An alternative, sensitive method to detect XXXX DNA in feces.

@entity1885 @entity281 @entity1534
BACKGROUND:    Despite the high sensitivity and specificity of PCR, detection of @entity1534 DNA in feces is still challenging. Fecal samples contain inhibitory molecules that can prevent amplification of the target DNA. Even by using specific DNA extraction kits for stools, monitoring of @entity281 by analyzing stool samples remains problematic and endorses the need for improved diagnostic methods. MATERIALS AND METHODS: The newly proposed method uses selective hybridization of target DNA with @entity1885 -labeled probes, followed by DNA isolation with streptavidin-coated magnetic beads. After three washing steps, the purified DNA can be amplified immediately using conventional or quantitative PCR. In order to test this technique on biological samples, Mongolian gerbils were infected with @entity1534 ATCC 43504 and fecal samples were analyzed on days 1, 4, and 10 post @entity281 . RESULTS: A detection limit of one bacterial cell per 100 mg stool sample was established, but only after removal of the magnetic beads from the target DNA by heating. This resulted in a 10-fold increase of sensitivity compared to a commercially available stool DNA extraction kit. Analysis of fecal samples from infected gerbils demonstrated the presence of @entity1534 DNA on each time point, while the uninfected animal remained negative. CONCLUSIONS:    The proposed technique allows detection of very low quantities of @entity1534 DNA in biological samples. In laboratory animal models, detailed monitoring of @entity281 and complete clearance of @entity281 can be demonstrated thanks to the low detection limit.
