Extremely low Helicobacter pylori prevalence in North Sulawesi, Indonesia and identification of a Maori-tribe type strain: a cross sectional study

Impact of local human microbiota on the allergic diseases: Organ-organ interaction

The homogeneous impact of local dysbiosis on the development of allergic diseases in the same organ has been thoroughly studied. However, much less is known about the heterogeneous influence of dysbiosis within one organ on allergic diseases in other organs. A comprehensive analysis of the current scientific literature revealed that most of the relevant publications focus on only three organs: gut, airways, and skin. Moreover, the interactions appear to be mainly unidirectional, that is, dysbiotic conditions of the gut being associated with allergic diseases of the airways and the skin. Similar to homogeneous interactions, early life appears to be not only a crucial period for the formation of the microbiota in one organ but also for the later development of allergic diseases in other organs. In particular, we were able to identify a number of specific bacterial and fungal species/genera in the intestine that were repeatedly associated in the literature with either increased or decreased allergic diseases of the skin, like atopic dermatitis, or the airways, like allergic rhinitis and asthma. The reported studies indicate that in addition to the composition of the microbiome, also the relative abundance of certain microbial species and the overall diversity are associated with allergic diseases of the corresponding organs. As anticipated for human association studies, the underlying mechanisms of the organ-organ crosstalk could not be clearly resolved yet. Thus, further work, in particular experimental animal studies are required to elucidate the mechanisms linking dysbiotic conditions of one organ to allergic diseases in other organs.

Biomarker Characterization and Prediction of Virulence and Antibiotic Resistance from Helicobacter pylori Next Generation Sequencing Data

The Gram-negative bacterium Helicobacter pylori colonizes c.a. 50% of human stomachs worldwide and is the major risk factor for gastric adenocarcinoma. Its high genetic variability makes it difficult to identify biomarkers of early stages of infection that can reliably predict its outcome. Moreover, the increasing antibiotic resistance found in H. pylori defies therapy, constituting a major human health problem. Here, we review H. pylori virulence factors and genes involved in antibiotic resistance, as well as the technologies currently used for their detection. Furthermore, we show that next generation sequencing may lead to faster characterization of virulence factors and prediction of the antibiotic resistance profile, thus contributing to personalized treatment and management of H. pylori-associated infections. With this new approach, more and permanent data will be generated at a lower cost, opening the future to new applications for H. pylori biomarker identification and antibiotic resistance prediction.

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 in the Indonesian Malay's descendants might be imported from other ethnicities

BACKGROUND

Even though the incidence of H. pylori infection among Malays in the Malay Peninsula is low, we observed a high H. pylori prevalence in Sumatra, which is the main residence of Indonesian Malays. H. pylori prevalence among Indonesian Malay descendants was investigated.

RESULTS

Using a combination of five tests, 232 recruited participants were tested for H- pylori and participants were considered positive if at least one test positive. The results showed that the overall H. pylori prevalence was 17.2%. Participants were then categorized into Malay (Aceh, Malay, and Minang), Java (Javanese and Sundanese), Nias, and Bataknese groups. The prevalence of H. pylori was very low among the Malay group (2.8%) and no H. pylori was observed among the Aceh. Similarly, no H. pylori was observed among the Java group. However, the prevalence of H. pylori was high among the Bataknese (52.2%) and moderate among the Nias (6.1%). Multilocus sequence typing showed that H. pylori in Indonesian Malays classified as hpEastAsia with a subpopulation of hspMaori, suggesting that the isolated H. pylori were not a specific Malays H. pylori.

CONCLUSIONS

Even though the ethnic groups live together as a community, we observed an extremely low H. pylori infection rate among Indonesian Malay descendants with no specific Indonesian Malay H. pylori. The results suggest that H. pylori was not originally among these groups and H. pylori was imported from other ethnic groups.

Noninvasive Helicobacter pylori Diagnostic Methods in Indonesia

Although the prevalence of Helicobacter pylori infection in Indonesia is lower than that in other countries, H. pylori is still an essential pathogen associated with severe gastric mucosal damage and dyspeptic symptoms. Invasive diagnostic methods are not ideal due to the lack of endoscopic centers and high costs without full coverage by social insurance. Among the noninvasive methods, the urea breath test is widely available in Indonesia and has been suggested as the primary option to ensure the successful eradication of H. pylori. There has been no local validation for the urea breath test utilizing ¹³C or ¹⁴C. The stool antigen test is inexpensive and suitable for use in active infections before and after eradication; however, customs and habits are obstacles to delivering fresh stool on time. Only polyclonal antibodies and qualitative stool antigen test kits with low sensitivity are available. Serology is a widely validated method and has good accuracy, but it cannot distinguish between active and inactive infections. According to our observations, serology is the main choice of experts and patients, as it is simple, inexpensive and widely known. The urine test is an alternative for reducing costs and endoscopic workload, with high accuracy but low sensitivity. Further studies are necessary to prove the validity of the urine test to be used throughout Indonesia, especially in areas with a low prevalence of H. pylori infection. In conclusion, the validated urea breath test and the stool antigen test are considered noninvasive practical approaches for the detection of H. pylori infection in Indonesia, with serological and urine tests as alternatives.

Structure of cytotoxic associated antigen A protein of Helicobacter pylori from Bali and Lombok isolates of Indonesia

Background and Aim:

Helicobacterpylori is a well-known zoonotic agent with worldwide distribution. In Indonesia, only one report regarding the variation within the cytotoxic associated antigen A (CagA) protein of H. pylori has been described in the literature, which was conducted in Manado, South Sulawesi. There remains no report concerning the structure of this protein, particularly for the Bali and Lombok isolates. The objective of this study was to investigate the diversity of H. pylori CagA amino acid sequences of Bali and Lombok isolates, to predict their molecular structures and conduct toxicity examination of CagA on gastric cells.

Materials and Methods:

A total of 36 samples were used in equal proportions for each pathologic condition. DNA extraction was performed to subculture H. pylori Bali isolates. The amplification of the CagA 3′ variable region was carried out using the primers P1 (5′-GATAACAGGCAAGCTTTTTGAGG-3′) and P2 (5′-CTGCAAAAGATTGTTTGGCAG-3′). The W2, W9, and W35 fragments were selected as a representation of H. pylori Bali isolates, which were modeled through the threading modeling approach using I-TASSER.

Results:

According to the 12 CagA sequences obtained and phylogenetic analyses, the H. pylori strain originating from Bali can be grouped within the East Asian genotypes and is identical to the Lombok strain. In addition, the Bali isolates are phylogenetically more closely related to Southeast Asian strains, particularly the Filipino strain. The relationship between degree of inflammation induced and CagA-positive infection was not statistically significant.

Conclusion:

The structure of the H. pylori Bali isolate is identical to that of Lombok isolate, which belongs to the same group of East Asian genotypes, and bacterial virulence is not related to structure.

Review of current diagnostic methods and advances in Helicobacter pylori diagnostics in the era of next generation sequencing

Helicobacter pylori (H. pylori) infection is highly prevalent in the human population and may lead to severe gastrointestinal pathology including gastric and duodenal ulcers, mucosa associated tissue lymphoma and gastric adenocarcinoma. In recent years, an alarming increase in antimicrobial resistance and subsequently failing empiric H. pylori eradication therapies have been noted worldwide, also in many European countries. Therefore, rapid and accurate determination of H. pylori’s antibiotic susceptibility prior to the administration of eradication regimens becomes ever more important. Traditionally, detection of H. pylori and its antimicrobial resistance is done by culture and phenotypic drug susceptibility testing that are cumbersome with a long turn-around-time. Recent advances in diagnostics provide new tools, like real-time polymerase chain reaction (PCR) and line probe assays, to diagnose H. pylori infection and antimicrobial resistance to certain antibiotics, directly from clinical specimens. Moreover, high-throughput whole genome sequencing technologies allow the rapid analysis of the pathogen’s genome, thereby allowing identification of resistance mutations and associated antibiotic resistance. In the first part of this review, we will give an overview on currently available diagnostic methods for detection of H. pylori and its drug resistance and their implementation in H. pylori management. The second part of the review focusses on the use of next generation sequencing technology in H. pylori research. To this end, we conducted a literature search for original research articles in English using the terms “Helicobacter”, “transcriptomic”, “transcriptome”, “next generation sequencing” and “whole genome sequencing”. This review is aimed to bridge the gap between current diagnostic practice (histology, rapid urease test, H. pylori culture, PCR and line probe assays) and new sequencing technologies and their potential implementation in diagnostic laboratory settings in order to complement the currently recommended H. pylori management guidelines and subsequently improve public health.

Analysis of risks of gastric cancer by gastric mucosa among Indonesian ethnic groups

Indonesia is a big country with multiethnic populations whose gastric cancer risks have not been elucidated. We performed a nationwide survey and obtained histological specimens from 1053 individuals in 19 cities across the country. We examined the gastric mucosa, the topography, the atrophic gastritis risk factors, and the gastric cancer risk scores. Almost half (46.1%) of the patients with dyspeptic symptoms had histological abnormalities; chronic (36.3%) and atrophic gastritis (28.9%) being the most frequent. Individuals of the Timor ethnicity had the highest prevalence of acute (52.6%) and chronic gastritis (68.4%), even those negative for H. pylori. Our topographic analysis showed the majority of patients had predominantly antral acute and chronic gastritis. A multivariate logistic regression model showed age (Odds ratio [OR], 1.107), Timor ethnicity (OR, 8.531), and H. pylori infection (OR, 22.643) as independent risk factors for presence of atrophic gastritis. In addition, the gastric cancer risk score was highest in those from Timor, Papuan, and Bugis ethnic populations. Overall, Indonesia is a low-risk gastric cancer country. However, several ethnic groups displayed severe gastric mucosa symptoms suggesting policy makers should focus on those ethnic groups to perform gastric cancer screenings and to eradicate H. pylori.

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.

Prevalence of CagA and antimicrobial sensitivity of H. pylori isolates of patients with gastric cancer in Egypt

BACKGROUND

Helicobacter pylori (H. pylori) infection has been recognized as a significant threat for gastric cancer. However, studies that investigated the oncogenic factors and antimicrobial resistance of H. pylori in Egyptian isolates with gastric cancer are rare. The current study aimed to examine: (1) The pattern of antimicrobial resistance of H. pylori isolates of Egyptian gastric cancer patients, and (2) the prevalence of Cytotoxin-associated gene A (CagA).

METHODS

Samples were collected from patients with gastric cancer. Isolation of H. pylori was performed using Columbia blood agar supplemented with 10% horse blood, and selective supplement of H. pylori for 3 to 5 days at 37 °C under microaerophilic condition. Isolates were identified by biochemical traits of H. pylori: oxidase, urease and catalase tests. Antimicrobial susceptibility of H. pylori isolates was examined against five antimicrobial agents using disc diffusion method. After that, extraction of DNA and Polymerase Chain Reaction (PCR) were performed to amplify the target genes.

RESULTS

Twelve samples were collected from six males and six females Egyptian patients with cancer with an age range from 22 to 65 years. These cases are scarce and samples were collected over a period of almost eleven months. All isolates were confirmed as positive H. pylori through colony morphology and biochemical tests. The most effective antibiotic found was ciprofloxacin whereas all isolates showed resistance to metronidazole and erythromycin. The target CagA oncogene gene with expected product size was reported and seven (out of twelve) isolates (58%) were identified as CagA positive.

CONCLUSION

The current study is unique in two main aspects. First, it reported the pattern of antimicrobial susceptibility and prevalence of CagA gene in H. pylori from Egyptian patients. Second, it exclusively recruited isolates from gastric cancer patients which were confirmed by clinical and laparoscopic examination. The moderately high prevalence of CagA gene in Egyptian cancer patients calls for more vigilance against that oncogene.

The role of the microbiome and the use of probiotics in gastrointestinal disorders in adults in the Asia-Pacific region - background and recommendations of a regional consensus meeting

The Asia-Pacific region is diverse, with regard to ethnicity, culture, and economic development incorporating some of the world's least and most developed nations. Gastrointestinal diseases are common in the Asia-Pacific region, and their prevalence, presentation, and management vary considerably within the region. There is growing evidence for an important role for the human gut microbiota in gastrointestinal health. As a consequence, geographic variations in the composition of the gut microbiota may contribute to variations in both the prevalence and response to therapy of specific diseases. Probiotics have been proposed as a valuable option in the prevention and treatment of a number of gastrointestinal illnesses, but the quality of available evidence to support their efficacy is variable. A meeting of international experts in adult and pediatric gastroenterology was held at the Sorbonne University, Paris, France, on April 11 and 12, 2016, to discuss current evidence supporting the use of probiotics in gastrointestinal disorders in the Asia-Pacific region. This article provides an overview of the discussions held at this meeting and recommends the formation of an Asia-Pacific Consortium on Gut Microbiota similar to those established in Europe and North America.

Gastric mucosal status in populations with a low prevalence of Helicobacter pylori in Indonesia

In Indonesia, endoscopy services are limited and studies about gastric mucosal status by using pepsinogens (PGs) are rare. We measured PG levels, and calculated the best cutoff and predictive values for discriminating gastric mucosal status among ethnic groups in Indonesia. We collected gastric biopsy specimens and sera from 233 patients with dyspepsia living in three Indonesian islands. When ≥5.5 U/mL was used as the best cutoff value of Helicobacter pylori antibody titer, 8.6% (20 of 233) were positive for H. pylori infection. PG I and II levels were higher among smokers, and PG I was higher in alcohol drinkers than in their counterparts. PG II level was significantly higher, whereas PG I/II ratios were lower in H. pylori-positive than in H. pylori-negative patients. PG I/II ratios showed a significant inverse correlation with the inflammation and atrophy scores of the antrum. The best cutoff values of PG I/II were 4.05 and 3.55 for discriminating chronic and atrophic gastritis, respectively. PG I, PG II, and PG I/II ratios were significantly lower in subjects from Bangli than in those from Makassar and Surabaya, and concordant with the ABC group distribution; however, group D (H. pylori negative/PG positive) was the lowest in subjects from Bangli. In conclusion, validation of indirect methods is necessary before their application. We confirmed that serum PG level is a useful biomarker determining chronic gastritis, but a modest sensitivity for atrophic gastritis in Indonesia. The ABC method should be used with caution in areas with a low prevalence of H. pylori.

Current situation of <em>Helicobacter pylori</em> infection in Indonesia

Data epidemiologi infeksi Helicobacter pylori (H. pylori) terus berubah dalam beberapa dekade terakhir. Indonesia dilaporkan memiliki prevalensi infeksi H. pylori yang rendah dibandingkan dengan negara lain di Asia. Beberapa penelitian di Indonesia melaporkan bahwa sanitasi yang buruk, usia, agama, etnis merupakan faktor risiko untuk infeksi H. pylori. Dibandingkan dengan tes diagnostik lainnya, tes urine merupakan tes yang dapat diandalkan untuk mendeteksi H. pylori di Indonesia karena tes tersebut bersifat non-invasif dengan harga yang cukup terjangkau dan memiliki akurasi yang tinggi. Meskipun banyak penelitian telah dilakukan mengenai prevalensi infeksi H. pylori pada beberapa etnis di Indonesia, peneliti masih memiliki beberapa pertanyaan yang belum terjawab mengenai infeksi H. pylori di Indonesia. Oleh karena itu, diperlukan untuk membangun pusat penelitian H. pylori yang menyediakan fasilitas untuk kultur, evaluasi resistensi antibiotik, dan memperoleh informasi genotipe yang dapat menjelaskan perbedaan dalam infeksi H. pylori di antara berbagai etnis di Indonesia The epidemiology of Helicobacter pylori (H. pylori) has been changing over the past decades. Indonesia was reported have a low prevalence of H. pylori infection compared to other countries in Asia. Some studies in Indonesia have evaluated that poor sanitation, age, religion, ethnicity are the risk factors for H. pylori infection. Compared to other diagnostic tests, the urine test will be reliable for the detection of H. pylori in Indonesia because it is non-invasive and low cost with high accuracy. Although we have already performed studies on the prevalence of H. pylori infection in several ethnics, we still have some questions that remain unclear regarding H. pylori infection in Indonesia. Therefore, we have a need to build a H. pylori center that provide facilities for culturing, evaluating antibiotic resistance, and obtaining the genotype information that may explain the differences in H. pylori infection among ethnic groups in Indonesia.

Prevalence and Risk Factors for Helicobacter Pylori Infection among Healthy Inhabitants in Northern Jakarta, Indonesia

Background: The prevalence of Helicobacter pylori (H. pylori) infection in Indonesia has been reported to be exceedingly low. The purpose of our study was to confirm whether this is the case in Northern Jakarta using a sensitive 13C-urea breath test (UBT), and to examine any associations with lifestyle/environment factors and potential routes of transmission. Methods: We recruited a total of 196 subjects from a low-income community in Northern Jakarta, Indonesia, data from 193 who completed a questionnaire about their lifestyle/environment and had UBT being included as the final. Odds ratios (ORs) adjusted for sex and age with 95% confidence intervals (CIs) were calculated using a logistic regression model. Results: The overall H. pylori infection rate was 15.0% (95%CI, 10.3-20.9), with variation among Javanese (9.1%, total=77), Buginese (40.0%, 35), Betawi (9.1%, 33), Sundanese (3.7%, 27), and Batak (40.0%, 5). On multivariate analysis, the ORs for intake of soybean milk, cucumber more than once a week, infrequent hand washing practice before meals, and alcohol consumption were 0.10 (95%CI: 0.01-0.97), 6.61 (95%CI: 1.87-23.3), 4.10 (95%CI: 1.15-14.6), and 61.9 (95%CI: 1.67-2300.8), respectively. Rates for Buginese (OR=7.84; 95%CI: 1.82-33.8) and Batak (OR=20.1; 95%CI: 1.90-213.2) were significantly higher than for Javanese. Conclusions: The H. pylori infection rate in this study was relatively low, in line with previous studies. Regarding ethnicity factors, Buginese and Batak reported eating food using fingers more frequently than Javanese, Betawi, and Sundanese. Our study indicated that person-person transmission is possible in this low prevalence area. The low infection rates for H. pylori among Javanese, Betawi, and Sundanese ethnics could be partly due to their sanitary practices.

Clinical value of detection of anti-Helicobacter pylori antibody in urine

Helicobacter pylori (H. pylori) is a kind of gram-negative anaerobic bacterium that was first successfully isolated and cultivated from the specimens of the gastric mucosa by Warren and Marshall in 1983. It is one of the risk factors for gastric cancer and is closely related with chronic gastritis, peptic ulcer, gastric cancer and other diseases of the digestive system. There are a variety of detection technologies and diagnostic methods available for H. pylori infection, including direct detection of the bacterium, urease detection, antigen and antibody detection, polymerase chain reaction and so on. Generally, these methods can be divided into two major categories: invasive and non-invasive. However, no single test can be considered the gold standard for the diagnosis of H. pylori infection. In this paper, we will summarize a kind of completely non-invasive detection method - detection of H. pylori antibody in urine, review its use in the diagnosis of ongoing infection, and discuss its value in clinical applications.

Diagnostic Methods of Helicobacter pylori Infection for Epidemiological Studies: Critical Importance of Indirect Test Validation

Among the methods developed to detect H. pylori infection, determining the gold standard remains debatable, especially for epidemiological studies. Due to the decreasing sensitivity of direct diagnostic tests (histopathology and/or immunohistochemistry [IHC], rapid urease test [RUT], and culture), several indirect tests, including antibody-based tests (serology and urine test), urea breath test (UBT), and stool antigen test (SAT) have been developed to diagnose H. pylori infection. Among the indirect tests, UBT and SAT became the best methods to determine active infection. While antibody-based tests, especially serology, are widely available and relatively sensitive, their specificity is low. Guidelines indicated that no single test can be considered as the gold standard for the diagnosis of H. pylori infection and that one should consider the method's advantages and disadvantages. Based on four epidemiological studies, culture and RUT present a sensitivity of 74.2–90.8% and 83.3–86.9% and a specificity of 97.7–98.8% and 95.1–97.2%, respectively, when using IHC as a gold standard. The sensitivity of serology is quite high, but that of the urine test was lower compared with that of the other methods. Thus, indirect test validation is important although some commercial kits propose universal cut-off values.

Validation of Urine Test for Detection of Helicobacter pylori Infection in Indonesian Population

We measured the accuracy of the urine test (RAPIRUN) for detection of Helicobacter pylori infection in Indonesia (Jakarta, Pontianak, and Jayapura) using histology confirmed by immunohistochemistry and/or culture as gold standards. We also used immunohistochemistry to identify CagA phenotype and analyzed H. pylori CagA diversity in Indonesia. The overall prevalence of H. pylori infection in 88 consecutive dyspeptic patients based on the urine test was 15.9% (14/88), 38.1% for patients in Jayapura that had higher prevalence of H. pylori infection than that in Jakarta (9.7%, P = 0.02) and Pontianak (8.3%, P = 0.006). Overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of RAPIRUN were 83.3%, 94.7%, 71.4%, 97.3%, and 93.2%, respectively. All of the H. pylori-positive patients were immunoreactive for anti-CagA antibody but not immunoreactive for East Asian specific anti-CagA antibody in all H. pylori-positive subjects. We confirmed the high accuracy of RAPIRUN in Indonesian population. In general, we found less virulent type of H. pylori in Indonesia, which partly explained the low incidence gastric cancer in Indonesia.

Risk Factors and Prevalence of Helicobacter pylori in Five Largest Islands of Indonesia: A Preliminary Study

The prevalence of Helicobacter pylori infection in Indonesia is still controversial and mainly investigated in the largest ethnic group, Javanese. We examined the prevalence of H. pylori infection using four different tests including culture, histology confirmed by immunohistochemistry and rapid urease test. We also analyzed risk factors associated with H. pylori infection in five largest islands in Indonesia. From January 2014–February 2015 we consecutively recruited a total of 267 patients with dyspeptic symptoms in Java, Papua, Sulawesi, Borneo and Sumatera Island. Overall, the prevalence of H. pylori infection was 22.1% (59/267). Papuan, Batak and Buginese ethnics had higher risk for H. pylori infection than Javanese, Dayak and Chinese ethnics (OR = 30.57, 6.31, 4.95; OR = 28.39, 5.81, 4.61 and OR = 23.23, 4.76, 3.77, respectively, P <0.05). The sensitivity and specificity for RUT and culture were 90.2%, 92.9% and 80.5%, 98.2%, respectively. The patients aged 50–59 years group had significantly higher H. pylori infection than 30–39 years group (OR 2.98, P = 0.05). Protestant had significantly higher H. pylori infection rate than that among Catholic (OR 4.42, P = 0.008). It was also significantly lower among peoples who used tap water as source of drinking water than from Wells/river (OR 9.67, P = 0.03). However only ethnics as become independent risk factors for H. pylori infection. Although we confirmed low prevalence of H. pylori in Javanese; predominant ethnic in Indonesia, several ethnic groups had higher risk of H. pylori infection. The age, religion and water source may implicate as a risk factor for H. pylori infection in Indonesia.

Helicobacter pylori virulence genes in the five largest islands of Indonesia

Background

It remains unclear whether the low incidence of gastric cancer in Indonesia is due to low infection rates only or is also related to low Helicobacter pylori pathogenicity. We collected H. pylori strains from the five largest islands in Indonesia and evaluated genetic virulence factors.

Methods

The genotypes of H. pylori virulence factors were determined by polymerase chain reaction (PCR)-based sequencing. Histological severity of the gastric mucosa was classified into 4 grades, according to the updated Sydney system.

Results

A total of 44 strains were analyzed. Forty-three (97.7 %) were cagA-positive: 26 (60.5 %) were East-Asian-type-cagA, 9 (20.9 %) were Western-type-cagA, and 8 (18.6 %) were novel ABB-type, most of which were obtained from Papuan. EPIYT sequences were more prevalent than EPIYA sequences (P = 0.01) in the EPIYA-B motif of all types of cagA. The majority of cagA-positive strains (48.8 %, 21/43) had a 6-bp deletion in the first pre-EPIYA region. Subjects infected with East-Asian-type-cagA strains with a 6-bp deletion had significantly lower inflammation and atrophy scores in the corpus than those infected with Western-type-cagA strains (both P = 0.02). In total, 70.4 % of strains possessed the vacA s1m1 genotype and 29.5 % were m2. All strains from peptic ulcer patients were of the iceA1 genotype, which occurred at a significantly higher proportion in peptic ulcer patients than that in gastritis patients (55.3 %, P = 0.04). The double positive genotype of jhp0562/β-(1,3)galT was predominant (28/44, 63.6 %), and subjects infected with this type had significantly higher inflammation scores in the corpus than those with the jhp0562 negative/β-(1,3)galT positive genotype (mean [median]; 1.43 [1] vs. 0.83 [1], P = 0.04). There were significant differences in cagA and pre-EPIYA cagA type, oipA status, and jhp0562/β-(1,3)galT type among different ethnic groups (P < 0.05).

Conclusions

In addition to a low H. pylori infection rate, the low incidence of gastric cancer in Indonesia might be attributed to less virulent genotypes in predominant strains, which are characterized by the East-Asian-type-cagA with a 6-bp deletion and EPIYT motif, a high proportion of m2, dupA negative or short type dupA, and the jhp0562/β-(1,3)galT double positive genotype.

Allergies, Helicobacter pylori and the continental enigmas

Helicobacter pylori, a gastric pathogen, is known to be associated with gastric and duodenal ulcers, and is also a strong risk factor for the development of gastric cancer and lymphoma of the mucosal-associated lymphoid tissue. Ordinarily, this should make a strong case for its eradication at par with any other infectious disease. However, the unique biology of H. pylori and the complexity of its interactions with humans, its only known natural host, do not permit the recommendation of unambiguous preventive and therapeutic measures. Moreover, this organism has co-evolved with humans as a practically universal member of the natural gastric microbiota over at least 100,000 years. H. pylori persists for a lifetime in mostly asymptomatic hosts, and causes clinical disease only in a minority of infections. Therefore, its potential contribution to the maintenance of human immune homeostasis, as is the case with the better-studied members of the intestinal microbiota, is certainly worthy of serious investigation. In this paper, we summarize some interesting and often anecdotal data drawn from recent studies, and examine their significance in the context of the hygiene hypothesis. We also examine whether the lower incidence of gastric cancer over large parts of the world in spite of a high prevalence of infection (the Asian and African enigmas) may be re-interpreted in terms of the hygiene hypothesis. Finally, it is suggested that an evolutionary-ecological approach to the study of H. pylori infection may help in the formulation of strategies for the management of this infection. This may well be an infectious disease wherein medical interventions may have to be personalized to ensure optimal outcomes.