J-Western forms of Helicobacter pylori cagA constitute a distinct phylogenetic group with a widespread geographic distribution.

ABSTRACT: Chronic infection with Helicobacter pylori strains expressing the bacterial oncoprotein CagA confers an increased risk of gastric cancer. While much is known about the ancestry and molecular evolution of Western, East Asian, and Amerindian cagA sequences, relatively little is understood about a fourth group, known as "J-Western," which has been detected mainly in strains from Okinawa, Japan. We show here that J-Western cagA sequences have a more widespread global distribution than previously recognized, occur in strains with multiple different ancestral origins (based on multilocus sequence typing [MLST] analysis), and did not arise recently. As shown by comparisons of Western and J-Western forms of CagA, there are 45 fixed or nearly fixed amino acid differences, and J-Western forms contai

SUBMITTER: Duncan SS 

PROVIDER: S-EPMC3294863 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature