The simple and fast isolation of Escherichia coli O157:H7 using magnet nanoparticle embedded silica nanotube for the nucleic acid based detection.

In this study, we developed a simple and fast isolation tool of Escherichia coli O157:H7 (E. coli O157:H7) using a magnet nanoparticle embedded silica nanotube (MNSNT) for the detection of E. coli O157:H7 in the sample with nucleic acid based amplification. This method does not require chaotropic salt and sophisticated equipment to isolate bacteria. The E. coli O157:H7 in the sample was effectively bound to the hydrophilic surface of MNSNT in low pH binding buffer containing divalent ions and PEG without the need for expensive biological reagents such as antibodies. This E. coli O157:H7 bound MNSNT was simply isolated by a magnet, prior to adding an amplification mixture to the same micro tube without transferring the sample to another tube. Using this novel method, the detection sensitivities of E. coli O157:H7 (102 cfu/1 g of seed sprout and 102 cfu/5 mL of water) were 80% and 100%, respectively, whereas that was 0% using the commercial method.