Oyuntsetseg, Khasag
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Oyuntsetseg, Khasag
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Oyuntsetseg Khasag
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Item type:Publication, Helicobacter Pylori Genotyping Among Mongolian Dyspeptic Patients(Mongolian National University of Medical Sciences, 2022-06-30) ;Tserentogtokh Tegshee; ; ; Battulga AdiyasurenObjective: 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, IDDF2023-ABS-0237 Characteristics of helicobacter pylori from mongolia where burdening high incidence of gastric cancer(2023-06-01); ; ; ;Yoshio YamaokaVo Phuoc TuanBackground 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. - Some of the metrics are blocked by yourconsent settings
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Item type:Publication, IDDF2022-ABS-0128 A novel pathogen enterococcus hirae induced dysbiosis in the stomach and the genomic instability to promote gastric cancer(2022-09-01); ; ;Junko K. Akada ;Takashi MatsumotoRicky Indra AlfarayBackground 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, High Antibiotic Resistance of Helicobacter pylori and Its Associated Novel Gene Mutations among the Mongolian Population(MDPI AG, 2020-07) ;Azzaya, Dashdorj; ; ; Matsumoto, TakashiMongolia 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 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Gastric Microbiota in Helicobacter pylori-Negative and -Positive Gastritis Among High Incidence of Gastric Cancer Area(MDPI AG, 2019-04); ;El-Serag, Hashem B ;Matsumoto, Takashi ;Ajami, Nadim JHelicobacter 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 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Western-Type Helicobacter pylori CagA are the Most Frequent Type in Mongolian Patients(MDPI AG, 2019-05) ;Tserentogtokh, Tegshee; ;Subsomwong, Phawinee; Bolor, DashdorjHelicobacter 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 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Utilization of an Automated Latex Agglutination Turbidity Assay for Assessing Gastric Mucosal Alteration during Helicobacter pylori Infection(The Editorial Office of Gut and Liver, 2024-01) ;Khangai, Ayush ;Akada, Junko; ; Azzaya, DashdorjBACKGROUND/AIMS: : A latex agglutination turbidity (LA) assay to test for serum antibodies has been approved in Japan and Korea for mass screening of Helicobacter pylori infection. In this study, we evaluated the LA assay for diagnosing H. pylori infection and predicting gastric mucosal changes in a Mongolian population. METHODS: : In total, 484 individuals were classified into H. pylori-positive (n=356) and H. pylori-negative (n=128) groups, as determined by histology and H. pylori culture. RESULTS: : The best cutoff, sensitivity, and specificity values for the LA assay were 18.35 U/mL, 74.2%, and 65.6%, respectively. The LA values in the atrophic gastritis group were statistically higher than those in the other groups (healthy, chronic gastritis, intestinal metaplasia, and gastric cancer, p<0.0001). The cutoff value to distinguish the atrophic gastritis group from the other four groups was 32.0 U/mL, and its area under the curve was 0.673, which was the highest among the E-plate, pepsinogen (PG) I, PG II, and PG I/II ratio tests in our data. The odds ratios for atrophic gastritis determined by the LA assay and PG I test in multiple logistic regression were 2.5 and 1.9, respectively, which were significantly higher than for the other tests. CONCLUSIONS: : The LA assay can determine the risk of atrophic gastritis, which in turn is a considerable risk factor for gastric cancer. We propose using this assay in combination with the PG I/II ratio to avoid missing gastric cancer patients who have a low LA value (less than 32.0 U/mL).Scopus© Citations 3 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Initial Trials With Susceptibility-Based and Empiric Anti-H. pylori Therapies in Mongolia(Frontiers Media SA, 2019); ; ; ; Background: Mongolia has a high prevalence of Helicobacter pylori infection and gastric cancer. We conducted a prospective, randomized, single-blind study to evaluate the efficacy of common regimens in Mongolia and to obtain specimens for susceptibility testing. Methods: Empiric treatments: 270 patients with confirmed H. pylori infection were randomized to receive 10 days clarithromycin-triple therapy (Clari-TT) (n = 90), modified bismuth quadruple therapy (M-BQT) (n = 90), or sequential therapy (ST) (n = 90). A second group of 46 patients received susceptibility-based Clari-TT. H. pylori was cultured from 131 patients and susceptibility testing was performed. H. pylori eradication was confirmed by stool antigen 4 weeks after the therapy. Results: Intention-to-treat (ITT) analysis cure rates were 71.1% (95% CI = 61.7-80.5%) for Clari-TT, 87.8% (95% CI = 81-94.6%) for M-BQT, 67.8% (95% CI = 58.1-77.5%) for ST vs. 89.1% (95% CI = 86-98.2%) for susceptibility-based Clari-TT. Per-protocol (PP) analysis results for these therapies were 72.7% (63.4-82%), 89.8% (83.5-96.1%), 68.5% (58.8-78.2%), and 97.6% (89.5-99.8%), respectively. Among 131 cultured H. pylori, resistance rates to amoxicillin, clarithromycin, and metronidazole were 8.4, 37.4, and 74%, respectively. Conclusion: In Mongolia, the prevalence of H. pylori resistance is high requiring bismuth quadruple therapy or susceptibility-based therapy to obtain acceptable cure rates.Scopus© Citations 12 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Evaluation of serum markers for gastric cancer and its precursor diseases among high incidence and mortality rate of gastric cancer area(Springer Science and Business Media LLC, 2019-01); ; ;Bolor, Dashdorj ;Erdene-Ochir, YansanBACKGROUND: Mongolia has the highest mortality rate of gastric cancer. The early detection of cancer and down-staging screening for high risk patients are essential. Therefore, we aimed to validate serum markers for stratifying patients for further management. METHODS: Endoscopy and histological examination were performed to determine high risk and gastric cancer patients. Rapid urease test, culture and histological tests were performed to diagnose Helicobacter pylori infection. Serum pepsinogen (PG) I and II and anti-H. pylori IgG were measured by ELISA. Receiver Operating Characteristic analysis was used to extract the best cut-off point. RESULTS: Totally 752 non-cancer and 50 consecutive gastric cancer patients were involved. The corpus chronic gastritis (72%: 36/50 vs. 56.4%: 427/752), corpus atrophy (42.0%: 21/50 vs. 18.2%: 137/752) and intestinal metaplasia (IM) (64.0%: 32/50 vs. 21.5%: 162/752) were significantly higher in gastric cancer than non-cancer patients, respectively. Therefore, corpus chronic gastritis, corpus atrophy and IM were considered as high risk disease. The best serum marker to predict the high risk status was PGI/II < 3.1 (sensitivity 67.2%, specificity 61%) and PGI/II further reduced to < 2.2 (sensitivity 66%, specificity 65.1%) together with PGI < 28 ng/mL (sensitivity 70%, specificity 70%) were the best prediction for gastric cancer. The best cut-off point to diagnose H. pylori infection was anti-H. pylori IgG > 8 U/mL. Multivariate analysis showed that anti-H. pylori IgG > 8 U/mL and PGI/II < 3.1 increased risk for high risk status and PGI/II < 3.1 remained to increase risk for gastric cancer. CONCLUSION: The serum diagnosis using PGI/II < 3.1 cut-off value is valuable marker to predict high risk patients for population based massive screening.Scopus© Citations 29
