Detection of circulating cell-free DNA to diagnose Schistosoma japonicum infection

Acta Trop. 2020 Nov:211:105604. doi: 10.1016/j.actatropica.2020.105604. Epub 2020 Jun 26.

Abstract

Schistosomiasis occurs in 240 million people worldwide and is a major public health concern. Thus, early diagnosis and monitoring of schistosomiasis progression are needed to treat patients. Cell-free DNA (cfDNA) is present as fragments of parasite-derived DNA in host body fluids. Detection of this cfDNA in host blood may be a promising diagnostic marker of schistosomiasis. Therefore, in this study, we investigated the potential of internal transcribed spacer 2 (ITS2), a molecular taxonomy and barcoding marker, in diagnosing schistosomiasis using infected rabbit and mice sera. A 192 bp fragment of ITS2 was detected in the serum-isolated DNA from the infected host on different days after infection. We also determined the sensitivity of detecting ITS2 in mice with varying numbers of cercaria: cfDNA was present even in mice with low abundance of the parasite. Overall, our results show that cfDNA may be a potential tool for the early diagnosis and therapeutic evaluation of S. japonicum infection.

Keywords: Cell-free DNA; Internal transcribed spacer 2; Molecular diagnosis; Schistosoma japonicum.

MeSH terms

  • Animals
  • Biomarkers / blood
  • Cell-Free Nucleic Acids / blood*
  • Cercaria / isolation & purification
  • DNA, Intergenic / blood
  • Humans
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Molecular Diagnostic Techniques
  • Rabbits
  • Schistosoma japonicum / genetics*
  • Schistosoma japonicum / isolation & purification
  • Schistosomiasis / diagnosis*
  • Schistosomiasis / genetics*
  • Schistosomiasis japonica / genetics*
  • Schistosomiasis japonica / parasitology*
  • Serum / parasitology*
  • Snails

Substances

  • Biomarkers
  • Cell-Free Nucleic Acids
  • DNA, Intergenic