Multiple-Locus Variable-Number Tandem Repeat Analysis of Helicobacter pylori Strains Isolated from Biopsy Samples

Background: Multiple-locus variable-number tandem-repeat analysis (MLVA) is a reliable, fast, and useful method for conducting phylogenetic and genotyping analyses. However, its application in Helicobacter pylorityping is limited. Objectives: This study aimed to determine the genetic diversity of H. pyloristrains isolated from biopsy samples using six variable loci in MLVA typing. Methods: Over one year, we collected 70 non-duplicative biopsy samples from patients at Rohani Hospital, Babol, in northern Iran. After DNA extraction, H. pyloristrains were confirmed through the amplification of the glmM gene in the PCR test. Multiple-locus variable-number tandem-repeat analysis typing utilized six VNTR markers: VNTR-180, VNTR-263, VNTR-614, VNTR-607, VNTR-2181, and VNTR-2457. The PHYLOViZE software was employed to construct the phylogenetic tree. Results: Out of the 70 specimens, 43 tested positive for H. pylori. The phylogenetic tree revealed some strains with completely similar MLVA patterns. Our findings indicated that type 2 is the dominant type in this region, with most patients infected with this type exhibiting gastritis. Conclusions: The high allelic variability observed at VNTR-614, -607, and -2457 indicates high intraspecific variability for these markers in all isolates from our region. Consequently, these VNTRs can be considered ideal sites for typing.