Salmonella is one of the most important foodborne pathogens. Fifty-three strains of Salmonella deposited in the Culture Collection of Industrial Microorganisms—Microbiological Resources Center (IAFB) were identified using molecular and proteomic analyses. Moreover, the genetic similarity of the tested strains was determined using the PFGE method. Main virulence genes were identified, and phenotypical antibiotic susceptibility profiles and prevalence of resistance genes were analyzed. Subsequently, the occurrence of the main mechanisms of β-lactam resistance was determined. Virulence genes, invA, fimA, and stn were identified in all tested strains. Phenotypic tests, including 28 antibiotics, showed that 50.9% of the strains were MDR. The tet genes associated with tetracyclines resistance were the most frequently identified genes. Concerning the genes associated with ESBL-producing Salmonella, no resistance to the TEM and CTX-M type was identified, and only two strains (KKP 1597 and KKP 1610) showed resistance to SHV. No strains exhibited AmpC-type resistance but for six Salmonella strains, the efflux-related resistance of PSE-1 was presented. The high number of resistant strains in combination with multiple ARGs in Salmonella indicates the possible overuse of antibiotics. Our results showed that it is necessary to monitor antimicrobial resistance profiles in all food chain links constantly and to implement a policy of proper antibiotic stewardship to contain or at least significantly limit the further acquisition of antibiotic resistance among Salmonella strains.

This study aimed to evaluate the effectiveness of the phage cocktail to improve the microbiological quality of five different mixed-leaf salads: rucola, mixed-leaf salad with carrot, mixed-leaf salad with beetroot, washed and unwashed spinach, during storage in refrigerated conditions. Enterobacterales rods constituted a significant group of bacteria in the tested products. Selected bacteria were tested for antibiotic resistance profiles and then used to search for specific bacteriophages. Forty-three phages targeting bacteria dominant in mixed-leaf salads were isolated from sewage. Their titer was determined, and lytic activity was assessed using the Bioscreen C Pro automated growth analyzer. Two methods of phage cocktail application including spraying, and an absorption pad were effective for rucola, mixed leaf salad with carrot, and mixed leaf salad with beetroot. The maximum reduction level after 48 h of incubation reached 99.9% compared to the control sample. In washed and unwashed spinach, attempts to reduce the number of microorganisms did not bring the desired effect. The decrease in bacteria count in the lettuce mixes depended on the composition of the autochthonous saprophytic bacteria species. Both phage cocktail application methods effectively improved the microbiological quality of minimally processed products. Whole-spectral phage cocktail application may constitute an alternative food microbiological quality improvement method without affecting food properties.

Bisphenols, such as bisphenol A and its analogs, which include bisphenol S, bisphenol F, bisphenol AF, and tetramethyl bisphenol F, are chemical contaminants commonly found in food that raise serious health concerns. These xenobiotics can potentially have harmful effects on human health. The gut microbiota plays a crucial role in metabolizing and neutralizing these substances, which is essential for their detoxification and elimination. Probiotic supplementation has been studied for its ability to modulate the gut microbiota’s composition and function, enhancing detoxification processes. Next-Generation Probiotics (NGPs) may exhibit better properties than traditional strains and are designed for targeted action on specific conditions, such as obesity. By modulating inflammatory responses and reducing the secretion of pro-inflammatory cytokines, they can significantly improve host health. Research on NGPs’ ability to neutralize obesogenic bisphenols remains limited, but their potential makes this a promising area for future exploration. This review aims to understand the mechanisms of the chemical transformation of bisphenol through its interactions with the gut microbiota and the role of probiotics, particularly NGPs, in these processes. Understanding the interplay between bisphenols, gut microbiota, and NGPs may pave the way for strategies to counteract the negative health effects associated with daily and chronic exposure to bisphenols, which is crucial for food safety and consumer health protection.

The food industry is still searching for novel solutions to effectively ensure the microbiological safety of food, especially fresh and minimally processed food products. Nowadays, the use of bacteriophages as potential biological control agents in microbiological food safety and preservation is a promising strategy. The aim of the study was the isolation and comprehensive characterization of novel bacteriophages with lytic activity against saprophytic bacterial microflora of minimally processed plant-based food products, such as mixed leaf salads. From 43 phages isolated from municipal sewage, four phages, namely Enterobacter phage KKP 3263, Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 have lytic activity against Enterobacter ludwigii KKP 3083, Citrobacter freundii KKP 3655, Enterobacter cloacae KKP 3082, and Serratia fonticola KKP 3084 bacterial strains, respectively. Transmission electron microscopy (TEM) and whole-genome sequencing (WGS) identified Enterobacter phage KKP 3263 as an Autographiviridae, and Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 as members of the Myoviridae family. Genome sequencing revealed that these phages have linear double-stranded DNA (dsDNA) with sizes of 39,418 bp (KKP 3263), 61,608 bp (KKP 3664), 84,075 bp (KKP 3262), and 148,182 bp (KKP 3264). No antibiotic resistance genes, virulence factors, integrase, recombinase, or repressors, which are the main markers of lysogenic viruses, were annotated in phage genomes. Serratia phage KKP 3264 showed the greatest growth inhibition of Serratia fonticola KKP 3084 strain. The use of MOI 1.0 caused an almost 5-fold decrease in the value of the specific growth rate coefficient. The phages retained their lytic activity in a wide range of temperatures (from −20 °C to 50 °C) and active acidity values (pH from 4 to 11). All phages retained at least 70% of lytic activity at 60 °C. At 80 °C, no lytic activity against tested bacterial strains was observed. Serratia phage KKP 3264 was the most resistant to chemical factors, by maintaining high lytic activity across a broader range of pH from 3 to 11. The results indicated that these phages could be a potential biological control agent against saprophytic bacterial microflora of minimally processed plant-based food products.

Salmonella, an etiological agent of salmonellosis, is one of the main foodborne pathogens. Due to irrational antibiotic stewardship, an increase in the incidence of multidrug resistance (MDR) in bacteria has been observed recently. Phage therapy represents an alternative method of treating infections, including foodborne pathogens. Therefore, this study aimed to isolate and comprehensively characterize a bacteriophage specific for MDR Salmonella enterica strain KKP 998, isolated from the food environment. Transmission electron microscopy (TEM) and whole-genome sequencing (WGS) analyses classified the identified phage as a member of the tailed phages from Epseptimavirus genus and Caudoviricetes class. Neither antibiotic resistance genes, toxin genes, nor genes associated with host genome integration (markers of temperate bacteriophages) were located in the phage genome. A newly isolated bacteriophage, Epseptimavirus KKP3831 (Salmonella phage KKP_3831), replicated in multiple serovars of S. enterica hosts. Active progeny particles were produced in 50 % of the S. enterica strains tested, indicating partial host specificity. Epseptimavirus KKP3831 can translocate through the Caco-2 monolayer in both directions, apical-to-basal and basal-to-apical, in a clearly dose-dependent manner and only subtly dependent on incubation time. The strictly lytic nature of replication and favorable physiological parameters (short latent period (20 min) and medium burst size (42 ± 4 PFU/cell)) suggest that Epseptimavirus KKP3831 is a promising candidate for biocontrol and treatment of salmonellosis caused by MDR S. enterica strains. The potential for translocation across the intestinal epithelium highlights the importance of studying the mechanisms of phage circulation in the body, as well as their effects beyond the site of administration, beyond just their antibacterial action.

Salmonella is one of the main foodborne pathogens. Irrational antibiotic management has led to an increase in the incidence of multidrug-resistant strains. Bacteriophages may be an alternative method of food biopreservation and contribute to reducing the number of food poisonings requiring pharmacotherapy. This study aimed to isolate a bacteriophage (phage) targeting indigenous multidrug-resistant (MDR) Salmonella strains, followed by their biological, morphological, and genomic characterization. In this study we isolated Salmonella phage KKP_3822, targeting MDR Salmonella Manchester strain KKP 1213. Salmonella phage KKP_3822 retained high activity in the temperature range from −20 °C to 40 °C and active acidity from pH 3 to 11. Temperatures of 70 °C and 80 °C and extreme pH values (2 and 12) significantly reduced the phage titer. Its activity decreased proportionally to the time of UV exposure. Genome analysis (linear dsDNA with a length of 114,843 bp) revealed the presence of 27 tRNA genes. Proteins encoded by the vB_Sen-IAFB3822 phage were divided into functional modules related to (i) phage structure/assembly, (ii) DNA replication/modification/regulation, (iii) phage lysis, and (iv) DNA packaging into the capsid. No genes associated with antibiotic resistance or integration into the host genome, markers of temperate bacteriophages, were annotated in the Salmonella phage KKP_3822 genome. Based on morphological features and whole-genome sequence analysis, the newly isolated Salmonella phage KKP_3822 shows the greatest similarity to representatives of tailed phages from the Caudoviricetes class, Demerecviridae family, and Epseptimavirus genus. Genome analysis confirmed the virulent nature of the Salmonella phage KKP_3822, making it a potential candidate for food biocontrol.