Editorial: Bacteriophages in the fight against foodborne pathogens

Editorial on the Research Topic Bacteriophages in the fight against foodborne pathogens(undefined)info:eu-repo/semantics/publishedVersio

A novel bacteriophage receptor binding protein for improved Salmonella detection

Salmonella is one of the most important foodborne pathogenic bacteria which can cause serious public health problems. The substantial health and economic impact of Salmonella infections, coupled with its antibiotic resistance demands the fast and reliable identification of this pathogen. Conventional approaches are time-consuming, present high detection limits, low specificity, and inability to differentiate viable from non-viable cells. These facts call for urgent improved detection methods to prevent the introduction of Salmonella into the food-chain and to provide timely guidance for clinical treatment and avoid disease progression. Due to their high specificity and binding ability, bacteriophages and their proteins can circumvent these limitations and provide the foundations for the development of novel cost-effective and improved diagnosis. In this study, we employed bioinformatic tools to identify potential receptor-binding proteins within the genome of a sequenced bacteriophage. Selected genes were cloned into Escherichia coli, fused with a green fluorescent protein (EGFP) and assessed for their ability to bind and decorate Salmonella cells. Results showed that phage protein gp27 exhibits strong binding affinity for Salmonella cells, enabling their identification under a fluorescent microscope. This protein demonstrated high specificity by effectively binding to Salmonella and not to other related genera. Its exceptional specificity minimizes the occurrence of false-positive results. Notably, this protein binds to Salmonella cells within a rapid 15-minute timeframe. Our research unveils a novel bacteriophage receptor-binding protein with remarkable specificity for Salmonella. This breakthrough paves the way for the development of novel advanced diagnostic tools, promising faster and more reliable Salmonella detection. These advancements will significantly enhance food safety measures and mitigate the impact of Salmonella-related infections on public health and the economy.info:eu-repo/semantics/publishedVersio

Novel Same-Day method for viable Salmonella Enteritidis detection in chicken meat combining phage amplification and LAMP

Salmonella enterica is a major foodborne pathogen worldwide. Poultry products, especially eggs and meat, are the main responsible for human salmonellosis cases. Culture-based methods require at least 3 days to detect Salmonella positive samples. To facilitate food chain processes and provide a rapid response to food outbreaks, a simple and rapid detection method is necessary. For this purpose, nucleic acid amplification-based techniques are a potential solution. Loop-Mediated isothermal AMPlification (LAMP) has emerged as an alternative to qPCR due to the simple equipment necessary to perform the analysis while allowing the detection of living cells when combined with bacteriophages. The aim of this work was to develop a same-day protocol based in the combination of LAMP and a Salmonella phage (vB-SenS_PVP-SE2) to detect viable Salmonella Enteritidis cells in chicken meat. Specific LAMP primers were designed to target the capsid and endolysin genes of Salmonella phage vB-SenS_PVP-SE2. Two different detection strategies were developed: real-time fluorescence; and colorimetric (naked-eye detection). The LAMP method developed could detect down to 0.2 fg/L of pure phage DNA and concentrations of viral particles in buffered peptone water (BPW) of 10 pfu/mL. After optimization in spiked chicken samples, a 3 h sample pre-enrichment diluted 1/10 in BPW before phage addition to the samples followed by a co-incubation (with phage) of 4 h was established. The proposed method could determine the presence of S. Enteritidis in less than 8 h including sample processing, DNA isolation and LAMP analysis with a LOD of 1.5 cfu/25g and a LOD of 6.6 cfu/25g, both by fluorescence and naked-eye observation. The results were in close concordance with the reference method for Salmonella spp., the ISO 6579-1:2017. The described method represents a promising alternative for the rapid detection of Salmonella in the food chain.info:eu-repo/semantics/publishedVersio

Modelling bacteria and bacteriophage population dynamics

Moreover, it is necessary to evaluate and to understand the phage and bacteria population dynamics in order to foresee its potential for use in vivo. To understand how natural communities are affected by environmental factors and will respond in time, it is important to develop predictive models. The aim of the present work was the development of a dynamic model that predicts the interaction between a Salmonella phage and its respective host. Simulated data are compared with the data obtained experimentally to assess the suitability of the model for two multiplicity of infection (MOI): 0.1 and 1.0. For a high multiplicity of infection (MOI=1.0), the simulated and experimental data have a better correlation than for a low MOI (0.1). In this case, the differences were also more notorious for bacterial concentration. From the results it can be concluded that the model produces better correlations in terms of phage concentration, when a higher MOI is used. So, for a high MOI (MOI=1), given the initial values and the parameters used in the model, we can predict the concentration of phage and bacteria. In this way, the model can be used to predict the amount of phage obtained in the production process. It is expected that the developed model may help the optimization of phage production and the guidance of the experimental studies of population dynamics by identifying and evaluating the relative contribution of phage and bacteria in the course and outcome of an infection