A salting out and resin procedure for extracting Schistosoma mansoni DNA from human urine samples

The description of the extraction procedure is given. This extraction procedure was tested for reproducibility and efficiency in artificially contaminated human urine samples. The reproducibility reached 100%, showing positive results in 5 assay repetitions of 5 tested samples each containing 20 ng DNA/5 ml. The efficiency of the extraction procedure was also evaluated in a serial dilution of the original 20 ng DNA/5 ml sample. Detectable DNA was extracted when it was at a concentration of 1.28 pg DNA/mL, revealing the high efficiency of this procedure.This methodology represents a promising tool for schistosomiasis diagnosis utilizing a bio-molecular technique in urine samples which is now ready to be tested under field conditions and may be applicable to the diagnosis of other parasitic diseases.Schistosomiasis caused by Schistosoma mansoni is a major public health problem in countries of Latin America, the Caribbean and Africa [1,2]. Routinely the diagnosis of this disease is based on the detection of parasite eggs in stool. This approach is relatively inexpensive and easy to perform, and provides basic information on prevalence and infection intensity. However, a well known limitation of these coproscopic methods is their lack of sensitivity, especially in low endemic areas and among individual infections with low parasite load [3-5]. In order to overcome this shortcoming multiple sampling and the examination of a larger amount of faeces are necessary, which increases costs considerably, making these techniques too cumbersome for accurate diagnosis under such conditions. Besides this intrinsic limitation of coproscopic stool examinations, the positive effect of successful control programs and the rising numbers of infected travelers and migrants urgently require more sensitive methods for diagnosing infection with Schistosoma mansoni [6-8].As an alternative, serological tests for antibody detection can be applied for the diagnosis of schistosomiasis [9,10]. Unfo