An integrated microfluidic chip for the detection of bacteria - A proof of concept

We designed a microfluidic chip as a proof of concept for the detection of bacterial DNA. The chip was fabricated with poly-dimethylsiloxane (PDMS). It included a solid phase extraction (SPE) chamber, two separate channels and multiple loop-mediated isothermal amplification (LAMP) chambers. Three bacterial strains (Escherichia coli O157:H7, methicillin-resistant Staphylococcus aureus and methicillin-sensitive S. aureus) were used to test the feasibility of the device. LAMP products were examined directly using a UV light and verified by agarose gel electrophoresis. Using this chip, we successfully detected E. coli O157:H7, MSSA and MRSA in less than 2 h. The detection limit for genes rfbE, spa and mecA (specific to E. coli O157:H7, MSSA and MRSA, respectively) was <10(2) CFU/100 μl. Further work is required to refine this approach and rigorously assess its analytical and diagnostic specificity and sensitivity.