Distribution and Evolution of cagA, cagE, and vacA Genes among Helicobacter pylori Isolates in Bulgaria

Helicobacter pylori is a species with a highly plastic genome encoding numerous virulence factors, such as the pathogenicity island ( cag PAI) and vacuolating cytotoxin A (VacA). cag PAI consists of more than 26 genes, with cagA and especially cagE being essential predictors of cag PAI intactness. vacA gene has numerous allelic variations, among which s1m1i1 is the most virulent. The aim of our…