Detection of Helicobacter pylori from Human Biological Samples (Feces) by Antigenic Screening and Culture

This research addressed the topic of timely diagnosis of Helicobacter pylori that is currently a problem for public health in Ecuador and worldwide. The prevalence of the pathogen has increased in the last decade, especially due to its direct participation in gastric cancer generation.
The present investigation was carried out to detect H. pylori in human stool samples by antigenic screening and culture.
The methodology used in this study was direct and indirect analysis of patients with H. pylori infection symptoms. Overall, 50 stool samples were collected (16 from males and 34 from females) and transferred immediately to the laboratory; patients were excluded due to causes such as contamination or insufficient amounts of sample for the analysis. From these samples, antigenic screening and culture in plates were carried out using the Brucella blood agar selective medium under controlled conditions. The two methods were analysed using the Kappa coefficient.
After antigenic screening analysis, 25 samples (50%) were positive for H. pylori with four false positives for both genders. The culture results showed that 19 samples (38%) were positive with 32 isolates characteristic for H. pylori. After agreement analysis, the kappa index was 0.28 (discrete).
The detection rate by antigenic screening was higher than that obtained by culture, this is mainly due to the lack of viable cells and the difficulty of adapting adequate isolation techniques.