DNA detection of Clostridium difficile infection based on real-time resistance measurement

Genet Mol Res. 2013 Sep 3;12(3):3296-304. doi: 10.4238/2013.September.3.6.


We used a newly developed electrochemical method, real-time resistance measurement, based on loop-mediated isothermal amplification (LAMP), with real-time resistance monitoring and derivative analysis. DNA extracted from specimens was amplified through LAMP reaction. The 2 products of LAMP, DNA and pyrophosphate, both are negative ions; they combine with positive dye (crystal violet) and positive ions (Mg(2+)), which leads to an increase in the resistivity of the reaction liquid. The changes of resistivity were measured in real-time with a specially designed resistance electrode, to detect Clostridium difficile DNA. We found that electrochemical detection of C. difficile could be completed in 0.5-1 h, with a detection limit of 10(2) CFU/mL, with high accuracy (95.0%), sensitivity (91.1%), and specificity (97.3%) compared to PCR methods. C. difficile is commonly associated with antibiotic-induced diarrhea. Due to the difficulty in performing anaerobic culture and cytotoxicity neutralization assays, a simple, rapid, sensitive, and accurate method is preferred. We conclude that real-time resistance measurement is a rapid, sensitive, and stable method for the diagnosis of C. difficile infection that could be applied to gene chips and pocket instruments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Clostridioides difficile / genetics
  • Clostridioides difficile / isolation & purification*
  • Clostridioides difficile / pathogenicity
  • Clostridium Infections / diagnosis*
  • Clostridium Infections / genetics
  • DNA, Bacterial / isolation & purification*
  • Feces / microbiology
  • Humans
  • Limit of Detection
  • Sensitivity and Specificity


  • DNA, Bacterial