Fast and reliable extraction of protozoan parasite DNA from fecal specimens

Background: Polymerase chain reaction (PCR) detection of intestinal protozoa in fecal specimens is hampered by poor recovery of DNA and by the presence of PCR inhibitors. In this study we describe a novel method for DNA extraction from such specimens containing spores and oocysts of Enterocytozoon bieneusi and Cryptosporidium parvum, respectively. Methods and Results: Extraction was done using commercial kits modified to maximize the recovery and purity of extracted DNA. In comparison with a procedure we previously reported, we estimate that this method may increase the sensitivity of parasite DNA detection in fecal specimens up to tenfold. An additional advantage of this method is that up to 12 samples may be processed simultaneously within 2 hours. Conclusions: By using this method, we were able to increase reproducibility of PCR amplification on fecal specimens and significantly reduce the hands-on time required to process the samples.