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. 2022 Mar 23;10(2):19.
doi: 10.3390/diseases10020019.

Helicobacter pylori in Native Americans in Northern Arizona

Fernando P Monroy  1   2 , Heidi E Brown  3 , Priscilla R Sanderson  1 , Gregory Jarrin  4 , Mimi Mbegbu  2 , Shari Kyman  2 , Robin B Harris  3
Affiliations

Helicobacter pylori in Native Americans in Northern Arizona

Fernando P Monroy et al. Diseases. .

Abstract

Background: In Arizona Helicobacter pylori prevalence of infection among Navajo adults is about 62% and gastric cancer incidence rate is 3-4 times higher than that of the non-Hispanic White population.

Aim: The aim of this study was to estimate the prevalence of specific H. pylori virulence factors (cagA and vacA) among Navajo patients undergoing and their association with gastric disease.

Methods: Virulence genes, cagA and vacA, in H. pylori were investigated in gastric biopsies from 96 Navajo patients over age 18 who were undergoing esophagogastroduodenoscopy. Biopsies from the antrum and fundus were used for molecular characterization to determine cagA type and number of EPIYA motifs and presence of alleles in the signal (s) and medium (m) regions of the vacA gene.

Results: H. pylori infection was found in 22.9% of the biopsy samples. The cagA gene amplified in 57.6% of samples and showed a predominant "Western cagA" type, with the EPIYA-ABC motif (45.4%), most prevalent. The vacA allele s1bm1 was the most prevalent (54.5%).

Conclusions: H. pylori genotypes were predominantly cagA Western-type and ABC EPIYA motifs. The vacA s1bm1 genotype was the most prevalent and seemed to be associated with gastritis. American Indian/Alaska Native populations are at higher risk for gastric cancer. It is important to identify genotypes of H. pylori and virulence factors involved in the high prevalence of H. pylori and associated disease among the Navajo population.

Keywords: American Indians; Helicobacter pylori; Native Americans; Navajos; gastric cancer; gastritis; ulcers; virulence factors.

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Conflict of interest statement

The authors report no potential conflicts of interest.

Figures

Figure 1
Figure 1
Amino acid sequence of the CagA 3’ terminal region from strains containing three EPIYA motifs. The reference strain F32 was isolated from a Japanese patient and it is representative of an Eastern sequence (ESS; AAF17597.1). The reference strain 26695 (NP207343.1) is representative of a Western CagA-specific sequence (WSS). The strains Co5007 (EU251000.1), Co5017 (EU250993.1) and 373H (JN390445.1) and 10N (JN390446.1) were isolated from indigenous groups in Colombia (Co) and Mexico, respectively. Boxes illustrate the regions containing the EPIYA domains and underline shows the cagA multimerization motif (CM).
Figure 2
Figure 2
Phylogenetic tree of Navajo vacAs alleles in Helicobacter pylori sequences. The vacAs1a alleles are shown on the left with two typical vacAs1a strains (26695-NC_000915.1:938415-942287 and AR-710-AY185128.1). Sequences shown on the right display vacAs1b alleles with reference strains (USA2754-AB057223.1, 60190-U05676.1 and J99-NC 000921.1). The vacAs2 allele is shown on the top with a representative strain (Tx30a-U29401.1) in this group.
See this image and copyright information in PMC

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