Bacteriophage-based advanced bacterial detection: Concept, mechanisms, and applications

Some bacterial species are deadly disease-causing pathogens with high morbidity and mortality in humans worldwide. Key interfaces in the transmission of bacterial pathogens include food, water, dairy products, peridomestic animals, and human interplay. Early-stage detection of such bacteria is crucial in minimizing the risk of bacterial diseases and ensuring early diagnosis. Majority of the conventional microbiological and biochemical detection methods are laborious, require skilled individuals, and are not always accurate. Various molecular diagnostic tools and assays, utilizing sensitive and specific biorecognition elements, such as enzymes, antibodies, and nucleic acids, have been developed and widely used for the detection of pathogenic bacteria. An ideal biorecognition element for the detection of pathogens should be highly specific, stable, sensitive, selective, rapid, easily available, and cost-effective. Bacteriophages, which meet such prerequisites, may be used as biorecognition element alternatives to the currently available molecular probes in the development of cost-effective, specific, quick, sensitive, and reliable platforms (sensors and assays) for the detection of bacterial pathogens. This review details bacteriophage biology and various recognition sites and receptor-binding proteins on the surfaces of tailed phages, which can be used as the recognition sites for specific bacterial detection. It highlights structures and receptors on the surface of bacteria for binding and attachment of specific phages. These features of bacteria and phages provide a basis for establishing methodologies for phage-based bacterial detection, including phage-induced bacterial lysis, phages immobilized on a transducer surface, fluorescently labelled phages, phage-conjugated quantum dots, and recombinant reporter phages, particularly monitored through optical and electrochemical transducer systems.