IV Jornadas Latinoamericanas de Bacteriófagos

Salmonella species cause approximately 94 million cases of gastroenteritis and 155,000 deaths worldwide each year. In Colombia, Salmonella shows a high prevalence in poultry production systems, reaching up to 41%, with Salmonella enterica serotypes Typhimurium and Enteritidis being the most frequently reported. Rapid, sensitive, and on-site detection of this pathogen remains a major challenge for food safety and public health.
Bacteriophages have emerged as highly specific and cost-effective biorecognition elements for biosensor development due to their natural host specificity and robustness. In this study, we developed an electrochemical biosensor based on the immobilization of the Salmonella enterica-infecting bacteriophage φSan23 onto an electrode surface for the detection and quantification of viable bacterial cells.
Surface functionalization strategies were evaluated to achieve stable bacteriophage immobilization while preserving phage infectivity. The presence and distribution of immobilized bacteriophages on the electrode surface were confirmed by atomic force microscopy (AFM), and their biological activity was validated through infection assays with the host strain. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements were performed using a portable potentiostat integrated into an Internet of Things (IoT)-based system that transmits electrochemical data to a web-based application via an internet connection. This platform enables real-time signal acquisition, visualization, and analysis using a smartphone or other connected devices, allowing remote access without specialized training.
This configuration allows the biosensor to provide results in approximately five minutes, supporting rapid decision-making to prevent economic losses and unnecessary animal culling in poultry production systems.
The biosensor was evaluated using the bacteriophage host strain at different bacterial concentrations, showing a clear concentration-dependent electrochemical response. Ongoing assays aim to assess the specificity of the biosensor against non-host bacterial strains. The proposed biosensor represents a low-cost, easy-to-use tool for on-site and remote monitoring of Salmonella enterica in poultry production and broiler farming environments.