The source of the infection and the route of transmission of Helicobacter pylori have not yet been clarified.
Dr Sonja Puz and colleagues from Austria introduced a noninvasive protocol allowing molecular typing of H pylori using stool specimens.
The team based the genotyping method on 2 H pylori–specific biprobe real-time polymerase chain reaction assays using fragments of the glmM and the recA genes as target sequences.
Discrimination between strains results from differences in the melting temperature during melting curve analysis.
|Clonal identities were found in 90% of European households|
In case of identical melting temperatures in both assays, sequence analysis of the glmM amplicon was performed to confirm strain identity.
The method was validated using gastric biopsy specimens.
The team also used stool specimens of 97 unrelated individuals suffering from abdominal pain, of members of 10 families in Austria, and 8 African households.
The researchers found that of the 97 patients, 27 were infected as shown by culture, histology, and rapid urease test.
The sensitivity of each of the assays was 100% in gastric biopsy specimens, and 92% in stool specimens.
The team noted that the specificity was 100%.
The discriminatory capacity of the method was 100%.
The team found clonal identities in 90% of European, and 88% of African households.
In 2 African households, 2 different clonal lineages each were found.
Dr Puz’s team concluded, “The genotyping protocol introduced allows for both accurate detection and discrimination of H pylori strains in stool samples.”
“Large-scale studies using this protocol may contribute to the clarification of the transmission pathways of infection with H pylori.”