Salmonellosis is an important worldwide food-borne disease. Increasing resistance to Salmonella spp. has been reported in recent years and now, the prevalence of multidrug resistant (MDR) Salmonella spp. is a worldwide problem. This necessitates alternative approaches like phage therapy. This study aimed to isolate bacteriophages specific for Salmonella enterica serovar Paratyphi B and Salmonella enterica serovar Typhimurium isolated from different sources (chicken meat, beef, and eggshells). The antibiotic resistance profiles of the bacteria were determined by phenotypic and genotypic methods. The prevalence of extended-spectrum β-lactamase genes was examined by PCR. Totally, 75% of the isolated Salmonella strains were resistant to tetracycline, while this was 70% for azithromycin. All of the isolates from beef were resistant to nalidixic acid. The most common ESBL genes among the isolates were blaSHV (15%) followed by blaTEM (10%) and blaCTX (5%). Two specific bacteriophages were isolated and characterized. The host range for vB_SparS-ui was Salmonella Paratyphi B, Salmonella enterica serovar Paratyphi A, and Salmonella enterica. This was Salmonella Typhimurium and Salmonella enterica serovar Enteritidis for vB_StyS-sam phage. The characteristics of the isolated phages indicate that they are proper candidates to be used to control some foodstuffs contaminations and also phage therapy of infected animals.

Background and objectives: are divided into two species: Salmonella enterica and Salmonella Salmonella bongori. S. enterica has more than 2,500 serotypes. Serovars of S. enterica such as Typhimurium, Enteritidis, Paratyphi B, Paratyphi A and Newport are associated with human infections. Approximately 75% of human Salmonella infections have been associated with contaminated food such as eggs, chicken, beef, pork, dairy products, fruits and vegetables. The aim of this study was to determine the frequency of Salmonella strains isolated from various food sources in Isfahan, Iran. Methods: Forty Salmonella strains were isolated from 450 suspected cases referred to the veterinary reference laboratory of Isfahan Province. The isolates were identified by differential and serotyping tests and then confirmed by PCR. A phylogenic tree was constructed with 34 sequences by neighbor-joining method using the MEGA7 software (version 7.1). Results: Overall, 10 Salmonella serovars were isolated from 32 chicken meat, three beef and five egg shell samples. S. enterica serovar Ouakum (20%), S. Enteritidis (17.5%) and S. Typhimurium (17.5%) were the most common serovars, while S. enterica serovar Nitra (2.5%) was found as the least prevalent isolate. Conclusion: In this study, S. Typhimurium species is placed in different clusters along with sequences reported from different parts of the world, indicating that the serovars are circulating all over the world.

Salmonella spp. antibiotics resistance increase is a global problem. Currently, S. Typhimurium is the world's second leading etiology of salmonellosis with resistance to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole. Bacteriophages have the potential to controlling Salmonella infections. In this study, the genome of a virulens Salmonella phage (vB_StyS-sam) isolated from Toshan backwater in Gorgan city of Golestan province in Iran (N364737 E542603) was analyzed. It contained 43221 base pairs with 49.77 (G + C) content that coded 66 proteins with eight promotor sequences. Twenty-four ORFs encoded functional proteins (replication, modification, and regulation). Eight unique ORFs with no similarity with any protein in the NCBI GenBank were found in this phage. Moreover, 29 Rho-dependent terminators are located in vB_StyS-sam phage genome. An anti-CRISPER sequence was found in the genome and BLASTn indicated that the vB_StyS-sam has homology with other Salmonella phages such as vB_SenS-Ent1 and other members of Jerseyvirus phages. Phage genome did not contain any antibiotic resistance and virulence genes. Thus, we suggested vB_StyS-sam phage has the potential to be used in phage therapy.

Introduction: Two of the most challenging viruses for vaccine development are SARS-COV-2 causing the current COVID-19 pandemic and influenza virus (H1N1) which spread annually causing seasonal epidemics or increase the pandemic risk. In this study, we analyzed the immonodominant epitope regions in Fusion peptides consisting of the Spike_S1_ N-terminal domain from SARS-COV-2 in-frame to hemagglutinin H2 (HA2) gene from Influenza A virus (H1N1) and also Human IFNɣ gene by two (G4S)3 linker. Method: The comprehensive analysis based on Immunoinformatic has been conducted on prediction servers to predict T and B cell epitopes. In silico cloning and expression in pET-28(+) expression vector and vaccine optimization were assessed. The overall model quality were accessed and the docking or binding affinity of designed vaccine to the Toll-like receptor 3 (TLR3) were analyzed. The efficiency of the constructed vaccine confirmed by appropriate expression of designed vaccine candidate tested by in silico cloning in pET–28(+) vector and codon optimization might increase the production of vaccine candidate into Escherichia coli strain k12.Result and discussion: In conclusion, we suggest that this fusion peptide would be an attractive design strategy toward developing bivalent vaccine against both COVID-19 and Influenza as promising vaccine candidate without need to reformulation or vaccination each year.

Introduction: Two of the most challenging viruses for vaccine development are SARS-COV-2 causing the current COVID-19 pandemic and influenza virus (H1N1) which spread annually causing seasonal epidemics or increase the pandemic risk. In this study, we analyzed the immonodominant epitope regions in Fusion peptides consisting of the Spike_S1_ N-terminal domain from SARS-COV-2 in-frame to hemagglutinin H2 (HA2) gene from Influenza A virus (H1N1) and also Human IFNɣ gene by two (G4S)3 linker. Method: The comprehensive analysis based on Immunoinformatic has been conducted on prediction servers to predict T and B cell epitopes. In silico cloning and expression in pET-28(+) expression vector and vaccine optimization were assessed. The overall model quality were accessed and the docking or binding affinity of designed vaccine to the Toll-like receptor 3 (TLR3) were analyzed. The efficiency of the constructed vaccine confirmed by appropriate expression of designed vaccine candidate tested by in silico cloning in pET–28(+) vector and codon optimization might increase the production of vaccine candidate into Escherichia coli strain k12. Result and discussion: In conclusion, we suggest that this fusion peptide would be an attractive design strategy toward developing bivalent vaccine against both COVID-19 and Influenza as promising vaccine candidate without need to reformulation or vaccination each year. Our study is not a clinical study and there is no need to have a Trial Registration Number (TRN)