Molecular characterization and phylogenetic analysis of babA gene of Helicobacter pylori isolated from Indian patients with gastrointestinal diseases

INTRODUCTION

Outer membrane protein (OMP) of Helicobacter pylori (H. pylori) i.e., blood group antigen binding adhesin (babA) is responsible for the attachment of H. pylori in the gastric epithelium. Its adherence is causative for gastric pathology such as gastritis, peptic ulcer disease (PUD), or digestive tract disorders like erosive reflux disease (ERD) and (NERD) non-erosive reflux disease and together called Gastroesophageal reflux disease (GERD). BabA manifests rapid and varied selection via substitution of amino acid in its Leb-carbohydrate binding domain (CBD) which enables better binding preferences for distinct human populations and ABO blood group phenotypes. The positive evolutionary selection of the pathogenic factor of this genetically diverse bacterium has enabled it to adapt to the host gastric environment. Analyzing the association of virulent genes (cagA, vacA) and babA will help us better understand bacteria's pathogenicity.

METHOD

109 H. pylori strains from patients with distinct gastrointestinal diseases were genotyped using Polymerase Chain Reaction(PCR) for cagA, vacA, and babA followed by Sanger sequencing and phylogenetic analysis.

RESULT

In the babA + ve genotype, a statistically significant association with p = 0.04 and < 0.0001 is seen in gastritis and ERD respectively. A significant association of genotype vacAs1m2 (p = 0.0002) was seen in gastritis, vacAs1m1 (p = 0.02) in NERD, vacAs1m1 (p < 0.0001) and vacAs1m2 (p = 0.002) in ERD. This relationship helps to detect gastritis or ERD where BabA gene can be used as an independent marker for detecting their presence.

CONCLUSION

The appearance of variants within distinct disease categories is due to local genetic variation.

Cancer patterns in Iran: a gender-specific spatial modelling of cancer incidence during 2014-2017

BACKGROUND

Cancer is a significant public health concern and the second leading cause of death. This study aims to visualize spatial patterns of top common cancer types and identify high-risk and low-risk counties for these cancers in Iran from 2014 to 2017.

METHODS

In this study, we analyzed 482,229 newly diagnosed cancer cases recorded by the Iranian National Population-Based Cancer Registry from 2014 to 2017. We employed a purely spatial scanning model and local Moran I analysis to explore spatial patterns across Iran.

RESULTS

Approximately 53% of all cases were male. The average age of cancer diagnosis was 62.58 ± 17.42 years for males and 56.11 ± 17.33years for females. Stomach cancer was the most common cancer in men. The northern and northwestern regions of Iran were identified as high-risk areas for stomach cancer in both genders, with a relative risk (RR) ranging from 1.26 to 2.64 in males and 1.19 to 3.32 in females. These areas recognized as high-risk areas for trachea, bronchus, and lung (TBL) cancer specifically in males (RR:1.15-2.02). Central regions of Iran were identified as high-risk areas for non-melanoma skin cancers in both genders, ranking as the second most common cancer (RR:1.18-5.93 in males and 1.24-5.38 in females). Furthermore, bladder cancer in males (RR:1.32-2.77) and thyroid cancer in females (RR:1.88-3.10) showed concentration in the central part of Iran. Breast cancer, being the most common cancer among women (RR:1.23-5.54), exhibited concentration in the northern regions of the country. Also, northern regions of Iran were identified as high-risk clusters for colon cancer (RR:1.31-3.31 in males and 1.33-4.13 in females), and prostate cancer in males (RR:1.22-2.31). Brain, nervous system cancer, ranked sixth among women (RR:1.26-5.25) in central areas.

CONCLUSIONS

The study's revelations on the spatial patterns of common cancer incidence in Iran provide crucial insights into the distribution and trends of these diseases. The identification of high-risk areas equips policymakers with valuable information to tailor targeted screening programs, facilitating early diagnosis and effective disease control strategies.

The global prevalence of gastric cancer in Helicobacter pylori-infected individuals: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is a gastrointestinal pathogen that infects around half of the world's population. H. pylori infection is the most severe known risk factor for gastric cancer (GC), which is the second highest cause of cancer-related deaths globally. We conducted a systematic review and meta-analysis to assess the global prevalence of GC in H. pylori-infected individuals.

METHODS

We performed a systematic search of the PubMed, Web of Science, and Embase databases for studies of the prevalence of GC in H. pylori-infected individuals published from 1 January 2011 to 20 April 2021. Metaprop package were used to calculate the pooled prevalence with 95% confidence interval. Random-effects model was applied to estimate the pooled prevalence. We also quantified it with the I2 index. Based on the Higgins classification approach, I2 values above 0.7 were determined as high heterogeneity.

RESULTS

Among 17,438 reports screened, we assessed 1053 full-text articles for eligibility; 149 were included in the final analysis, comprising data from 32 countries. The highest and lowest prevalence was observed in America (pooled prevalence: 18.06%; 95% CI: 16.48 - 19.63; I2: 98.84%) and Africa (pooled prevalence: 9.52%; 95% CI: 5.92 - 13.12; I2: 88.39%). Among individual countries, Japan had the highest pooled prevalence of GC in H. pylori positive patients (Prevalence: 90.90%:95% CI: 83.61-95.14), whereas Sweden had the lowest prevalence (Prevalence: 0.07%; 95% CI: 0.06-0.09). The highest and lowest prevalence was observed in prospective case series (pooled prevalence: 23.13%; 95% CI: 20.41 - 25.85; I2: 97.70%) and retrospective cohort (pooled prevalence: 1.17%; 95% CI: 0.55 - 1.78; I 2: 0.10%).

CONCLUSIONS

H. pylori infection in GC patients varied between regions in this systematic review and meta-analysis. We observed that large amounts of GCs in developed countries are associated with H. pylori. Using these data, regional initiatives can be taken to prevent and eradicate H. pylori worldwide, thus reducing its complications.

Geo-epidemiological reporting and spatial clustering of the 10 most prevalent cancers in Iran

Cancer is a problem of both global and local concern. We determined the geo-epidemiological and spatial distribution of the 10 most common cancers in Iran. We used the data of the Iranian Cancer Registry for the year 2014 analysing the prevalence of 112,131 registered cancer cases with the aim of detecting potential geographical underlying causes. The geographic distribution of cancers is reported as standardized incidence rates at the provincial level considering risk with respect to sex and age. A geographical information systems (GIS) approach based on Anselin Local Moran's index method was used to map clusters and spatial autocorrelation patterns. The mean age of the patients was 55.6 (±17.8) and 61.7 (±18.2) for females and males, respectively, in the database which showed 46.1% (n=51,665) of all cases to be female. Analysis of the spatial distribution of cancers showed significant differences among the different provinces. Stomach and breast cancers were the most prevalent cancers in men and females, respectively. The highest incidence rates of stomach cancer were found in Ardabil and Zanjan provinces, with 48.38 and 48.08 per 100,000 population, respectively, while Tehran and Yazd provinces had the highest incidences of breast cancer, 51.0 and 47.5 per 100,000 population, respectively. Strong clustering patterns for stomach and breast cancers were identified in the north-western provinces and in Semnan Province, respectively. These patterns indicate a diversity of geo-epidemiological contributing factors to cancer incidence in Iran.

Cost-effectiveness analysis of two routine therapeutic methods for Helicobacter pylori eradication: a Persian cohort-based study

AIM

This study aimed to analyze the cost-effectiveness of two routine therapeutic methods for H. pylori eradication in Iran.

BACKGROUND

Because of the importance of Helicobacter pylori (H. pylori) eradication on gastric cancer prevalence and costs, an economic analysis of the eradication methods is essential for health systems.

METHODS

This cross-sectional study was conducted on 7,496 participants with positive Hepadnaviridae (HPsAg) test results for H. pylori; 6,163 of them were treated with furazolidone (group A), and 1,333 participants were treated with clarithromycin (group B). Data on GP visits, medications, and HPsAg costs as direct costs and absence from work and transportation as indirect costs was collected by researcher-made questionnaire. Indirect costs were calculated based on face-to-face interviews with 365 patients of the Persian Cohort Center. Successful eradication of H. pylori infection (negative HPsAg) was defined as the effectiveness of the interventions. Incremental cost-effectiveness ratio (ICER) was used to compare the overall results.

RESULTS

The total direct cost of H. pylori for groups A and B were estimated at 13.7 and 5.83 billion IRR, respectively. The highest and lowest percentages of total costs were the cost of diagnostic services and the time cost, respectively. There was a significant difference between the two groups in drug costs (p<0.001). The effect ratio for groups A and B was 85.93% and 96.54%, respectively. Cost per effectiveness was higher for clarithromycin (CE=3,250,170 IRR) than for furazolidone (CE=2,988,488 IRR), and ICER showed that 5.1 Million IRR per participant is needed to eradicate H. pylori.

CONCLUSION

Based on the results, furazolidone was more cost-effective than clarithromycin for H. pylori treatment. Therefore, due to the high prevalence of H. pylori and the economic conditions of the health system in Iran, furazolidone can be a cost-effective choice between the two conventional treatment methods considering the results of further research and possible side effects.

Epidemiologic Study of Gastric Cancer in Iran: A Systematic Review

BACKGROUND

Gastric cancer (GC) is one of the most common cancers in Iran. Knowledge of the epidemiology of the disease is essential in planning for prevention. So this study aimed to investigate the epidemiological aspects of gastric cancer including prevalence, incidence, mortality, and risk factors of Iran.

METHODS

This systematic review study was based on articles published in both English and Persian languages during the years of 1970-2020 in international databases (PubMed, Web of Science, Scopus) and national databases (including SID, Magiran, and IranDoc). Papers related to epidemiological aspects of the disease including mortality, prevalence, incidence, and risk entered the final review.

RESULTS

According to the studies, the minimum and maximum prevalence of gastric cancer in northwestern Iran (Ardabil) is between 0.2 and 100 per 100,000. Also, the death rate per 100,000 people ranged from 10.6 to 15.72 and the ASMR ranged from 4.2 to 32.2%. On the other hand, the incidence of GC was higher in men than in women (74.9 vs 4.6%). The GC risk ratio was 8-times higher in the elderly than in the other age groups (HR=8.0, 2.7-23.5). The incidence of gastric cancer in patients with H. pylori infection was 18-times and that of smokers 2-times higher than other populations. Low level of economic situation and food insecurity increased the odds of GC by 2.42- and 2.57-times, respectively. It should be noted that there was a direct relationship between consumption of processed red meat, dairy products, fruit juice, smoked and salty fish and legumes, strong and hot tea, and consumption of salt and gastric cancer incidence. There was also an inverse relationship between citrus consumption, fresh fruit, garlic, and gastric cancer. In addition, the mRNA genes are the most GC-related genes.

CONCLUSION

Given the high incidence of GC in Iran, changing lifestyle and decreasing consumption of preservatives in food, increasing consumption of fruits and vegetables, and improving the lifestyle can be effective in reducing the incidence of this disease.

Prevalence of Helicobacter pylori virulence genes among Iranian infected patients: a systematic review and meta-analysis

Introduction:

Helicobacter pylori infection as the worldwide problem is related to many gastrointestinal disorders. Because of antithesis results among different articles; we systematically reviewed articles about the prevalence of H. pylori virulence factors among different diseases (gastritis, gastric cancer, nonulcer disease, peptic ulcer disease, duodenal ulcer) in different regions of Iran.

Methods:

We used the Preferred Reporting Items for Systematic Review and Meta-Analysis statement for reporting systematic review and meta-analysis of this study in national and international databases. We searched the cagA, vacA, oipA, babA, iceA, dupA prevalence among infected patients in Iran. We used Newcastle--Ottawa quality for assessing the quality of studies in meta-analyses. Due to significant heterogeneity of the results, random effects model to calculate pooled prevalence estimates with 95% confidence intervals, weighted by study size.

Results:

Among 1106 reports screened, 28 related articles were eligible for meta-analysis. The pooled prevalence (95% confidence interval) of cagA, vacA, oipA, babA, iceA1, iceA2, dupA were estimated as 62% (21--95), 71.2% (38–82), 71% (13–99), 61.6% (3–96), 36.2% (12–90), 26.2% (13–37), 40.8% (12–55), respectively.

Discussion:

The frequency of virulence factor genes among H. pylori strains isolated in Iranian patients to be more frequently associated with the gastrointestinal disease compared with the other countries and these data can be considered in development of eradication strategies.

Association of Helicobacter pylori babA2 gene and gastric cancer risk: a meta-analysis

Background

The association of Helicobacter pylori (H. pylori) babA2 gene with gastric cancer (GC) was reported by several studies, but results were inconsistent. This meta-analysis was performed to investigate the relationship between H. pylori babA2 gene and GC risk.

Methods

Case-control studies involving the association between H. pylori babA2 gene and GC risk were systematically identified from PubMed databases. A meta-analysis was used to pool studies and to estimate odds ratios (ORs) with 95% confidence intervals (CIs) of H. pylori babA2 gene associated with GC risk.

Results

Twenty studies were identified with a total of 1289 GC cases and 1081 controls. H. pylori babA2 gene was associated with an increased risk of GC by 2.05 fold (95% CI, 1.30–3.24, P = 0.002). In subgroup analysis, we found that H. pylori babA2 gene was significantly associated with GC risk in Asian population (OR = 2.63, 95% CI: 1.36–5.09 P = 0.004) but not in South American population (OR = 1.35, 95% CI: 0.69–2.64, P = 0.379).

Conclusions

This meta-analysis indicates that H. pylori babA2 gene may be associated with increased risk of GC, especially in Asian population.

Cancer incidence in Iran in 2014: Results of the Iranian National Population-based Cancer Registry

BACKGROUND

We aimed to report, for the first time, the results of the Iranian National Population-based Cancer Registry (INPCR) for the year 2014.

METHODS

Total population of Iran in 2014 was 76,639,000. The INPCR covered 30 out of 31 provinces (98% of total population). It registered only cases diagnosed with malignant new primary tumors. The main sources for data collection included pathology center, hospitals as well as death registries. Quality assessment and analysis of data were performed by CanReg-5 software. Age standardized incidence rates (ASR) (per 100,000) were reported at national and subnational levels.

RESULTS

Overall, 112,131 new cancer cases were registered in INPCR in 2014, of which 60,469 (53.9%) were male. The diagnosis of cancer was made by microscopic confirmation in 76,568 cases (68.28%). The ASRs of all cancers were 177.44 and 141.18 in male and female, respectively. Cancers of the stomach (ASR = 21.24), prostate (18.41) and colorectum (16.57) were the most common cancers in men and the top three cancers in women were malignancies of breast (34.53), colorectum (11.86) and stomach (9.44). The ASR of cervix uteri cancer in women was 1.78. Our findings suggested high incidence of cancers of the esophagus, stomach and lung in North/ North West of Iran.

CONCLUSION

Our results showed that Iran is a medium-risk area for incidence of cancers. We found differences in the most common cancers in Iran comparing to those reported for the World. Our results also suggested geographical diversities in incidence rates of cancers in different subdivisions of Iran.