Helicobacter pylori genetic diversity and gastro-duodenal diseases in Malaysia

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.

Changes in Calprotectin (S100A8-A9) and Aldolase in the Saliva of Horses with Equine Gastric Ulcer Syndrome

Equine gastric ulcer syndrome (EGUS) is a highly prevalent disease that affects horses worldwide. Within EGUS, two different forms have been described: equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD). The associated clinical signs cause detrimental activity performance, reducing the quality of life of animals. Saliva can contain biomarkers for EGUS that could be potentially used as a complementary tool for diagnosis. The objective of this work was to evaluate the measurements of calprotectin (CALP) and aldolase in the saliva of horses as potential biomarkers of EGUS. For this purpose, automated assays for the quantification of these two proteins were analytically validated and applied for detecting EGUS in a total of 131 horses divided into 5 groups: healthy horses, ESGD, EGGD, combined ESGD and EGGD, and horses with other intestinal pathologies. The assays showed good precision and accuracy in analytical validation, and they were able to discriminate between horses with EGUS and healthy horses, especially in the case of CALP, although they did not show significant differences between horses with EGUS and horses with other diseases. In conclusion, salivary CALP and aldolase can be determined in the saliva of horses and further studies are warranted to elucidate the potential of these analytes as biomarkers in EGUS.

Antimicrobial resistance patterns and genetic elements associated with the antibiotic resistance of Helicobacter pylori strains from Shanghai

BACKGROUND

Shanghai, in east China, has one of the world's highest burdens of Helicobacter pylori infection. While multidrug regimens can effectively eradicate H. pylori, the increasing prevalence of antibiotic resistance (AR) in H. pylori has been recognized by the WHO as 'high priority' for urgent need of new therapies. Moreover, the genetic characteristics of H. pylori AR in Shanghai is under-reported. The purpose of this study was to determine the resistance prevalence, re-substantiate resistance-conferring mutations, and investigate novel genetic elements associated with H. pylori AR.

RESULTS

We performed whole genome sequencing and antimicrobial susceptibility testing of 112 H. pylori strains isolated from gastric biopsy specimens from Shanghai patients with different gastric diseases. No strains were resistant to amoxicillin. Levofloxacin, metronidazole and clarithromycin resistance was observed in 39 (34.8%), 73 (65.2%) and 18 (16.1%) strains, respectively. There was no association between gastroscopy diagnosis and resistance phenotypes. We reported the presence or absence of several subsystem protein coding genes including hopE, hofF, spaB, cagY and pflA, and a combination of CRISPRs, which were potentially correlated with resistance phenotypes. The H. pylori strains were also annotated for 80 genome-wide AR genes (ARGs). A genome-wide ARG analysis was performed for the three antibiotics by correlating the phenotypes with the genetic variants, which identified the well-known intrinsic mutations conferring resistance to levofloxacin (N87T/I and/or D91G/Y mutations in gyrA), metronidazole (I38V mutation in fdxB), and clarithromycin (A2143G and/or A2142G mutations in 23S rRNA), and added 174 novel variations, including 23 non-synonymous SNPs and 48 frameshift Indels that were significantly enriched in either the antibiotic-resistant or antibiotic-susceptible bacterial populations. The variant-level linkage disequilibrium analysis highlighted variations in a protease Lon with strong co-occurring correlation with a series of resistance-associated variants.

CONCLUSION

Our study revealed multidrug antibiotic resistance in H. pylori strains from Shanghai, which was characterized by high metronidazole and moderate levofloxacin resistance, and identified specific genomic characteristics in relation to H. pylori AR. Continued surveillance of H. pylori AR in Shanghai is warranted in order to establish appropriate eradication treatment regimens for this population.

Genomic diversity of Helicobacter pylori populations from different regions of the human stomach

Individuals infected with Helicobacter pylori harbor unique and diverse populations of quasispecies, but diversity between and within different regions of the human stomach and the process of bacterial adaptation to each location are not yet well understood. We applied whole-genome deep sequencing to characterize the within- and between-stomach region genetic diversity of H. pylori populations from paired antrum and corpus biopsies of 15 patients, along with single biopsies from one region of an additional 3 patients, by scanning allelic diversity. We combined population deep sequencing with more conventional sequencing of multiple H. pylori single colony isolates from individual biopsies to generate a unique dataset. Single colony isolates were used to validate the scanning allelic diversity pipelines. We detected extensive population allelic diversity within the different regions of each patient's stomach. Diversity was most commonly found within non-coding, hypothetical, outer membrane, restriction modification system, virulence, lipopolysaccharide biosynthesis, efflux systems, and chemotaxis-associated genes. Antrum and corpus populations from the same patient grouped together phylogenetically, indicating that most patients were initially infected with a single strain, which then diversified. Single colonies from the antrum and corpus of the same patients grouped into distinct clades, suggesting mechanisms for within-location adaptation across multiple H. pylori isolates from different patients. The comparisons made available by combined sequencing and analysis of isolates and populations enabled comprehensive analysis of the genetic changes associated with H. pylori diversification and stomach region adaptation.

Time trends in the prevalence of Helicobacter pylori infection in patients with peptic ulcer disease: a single-center retrospective study in Shanghai

Objective

The present study aimed to investigate the recent trends in Helicobacter pylori infection associated with peptic ulcer disease in a large population in Shanghai.

Methods

We analyzed the medical records of all patients who had undergone upper gastrointestinal endoscopy (EGD) for uninvestigated dyspepsia at Ren Ji Hospital between 2013 and 2019 to determine the prevalence of H. pylori infection in patients with peptic ulcers.

Results

Peptic ulcers were found in 40,385 of the 383,413 patients who underwent EGD during the study period. Over the 7-year study period, the annual prevalence of H. pylori among patients receiving EGD declined from 32.2% to 26.5%. H. pylori was present in 60% of ulcers and the incidence was higher (66.9%) in duodenal compared with gastric ulcers (48.5%). The proportion of H. pylori-associated gastric ulcers declined from 52.2% to 49.3% and that of H. pylori-positive duodenal ulcers declined from 70.0% to 63.9%.

Conclusion

The prevalence of H. pylori-positive peptic ulcers, mainly duodenal ulcers, fell from 2013 to 2019. However, the proportion of non-H. pylori-associated peptic ulcer disease increased, especially in elderly people, possibly due to the use of nonsteroidal anti-inflammatory drugs. Further research is needed to confirm this hypothesis.

Overview of Helicobacter pylori Infection in Indonesia: What Distinguishes It from Countries with High Gastric Cancer Incidence?

Helicobacterpylori infects more than half the human population. However, the prevalence in Indonesia is low, as is the prevalence of gastric cancer. Hence, it could be instructive to compare these prevalence rates and their determining factors with those of countries that have high gastric cancer incidence. Ethnicity and genetic characteristics of H. pylori are important determinants of the H. pylori infection rate in Indonesia. The infection rate is higher in Bataknese, Papuans and Buginese than in Javanese, the predominant ethnic group. Ethnicity is also an important determinant of the genetic characteristics of H. pylori. Analysis of CagA in the EPIYA segment showed that the predominant genotypes in Papuans, Bataknese and Buginese are ABB-, ABD- and ABC-type CagA, respectively. Meanwhile, in the countries with high gastric cancer incidence, almost all strains had East Asian type CagA. An antibiotic susceptibility evaluation showed that the standard triple therapy can still be used with caution in several cities. There is a very high rate of resistance to second-line regimens such as levofloxacin and metronidazole. Recent studies have shown that furazolidone, rifabutin and sitafloxacin are potential alternative treatments for antibiotic-resistant H. pylori infection in Indonesia. Rather than focusing on early detection and eradication as in countries with high gastric cancer prevalence, countries with low gastric cancer prevalence should focus on screening the several groups that have a high risk of gastric cancer. (Gut Liver 2021;15:-665)

Helicobacter pylori and association between its positivity and anatomotopographic settlement in the stomach with the host age range

Helicobacter pylori (H. pylori) is a Gram-negative, helically shaped flagellated bacterium. Major diseases associated with H. pylori infection include peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. The incidence of H. pylori in the anatomotopographic regions of the stomach, such as antrum, corpus, fundus, and incisura angularis, has been investigated. Do the rates of H. pylori in the settlements change over time according to the age ranges of the hosts? Does this change affect the diseases caused by or related to H. pylori? It is estimated that the outcomes, which have been obtained, may provide a new perspective in terms of understanding the etiopathogenesis of H. pylori-induced diseases. A comprehensive literature search of PubMed/MEDLINE databases had been conducted using a combination of terms, “Helicobacter pylori,” “Sydney System,” “stomach,” “pyloric antrum,” “gastric corpus,” “stomach cancer,” and “Helicobacter pylori and age.” There are very few articles examining the relationship between the topographic locations of H. pylori and host age range in the English language literature. Therefore, it is also purposed to emphasize the outcomes of our current research about the mentioned topic. In our opinion, similar studies should reveal the settlement and age range in the different geographic locations and societies as in our study. We believe that these findings will contribute to the efforts for understanding overtly of H. pylori-induced disease of the stomach.

A Review of Gastric Cancer Research in Malaysia

Incidence rates of gastric cancer in Malaysia has declined by 48% among males and 31% among females in the latest reporting period of 13 years. Malays used to have age-standardized-rates only a fifth of those in Chinese and Indians, but the incidence among them is slightly rising even as the rates drop in the other races. Besides ethnicity, a low level of education, high intake of salted fish and vegetables, H pylori infection and smoking are risk factors. Consumption of fresh fruit and vegetable is protective. Variation in the strains of H pylori infection affect gastric cancer risk, with hspEAsia isolates among Chinese appearing linked to a high incidence than with hpAsia2 or hpEurope strains among Indians and Malays. It was reported in the 1980s that only about 3% of patients presented with early gastric cancer, but more encouraging rates reaching 27% with Stage 1 and 2 disease have been reported in the twenty-first century from leading centres. More tumours occur in the distal stomach except in Kelantan, where the incidence is low and main site is the cardia. Prompt endoscopy is advocated and open access, with direct referrals, to such services using a weighted scoring system should be more utilized. In view of the high rate of late disease laparoscopic staging unnecessary laparotomy needs to be avoided. Late presentation of gastric cancer however, is still predominant and the mortality to incidence ratio is relatively high. Besides seeking to reduce risk factors and achieve early detection, implementation of improved care for patients with late disease must be promoted in Malaysia.

Helicobacter pylori in patients with gastritis in West Cameroon: prevalence and risk factors for infection

Objectives

Helicobacter pylori is a pathogenic bacterium that parasitizes the gastric mucous layer and the epithelial lining of the stomach causing duodenal ulcers, gastric ulcers and cardiovascular disease amongst others. This study aimed at establishing the epidemiologic profile of H. pylori infection in gastritis patients presenting at the Melong District Hospital.

Results

Blood, stool and epidemiological data collected from 500 patients were analyzed for the presence of H. pylori antibody in serum, antigen in stool and elucidation of risk factors captured in questionnaires. Of 500 blood samples, 217 (43.4%) were seropositive with male and female seroprevalences of 45.5% (61/134) and 42.6% (156/366) respectively. Similarly, 47.4% (237/500) samples tested positive for stool antigen with prevalences of 47.0% (63/134) for males and 47.5% (174/366) for females. The antigen prevalence was higher (53.2%; 118/222) in older patients (> 50 years) than in younger patients (42.8%; 119/278; P = 0.021). The antigen test had a higher (47.4%) prevalence than the antibody test (43.4%). Educational level, source of income, source of drinking water, age of patients, and alcohol consumption had positive associations with H. pylori infection. These results have clinical and epidemiological significance and call for intervention to mitigate the situation.

Rise and fall of peptic ulceration: A disease of civilization?

Humans and Helicobacter pylori have evolved and adapted over tens of thousands of years. Yet peptic ulcer disease appeared to be rare prior to the 19th century. The prevalence of peptic ulcer disease increased between 1850 and 1900 and culminated in a cohort at high risk that was born at the end of the 19th century. This coincided with the provision of safe water and improvements in sanitation and personal hygiene. One hypothesis for the emergence of peptic ulcer disease focuses on the rate of development of atrophic gastritis induced by H. pylori. The hypothesis developed in this article focuses on delay in the age of acquisition of H. pylori to a time when immune and inflammatory responses to the infection were more mature. Whereas the acquisition of H. pylori in infancy usually resulted in mild pangastritis, hypochlorhydria, and a low risk for peptic ulcer disease, delayed acquisition could cause either more severe pangastritis (predisposing to gastric ulceration) or gastritis largely restricted to the antrum of the stomach (predisposing to duodenal ulceration). The decline in the prevalence of peptic ulcer disease over the past 100 years parallels the decline in the prevalence of H. pylori. The epidemic of ulcer disease in the first half of the 20th century seems likely to be an adverse effect of important public health measures undertaken in the latter half of the 19th century.

Management of multi-drug resistant Helicobacter pylori infection by supplementary, complementary and alternative medicine; a review

Helicobacter pylori is recognized as the most common bacterial pathogens colonizing the gastric epithelium of nearly half of the world's population. This bacterium is the main etiological cause of gastroduodenal ulcers, and more importantly as the substantial risk factor for development of gastric cancer. The emergence and rapid increase in the prevalence of multi-drug resistant phenotypes have posed major pitfalls in effectiveness of various treatment regimens and eradication strategies against H. pylori infections. Several natural products and supplementary food components have been reported to have established anti-H. pylori activity. Herein, we review the application and efficacy of some specific natural products and foodstuffs such as milk, bee products (honey and propolis), fish oil, vitamins C and E, and also a nickel free-diet used as anti-H. pylori alternative treatment regimens.