacterial effect, this study is expected to provide a theoretical basis for the wide application of C. glanduliferum 'Honganzhang' in multiple fields such as medicine, health care, food, and industry. [ABSTRACT FROM AUTHOR]

Eggs are considered a nutritionally complete food and an excellent source of protein. However, they are prone to bacterial contamination, which can affect their internal quality and safety. This study aimed to evaluate the effectiveness of essential oils (EOs) as natural sanitizers for eggshells to reduce the bacterial load and improve shelf life. Ten EOs—cinnamon, clove, lavender, peppermint, thyme, rosemary, green tea, mustard, basil, and marjoram—were tested for antibacterial activity against three Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis, and Listeria monocytogenes) and three Gram-negative bacteria (Salmonella Enteritidis, Pseudomonas aeruginosa, and Escherichia coli) using the well diffusion method. The most effective EOs were assessed in vapor form using a disc volatilization technique. A total of 288 eggs from a local farm in South Lebanon were treated with selected EOs and stored at room temperature for three weeks to evaluate microbial load and quality. The eggs were grouped into six categories: dry control, ultraviolet (UV) treated, and eggs sprayed with EOs, based on the recorded minimum inhibitory concentration (MIC) values. At each time point, 12 eggs from each group were analyzed for microbiological testing and external and internal quality. Results indicated that nine of the ten EOs showed antibacterial activity, with the highest inhibition zones recorded for cinnamon against S. Enteritidis (14 mm) and E. coli (9 mm), peppermint against P. aeruginosa (10 mm), and rosemary against L. monocytogenes (22 mm), S. aureus (19 mm), and E. faecalis (12 mm). Vapor phase testing showed that rosemary, thyme, clove, and cinnamon EOs had average inhibition zones ranging from 21 to 33 mm against the tested bacteria, and peppermint EO achieved complete inhibition of P. aeruginosa. Clove EO consistently reduced the bacterial load as a sanitizer on eggs, initially achieving complete inhibition. While egg quality parameters such as weight, shell thickness, Haugh unit, and yolk color declined over time, EOs helped maintain better quality compared to dry controls. GC-MS analysis of the tested EOs revealed that monoterpene alcohols are the major constituents of most oils. This study concludes that EOs are effective natural sanitizers for eggs, enhancing safety and preserving quality during storage. [ABSTRACT FROM AUTHOR]

This work aimed to develop a nanosuspension (NSps) as an acetogenin (ACGs) carrier, using soy lecithin (SL) and hydroxypropyl-β-cyclodextrin (βCD) named NSps-βCDSL-ACGs. It was characterized by various spectroscopic techniques (DLS, FTIR, UV-vis diffuse reflectance). Moreover, the NSps morphology was observed by transmission electron microscopy (TEM). Also, the antibacterial activity of NSps-βCDSL-ACGs was evaluated against strains of interest in the poultry sector. NSps-βCDSL-ACGs presented nanometric size (207–239 nm), acceptable polydispersity index (PDI) values (0.13–0.17) and a high Z potential value (−47.17–50.36 mV), demonstrating high stability. The presence of ACGs in NSps-βCDSL-ACGs was confirmed by FTIR analysis. The nanoparticles had a spherical shape and exhibited high inhibition potential against Salmonella Enteritidis (88.18%), Streptococcus gallolyticus (88.01%), Salmonella Typhimurium (86.28%) and Salmonella Infantis (77.02%) strains up to 48 h, and a reduction of up to 3 log CFU/mL was achieved for S. Typhimurium. Therefore, NSps-βCDSL-ACGs is an attractive option for implementing ACGs administration in the poultry sector to reduce the use of antibiotics and minimize bacterial resistance. [ABSTRACT FROM AUTHOR]

Simple Summary: As a major economic pillar in Tibet, the yak breeding industry is an important source of income and livelihood for local farmers and herdsmen. Salmonella, one of the most important foodborne pathogens globally, has seriously threatened the healthy development of this industry for many years, causing huge economic losses for local herdsmen and related industries. Furthermore, there are many serotypes of Salmonella that can infect different hosts, causing varying degrees of damage. The aim of this study was to investigate the prevalence of Salmonella in yak farms in the Qinghai–Tibet Plateau area. A total of 223 strains of Salmonella were isolated from 1222 fecal samples from yaks from Tibet and Qinghai, with an overall isolation rate of 18.25% (223/1222). These 223 Salmonella isolates were serotyped, and their antimicrobial susceptibility, resistance genes, and virulence genes were investigated. Furthermore, MLST (Multi-Locus Sequence Typing) was applied to the isolates. The results showed that the carriage of Salmonella in Tibetan yaks is quite serious in the Qinghai–Tibet Plateau area, with Enteritidis Salmonella (17.94%) and Typhimurium Salmonella (13.90%) representing the predominant serotypes. Given that the Salmonella isolates also showed resistance to antimicrobial drugs, continuous monitoring of Salmonella infections and resistance in the Qinghai–Tibet Plateau area is needed to avoid the potential risk of foodborne disease transmission. Salmonella is an important foodborne pathogen that can cause a range of illnesses in humans; it has also been a key focus for monitoring in the field of public health, including gastroenteritis, sepsis, and arthritis, and can also cause a decline in egg production in poultry and diarrhea and abortion in livestock, leading to death in severe cases, resulting in huge economic losses. This study aimed to investigate the isolation rate, antimicrobial resistance, serotypes, and genetic diversity of Salmonella isolated from yak feces in various regions on the Qinghai–Tibet Plateau. A total of 1222 samples of yak dung were collected from major cities in the Qinghai–Tibet Plateau area, and the sensitivity of the isolated bacteria to 10 major classes of antibiotics was determined using the K-B paper disk diffusion method for drug susceptibility. Meanwhile, the serotypes of the isolated bacteria were analyzed using the plate agglutination test for serum antigens, and their carriage of drug resistance and virulence genes was determined using PCR and gel electrophoresis experiments. The isolated bacteria were also classified using MLST (Multi-Locus Sequence Typing). The overall isolation rate for Salmonella was 18.25% (223/1222), and the results of the antibiotic susceptibility tests showed that 98.65% (220/223) of the isolated bacteria were resistant to multiple antibiotics. In the 223 isolates of Salmonella, eight classes of 20 different resistance genes, 30 serotypes, and 15 different types of virulence genes were detected. The MLST analysis identified 45 distinct sequence types (STs), including five clonal complexes, of which ST34, ST11, and ST19 were the most common. These findings contribute valuable information about strain resources, genetic profiles, and typing data for Salmonella in the Qinghai–Tibet Plateau area, facilitating improved bacterial surveillance, identification, and control in yak populations. They also provide certain data supplements for animal Salmonella infections globally, filling research gaps. [ABSTRACT FROM AUTHOR]

Salmonella enteritidis plays a significant role in zoonotic infections. This pathogen settles in the intestinal tract of poultry and contaminates meat and egg products during production for slaughter. Consequently, it can also be transmitted to humans along the food chain, posing a significant risk to public health. Bacteriophages offer a viable substitute for antibiotics in treating Salmonella enteritidis due to their specific bactericidal effect and safety. This study aimed to investigate the protective effect of bacteriophage against Salmonella enteritidis infection in chicken intestinal epithelial cells. Chicken intestinal epithelial cells were treated with various concentrations of bacterial suspension, and the impact on cell damage was assessed by measuring changes in cell viability and observing structural changes via transmission electron microscopy. In the phage protection experiment, the phages were co-incubated with Salmonella enteritidis for 2, 4, and 6 h. Thereafter, the adhesion rate and invasion rate of bacteria and gene transcription levels of Occludin, Claudin-1, ZO-1, NF-κB p65, TNF-α and IL-6 in cells were determined. The results indicated that the phage could significantly reduce both adhesion and invasion rates of Salmonella enteritidis at MOI = 10 (P < 0.05). Following phage treatment of the co-culture of chicken intestinal epithelial cells and Salmonella enteritidis (CICC10467), there was a significant reduction in the gene expression of pro-inflammatory cytokines NF-κB p65, TNF-α and IL-6, and a significant increase in the gene expression of anti-inflammatory cytokines Occludin, Claudin-1, and ZO-1. This indicates that the phage can inhibit the infection of chicken small intestinal epithelial cells by Salmonella enteritidis. Furthermore, phages were able to significantly alleviate inflammation and barrier integrity disruption caused by the bacteria in the co-culture. These observations suggest that phages are promising candidates for preventing and treating gastrointestinal bacterial infections. [ABSTRACT FROM AUTHOR]

Objectives To assess the impact of mutations in the two-component sensor envZ on antibiotic resistance and virulence in the evolutionary dynamics of MDR Salmonella enteritidis (S. enteritidis). Methods Five S. enteritidis isolates obtained from a patient with multisite invasive infections were analysed. Analysis of antibiotic resistance genes, virulence genes and SNP was performed through WGS. RNA sequencing, quantitative RT–PCR, virulence testing in a Galleria mellonella (G. mellonella) infection model and in vitro cell experiments were used to examine the effects of envZ mutations. Results WGS revealed identical resistance and virulence genes on an IncFIB(S)/IncFII(S)/IncX1 fusion plasmid in all strains. The faecal strains harboured envZ mutations, reducing outer membrane protein ompD and ompF transcriptional level. Virulence testing demonstrated elevated virulence in envZ mutant strains. In vitro experiments revealed increased adhesion, invasion and phagocytosis resistance in envZ mutants, along with reduced biofilm formation and growth rates. Conclusions These findings highlight novel genetic locations on envZ influencing antibiotic resistance and virulence in clinical S. enteritidis strains. envZ mutations impact antibiotic resistance by down-regulating ompD and ompF expression and enhance virulence, contributing to multisite infections with increased fitness costs. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a product consisting of four bacteriophages infecting Salmonella enterica ser. Gallinarum B/00111, intended for be as a zootechnical additive (functional group: other zootechnical additives) for all poultry species. Bafasal® is proposed for use in water for drinking and liquid complementary feed to guarantee a minimum daily dose of 2 × 106 PFU/bird, to reduce the Salmonella spp. contamination of poultry carcasses and load in the environment, and to improve the zootechnical performance of the treated animals. In previous opinions, the FEEDAP Panel concluded that Bafasal® is safe for the target species, consumers and the environment and is not a skin or eye irritant but should be considered a respiratory sensitiser. No conclusion could be drawn on its dermal sensitisation potential. The additive showed the potential to decrease the counts of two Salmonella Enteritidis strains in boots swabs and caecal digesta of chickens for fattening. However, the Panel was not in the position to conclude on the capacity of Bafasal® to improve the zootechnical performance of poultry, to reduce the contamination of other Salmonella enterica strains, serovars or other Salmonella spp. in chickens, or to reduce the Salmonella spp. contamination of poultry other than chickens. In the current application, the claim on zootechnical performance has been withdrawn. Bafasal® is not a skin or eye irritant but should be considered a potential skin and respiratory sensitiser and inhalation and dermal exposure is considered a risk. Based on the new data provided, the Panel concluded that Bafasal® has the potential to reduce the environmental contamination with S. Enteritidis when used in feed and water for all poultry species. No conclusions could be drawn on the effects of the additive on other Salmonella serotypes. [ABSTRACT FROM AUTHOR]

This report by the European Food Safety Authority and the European Centre for Disease Prevention and Control presents the results of zoonoses monitoring and surveillance activities carried out in 2023 in 27 Member States (MSs), the United Kingdom (Northern Ireland) and 10 non‐MSs. Key statistics on zoonoses and zoonotic agents in humans, food, animals and feed are provided and interpreted historically. In 2023, the first and second most reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. For both agents, an increase in the absolute number of cases was observed in comparison with 2022. Fifteen MSs and the United Kingdom (Northern Ireland) reached all the established targets in poultry populations with regard to the reduction in Salmonella prevalence for the relevant serovars. Salmonella samples from carcases of various animal species, and samples for Campylobacter quantification from broiler carcases, were more frequently positive when performed by the competent authorities than when own‐checks were conducted. Shiga toxin‐producing Escherichia coli (STEC) was the third most reported zoonotic agent in humans, followed by Yersinia enterocolitica and Listeria monocytogenes. L. monocytogenes and West Nile virus infections were the most severe zoonotic diseases, with the highest percentage of hospitalisations among cases and the highest case fatality rates. Twenty‐seven MSs and the United Kingdom (Northern Ireland) reported a slight decrease in food‐borne outbreaks in 2023 overall in comparison with 2022, although the overall number of reported human cases and hospitalisations increased. Salmonella Enteritidis remained the most frequently reported causative agent for reported cases and food‐borne outbreaks. Salmonella in 'eggs and egg products' was the agent/food pair of most concern. In 2023 this combination caused the largest number of outbreaks and cases among all agent/food combination and ranked second in number of hospitalisations. Salmonella was also the causative agent associated with the majority of multi‐country outbreaks reported in the EU in 2023. This report also provides updates on brucellosis, echinococcosis, Q fever, rabies, toxoplasmosis, trichinellosis, tuberculosis due to Mycobacterium bovis or M. caprae, and tularaemia. [ABSTRACT FROM AUTHOR]

Optimization of existing antimicrobial therapies is a strategy proposed for extending antimicrobial activity and delaying resistance development. This study aimed to assess the effect of inactivated E. faecalis CECT7121 (I-EFCECT7121) in a combined therapy with Enrofloxacin or Ciprofloxacin in a S. Enteritidis murine sepsis model. Firstly, dose titration studies were performed to set up: (a) Salmonella Enteritidis (SE) Lethal dose 99 (LD99) and (b) safety of I-EFCECT7121 (c) I-EFCECT7121 dosage scheme. Then, I-EFCECT7121 in combined therapy with 4 doses (5 mg/kg) per 12 h of CFX and EFX in an LD99 BALB/c infection, were evaluated. Survival rate was monitored for 20 days in order to estimate the treatment success. The efficacy of both drugs was improved by combining them with the inactivated bacteria. However, only a significant increase (p < 0.05) was observed after I-EFCECT7121 and CFX combined treatment (40% of survival rate). By contrast, each drug alone achieved a 10% of survival rate. These outcomes showed a potential therapeutic synergism when I-EFCECT7121 was concomitantly given with ciprofloxacin. [ABSTRACT FROM AUTHOR]

BACKGROUND: Salmonella Enteritidis (SE) in chickens is associated with growth depression and mortality of young chicks. Moreover, poultry products are identified as a prominent source of SE, which can cause food-borne diseases in humans. Therefore, considering the economic and public health significance of SE, control of this bacterial infection is important. OBJECTIVES: This study aims to assess colonization and invasion of SE after exposure to the thyme essential oils in experimentally infected broiler chickens. METHODS: Minimum inhibitory concentration (MIC) of thyme essential oils was measured by broth microdilution method. A total of 75 one-day-old Ross 308 chicks were randomized to three experimental groups of 25 (A, B and C). At 9 days old, groups A and B were challenged with 108 colony-forming unit (CFU) of SE with and without previous exposure to thyme essential oils at 50% MIC. Group C (control) received a bacteria-free buffer. On days 9, 16 and 24 after the challenge, cloacal swabs and samples from visceral organs were collected from slaughtered birds and evaluated for the presence of Salmonella. RESULTS: The MIC of thyme essential oil for SE was obtained 1.25 mg/mL. Results of experimental infection showed a significant reduction of SE in the cloaca, ceca, liver, and spleen of group A compared to group B throughout the sampling times. On day 16 after infection, Salmonella was isolated at 1 and 7.4 log CFU/g of cloacal swabs and at 3.2 and 9.2 log CFU/g of ceca in groups A and group B, respectively. CONCLUSIONS: According to the results, previous exposure of SE to the thyme essential oil at a sub-inhibitory concentration can reduce the colonization and invasion of this pathogen in broiler chickens. [ABSTRACT FROM AUTHOR]

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Simple Summary: Salmonella spp. are common in Africa and amongst the main causes of morbidity and mortality in humans, with a public health impact. However. there is a lack of scientific record on the situation in Angola, despite the numerous reports of informal and clinical suspicions of these infections as the cause of enteric disease. This work involved the isolation and characterization of the different Salmonella serovars circulating in Luanda, Angola, focusing on their antimicrobial resistance patterns and epidemiological relationship, particularly between clinical, environmental and food isolates and their impact on public health in Angola. This study provides an initial microbiological and molecular characterization of the real epidemiological situation of Salmonella spp. occurrence in Luanda and demonstrates the need for continuous monitoring of this pathogenic agent at the clinical, food and environmental levels to implement epidemiological strategies for the control of salmonellosis in Angola. The aim of this study was to characterize the antimicrobial resistance phenotype and genotype of non-typhoidal Salmonella spp. isolated in Luanda, Angola. Between 2013 and 2015, human clinical samples, food, and environmental samples (n = 290) were collected at different regions of Luanda city and screened for the presence of Salmonella spp. Bacterial isolates were preliminarily identified using the API 20E Kit, and their identification was confirmed using PCR and serotyping. All Salmonella spp. isolates were tested by minimum inhibitory concentration against 19 antimicrobials. The isolates were also screened using PCR for the presence of resistance genes (blaOXA-1, blaSHV, blaTEM, sul1, sul2, sul3, qnrA, qnrB, qnrS, qnrC, qnrD, aac(6′)-Ib, dfrIa [targeting dfrA1, dfrA5, dfrA15, dfrA15b, dfrA16, dfrA16b] and dfrA12, cmlA, and floR) and typed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Salmonella enterica non-typhoidal was detected in 21.3% of the clinical samples (n = 32/150), 11.1% of the food samples (n = 10/90), and 26% of the environmental samples (n = 13/50). Serotyping revealed that the monophasic variant of Salmonella Typhimurium (Salmonella enterica serovar 4,[5],12:i:-) was detected in 38.1% of the samples. Moreover, serovar Salmonella Enteritidis was the second most frequent. Only 7.3% of the isolates were resistant to at least one antimicrobial. Furthermore, isolates from different origins (clinical, environmental, and food) were associated with the same lineages, Salmonella Enteritidis ST11 and S. enterica ser. Typhimurium ST313. The detection of S. enterica serovar 4,[5],12:i:- in different settings reinforces the need for a One Health approach to control this zoonosis in Angola. [ABSTRACT FROM AUTHOR]

Background and objective: Salmonella typhi is the causative agent of enteric fever while Salmonella enteritidis causes gastroenteritis. Lytic bacteriophages can be applied as biocontrol agents to prevent Salmonella infections. The purpose of this study was to prepare a proper Salmonella phage therapy candidate to be used against pathogenic Salmonella enteritidis and Salmonella typhi. Methods: We used clinical isolates of Salmonella typhi and Salmonella enteritidis as host bacteria, to isolate Salmonella-specific phages from raw sewage water in four locations (Bahrka, Farmnbaran neighborhoods, Korey and Shaqlawa towns) in Erbil district. We assessed the efficacy of this phage as a biocontrol agent against Salmonella enteritidis in-vivo using four groups of 8 pathogen-free duck chicks. A group was kept as uninfected control while the other three groups were artificially infected with a clinical strain of Salmonella enteritidis. Two of the infected groups were treated by oral administration of phage suspension using two different doses of Salmonella enteritidis phage (7 and 12 Log10 Plague Forming Unit respectively). To compare the bacterial growth dynamics among the infected groups, one group was kept untreated. Results: We found that the four sewage samples contained bacteriophages for the two bacterial isolates with different plaque diameters and morphology. Salmonella enteritidis phage isolates collected from the Farmanbaran neighborhood showed the best lysing efficacy in-vitro hence it was selected to be tested in-vivo experiment. Phage-treatment significantly reduced the colonization burden of Salmonella enteritidis in feces and cecum contents of the experimentally infected chicks. Conclusion: These results suggest that using Salmonella phage could be a good agent to control Salmonella.

The use of copper nanoparticles (CuNP) in the diet of broiler chickens has been studied as a potential alternative to antibiotic growth promoters. This study aimed to analyse the antimicrobial properties of CuNP in the feed and water of broiler chickens against Salmonella Enteritidis and to assess the intestinal integrity and toxicity of CuNP supplementation in their diet. The antimicrobial activity of CuNP against S. Enteritidis was tested in microplates to evaluate three water samples with different mineral compositions and in an in vitro digestibility model that simulated the three primary intestinal compartments of birds to assess feed samples. To evaluate in vivo intestinal integrity and toxicity, the birds were divided into four groups (30 birds per group): (1) basal diet (control); (2) basal diet + CuNP (100 ppm); (3) basal diet + enramycin (10 ppm); and (4) basal diet + CuNP (100 ppm) + enramycin (10 ppm). Intestinal samples were collected for histomorphometric evaluation and lactic acid bacteria count, while chest muscle and whole blood samples were collected to determine copper content. A significant reduction in the S. Enteritidis count was observed in both in vitro treatments (water and feed) with CuNP inclusion, compared to the control group. No significant differences in histomorphometric measurements, weight gain, or total lactic acid bacterial counts were found compared to those in the control. These results demonstrate the effectiveness of CuNP in reducing the occurrence of S. Enteritidis and their non-interference with the intestinal integrity of broiler chickens, highlighting the potential of CuNP as an alternative antimicrobial agent in the poultry production chain. RESEARCH HIGHLIGHTS Supplementation with CuNP in feed and water reduced Salmonella Enteritidis count. Supplementation with CuNP did not affect intestinal integrity of broilers. CuNP did not affect weight gain or total lactic acid bacterial counts. The results demonstrate the potential of CuNP as alternative antimicrobials. [ABSTRACT FROM AUTHOR]

Salmonella Enteritidis is a major foodborne pathogen, and the emergence of multidrug-resistant (MDR) S. Enteritidis poses a serious public health challenge. In this study, we report the genomic characterization of five S. Enteritidis isolates from clinical. These isolates exhibited resistance to seven classes of antimicrobials with four of the five characterized as MDR. Isolate 33 A exhibited resistance to colistin and polymyxin B, while no associated antimicrobial resistance genes (ARGs) were identified in its genome. Isolate 21 A and 44 A were extended-spectrum beta-lactamases-producing (ESBLs). Whole genome sequencing analysis revealed the presence of multiple mobile genetic elements (MGEs), including plasmids, prophages, and genomic islands, which may have facilitated the acquisition and dissemination of ARGs. Notably, several ARGs, including blaCTX−M−55, blaTEM−141, blaTEM−1B, aph(3')-IIa, aph(3")-Ib, aph(6)-Id, tet(A), floR, fosA3, and sul2, were identified on plasmids. In addition, chromosomal point mutations in gyrA (D87G and D87Y) and acrB (F28L and L40P) were also observed in each isolate. Multiple virulence genes associated with the type III secretion system were identified on Salmonella pathogenicity islands (SPIs) SPI-1 and SPI-2. Phylogenetic analysis revealed that the five isolates, along with a clinical and chicken origin isolates in the database, clustered together, suggesting a probable common source of infection. Our findings highlight the intricate genetic mechanisms behind MDR in S. Enteritidis, emphasizing the ongoing necessity for surveillance and appropriate antimicrobial usage. This contributes to our understanding of S. Enteritidis transmission within the food chain. [ABSTRACT FROM AUTHOR]

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Two-component systems (TCS) of Salmonella enterica serovar Enteritidis are composed of a histidine kinase and a response regulator (RR) and represent a critical mechanism by which bacteria develop resistance to environmental stress. Here, we characterized the functions of RRs in TCS in the formation of stress tolerance, motility and biofilm using twenty-six S. Enteritidis RR-encoding gene deletion mutants. The viability results unraveled their essential roles in resistance to elevated temperature (GlrR), pH alterations (GlrR, TctD, YedW, ArcA and YehT), high salt (PhoB, BaeR, CpxR, PhoP, UvrY and TctD), oxidative stress (PhoB, YedW, BaeR, ArcA, PhoP, UvrY, PgtA and QseB) and motility (ArcA, GlnG, PgtA, PhoB, UhpA, OmpR, UvrY and QseB) of S. Enteritidis. The results of the crystal violet staining, microscopy observation and Congo red binding assays demonstrated that the absence of ArcA, GlnG, PhoP, OmpR, ZraR or SsrB in S. Enteritidis led to a reduction in biofilms and an impairment in red/dry/rough macrocolony formation, whereas the absence of UvrY exhibited an increase in biofilms and formed a brown/smooth/sticky macrocolony. The results indicated the regulatory effects of these RRs on the production of biofilm matrix, curli fimbriae and cellulose. Our findings yielded insights into the role of TCSs, making them a promising target for combating S. Enteritidis. [ABSTRACT FROM AUTHOR]

Whole-genome sequencing of bacterial pathogens is used by public health agencies to link cases of food poisoning caused by the same source of contamination. The vast majority of these appear to be sporadic cases associated with small contamination episodes and do not trigger investigations. A "contamination episode" refers to one or more contamination events from a single source over a period of time. We examine clusters of sequenced clinical isolates of Salmonella, Escherichia coli, Campylobacter, and Listeria that differ by only a small number of mutations (SNPs) to identify features of the underlying contamination episodes. These analyses provide additional evidence that the youngest age groups have greater susceptibility to infection by Salmonella, E. coli, and Campylobacter than older age groups. This age bias is weaker for the common Salmonella serovar Enteritidis than Salmonella in general. A large fraction of the contamination episodes causing sickness appear to have a long duration. For example, 50% of the Salmonella cases are in clusters that persist for almost 3 y. For all four pathogen species, the majority of the cases were part of genetic clusters with illnesses in multiple states and likely to be caused by contaminated commercially distributed foods. Salmonella infections in infants under 3 mo are predominantly acquired from the same contaminated food, pet food, or environmental sources as older individuals, rather than infant formula contaminated during production. [ABSTRACT FROM AUTHOR]

Background: The investigation on natural antimicrobial compounds against zoonotic pathogens has gained more attention due to the public health concerns regarding the emergence of antimicrobial resistance. Objectives: The current study aimed to assess the effects of thyme essential oil at sub‐minimal inhibitory concentrations (sub‐MICs) on bacterial growth and expression of some virulence genes in Salmonella enteritidis. Methods: The bacterial growth rate and the expression of four virulence genes in S. enteritidis during 18–72 h of exposure to the essential oil at 25%–75% MIC were evaluated via colony counting and real‐time polymerase chain reaction (PCR), respectively. Results: Sub‐inhibitory concentrations of thyme essential oil significantly reduced the growth rate compared to the control. Expression of all tested virulence genes was also reduced by the essential oil in a significant dose‐ and time‐dependent manner. As an example, decreased down‐regulation of hilA, spv, sefA and invA as 1.7‐, 4.14‐, 2.92‐ and 1.04‐fold in 25% MIC and 6.42‐, 7.81‐, 4.4‐ and 3.75‐fold in 75% MIC was observed, respectively, after 24 h of incubation. Likewise, levels of transcription for hilA, spv, sefA and invA were reduced 4.75‐, 6.95‐, 3.75‐ and 2.98‐fold after 18 h and 9.54‐, 8.81‐, 5.65‐ and 4.77‐fold, respectively, after 72 h in 75% MIC compared to the control. Conclusions: According to our data, aside from the growth inhibitory effect of thyme essential oil, the results of current study highlight the potential of thyme for reducing the transcriptional level of virulence genes and therefore the pathogenicity of S. enteritidis. [ABSTRACT FROM AUTHOR]

Background: Salmonella enteritidis (SE), a previously widespread infectious disease, is still cited as a major factor in economic losses in commercial chicken production. The host's genetic immune system determines the pathogenicity of a particular bacterium. To shed light on this topic, it was necessary to understand the key candidate genes essential for regulating susceptibility and resistance to the target disease. The field of poultry farming in particular has benefited greatly from the connection between quantitative and molecular genetics. Objectives: This study aims to identify the most important immune‐related genes and their signalling pathways (gene ontology, co‐expression and interactions) and to analyse their accumulation in host‐resistant SE diseases by combining gene expression assays with model‐based in silico evidence. Methods: A two‐step experimental design is followed. To start, we used free computational tools and online bioinformatics resources, including predicting gene function using a multiple association network integration algorithm (geneMania), the Kyoto Encyclopedia of Genes and Genomes, the Annotation, Visualization and Integrated Discovery (DAVID) database and the stimulator of interferon genes. Natural resistance‐associated macrophage protein 1 (NRAMP1), Toll‐like receptor 4 (TLR4), interferon‐γ (IFNγ), immunoglobulin Y (IgY) and interleukin 8 (IL8) were among the five genes whose expression levels in liver, spleen, and cecum were evaluated at 1107 SE after 48 h of inoculation. This molecular study was developed in the second phase of research to validate the in silico observations. Next, we use five promising biomarkers for relative real‐time polymerase chain reaction (PCR) quantification: TLR4, IL8, NRAMP1, IFNγ and IgY genes in two case and control assays. The 2−∆∆Ct Livak and Schmittgen method was used to compare the expression of genes in treated and untreated samples. This method normalizes the expression of the target gene to that of actin, an internal control and estimates the change in expression relative to the untreated control. Internal control was provided by the Beta actin gene. Next, statistically, the postdoc test was used for the evaluation of treatments using SAS version 9.4, and p values of 0.05 and 0.01 were chosen for significant level. Results: Interestingly, the results of our study suggest the involvement of various factors in the host immune response to Salmonella. These include inducible nitric oxide synthase, NRAMP1, immunoglobulin light chain (IgL), transforming growth factor B family (TGFb2, TGFb3 and TGFb4), interleukin 2 (IL2), apoptosis inhibitor protein 1 (IAP1), TLR4, myeloid differentiation protein 2 (MD2), IFNγ, caspase 1 (CASP1), lipopolysaccharide‐induced tumour necrosis factor (LITAF), cluster of differentiation 28 (CD28) and prosaposin (PSAP). The summary of gene ontology and related genes found for SE resistance was surprisingly comprehensive and covered the following topics: positive regulation of endopeptidase activity, interleukin‐8 production, chemokine production, interferon‐gamma production, interleukin‐6 production, positive regulation of mononuclear cell proliferation and response to interferon‐gamma. The role of these promising biomarkers in our networks against SE susceptibility is essentially confirmed by these results. After 48 h, the spleen showed significant expression of the tissue‐specific gene expression patterns for NRAMP1 and IL8 in the cecum, spleen and liver. Based on this information, this report searches for resistance and susceptibility lineages in most genomic regions for SE. Conclusions: In conclusion, the development of an appropriate selection program to improve resistance to salmonellosis can be facilitated by a comprehensive understanding of the immune responses of the chicken immune system after SE exposure. [ABSTRACT FROM AUTHOR]

The main objective of this study was to evaluate the tolerance of stationary phase (STAT) and long-term survival phase (LTS) Salmonella Enteritidis ATCC 13076 to atmospheric cold plasma (ACP) in phosphate buffered saline (PBS, pH 7.0) and on shell eggs. Salmonella Enteritidis was cultured in tryptic soy broth supplemented with 0.6% (w/v) yeast extract (35°C) for 20 h (STAT) and 21 days (LTS). Cell morphology was determined by light microscopy. The PBS and shell eggs were inoculated with STAT or LTS cells to obtain ~7.0 log10 CFU/mL or egg. The ACP was applied at 45 kV (PBS) and 60 kV (shell eggs) for 1-4 min and 1-5 min, respectively. Pathogen survivors were enumerated on thin agar layer (TAL) medium and on xylose lysine tergitol-4 (XLT-4) agar after 48 h of incubation (35°C). For survivors on shell eggs, R2 and mean square error values were obtained using Log-linear with Tail and Weibull models. The STAT cells were predominantly rod-shaped whereas LTS cells were coccoid. In PBS, reductions (log10 CFU/mL) of STAT cells were 1.0, 0.95, 1.45, and 1.44 after exposure to ACP for 1, 2, 3, and 4 min, respectively. In contrast, reductions in LTS cells were significantly lower (p< 0.05) at 0.04 (1 min), 0.06 (2 min) 0.01 (3 min), and 0.11 (4 min). A similar pattern was observed for shell eggs whereby LTS cells exhibited much higher tolerance to ACP than STAT cells (p < 0.05). The Log-linear with Tail model produced a better fit of the survival data for STAT cells; times to achieve a 4- and 5- log reduction were 5.29 and 5.78 min, respectively. Sub-lethal injury occurred in both STAT and LTS survivors; however, differences were not significant (P > 0.05). Additionally, there were no observed differences in shell strength and yolk color between ACP-treated and control eggs. Based on these results, LTS cells of S. Enteritidis are more tolerant to ACP than STAT cells and should be considered when developing process validation protocols involving application of ACP to inactivate Salmonella on shell eggs. [ABSTRACT FROM AUTHOR]

Invasive non-typhoidal Salmonella (iNTS) poses a significant threat to global public health. Salmonella enterica Enteritidis and Typhimurium are the primary serovars responsible for both invasive diseases and gastroenteritis. This study aims to investigate the genomic and transcriptomic differences between isolates associated with these contrasting clinical presentations. We retrieved genomes of Salmonella Enteritidis and Salmonella Typhimurium from Enterobase, utilizing blood and stool isolates as representatives for iNTS and non-iNTS, respectively. An indistinguishable phylogenetic relationship was revealed between the blood and stool isolates for both serovars. Few genes were specifically identified in iNTS. Random forest and principal coordinates analysis permitted moderate discrimination between the two sources of isolates based on overall genome content. Notably, the blood isolates of Salmonella Typhimurium displayed an elevated level of antimicrobial resistance and genome degradation compared to stool isolates. Meanwhile, transcriptome sequencing identified few genes that were differentially expressed between blood and stool isolates. Hierarchical clustering and principal component analysis did not effectively differentiate the expression profile of iNTS from non-iNTS. In summary, few genes could serve as reliable biomarkers to distinguish iNTS and non-iNTS at either the genomic or transcriptomic level. Nevertheless, iNTS has indeed accumulated subtle genomic differences from non-iNTS, which might contribute to invasiveness. [ABSTRACT FROM AUTHOR]

There are extensive differences in the caecal microbiota of chicks from hatcheries and those inoculated with faecal material from adult hens. Besides differences in microbial composition, the latter chickens are highly resistant to Salmonella Enteritidis challenges, while the former are susceptible. In this study, we tested whether strains from genera Bacteroides, Megamonas, or Megasphaera can increase chicken resistance to Salmonella and Campylobacter jejuni when defined microbial mixtures consisting of these bacterial genera are administered. Mixtures consisting of different species and strains from the above-mentioned genera efficiently colonised the chicken caecum and increased chicken resistance to Salmonella by a factor of 50. The tested mixtures were even more effective in protecting chickens from Salmonella in a seeder model of infection (3–5 log reduction). The tested mixtures partially protected chickens from C. jejuni infection, though the effect was lower than that against Salmonella. The obtained data represent a first step for the development of a new type of probiotics for poultry. [ABSTRACT FROM AUTHOR]

Copyright of Karaelmas Science & Engineering Journal / Karaelmas Fen ve Mühendislik Dergisi is the property of Karaelmas Science & Engineering Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Campylobacter and invasive non-typhoidal Salmonella (iNTS) are among the most common causative agents of gastroenteritis worldwide. As of now, no single combination licensed vaccine is available for public health use against both iNTS and Campylobacter species. Outer-membrane vesicles (OMVs) are nanoscale proteoliposomes released from the surface of gram-negative bacteria during log phase and harbor a variety of immunogenic proteins. Based on epidemiology of infections, we formulated a novel trivalent outer membrane vesicles (TOMVs)-based vaccine candidate against Campylobacter jejuni (CJ), Salmonella Typhimurium (ST) and Salmonella Enteritidis (SE). Isolated OMVs from CJ, ST and SE were combined in equal ratios for formulation of TOMVs and 5 µg of the developed vaccine candidate was used for intraperitoneal immunization of adult BALB/c mice. Immunization with TOMVs significantly activated both the humoral and cellular arm of adaptive immune response. Robust bactericidal effect was elicited by TOMVs immunized adult mice sera. TOMVs immunization induced long-term protective efficacy against CJ, ST and SE infections in mice. The study illustrates the ability of TOMVs-based combination immunogen in eliciting broad-spectrum protective immunity against prevalent Campylobacter and iNTS pathogens. According to the findings, TOMVs can work as a potent combination-based acellular vaccine candidate for amelioration of Campylobacter and iNTS-mediated gastroenteritis. [ABSTRACT FROM AUTHOR]

Salmonella Enteritidis is a major foodborne pathogen throughout the world and the increase in antibiotic resistance of Salmonella poses a significant threat to public safety. Natural nanobodies exhibit high affinity, thermal stability, ease of production, and notably higher diversity, making them widely applicable for the treatment of viral and bacterial infections. Recombinant expression using Lactococcus lactis leverages both acid resistance and mucosal colonization properties of these bacteria, allowing the effective expression of exogenous proteins for therapeutic effects. In this study, nine specific nanobodies against the flagellar protein FliC were identified and expressed. In vitro experiments demonstrated that FliC-Nb-76 effectively inhibited the motility of S. Enteritidis and inhibited its adhesion to and invasion of HIEC-6, RAW264.7, and chicken intestinal epithelial cells. Additionally, a recombinant L. lactis strain secreting the nanobody, L. lactis-Nb76, was obtained. Animal experiments confirmed that it could significantly reduce the mortality rates of chickens infected with S. Enteritidis, together with alleviating the inflammatory response caused by the pathogen. These results provide a novel strategy for the treatment of antibiotic-resistant S. Enteritidis infection in the intestinal tract. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The safety of sea bass is critical for the global food trade. This study evaluated the effectiveness of atmospheric cold plasma in reducing food safety risks posed by Salmonella Enteritidis and Listeria monocytogenes, which can contaminate sea bass post harvest. Cold plasma was applied to inoculated sea bass for 2 to 18 min, achieving a maximum reduction of 1.43 log CFU/g for S. Enteritidis and 0.80 log CFU/g for L. monocytogenes at 18 min. Longer treatments resulted in greater reductions; however, odor and taste quality declined to a below average quality in samples treated for 12 min or longer. Plasma treatment did not significantly alter the color, texture, or water activity (aw) of the fish. Higher levels of thiobarbituric acid reactive substances (TBARSs) were observed with increased exposure times. Cold plasma was also tested in vitro on S. Enteritidis and L. monocytogenes on agar surfaces. A 4 min treatment eliminated the initial loads of S. Enteritidis (2.71 log CFU) and L. monocytogenes (2.98 log CFU). The findings highlight the potential of cold plasma in enhancing the safety of naturally contaminated fish. Cold plasma represents a promising technology for improving food safety in the global fish trade and continues to be a significant area of research in food science. [ABSTRACT FROM AUTHOR]

Salmonellosis represents a significant economic and public health concern for the poultry industry in Africa, leading to substantial economic losses due to mortality, reduced productivity, and food safety problems. However, comprehensive information on the burden of poultry salmonellosis at the continental level is scarce. To address this gap, a systematic review and meta-analysis were conducted to consolidate information on the prevalence and circulating serotypes of poultry salmonellosis in African countries. This involved the selection and review of 130 articles published between 1984 and 2021. A detailed systematic review protocol was structured according to Cochrane STROBE and PRISMA statement guideline. From the 130 selected articles from 23 different African countries, the overall pooled prevalence estimate (PPE) of poultry salmonellosis in Africa was found to be 14.4% (95% CI = 0.145–0.151). Cameroon reported the highest PPE at 71.9%. The PPE was notably high in meat and meat products at 23%. The number of research papers reporting poultry salmonellosis in Africa has shown a threefold increase from 1984 to 2021. Salmonella Enteritidis and Typhimurium were the two most prevalent serotypes reported in 18 African countries. Besides, Salmonella Kentucky, Virchow, Gallinarum, and Pullorum were also widely reported. Western Africa had the highest diversity of reported Salmonella serotypes (141), in contrast to southern Africa, which reported only 27 different serotypes. In conclusion, poultry salmonellosis is highly prevalent across Africa, with a variety of known serotypes circulating throughout the continent. Consequently, it is crucial to implement strategic plans for the prevention and control of Salmonella in Africa. RESEARCH HIGHLIGHTS The pooled sample prevalence of poultry salmonellosis in Africa is high (14.4%). The highest PPE was recorded in meat and meat products. Salmonella serotypes of zoonotic importance were found in all sample types. Salmonella Enteritidis and Typhimurium are common serotypes spreading in Africa. [ABSTRACT FROM AUTHOR]