Abstract
BACKGROUND: This study has investigated designing, producing, and evaluating a newly developed immunoelectric device for the identification of the Staphylococcus aureus and Escherichia coli in experimentally or clinically polluted milk samples. METHODS: The design of the immunoelectric tool parts was carried out and produced by using a 3D printer. The animals were immunized against S. aureus and E. coli; purification of the specific IgG from hyperimmune serum was carried out by ion exchange and affinity chromatography methods. Coupling of the specific rabbit antibodies to the polystyrene filters was performed by DTPA linker. The purified rat antibodies were coupled to Fe nanoparticles and used as detector elements. The experimentally polluted milk and PBS samples were prepared. After optimization, the minimum traceable number of the bacteria was determined using immunoelectric tool. Also, the cow's milk samples with clinical mastitis were tested for bacterial detection by bacterial culture and immunoelectric methods. RESULTS: Coupling of the antibody to the filters and capturing of the target bacteria to the filters were successfully confirmed using enzyme immune assay and electron microscopy. The detection limit of the developed immunoelectric tool was equal to 15 cells/mL in PBS or milk samples for 30 min. Also, in agreement with bacterial cell culture, the clinically infected milk samples by S. aureus and E. coli were successfully detected using the immunoelectric device. CONCLUSIONS: The developed immunoelectric device could be utilized for rapid and cost-benefit detection of the bacterial organism.