Distribution of Helicobacter pylori cagA, cagE, oipA and vacA in different major ethnic groups in Tehran, Iran

Abstract

Background and Aim There are geographical variations in Helicobacter pylori virulence genes; cagA, cagE, vacA and oipA. The present study compared the distribution of these genotypes in major ethnic groups residing in Tehran, Iran and their association with clinical outcomes. Methods A total of 124 H. pylori-positive patients living in Tehran were enrolled in this study. The ethnic distribution was 74 Persians, 33 Turks and 17 other ethnics including Kurds, Lurs, Afghanis and Arabs. The presence of the cagA, cagE and oipA genes and vacA alleles (signal [s] and middle [m] region) were determined by polymerase chain reaction (PCR) from H. pylori DNA. Results The cagA-positive status was predominant in all three ethnic groups (e.g. 65% in Persians and 73% in Turks). In contrast, the cagE-positive status was less than half in Persians (47%) and Turks (30%), whereas it was 77% in other ethnicities (P = 0.008). The predominant vacA genotypes were s1 and m1 in all three ethnic groups (e.g. 68% in Persians and 70% in Turks were s1). There was no significant association between cagA and cagE status or vacA genotypes and clinical outcomes. The oipA-positive strains were more common in non-ulcer dyspepsia (NUD) (63%) than in peptic ulcer patients (15%) (P = 0.001) in Persians, but the association was not observed in other ethnic groups. Conclusion There are some differences in the H. pylori genotypes among the ethnic groups in Iran. However, none of these markers seemed to be clinically helpful in predicting the clinical presentation of a H. pylori infection in Iran.

Analysis of vacA/cagA genotypes/status in Helicobacter pylori isolates from Iranian children and their association with clinical outcome

“…We found that the mosaic genotype of vacAs1m2 was the most prevalent, which was similar to the cases of adults in Iran (26,38,39). The vacAs2m1 genotype that was the least prevalent in this work (Table 3) was also the least prevalent in Iranian adults (25)(26)(27)38,39). However, data on prevalence of other combinations of s and m alleles in Iranian adults have been controversial (25,(38)(39)(40)(41)44).…”

“…While a great number of studies in Iran indicated no influence of cagA status or its 3' variable region on the progression of disease (26)(27)(28)(29)(30)(31)(32)(33)(34), correlation between positive cagA status and severe clinical outcomes was reported in some other studies (35)(36)(37). Consistent with the cases of Iranian adult populations (27,28,(38)(39)(40)(41), vacA s1 was the most prevalent in the present investigation (Table 3). This dominance was also consistent with the cases of other countries in the northern part of the Middle East (42,43).…”

Prevalence of cagA and vacA among Helicobacter pylori-infected patients in Iran: a systematic review and meta-analysis

“…Of these studies, 17 were excluded because they were repetitive, 8 were not consistent with the study criteria, the full texts of 11 papers were not accessible and their abstracts did not contain enough information, and 8 papers did not reveal the prevalence of cagA; all of these papers were withdrawn (Flowchart 1). Finally, 23 relevant papers [2][3][4]6,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] were identified. Their data were entered into the data collection forms, and then these data were entered into Microsoft Excel and were analyzed using R software (version 11.2) and STATA (version 10).…”

Helicobacter pylori vacuolating cytotoxin genotypes and preneoplastic lesions or gastric cancer risk: a meta‐analysis

“…The prevalence of the vacA-m1 genotype in GC patients was investigated in 23 studies. 7,9,10,[13][14][15][16][17]23,[28][29][30][31][32][33]36,[38][39][40][41][42][43][44] The overall prevalence of the vacA-m1 genotype was 64.8% (402/620) in GC patients and 52.8% (948/1796) in controls. The pooled RR in a random-effects model was 1.431 (95% CI, 1.180-1.735, P = 0; Fig.…”