An ancient ecospecies of Helicobacter pylori.

Helicobacter pylori disturbs the stomach lining during long-term colonization of its human host, with sequelae including ulcers and gastric cancer1,2. Numerous H. pylori virulence factors have been identified, showing extensive geographic variation1. Here we identify a 'Hardy' ecospecies of H. pylori that shares the ancestry of 'Ubiquitous' H. pylori from the same region in most of the genome but has nearly fixed single-nucleotide polymorphism differences in 100 genes, many of which encode outer membrane proteins and host interaction factors. Most Hardy strains have a second urease, which uses iron as a cofactor rather than nickel3, and two additional copies of the vacuolating cytotoxin VacA. Hardy strains currently have a limited distribution, including in Indigenous populations in Siberia and the Americas and in lineages that have jumped from humans to other mammals. Analysis of polymorphism data implies that Hardy and Ubiquitous coexisted in the stomachs of modern humans since before we left Africa and that both were dispersed around the world by our migrations. Our results also show that highly distinct adaptive strategies can arise and be maintained stably within bacterial populations, even in the presence of continuous genetic exchange between strains.

Genetic determinants of Biofilm formation of Helicobacter pylori using whole-genome sequencing.

BACKGROUND: Infection with Helicobacter pylori as the cause of gastric cancer is a global public health concern. In addition to protecting germs from antibiotics, biofilms reduce the efficacy of H. pylori eradication therapy. The nucleotide polymorphisms (SNPs) related with the biofilm forming phenotype of Helicobacter pylori were studied. RESULTS: Fifty-six H. pylori isolate from Bangladeshi patients were included in this cross-sectional study. Crystal violet assay was used to quantify biofilm amount, and the strains were classified into high- and low-biofilm formers As a result, strains were classified as 19.6% high- and 81.4% low-biofilm formers. These phenotypes were not related to specific clades in the phylogenetic analysis. The accessories genes associated with biofilm from whole-genome sequences were extracted and analysed, and SNPs among the previously reported biofilm-related genes were analysed. Biofilm formation was significantly associated with SNPs of alpA, alpB, cagE, cgt, csd4, csd5, futB, gluP, homD, and murF (P < 0.05). Among the SNPs reported in alpB, strains encoding the N156K, G160S, and A223V mutations were high-biofilm formers. CONCLUSIONS: This study revealed the potential role of SNPs in biofilm formation and proposed a method to detect mutation in biofilm from whole-genome sequences.

Low-grade intestinal metaplasia in Indonesia: Insights into the expression of proinflammatory cytokines during Helicobacter pylori infection and unique East-Asian CagA characteristics.

Helicobacter pylori infection is a major cause of intestinal metaplasia. In this study, we aimed to understand the reason underlying the low grade and incidence of intestinal metaplasia in Indonesia, based on the expression of genes encoding proinflammatory cytokines in gastric biopsy specimens. The possible reasons for the lesser virulence of the East-Asian-type CagA in Indonesia than that of the Western-type CagA, which is not common in other countries, were also investigated. The mRNA expression of cytokines was evaluated using real-time PCR. CagA characteristics were analyzed using in silico analysis. The expression of cytokines was typically not robust, among H. pylori-infected subjects in Indonesia, despite them predominantly demonstrating the East-Asian-type CagA. This might partially be explained by the characteristics of the East-Asian-type CagA in Indonesia, which showed a higher instability index and required higher energy to interact with proteins related to the cytokine induction pathway compared with the other types (p < 0.001 and p < 0.05, respectively). Taken together, besides the low prevalence of H. pylori, the low inflammatory response of the host and low CagA virulence, even among populations with high infection rates, may play an essential role in the low grade and low incidence of intestinal metaplasia in Indonesia. We believe that these findings would be relevant for better understanding of intestinal metaplasia, which is closely associated with the development of gastric cancer.

Pharmacomicrobiomics: Influence of gut microbiota on drug and xenobiotic metabolism.

Gut microbiota is the most diverse and complex biological ecosystem, which is estimated to consist of greater than 5 million distinct genes and 100 trillion cells which are in constant communication with the host environment. The interaction between the gut microbiota and drugs and other xenobiotic compounds is bidirectional, quite complicated, and not fully understood yet. The impact of xenobiotics from pollution, manufacturing processes or from the environment is harmful to human health at varying degrees and this needs to be recognized and addressed. The gut microbiota is capable of biotransforming/metabolizing of various drugs and xenobiotic compounds as well as altering the activity and toxicity of these substances, thereby influencing how a host responds to drugs and xenobiotics and this emerging field is known as pharmacomicrobiomics. In this review, we discussed different mechanisms of drug-gut microbiota interaction and highlighted the influence of drug-gut microbiome interactions on the clinical response in humans.

A comprehensive evaluation of an animal model for Helicobacter pylori-associated stomach cancer: Fact and controversy.

Even though Helicobacter pylori infection was the most causative factor of gastric cancer, numerous in vivo studies failed to induce gastric cancer using H. pylori infection only. The utilization of established animal studies in cancer research is crucial as they aim to investigate the coincidental association between suspected oncogenes and pathogenesis as well as generate models for the development and testing of potential treatments. The methods to establish gastric cancer using infected animal models remain limited, diverse in methods, and showed different results. This study investigates the differences in animal models, which highlight different pathological results in gaster by literature research. Electronic databases searched were performed in PubMed, Science Direct, and Cochrane, without a period filter. A total of 135 articles were used in this study after a full-text assessment was conducted. The most frequent animal models used for gastric cancer were Mice, while Mongolian gerbils and Transgenic mice were the most susceptible model for gastric cancer associated with H. pylori infection. Additionally, transgenic mice showed that the susceptibility to gastric cancer progression was due to genetic and epigenetic factors. These studies showed that in Mongolian gerbil models, H. pylori could function as a single agent to trigger stomach cancer. However, most gastric cancer susceptibilities were not solely relying on H. pylori infection, and numerous factors are involved in cancer progression. Further study using Mongolian gerbils and Transgenic mice is crucial to conduct and establish the best models for gastric cancer associated H. pylori.

Real-world practice of Helicobacter pylori management: A survey among physicians in Southeast Asia.

BACKGROUND: Multidrug-resistant Helicobacter pylori strains are emerging in Southeast Asia. This study evaluates the region's real-world practice in H. pylori management. MATERIALS AND METHODS: Physicians who managed H. pylori eradication in daily practice across 10 Southeast Asian countries were invited to participate in an online questionnaire, which included questions about the local availability of antimicrobial susceptibility tests (ASTs) and their preferred eradication regimens in real-world practice. An empiric regimen was considered inappropriate if it did not follow the local guidelines/consensus, particularly if it contained antibiotics with a high reported resistance rate or was recommended not to be empirically used worldwide. RESULTS: There were 564 valid responses, including 314 (55.7%) from gastroenterologists (GIs) and 250 (44.3%) from non-GI physicians. ASTs were unavailable in 41.7%. In countries with low and intermediate clarithromycin resistance, the most common first-line regimen was PAC (proton pump inhibitor [PPI], amoxicillin, clarithromycin) (72.7% and 73.2%, respectively). Regarding second-line therapy, the most common regimen was bismuth-based quadruple therapy, PBMT (PPI, bismuth, metronidazole, tetracycline) (50.0% and 59.8%, respectively), if other regimens were used as first-line treatment. Concomitant therapy (PPI, amoxicillin, clarithromycin, metronidazole) (30.5% and 25.9%, respectively) and PAL (PPI, amoxicillin, levofloxacin) (22.7% and 27.7%, respectively) were favored if PBMT had been used as first-line treatment. In countries with high clarithromycin resistance, the most common first-line regimen was PBMT, but the utilization rate was only 57.7%. Alarmingly, PAC was prescribed in 27.8% of patients, ranking as the second most common regimen, and its prescription rate was higher in non-GI physicians than GI physicians (40.1% vs. 16.2%, p < 0.001). CONCLUSIONS: Choosing inappropriate regimens containing antibiotics with high resistance rates is not uncommon in Southeast Asia, especially among non-GI physicians. In countries with high clarithromycin resistance, the PBMT regimen is underutilized.

Characterization of Helicobacter pylori tlyA and Its Association with Bacterial Density.

BACKGROUND: In the recent studies, a less virulent Helicobacter pylori variant could still colonize the human stomach and induce gastric inflammation, suggesting the involvement of other virulence factors, such as TlyA hemolysin. Nevertheless, the association of TlyA in the pathogenesis of H. pylori infection remains unclear. We investigated the tlyA profile and determined its relationship with gastritis severity. METHODS: An observational study was conducted using DNA stocks and secondary data from previous studies. The tlyA variant was examined by NGS and confirmed with polymerase chain reaction. Gastritis severity was categorized by the Updated Sydney System. The relationship between a variant of tlyA and gastritis severity was determined, in which discrete variables were tested using the χ2 test or Fisher exact test. RESULTS: Two H. pylori tlyA variants were observed and characterized as tlyA1 and tlyA2. We noted a unique variant in the amino acid sequence 32-35 that is exclusively detected among H. pylori isolated from the Papua island. In addition, we observed that the tlyA variant had a significant association with the H. pylori density in the antral (p = 0.002). Histological analyses revealed that TlyA1 was associated with higher H. pylori density than TlyA2. However, we did not observe any significant association of tlyA with the infiltration of inflammation cells. CONCLUSIONS: We observed 2 tlyA variants (tlyA1 and tlyA2). A significant association of tlyA with bacterial density suggested that tlyA plays a more significant role in the colonization process than its influence on the severity of inflammation in gastric mucosa.

Lower Number and Percentage of Activated Natural Killer Cells in Colorectal Cancer Patients.

BACKGROUND: Colorectal cancer is a type of cancer that begins in the colon and/or rectum tissue. Natural killer (NK) cells play a critical role in the first line of defense against infection and tumors, as well as in autoimmunity and hypersensitivity reactions. NK cells also play a role in regulating tumor cell growth and metastasis. The number and percentage of activated natural killer cells have been determined in patients with colorectal cancer and benign lesion. METHODS: This was a cross-sectional observational analytic study. The number and percentage of activated NK cells in peripheral blood were determined using the flow cytometry method in 50 samples from patients who underwent colonoscopy and obtained a mass as evidenced by histopathological examination. RESULTS: Among the 50 samples, 24 samples included in the colorectal cancer group and 26 samples from benign lesion group. The mean number of NK cells in colorectal cancer was 161.71 ± 62.666 cells/µL, benign lesion was 553.92 ± 269.173 cells/µL. The mean percentage of activated NK cells in colorectal cancer was 2.82 ± 1.19%, benign lesion was 5.10 ± 2.48%. There was a significant difference in the number of NK cells and the percentage of activated NK cells between colorectal cancer and benign lesion patients (p = 0.000). CONCLUSION: The number and activity of NK cells decreases in patients with colorectal cancer.

Urease Levels and Gastritis Stage in Dyspeptic Patients.

BACKGROUND: Dyspepsia is a frequent main symptom of inpatients and outpatients scenario in Indonesia. However, the number of endoscopy facilities are still low, thus the use of non-invasive method to detect gastritis is necessary. We measured the relationship between urease levels and the stage of gastritis in dyspeptic adult patients. METHODS: A cross-sectional study included outpatient dyspepsia patient from November 2018 to February 2019. We examined 14C-Urea Breath Test (UBT) and determined the stage of gastritis based on the Updated Sydney System classification. RESULTS: The urease level of acute and chronic gastritis positive patients were higher than negative patients (p = 0.001, r = 0.353; p <0.0001, r = 0.433, respectively). The AUC value of 14C-UBT to detect acute, chronic, and atrophic gastritis are 0.889, 0.632 and 0.544, respectively. The best cut-off points of 14C-UBT to predict acute gastritis was ≥26.50δ‰ with sensitivity and specificity being 88.89% and 63.95%, respectively. Whereas the best cut-off points for chronic gastritis was ≥34.50δ‰ with 82.89% sensitivity, 63.16% specificity. As for atrophic gastritis, it showed very low AUC value, hence it is not a sufficient test modality to predict atrophic gastritis cases. CONCLUSION: 14C-UBT is sufficient for predicting acute or chronic gastritis but not for atrophic gastritis.

Serum pepsinogen level as a biomarker for atrophy, reflux esophagitis, and gastric cancer screening in Indonesia.

Background: Chronic dyspepsia's symptoms are frequently seen in primary to tertiary healthcare in Indonesia. This study aimed to describe the potential usability of pepsinogen (PG) values in determining gastric mucosal conditions, including superficial gastritis and atrophic gastritis. Materials and Methods: We recruited 646 adult dyspeptic patients and then analyzed PG values (including PGI, PGII, and PGI/II ratio) with endoscopic findings, gastric mucosal damages, and Helicobacter pylori infection. The gastric mucosal damage and H. pylori infection were evaluated using histological examination based on the updated Sydney system. Results: Among 646 enrolled patients, 308 (47.2%), 212 (32.8%), 91 (14.1%), 34 (5.2%), and 1 (0.2%) patient were diagnosed with normal mucosa, gastritis, reflux esophagitis, peptic ulcer disease, and gastric cancer, respectively. Significant differences in PGI, PGII, and PGI/II ratio values were observed among ethnic groups (all P < 0.01). The PGI and PGII levels were significantly higher and PGI/II was significantly lower in H. pylori-infected patients than in uninfected ones (all P < 0.001). The optimal cutoff value for PGII and PGI/II was 12.45 ng/mL with an area under the curve (AUC) value of 0.755 (0.702-0.811), sensitivity 59.3%, and specificity 77.1%; and 4.75 with AUC value of 0.821 (0.763-0.855), sensitivity 81.5%, and specificity 78.7%, respectively, to determine moderate-severe atrophy. Conclusion: Serum PG levels, a useful biomarker, represent the endoscopic findings, especially for reflux esophagitis. In addition, the benefits of PG values detecting atrophic gastritis were limited to moderate-severe atrophic gastritis. This usefulness requires careful attention for several ethnic groups in Indonesia.

Serum Helicobacter pylori antibody reactivity in seven Asian countries using an automated latex aggregation turbidity assay.

BACKGROUND AND AIM: To determine the application range of diagnostic kits utilizing anti-Helicobacter pylori antibody, we tested a newly developed latex aggregation turbidity assay (latex) and a conventional enzyme-linked immunosorbent assay (E-plate), both containing Japanese H. pylori protein lysates as antigens, using sera from seven Asian countries. METHODS: Serum samples (1797) were obtained, and standard H. pylori infection status and atrophy status were determined by culture and histology (immunohistochemistry) using gastric biopsy samples from the same individuals. The two tests (enzyme-linked immunosorbent assay and latex) were applied, and receiver operating characteristics analysis was performed. RESULTS: Area under the curve (AUC) from the receiver operating characteristic of E-plate and latex curves were almost the same and the highest in Vietnam. The latex AUC was slightly lower than the E-plate AUC in other countries, and the difference became statistically significant in Myanmar and then Bangladesh as the lowest. To consider past infection cases, atrophy was additionally evaluated. Most of the AUCs decreased using this atrophy-evaluated status; however, the difference between the two kits was not significant in each country, but the latex AUC was better using all samples. Practical cut-off values were 3.0 U/mL in the E-test and 3.5 U/mL in the latex test, to avoid missing gastric cancer patients to the greatest extent possible. CONCLUSIONS: The kits were applicable in all countries, but new kits using regional H. pylori strains are recommended for Myanmar and Bangladesh. Use of a cut-off value lower than the best cut-off value is essential for screening gastric cancer patients.

The role of SpyGlass Direct Visualization System on Patient with Indeterminate biliary strictures: A case report.

Biliary strictures diagnosis has become a challenge where benign conditions could mimic a malignant process. Recently, SpyGlass DS overcame the limitations by allowing direct visualization of the biliary tree. A 65 years old Indian patient complaints of jaundice with total and direct bilirubin of 23.3 mg/dL and 16.2 mg/dL, respectively. Liver function test, gamma-glutamyltransferase and CA 19-9 were increased. Transabdominal ultrasound and abdominal CT supported dilatation of common bile duct (CBD) with abrupt narrowing showing periductal enhancement at supra pancreatic level and stricture. Endoscopic ultrasound showed intrahepatic CBD stricture with dilated proximal CBD and sludge ball. Endoscopic retrograde cholangiopancreatography showed mid CBD stricture. Although brush cytology results suggested low grade dysplasia and no definite evidence of malignancy, cholangioscopy using SpyGlass DS found nodularity with abnormal vascularity seen in mid of CBD suggesting malignancy, confirmed with histopathology as cholangiocarcinoma. We reported additional value of SpyGlass DS for detecting cholangiocarcinoma in an indeterminate biliary stricture patient.

Minimal Hepatic Encephalopathy in Patients with Alcohol Related and Non-alcoholic Steatohepatitis Related Cirrhosis by Psychometric Hepatic Cephalopathy Score and Critical Flicker Frequency.

BACKGROUND: alcohol may have additional neurotoxic ill-effects in patients with alcohol related cirrhosis apart from hepatic encephalopathy. We aimed to evaluate minimal hepatic encephalopathy (MHE) with Psychometric Hepatic Encephalopathy (PHES) score and Critical Flicker Frequency (CFF) in alcohol (ALD) and non-alcoholic steatohepatitis related (NASH) related cirrhosis. METHODS: 398 patients were screened between March 2016 and December 2018; of which 71 patients were included in ALD group and 69 in NASH group. All included patients underwent psychometric tests which included number connection test A and B (NCT-A and NCT-B), serial dot test (SDT), digit symbol test (DST), line tracing test (LTT) and CFF. MHE was diagnosed when their PHES was <-4. RESULTS: the prevalence of MHE was significantly higher in ALD group compared to NASH (69.01% vs 40.58%; P=0.007). The performance of individual psychometric tests was significantly poorer in ALD (P<0.05). Overall sensitivity and specificity of CFF was 76.62% (95%CI 65.59 - 85.52) and 46.03% (95%CI 33.39 - 59.06) respectively. Mean CFF was significantly lower in ALD than NASH (37.07 (SD 2.37) vs 39.05 (SD 2.40), P=0.001); also in presence of MHE (36.95 (SD 2.04) vs 37.96 (SD 1.87), P=0.033) and absence of MHE (37.34 (SD 3.01) vs 39.79 (SD 2.46), P=0.001). CONCLUSION: MHE is significantly more common in patients with ALD cirrhosis than NASH counterparts. Overall CFF values are less in alcohol related cirrhosis than NASH related cirrhosis, even in presence or absence of MHE. We recommend additional caution in managing MHE in ALD cirrhosis.

The Challenging Anticoagulant Therapy in COVID19 Patient with Associated Coagulopathy.

COVID-19 became a widespread infectious disease in late 2019. Indonesia currently has the highest COVID-19 mortality rate in Asia, between 4-5 percent. Interestingly, COVID-19-associated coagulopathy characterized by an increase of several procoagulant factor levels, including fibrinogen and D-dimer, that has been associated with higher mortality and unfavorable outcomes. We report a case of a 30-year-old male admitted to the hospital with a profuse vomiting and worsening fever, cough and shortness of breath, and was diagnosed with COVID-19-associated coagulopathy. Seven days after admission, he became deteriorated with significant reduction of oxygen saturation and his coagulation parameter levels were increased with highly suspicion of pulmonary embolism. He was treated with azithromycin, isoprinosine, lopinavir, and fondaparinux with thromboprophylaxis dosage since admission. The role of increased fondaparinux dosage at the time of clinical deterioration was then followed by clinical improvement and reduced D-dimer level. Anticoagulant therapy, mainly with fondaparinux, showed a better prognosis in patients with markedly elevated D-Dimer. Fondaparinux needs to be monitored appropriately to prevent bleeding and adverse. The patient was discharged from the hospital in an improved condition and normal D-Dimer levels. There was no bleeding event nor other major side effects had been found in this case. The decision for increasing dose of anticoagulant may be determined on individual basis, considering risks, benefits, and also the most important is clinical findings.

Characterization of a novel Helicobacter pylori East Asian-type CagA ELISA for detecting patients infected with various cagA genotypes.

Currently, Western-type CagA is used in most commercial Helicobacter pylori CagA ELISA kits for CagA detection rather than East Asian-type CagA. We evaluated the ability of the East Asian-type CagA ELISA developed by our group to detect anti-CagA antibody in patients infected with different cagA genotypes of H. pylori from four different countries in South Asia and Southeast Asia. The recombinant CagA protein was expressed and later purified using GST-tag affinity chromatography. The East Asian-type CagA-immobilized ELISA was used to measure the levels of anti-CagA antibody in 750 serum samples from Bhutan, Indonesia, Myanmar, and Bangladesh. The cutoff value of the serum antibody in each country was determined via Receiver-Operating Characteristic (ROC) analysis. The cutoff values were different among the four countries studied (Bhutan, 18.16 U/mL; Indonesia, 6.01 U/mL; Myanmar, 10.57 U/mL; and Bangladesh, 6.19 U/mL). Our ELISA had better sensitivity, specificity, and accuracy of anti-CagA antibody detection in subjects predominantly infected with East Asian-type CagA H. pylori (Bhutan and Indonesia) than in those infected with Western-type CagA H. pylori predominant (Myanmar and Bangladesh). We found positive correlations between the anti-CagA antibody and antral monocyte infiltration in subjects from all four countries. There was no significant association between bacterial density and the anti-CagA antibody in the antrum or the corpus. The East Asian-type CagA ELISA had improved detection of the anti-CagA antibody in subjects infected with East Asian-type CagA H. pylori. The East Asian-type CagA ELISA should, therefore, be used in populations predominantly infected with East Asian-type CagA.

Gastric microbiota and Helicobacter pylori in Indonesian population.

BACKGROUND: The profile of gastric mucosal microbiota has not yet been described in the Indonesian population where the prevalence of Helicobacter pylori is low. METHODS: This is a cross-sectional study analyzing 16S rRNA of 137 gastric biopsy specimens. We analyzed the association between gastric microbiota, H. pylori infection, and gastric mucosal damage. RESULT: Among 137 analyzed samples, 27 were H. pylori-positive and 110 were H. pylori -negative based on culture, histology, and 16S rRNA gene analysis. Significantly lower α-diversity parameters, including Pielou's index, was observed in H. pylori-infected individuals compared with noninfected individuals (all P < .001). Among H. pylori-negative individuals, the permutational analysis of variance of Bray-Curtis dissimilarity distances showed a significant association with different ethnicities, suggesting some ethnic groups had specific microbiota profiles based on the presence of different operational taxonomic units. The linear discriminant analysis effect size (LEfSe) of the H. pylori-negative group showed significant associations between the presence of Micrococcus luteus and Sphingomonas yabuuchiae with Timor and Papuan ethnicities, respectively. The presence of Bulledia sp and Atopobium sp was associated with the Javanese ethnicity. We observed lower α-diversity scores in individuals with gastric mucosal damage and profiles with high abundances of Paludibacter sp and Dialister sp based on LEfSe analysis. CONCLUSION: Our findings suggest the presence of H. pylori is more correlated with a distinct microbiome profile than ethnic precedence.

Helicobacter pylori as an oncogenic pathogen, revisited.

Gastric cancer is an inflammation-associated malignancy aetiologically related to infection with the bacterium, Helicobacter pylori, which is considered a necessary but insufficient cause. Unless treated, H. pylori causes life-long acute and chronic gastric inflammation resulting in progressive gastric mucosal damage that may result in gastric cancer. The rate of progression from superficial gastritis, to an atrophic metaplastic mucosa, and ultimately to cancer relates to the virulence of the infecting H. pylori as well as host and environmental factors. H. pylori virulence is a reflection of its propensity to cause severe gastric inflammation. Both mucosal inflammation and H. pylori can cause host genomic instability, including dysregulation of DNA mismatch repair, stimulation of expression of activation-induced cytidine deaminase, abnormal DNA methylation and dysregulation of  micro RNAs, which may result in an accumulation of mutations and loss of normal regulation of cell growth. The difference in cancer risk between the most and least virulent H. pylori strain is only approximately 2-fold. Overall, none of the putative virulence factors identified to date have proved to be disease-specific. The presence, severity, extent and duration of inflammation appear to be the most important factors and current evidence suggests that any host, environmental or bacterial factor that reliably enhances the inflammatory response to the H. pylori infection increases the risk of gastric cancer.

Emerging Helicobacter pylori levofloxacin resistance and novel genetic mutation in Nepal.

BACKGROUND: The prevalence of Helicobacter pylori antibiotic susceptibility in the Nepalese strains is untracked. We determined the antibiotic susceptibility for H. pylori and analyzed the presence of genetic mutations associated with antibiotic resistance in Nepalese strains. RESULTS: This study included 146 consecutive patients who underwent gastroduodenal endoscopy in Kathmandu, Nepal. Among 42 isolated H. pylori, there was no resistance to amoxicillin and tetracycline. In contrast, similar with typical South Asian patterns; metronidazole resistance rate in Nepalese strains were extremely high (88.1 %, 37/42). Clarithromycin resistance rate in Nepalese strains were modestly high (21.4 %, 9/42). Most of metronidazole resistant strains had highly distributed rdxA and frxA mutations, but were relative coincidence without a synergistic effect to increase the minimum inhibitory concentration (MIC). Among strains with the high MIC, 63.6 % (7/11) were associated with frameshift mutation at position 18 of frxA with or without rdxA involvement. However, based on next generation sequencing data we found that one strain with the highest MIC value had a novel mutation in the form of amino acid substituted at Ala-212, Gln-382, Ile-485 of dppA and Leu-145, Thr-168, Glu-117, Val-121, Arg-221 in dapF aside from missense mutations in full-length rdxA. Mutations at Asn-87 and/or Asp-91 of the gyrA were predominantly in levofloxacin-resistant strains. The gyrB mutation had steady relationship with the gyrA 87-91 mutations. Although three (44.4 %) and two (22.2 %) of clarithromycin resistant strains had point mutation on A2143G and A2146G, we confirmed the involvement of rpl22 and infB in high MIC strains without an 23SrRNA mutation. CONCLUSIONS: The rates of resistance to clarithromycin, metronidazole and levofloxacin were high in Nepalese strains, indicating that these antibiotics-based triple therapies are not useful as first-line treatment in Nepal. Bismuth or non-bismuth-based quadruple regimens, furazolidone-based triple therapy or rifabutin-based triple therapy may become alternative strategy in Nepal.

An East-Asian-type cagA Helicobacter pylori Infected Patient with Clinical Manifestation of Gastric Ulcer.

We reported a male, 72 yo, Chinese ethnic with chief complaint black mushy defecation. Physical examination revealed pale on conjunctival palpebra which confirmed as anemia on complete blood count. Gastroduodenoscopy revealed a 3 mm ulcer at the antrum (Forrest stage III). H. pylori infection was positive based on five different test methods (urinary antibody tests, rapid urease test, culture, histology ad immunohistochemistry). Used polymerase chain reaction-based sequencing, we found the patient infected by CagA producing, East-Asian-type cagA and vacA s1m1-strain. Further analysis using 7 housekeeping genes confirmed that the strain categorized in to hspEAsia group. The patient was given continuous intravenous infusions of proton pump inhibitor and standard triple therapy regimens eradication of H. pylori.