Evaluation of a digital microfluidic real-time PCR platform to detect DNA of Candida albicans in blood

Eur J Clin Microbiol Infect Dis. 2012 Sep;31(9):2237-45. doi: 10.1007/s10096-012-1561-6. Epub 2012 Feb 11.

Abstract

Species of Candida frequently cause life-threatening infections in neonates, transplant and intensive care unit (ICU) patients, and others with compromised host defenses. The successful management of systemic candidiasis depends upon early, rapid diagnosis. Blood cultures are the standard diagnostic method, but identification requires days and less than half of the patients are positive. These limitations may be eliminated by using real-time polymerase chain reaction (PCR) to detect Candida DNA in the blood specimens of patients at risk. Here, we optimized a PCR protocol to detect 5-10 yeasts in low volumes of simulated and clinical specimens. We also used a mouse model of systemic candidiasis and determined that candidemia is optimally detectable during the first few days after infection. However, PCR tests are often costly, labor-intensive, and inconvenient for routine use. To address these obstacles, we evaluated the innovative microfluidic real-time PCR platform (Advanced Liquid Logic, Inc.), which has the potential for full automation and rapid turnaround. Eleven and nine of 16 specimens from individual patients with culture-proven candidemia tested positive for C. albicans DNA by conventional and microfluidic real-time PCR, respectively, for a combined sensitivity of 94%. The microfluidic platform offers a significant technical advance in the detection of microbial DNA in clinical specimens.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Candida albicans / genetics
  • Candida albicans / isolation & purification*
  • Candidemia / diagnosis*
  • Candidemia / microbiology
  • Clinical Laboratory Techniques / methods*
  • Disease Models, Animal
  • Humans
  • Mice
  • Microfluidics / methods*
  • Real-Time Polymerase Chain Reaction / methods*
  • Sensitivity and Specificity