Distribution of main variants in reactions of cytotoxin vaca of h. pylori in gastric biopsy specimens

Shiva Atefi,1,* Mohsen mirzaee,2

1. Master's Degree, Department of Microbiology, Borujerd Branch Islamic Azad University, Borujerd, Iran.
2. Department of Laboratory Sciences, Borujerd Branch Islamic Azad University, Borujerd, Iran.



Humans have suffered digestive problems for centuries, and we now know that h. pylori are one of their most important causal agents. helicobacter pylori reside in the human digestive system and cause various complications including gastroenteritis, duodenal ulcer, gastric ulcer, and cancer. one of the most important and most widely found genes of h. pylori is vaca, a candidate from which gastric cancer arises. the “s” and “m” variants, two of the important ones in this gene, enhance h. pylori pathogenecity.


The present project is the first one conducted in khorramabad to determine distribution of the main variants involved in toxic (s) and adhesion (m) reactions of the vaca gene in h. pylori. biopsy specimens were taken from 100 patients with gastroduodenal ulcer at the endoscopy unit of the shafa hospital in khorramabad. after performing the urease test and making sure the specimens were h. pylori positive, dna extraction was performed using dngplus kits, specific primers were designed, amplification of the extracted genome was carried out using pcr, and results obtained from agarose gel electrophoresis were studied.


All biopsy specimens were infected with the 16srrna gene and the distribution of the variants was as follows: s1 (63%), s1a (44%), s1b (19%), s2 (30%), m1 (12%), and m2 (43%).


Considering the distribution and diversity of the vaca genotypes and the mechanism of action of this gene and the importance of the presence of the s and m regions in increasing the risk for h. pylori infections, the presence of this gene can be a warning for the development and progress of digestive diseases caused by these bacteria and, along with other genes, can be an extremely effective factor in enhancing severity of h. pylori pathogenecity.


helicobacter pylori, gastric cancer, vaca gene, biopsy, pcr