Oyuntsetseg, Khasag

Товч нэр

Oyuntsetseg, Khasag

Бүтэн нэр

Oyuntsetseg Khasag

Латин нэр

Oyuntsetseg Khasag

Албан тушаал

Судлаач

Харьяалал

Анагаахын Шинжлэх Ухааны Үндэсний Их Сургууль

ORCID

0000-0003-3037-5922

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Helicobacter Pylori Genotyping Among Mongolian Dyspeptic Patients
(Mongolian National University of Medical Sciences, 2022-06-30)
Tserentogtokh Tegshee
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Boldbaatar Gantuya
;
Khasag Oyuntsetseg
;
Davaadorj Duger
;
Battulga Adiyasuren
Objective: The prevalence of H. pylori infection varies significantly and developing countries are found to be the highest in Asia. In the present study, we have aimed to perform a combined analysis of histochemical stains and IHC to confirm the H.pylori infection of patients in 5 different provinces and Ulaanbaatar city, Mongolia. Method: Five hundred and thirty-eight patients were enrolled in this study (142 gastric mucosal atrophy, 333 gastritis and 62 gastroesophageal reflux). Results: 67.1 % of participants had CagA positive and 69.3 % were immunohistochemically positive. All histological results showed that the gastritis group was significantly higher in patients who were positive for H. pylori than in antral-predominant gastritis. By the hematoxylin and eosin staining with May– Giemsa confirmation by IHC, the prevalence of H. pylori infection in the gastric mucosal atrophy group was 62.1 %, while in the gastritis and gastroesophageal reflux group, the rate was 74.3 % and 59.1 %, respectively. Conclusion: CagA sequence profile in each group of patients revealed that 22.6 % of the gastric mucosal atrophy group was ABC type, 43.4 % was ABCC type and 33.9 % was ABTC type. On the other hand, in the gastritis group, the dominant type was ABTC (41.3 %). In the gastroesophageal reflux group, the ABCC type was dominant while 23.1% was the ABC type.
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1257 ENTEROCCUS HIRAE ATTENUATES CHEMOKINE AND INDUCES DNA DAMAGE IN GASTRIC EPITHELIAL CELLS
(Elsevier BV, 2023-05-01)
Batsaikhan Saruuljavkhlan
;
Boldbaatar Gantuya
;
Ricky Indra Alfaray
;
Junko K. Akada
;
Takashi Matsumoto
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IDDF2023-ABS-0237 Characteristics of helicobacter pylori from mongolia where burdening high incidence of gastric cancer
(2023-06-01)
Boldbaatar Gantuya
;
Batsaikhan Saruuljavkhlan
;
Khasag Oyuntsetseg
;
Yoshio Yamaoka
;
Vo Phuoc Tuan
Background Globally Mongolia is the top country in the incidence of gastric cancer followed by Japan and Korea which are East Asian countries. Helicobacter pylori (H. pylori) infection possessing East-Asian-type CagA is more associated with gastric carcinogenesis than Western-type CagA. The prevalence of H. pylori is around 70% in Mongolia; however, the previous study reported Mongolians infected with H. pylori possessing Western-type CagA. Therefore, we aimed to characterize Mongolian H. pylori infection based on a whole genome sequencing method. Methods Totally 130 strains are sequenced from Mongolian H. pylori isolates (20 gastric cancer and 110 non-cancer cases) and 401 data from 38 countries H. pylori whole genome data were extracted for the FineStructure analysis. The complete CagA gene and 7 housekeeping genes were extracted for constructing a phylogenetic tree. Results Based on whole genomic FineStructure analysis we found new H. pylori population named as HpMongolia among Mongolian gastric cancer and non-gastric cancer cases which are separately clustered among published global H. pylori populations (IDDF2023-ABS-0237-Figure 1. FineStructure analysis for H.pylori population). Complete CagA gene sequencing data showed that HpMongolia possessed with J-Western type cagA and it was the highest distribution of J-Western cagA positive H. pylori strains identified in Mongolia (67.7%) followed by Canada, North America (10%), and Okinawa, Japan (5.9%) among the published population (IDDF2023-ABS-0237-Figure 2. Global H.pylori phylogenetic tree based on 7-housekeeping genes). The phylogenetic tree constructed based on 7 housekeeping genes result showed the closest H. pylori population with HpMongolia is the HpAmerind which is isolated from native American people (IDDF2023-ABS-0237-Figure 3. H.pylori CagA genotyping map). Conclusions Mongolians provide new H. pylori population is named as HpMongolia which contains most of the cases Japanese-Western type cagA both for cancer and non-cancer cases. Therefore Japanese-Western type cagA might have advantageous for human migration study markers and further clinical implications.
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IDDF2023-ABS-0226 Initial results of screening program in mongolia where burdening high gastric cancer
(2023-06-01)
Gantuya Boldbaatar
;
Khasag Oyuntsetseg
;
Sarantuya Tserenchimed
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Tsevelnorov Khurelbaatar
;
Bilguun Jargalsaikhan
Background Mongolia is the leading country in the incidence and mortality rate of gastric cancer. According to the national data, TNM stage at the time of cancer diagnosis, a gastric cancer diagnosis is 0.4% in the carcinoma-in-situ stage, 5.1% in stage I, 15.2% in stage II, 42.7% in stage III and 36.5% in stage IV 36.5% were diagnosed respectively. Whereas almost 80% of people are diagnosed with early-stage of gastric cancer in Japan and Korea, where national cancer screening programs have been initiated for several decades. In 2022 national cancer screening program for upper gastrointestinal neoplasia was initiated; therefore, we aimed to conduct a multi-center study to determine gastric cancer incidence among the Mongolian population. Methods The cross-sectional study was performed to examine the detection rate of gastric cancer cases based on a national screening program from May to December 2022. The primary outcomes of this study were to define the detection rate (proportion of positive cases among individuals who underwent endoscopic screening) and to determine the characteristics of the cancer type, including its precursor disease based on histological examination. Results During the screening program, a total of 34581 participants’ data were collected from 28 endoscopy centers from Ulaanbaatar city and the western eastern, southern, and northern parts of the Mongolian province’s hospitals. The age range of the study participants was 35 to 93 years old. In terms of gender, 56.8% are men and 43.13% are women. The mean with SD age of people diagnosed with gastric cancer was 61.56±1.11, while the mean with SD age of healthy people was 53.84 ± 0.29 (p-value 0.0001). Among them, 113 (0.1%) patients were diagnosed with gastric cancer. The proportion of early-stage gastric cancer cases was 34 (30%) based on endoscopic and histological evaluation. The overall cases included in the national screening program are summarized in Figure 1 (IDDF2023-ABS-0226 Figure 1. Initial result from the national screening program for gastric cancer). Conclusions The initiation of the Mongolian national gastric cancer screening program could increase to detect the proportion of gastric cancer in its early stage. Therefore, screening programs should be continuous further. However, the quality of endoscopic examination should be improved.
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P57-6 Helicobacter pylori isolates from Mongolia describing gastric carcinogenesis and human migration
(Elsevier BV, 2022-07-01)
Boldbaatar Gantuya
;
Yoshio Yamaoka
;
Khasag Oyuntsetseg
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IDDF2022-ABS-0128 A novel pathogen enterococcus hirae induced dysbiosis in the stomach and the genomic instability to promote gastric cancer
(2022-09-01)
Batsaikhan Saruuljavkhlan
;
Boldbaatar Gantuya
;
Junko K. Akada
;
Takashi Matsumoto
;
Ricky Indra Alfaray
Background Previous our microbiome analysis indicates that Enterococcus sp. predominance of microbial composition has been determined in patients with gastric cancer (GC) by 16S rRNA metagenomic analysis. We aimed to determine whether this bacterium could promote the emergence and progression of GC. Methods The effects of E. hirae and Helicobacter pylori (clinical strain Mon-Ke2 as control) were assessed in a gastric epithelial cell line (AGS cells). The cell toxicity of AGS cells is identified by lactate dehydrogenase levels. The DNA double-strand breaks (DSBs) were assessed by gamma-H2AX expressions using immunoblotting; and single-cell gel electrophoresis (SCGE). AGS cells were analyzed for the rapid oxygen species (ROS) expressions response after E. hirae and H. pylori infections. Results E. hirae was successfully isolated from the gastric mucosal specimen of a GC patient for the first time. The whole-genome sequence of E. hirae was confirmed by next-generation sequencing. E. hirae-infected AGS cells showed abnormal morphological changes. Infections of E. hirae and H. pylori significantly induced cell death and expression of gH2AX in AGS cells. Besides, the expression of gH2AX and DSBs was confirmed by SCGE comet formation. Interestingly, co-infection of H. pylori and E. hirae had a synergistic effect on the severity of DSBs. E. hirae could induce intranucleus and mitochondrial ROS in AGS cells same as H. pylori. We investigated whether only live E. hirae, or its released factor(s) can cause DNA damage. Supernatant from AGS cells infected with E. hirae could induce the gH2AX, whereas H. pylori required cell adhesion to induce gH2AX. The complete genome of E. hirae totally contained 2570 genes and 10 known virulence factor genes (e.g., Enterococcus pore-forming toxin). Conclusions E. hirae-related dysbiosis in the stomach might increase the risk for GC, resulting in gained the genomic instability of gastric cells, as well as H. pylori infection. Further research investigating the impacts of this pathogen on the human host using the gastric organoid model is needed since several studies have shown that other species of Enterococcus induce cancer-promoting events resulting in DNA damage in gastric/colonic mucosa, and hepatic cells.
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High Antibiotic Resistance of Helicobacter pylori and Its Associated Novel Gene Mutations among the Mongolian Population
(MDPI AG, 2020-07)
Azzaya, Dashdorj
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Gantuya, Boldbaatar
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Oyuntsetseg, Khasag
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Davaadorj, Duger
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Matsumoto, Takashi
Mongolia has a high prevalence of Helicobacter pylori infection and the second highest incidence of gastric cancer worldwide. Thus, investigating the prevalence of antibiotic resistance and its underlying genetic mechanism is necessary. We isolated 361 H. pylori strains throughout Mongolia. Agar dilution assays were used to determine the minimum inhibitory concentrations of five antibiotics; amoxicillin, clarithromycin, metronidazole, levofloxacin, and minocycline. The genetic determinants of antibiotic resistance were identified with next-generation sequencing (NGS) and the CLC Genomics Workbench. The resistance to metronidazole, levofloxacin, clarithromycin, amoxicillin, and minocycline was 78.7%, 41.3%, 29.9%, 11.9% and 0.28%, respectively. Multidrug resistance was identified in 51.3% of the isolates investigated which were further delineated into 9 antimicrobial resistance profiles. A number of known antibiotic resistance mutations were identified including rdxA, frxA (missense, frameshift), gyrA (N87K, A88P, D91G/N/Y), 23S rRNA (A2143G), pbp1A (N562Y), and 16S rRNA (A928C). Furthermore, we detected previously unreported mutations in pbp1A (L610*) and the 23S rRNA gene (A1410G, C1707T, A2167G, C2248T, and C2922T). The degree of antibiotic resistance was high, indicating the insufficiency of standard triple therapy in Mongolia.
Scopus© Citations 36
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Gastric Microbiota in Helicobacter pylori-Negative and -Positive Gastritis Among High Incidence of Gastric Cancer Area
(MDPI AG, 2019-04)
Gantuya, Boldbaatar
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El-Serag, Hashem B
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Matsumoto, Takashi
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Ajami, Nadim J
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Oyuntsetseg, Khasag
Helicobacter pylori (H. pylori) related chronic gastritis is a well-known major etiological factor for gastric cancer development. However, H. pylori-negative gastritis (HpN) is not well described. We aimed to examine gastric mucosal microbiota in HpN compared to H. pylori-positive gastritis (HpP) and H. pylori-negative non-gastritis group (control). Here, we studied 11 subjects with HpN, 40 with HpP and 24 controls. We performed endoscopy with six gastric biopsies. Comparison groups were defined based on strict histological criteria for the disease and H. pylori diagnosis. We used 16S rRNA gene amplicon sequencing to profile the gastric microbiota according to comparison groups. These results demonstrate that the HpP group had significantly lower bacterial richness by the operational taxonomic unit (OTU) counts, and Shannon and Simpson indices as compared to HpN or controls. The linear discriminant analysis effect size analysis showed the enrichment of Firmicutes, Fusobacteria, Bacteroidetes and Actinobacteria at phylum level in the HpN group. In the age-adjusted multivariate analysis, Streptococcus sp. and Haemophilus parainfluenzae were at a significantly increased risk for HpN (odds ratio 18.9 and 12.3, respectively) based on abundance. Treponema sp. was uniquely found in HpN based on occurrence. In this paper, we conclude that Streptococcus sp., Haemophilus parainfluenzae and Treponema sp. are candidate pathogenic bacterial species for HpN. These results if confirmed may have important clinical implications.
Scopus© Citations 74
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Advantage of 16S rRNA amplicon sequencing in Helicobacter pylori diagnosis
(Wiley, 2021-06)
Gantuya, Boldbaatar
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El Serag, Hashem B
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Saruuljavkhlan, Batsaikhan
;
Azzaya, Dashdorj
;
Matsumoto, Takashi
BACKGROUND: 16S rRNA amplicon sequencing is an accurate method of detecting microbial infection without culture. It is unclear if sequencing has additional benefits over routine diagnostic methods for Helicobacter pylori testing. METHODS: We enrolled Mongolian volunteers with dyspepsia. Using routine diagnostic methods, positive H. pylori was defined as positive results on histology/immunohistochemistry, culture, rapid urease test, or serology; negative H. pylori was defined by negative results from all these tests. We performed 16S rRNA sequencing on gastric biopsy specimens and calculated cutoffs for operational taxonomic units (OTUs) and relative abundance (RA) to define positive results using ROC curves. RESULTS: We examined 161 individuals with a mean age of 43.6 years, and 64.6% were women. Using routine diagnostic methods, 122 (75.8%) participants were H. pylori positive, the sensitivity and specificity for 16S rRNA sequencing were 94.3% and 82.1% or 93.4% and 82.1% when cutoff values were set to 1113 (OTU number) or 4.4% RA, respectively (both p < .001). When combining the validated values, the concordance rate was high (91.1%); however, 16S rRNA sequencing had additional positive yield in 9 cases (5.6%) compared with routine diagnostic methods, and much greater additional positive yield compared to histopathology/IHC, culture, RUT, serology separately with 12 (7.4%), 37 (23.0%) and 43 (26.7%). CONCLUSION: 16S rRNA amplicon sequencing detects potentially important proportion of H. pylori-positive cases that test negative with routine diagnostic methods. The quantitative number of H. pylori can help to understand how it can be changing by diseases and RA give opportunity to understand how H. pylori communicate with other microbiota.
Scopus© Citations 27
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Western-Type Helicobacter pylori CagA are the Most Frequent Type in Mongolian Patients
(MDPI AG, 2019-05)
Tserentogtokh, Tegshee
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Gantuya, Boldbaatar
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Subsomwong, Phawinee
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Oyuntsetseg, Khasag
;
Bolor, Dashdorj
Helicobacter pylori infection possessing East-Asian-type CagA is associated with carcinogenesis. Mongolia has the highest mortality rate from gastric cancer. Therefore, we evaluated the CagA status in the Mongolian population. High risk and gastric cancer patients were determined using endoscopy and histological examination. H. pylori strains were isolated from different locations in Mongolia. The CagA subtypes (East-Asian-type or Western-type, based on sequencing of Glu-Pro-Ile-Tyr-Ala (EPIYA) segments) and vacA genotypes (s and m regions) were determined using PCR-based sequencing and PCR, respectively. In total, 368 patients were examined (341 gastritis, 10 peptic ulcer, and 17 gastric cancer). Sixty-two (16.8%) strains were cagA-negative and 306 (83.1%) were cagA-positive (293 Western-type, 12 East-Asian-type, and one hybrid type). All cagA-negative strains were isolated from gastritis patients. In the gastritis group, 78.6% (268/341) had Western-type CagA, 2.9% (10/341) had East-Asian-type, and 18.2% (61/341) were cagA-negative. However, all H. pylori from gastric cancer patients possessed Western-type CagA. Histological analyses showed that East-Asian-type CagA was the most virulent strains, followed by Western-type and cagA-negative strains. This finding agreed with the current consensus. CagA-positive strains were the most virulent type. However, the fact that different CagA types can explain the high incidence of gastric cancer might be inapplicable in Mongolia.
Scopus© Citations 21

Oyuntsetseg, Khasag

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