Rapid Identification of Viable H. pylori Cells in Feces by DVCFISH

Abstract

[EN] Helicobacter pylori isolation in fecal samples is a less invasive and more comfortable practice than those that require patient endoscopy, particularly in children. However, culture of this pathogen from stools is usually unsuccessful. Other techniques such as PCR or H. pylori Stool Antigen (HpSA) are used to detect the presence of H. pylori in feces; nevertheless, a positive result by using these techniques does not involve viability of the pathogen. Direct Viable Count combined with Fluorescent in situ Hybridization (DVC-FISH) technique has been successfully applied to detect viable H. pylori cells in highly contaminated environmental samples. To assess the suitability of DVC-FISH technique to identify viable H. pylori cells in stools, experimentally inoculated feces and fecal samples from infected patients were analyzed. qPCR and culture techniques were also used. Viable H. pylori cells were detected by DVC-FISH in all inoculated samples with a specific DNA/LNA probe. H. pylori colonies were also identified on agar. DVC-FISH gave positive results in all the patients' fecal samples, while qPCR only detected H. pylori in two patients. DVC-FISH technique with LNA/DNA probes has the potential to be used as a specific and effective non-invasive method for the detection of viable H. pylori in stools samples. Moreover, our results evidence the presence of viable H. pylori cells in fecal samples from infected patients, supporting the evidence that H. pylori is transmitted via the fecal route.