We report a severe case of a 25-year-old girl presented with complaints of weakness, diarrhoea, vomiting, pain in abdomen and hypotension at Infectious Diseases and Clinical Immunology Research Center. From history on 25 February till 29 February she was in India and on 1 march this problem started with watery diarrhoea followed by vomiting. She ate pizza with mushroom following which her condition worsened. Stool culture revealed salmonella nontyphi (nonthyphodal Salmonella)and this is leading cause for gastroenteritis, bacteremia and affects several other bodily system. Her condition deteriorated due to the development of ARDS (acute respiratory distress syndrome) and for this she was on mechanical ventilation. Vitec machine was performed, which identified Salmonella typhi murium. Our goal is to manage and treat this patient well by early diagnosis. She was given ceftriaxone, iv fluids and symptomatic treatment but due to resistance meropenem was started and the patient\'s condition improved. From serology there was no evidence of immunocompromised state so being a severe case of immunocompetent patient this case reflects the importance of timely diagnosis and management together with food safety practices in population. On follow up she was stable and discharged after 3 weeks. Future research studies need to be continued regarding newer strains, effective treatment strategies and diagnostics to prevent morbidity and mortality.

The bacterial species Salmonella enterica (S. enterica) is a highly diverse pathogen containing more than 2600 distinct serovars, which can infect a wide range of animal and human hosts. Recent global emergence of multidrug resistant strains, from serovars Infantis and Muenchen is associated with acquisition of the epidemic megaplasmid, pESI that augments antimicrobial resistance and pathogenicity. One of the main pESI\'s virulence factors is the potent iron uptake system, yersiniabactin encoded by fyuA, irp2-irp1-ybtUTE, ybtA, and ybtPQXS gene cluster. Here we show that yersiniabactin, has an underappreciated distribution among different S. enterica serovars and subspecies, integrated in their chromosome or carried by different conjugative plasmids, including pESI. While the genetic organization and the coding sequence of the yersiniabactin genes are generally conserved, a 201-bp insertion sequence upstream to ybtA, was identified in pESI. Despite this insertion, pESI-encoded yersiniabactin is regulated by YbtA and the ancestral Ferric Uptake Regulator (Fur), which binds directly to the ybtA and irp2 promoters. Furthermore, we show that yersiniabactin genes are specifically induced during the mid-late logarithmic growth phase and in response to iron-starvation or hydrogen peroxide. Concurring, yersiniabactin was found to play a previously unknown role in oxidative stress tolerance and to enhance intestinal colonization of S. Infantis in mice. These results indicate that yersiniabactin contributes to Salmonella fitness and pathogenicity in vivo and is likely to play a role in the rapid dissemination of pESI among globally emerging Salmonella lineages.

Salmonella infections pose a significant global public health concern due to the substantial expenses associated with monitoring, preventing, and treating the infection. In this study, we explored the core proteome of Salmonella to design a multi-epitope vaccine through Subtractive Proteomics and immunoinformatics approaches. A total of 2395 core proteins were curated from 30 different isolates of Salmonella (strain NZ CP014051 was taken as reference). Utilizing the subtractive proteomics approach on the Salmonella core proteome, Curlin major subunit A (CsgA) was selected as the vaccine candidate. csgA is a conserved gene that is related to biofilm formation. Immunodominant B and T cell epitopes from CsgA were predicted using numerous immunoinformatics tools. T lymphocyte epitopes had adequate population coverage and their corresponding MHC alleles showed significant binding scores after peptide-protein based molecular docking. Afterward, a multi-epitope vaccine was constructed with peptide linkers and Human Beta Defensin-2 (as an adjuvant). The vaccine could be highly antigenic, non-toxic, non-allergic, and have suitable physicochemical properties. Additionally, Molecular Dynamics Simulation and Immune Simulation demonstrated that the vaccine can bind with Toll Like Receptor 4 and elicit a robust immune response. Using in vitro, in vivo, and clinical trials, our findings could yield a Pan-Salmonella vaccine that might provide protection against various Salmonella species.

In order to survive and replicate, Salmonella has evolved mechanisms to gain access to intestinal epithelial cells of the crypt. However, the impact of Salmonella Typhimurium on stem cells and progenitors, which are responsible for the ability of the intestinal epithelium to renew and protect itself, remains unclear. Given that intestinal organoids growth is sustained by stem cells and progenitors activity, we have used this model to document the effects of Salmonella Typhimurium infection on epithelial proliferation and differentiation, and compared it to an in vivo model of Salmonella infection in mice. Among gut segments, the caecum was preferentially targeted by Salmonella. Analysis of infected crypts and organoids demonstrated increased length and size, respectively. mRNA transcription profiles of infected crypts and organoids pointed to upregulated EGFR-dependent signals, associated with a decrease in secretory cell lineage differentiation. To conclude, we show that organoids are suited to mimic the impact of Salmonella on stem cells and progenitors cells, carrying a great potential to drastically reduce the use of animals for scientific studies on that topic. In both models, the EGFR pathway, crucial to stem cells and progenitors proliferation and differentiation, is dysregulated by Salmonella, suggesting that repeated infections might have consequences on crypt integrity and further oncogenesis.

UNASSIGNED: Salmonella infections are considered the most common foodborne pathogens responsible for zoonotic infections and food poisoning in humans and animal species such as birds. Antimicrobial resistance is considered a global anxiety because it causes human public health repercussions, as well as leads to an increase in animal morbidity and death.
UNASSIGNED: The aims of this study are the isolation and identification of Salmonella enterica, as well as to investigate the antimicrobial susceptibility test (AST) and the molecular characteristics using polymerase chain reaction (PCR) and sequences for isolates from chicken products (eggs, livers, and minced meat) and human in the Wasit Governorate of Iraq.
UNASSIGNED: A total of 300 samples (150 chicken product samples including eggs, livers, and minced meat, and 150 human fecal samples) were collected from the Wasit governorate of Iraq from January to December 2022. The bacterial isolation was done according to recommendations of ISO 6579 standard and the Global Foodborne Infections Network laboratory protocol. Serotyping test and AST were done by using 19 antibiotic agents according to the recommendations of the Clinical and Laboratory Standards Institute, 2022 by using disc diffusion susceptibility test and Vitik 2 test. Finally, the suspected isolates were confirmed using the conventional PCR method and sequencing for a unique rRNA gene.
UNASSIGNED: The results showed that the isolation percentage of S. enterica in chicken products was 8.66% (12% eggs, 6% livers, and 8% minced meat), while in humans it was 4.6%. Also, showed 100% of Salmonella typhi in humans. While, in chicken eggs S. typhi, Salmonella typhimurium, and Salmonella enteritidis were 50%, 33.33%, and 16.66%, respectively. Also, showed 100% of S. typhimurium in both livers and minced meat. The AST in human isolates showed resistance to Ampicillin, Cefotaxime, Ceftazidime, Cefepime, Amikacin, Gentamicin, Ciprofloxacin, Norfloxacin, and Ceftriaxone, while no resistance to Amoxicillin, Pipracillin, Ertapenem, Imipenem, Meropenem, Fosfomycin, Nitrofurantoin, Trimethoprim, Azithromycin, and Tetracycline. In chicken products, isolates were resistant with different percentages to Amikacin, Gentamicin, Tetracycline, Ciprofloxacin, Norfloxacin, Nitrofurantoin, Ampicillin, Cefotaxime, Ceftazidime, Cefepime, and Trimethoprim; while no resistance to Amoxicillin, Pipracillin, Ertapenem, Imipenem, Meropenem, Fosfomycin, Azithromycin, and Ceftriaxone. Sequencing by using rRNA gene was done for four PCR products.
UNASSIGNED: This study showed the presence of genetic mutations for S. enterica which led to variations in the molecular characteristics, and antimicrobial drug resistance of S. enterica isolated from chicken products and humans.

UNASSIGNED: Non-typhoidal Salmonella (NTS) generally causes self-limiting gastroenteritis. However, older adults (≥65 years) can experience more severe outcomes from NTS infection. We have previously shown that a live attenuated S. Typhimurium vaccine, CVD 1926 (I77 ΔguaBA ΔclpP ΔpipA ΔhtrA), was immunogenic in adult but not aged mice. Here we describe modification of CVD 1926 through deletion of steD, a Salmonella effector responsible for host immune escape, which we hypothesized would increase immunogenicity in aged mice.
UNASSIGNED: Mel Juso and/or mutuDC cells were infected with S. Typhimurium I77, CVD 1926, and their respective steD mutants, and the MHC-II levels were evaluated. Aged (18-month-old) C57BL/6 mice received two doses of PBS, CVD 1926, or CVD 1926 ΔsteD perorally (109 CFU) and the number of FliC-specific CD4+ T cells were determined. Lastly, aged C57BL/6 mice received three doses of PBS, CVD 1926, or CVD 1926 ΔsteD perorally (109 CFU) and then were challenged perorally with wild-type S. Typhimurium SL1344 (108 CFU). These animals were also evaluated for antibody responses.
UNASSIGNED: MHC-II induction was higher in cells treated with steD mutants, compared to their respective parental strains. Compared to PBS-vaccinated mice, CVD 1926 ΔsteD elicited significantly more FliC-specific CD4+ T cells in the Peyer\'s Patches. There were no significant differences in FliC-specific CD4+ T cells in the Peyer\'s patches or spleen of CVD 1926- versus PBS-immunized mice. CVD 1926 and CVD 1926 ΔsteD induced similar serum and fecal anti-core and O polysaccharide antibody titers after three doses. After two immunizations, the proportion of seroconverters for CVD 1926 ΔsteD was 83% (10/12) compared to 42% (5/12) for CVD 1926. Compared to PBS-immunized mice, mice immunized with CVD 1926 ΔsteD had significantly lower S. Typhimurium counts in the spleen, cecum, and small intestine upon challenge. In contrast, there were no differences in bacterial loads in the tissues of PBS-vaccinated and CVD 1926-immunized animals.
UNASSIGNED: These data suggest that the steD deletion enhanced the immunogenicity of our live attenuated S. Typhimurium vaccine. Deletion of immune evasion genes could be a potential strategy to improve the immunogenicity of live attenuated vaccines in older adults.

Mass spectrometry-based proteomics provides a wealth of information about changes in protein production and abundance under diverse conditions, as well as mechanisms of regulation, signaling cascades, interaction partners, and communication patterns across biological systems. For profiling of intracellular pathogens, proteomic profiling can be performed in the absence of a host to singularly define the pathogenic proteome or during an infection-like setting to identify dual perspectives of infection. In this chapter, we present techniques to extract proteins from the human bacterial intracellular pathogen, Salmonella enterica serovar Typhimurium, in the presence of macrophages, an important innate immune cell in host defense. We outline sample preparation, including protein extraction, digestion, and purification, as well as mass spectrometry measurements and bioinformatics analysis. The data generated from our dual perspective profiling approach provides new insight into pathogen and host protein modulation under infection-like conditions.

Genomics has revolutionized how we characterize and monitor infectious diseases for public health. The surveillance and characterization of Salmonella has improved drastically within the past decade. In this chapter, we discuss the prerequisites for good bacterial genomics studies and make note of advantages and disadvantages of this research approach. We discuss methods for outbreak detection and the evolutionary and epidemiological characterization of Salmonella spp. We provide an outline for determining the sequence type and serotype of isolates, building a core genome phylogenetic tree, and detecting antimicrobial resistance genes, virulence factors, and mobile genetic elements. These methods can be used to study other pathogenic bacterial species.

BACKGROUND: Salmonella, an important foodborne pathogen, was estimated to be responsible for 95.1 million cases and 50,771 deaths worldwide. Sixteen serovars were responsible for approximately 80% of Salmonella infections in humans in China, and infections caused by a few uncommon serovars have been reported in recent years, though not with S. Welikade. This study reports the first clinical case caused by S. Welikade in China and places Chinese S. Welikade isolates in the context of global isolates via genomic analysis. For comparison, S. Welikade isolates were also screened in the Chinese Local Surveillance System for Salmonella (CLSSS). The minimum inhibitory concentrations (MICs) of 28 antimicrobial agents were determined using the broth microdilution method. The isolates were sequenced on an Illumina platform to identify antimicrobial resistance genes, virulence genes, and phylogenetic relationships.
RESULTS: The S. Welikade isolate (Sal097) was isolated from a two-year-old boy with acute gastroenteritis in 2021. Along with the other two isolates found in CLSSS, the three Chinese isolates were susceptible to all the examined antimicrobial agents, and their sequence types (STs) were ST5123 (n = 2) and ST3774 (n = 1). Single nucleotide polymorphism (SNP)-based phylogenetic analysis revealed that global S. Welikade strains can be divided into four groups, and these three Chinese isolates were assigned to B (n = 2; Sal097 and XXB1016) and C (n = 1; XXB700). In Group B, the two Chinese ST5123 isolates were closely clustered with three UK ST5123 isolates. In Group C, the Chinese isolate was closely related to the other 12 ST3774 isolates. The number of virulence genes in the S. Welikade isolates ranged from 59 to 152. The galF gene was only present in Group A, the pipB2 gene was only absent from Group A, the avrA gene was only absent from Group B, and the allB, sseK1, sspH2, STM0287, and tlde1 were found only within Group C and D isolates. There were 15 loci unique to the Sal097 isolate.
CONCLUSIONS: This study is the first to characterize and investigate clinical S. Welikade isolates in China. Responsible for a pediatric case of gastroenteritis in 2021, the clinical isolate harbored no antimicrobial resistance and belonged to phylogenetic Group B of global S. Welikade genomes.

Primary aortoenteric fistulas (AEF) are rare. The majority of these are due to atherosclerotic aortic aneurysms. Mycotic aortic aneurysms leading to primary AEF are exceedingly uncommon. Here we report a rare case of primary AEF secondary to Salmonella-related mycotic aneurysm and discuss the diagnostic and therapeutic issues.