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Exploring the relationship between Helicobacter pylori and Native Americans living in northern Arizona

Pereira Costa Sobrinho Jr, Enoque (2021) Exploring the relationship between Helicobacter pylori and Native Americans living in northern Arizona. Masters thesis, Northern Arizona University.

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Incidence and mortality rate of gastric cancer among Native Americans issignificantly higher than for Non-Hispanic White people. Many factors can contribute to this discrepancy such as diet, lifestyle, adequate sanitary living conditions and genetic factors. One known cause of stomach cancer is infection with the bacterium Helicobacter pylori. Some bacterial genetic factors give an advantage to the bacterium, the presence of the cagA gene and the genotype of the vacA gene (“s” and “m” regions). In this study, we collected and screened 210 biopsies from Native Americans patients living in Northern Arizona. DNA was isolated from these specimens and tested for the presence of H. pylori. If positive, a PCR was conducted to determine the status of cagA and vacA genes. Sequencing allowed us to determine the genotypes of these two genes and epidemiological data from patients was used to determine associations between clinical findings and H. pylori cagA and vacA genotypes. Our research found a positive association between the cagA genotype and esophageal findings. Severe cases of gastric disease were linked with presence of the vacA “m1” allele. The vacA s1m1genotype was the most common and was associated with cagA presence. The cagA ABC EPIYA motif was the most common genotype, and isolates expressing cagA ABC EPIYA motifs and vacA s1m1 alleles are known to be virulent. These results show that more virulent H. pylori strains are associated with more severe outcomes among Native Americans living in Northern Arizona.

Item Type: Thesis (Masters)
Publisher’s Statement: © Copyright is held by the author. Digital access to this material is made possible by the Cline Library, Northern Arizona University. Further transmission, reproduction or presentation of protected items is prohibited except with permission of the author.
Keywords: Navajo Indians; Genetics; Bacterial infections; Helicobater pylori; Stomach cancer
Subjects: R Medicine > RB Pathology
MeSH Subjects: C Diseases > C01 Bacterial Infections and Mycoses
NAU Depositing Author Academic Status: Student
Department/Unit: Graduate College > Theses and Dissertations
College of the Environment, Forestry, and Natural Sciences > Biological Sciences
Date Deposited: 11 Feb 2022 21:35
Last Modified: 26 Aug 2022 08:30
URI: https://openknowledge.nau.edu/id/eprint/5690

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