[EMA-pCR detection of enterohemorrhagic Eschrichia coli O157:H7].

Objective: A rapid and effective method with ethidium monoazide bromide (EMA) in combination with PCR (EMA-PCR) was established to detect live Enterohemorrhagic Eschrichia Coli O157:H7.

Methods: The rfbE gene was used as the target gene for PCR detection of Eschrichia Coli O157:H7 by utilizing its pure isolates after the treatment of EMA as the template. The EMA concentration and reaction time was optimized.

Results: The use of 10 microg/mL or less EMA did not inhibit the PCR amplification of DNA derived from viable bacteria. The PCR amplification of DNA derived from 2 x 10(7) CFU/mL dead cells can be inhibited by 0.5 microg/mL EMA. The sensitivity of the method was 2 x 10(4) CFU/mL. The results demonstrated that it could detect 1% live bacteria from a mixed bacterial population.

Conclusion: EMA-PCR can effectively detect live bacteria of O157:H7, it could be a potential rapid detection method applied in public health emergent events.