The accessibility of a rapid method for detection and identification of food‐borne pathogens is crucial for food industry worldwide. Antibiotic resistance bacteria (eg, E. coli) that can enter the food chain in different ways, can indeed survive on foods causing disease to humans. Hence, the introduction of a rapid detection technology becomes necessary for the food industry to ensure consumer safety, especially for products with short shelf lives. Bacteriophages can be used to detect and identify bacteria. In this study, a novel biosensor is proposed to detect pathogens by means of phage‐based baroreceptor. The biosensing technique is based on millimeter‐waves technology in the 30 to 60 GHz frequency range. The proposed biosensor can detect the pathogenic bacteria in different food samples by using a diamond‐shape microstrip slot antenna. The bacteriophage‐bacterium interaction is detected through the dynamic changes in transmission lines and antennas responses. The correctness of the antenna to detect E. coli in real food sample (tomato) is also investigated. The results indicate that, through the designed sensing elements, the transient interaction between bacteria and phage can effectively be detected. This sensing mechanism allows for a faster, more accurate, and low‐cost detection of pathogenic bacteria than traditional assays. Finally, the results are compared with previously reported sensing techniques.

IntroductionThe rise of infections by antibiotic-resistant bacterial pathogens is alarming. Among these, Klebsiella pneumoniae is a leading cause of death by hospital-acquired infections, and its multidrug-resistant strains are flagged as a global threat to human health, which necessitates finding novel antibiotics or alternative therapies. One promising therapeutic alternative is the use of virulent bacteriophages, which specifically target bacteria and coevolve with them to overcome potential resistance. Here, we aimed to discover specific bacteriophages with therapeutic potential against multiresistant K. pneumoniae clinical isolates.Methods and ResultsOut of six bacteriophages that we isolated from urban and medical sewage, phage vB_Kpn_ZCKp20p had the broadest host range and was thus characterized in detail. Transmission electron microscopy suggests vB_Kpn_ZCKp20p to be a tailed phage of the siphoviral morphotype. In vitro evaluation indicated a high lytic efficiency (30 min latent period and burst size of ∼100 PFU/cell), and extended stability at temperatures up to 70°C and a wide range of (2-12) pH. Additionally, phage vB_Kpn_ZCKp20p possesses antibiofilm activity that was evaluated by the crystal violet assay and was not cytotoxic to human skin fibroblasts. The whole genome was sequenced and annotated, uncovering one tRNA gene and 33 genes encoding proteins with assigned functions out of 85 predicted genes. Furthermore, comparative genomics and phylogenetic analysis suggest that vB_Kpn_ZCKp20p most likely represents a new species, but belongs to the same genus as Klebsiella phages ZCKP8 and 6691. Comprehensive genomic and bioinformatics analyses substantiate the safety of the phage and its strictly lytic lifestyle.ConclusionPhage vB_Kpn_ZCKp20p is a novel phage with potential to be used against biofilm-forming K. pneumoniae and could be a promising source for antibacterial and antibiofilm products, which will be individually studied experimentally in future studies.