An alternative, sensitive method to detect Helicobacter pylori DNA in feces |
| |
Authors: | Horemans Tessa Deschacht Maartje Clais Sofie Van Camp John de Rijk Pim Holvoet Jan Van Assche Tim Maes Louis Cos Paul |
| |
Institution: | Laboratory of Microbiology, Parasitology, and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical, and Veterinary Sciences, University of Antwerp, Antwerp, Belgium. |
| |
Abstract: | Background: Despite the high sensitivity and specificity of PCR, detection of Helicobacter pylori 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 infection 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 biotin‐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 H. pylori ATCC 43504 and fecal samples were analyzed on days 1, 4, and 10 post infection. 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 H. pylori DNA on each time point, while the uninfected animal remained negative. Conclusions: The proposed technique allows detection of very low quantities of H. pylori DNA in biological samples. In laboratory animal models, detailed monitoring of infection and complete clearance of infection can be demonstrated thanks to the low detection limit. |
| |
Keywords: | Helicobacter pylori animal model feces real‐time PCR |
本文献已被 PubMed 等数据库收录! |
|