Systemic Bile Acids Affect the Severity of Acute Pancreatitis in Mice Depending on Their Hydrophobicity and the Disease Pathogenesis.

Acute pancreatitis (AP) is a major, globally increasing gastrointestinal disease and a biliary origin is the most common cause. However, the effects of bile acids (BAs), given systemically, on the pancreas and on disease severity remains elusive. In this study, we have investigated the roles of different circulating BAs in animal models for AP to elucidate their impact on disease severity and the underlying pathomechanisms. BAs were incubated on isolated acini and AP was induced through repetitive injections of caerulein or L-arginine; pancreatic duct ligation (PDL); or combined biliopancreatic duct ligation (BPDL). Disease severity was assessed using biochemical and histological parameters. Serum cholecystokinin (CCK) concentrations were determined via enzyme immunoassay. The binding of the CCK1 receptor was measured using fluorescence-labeled CCK. In isolated acini, hydrophobic BAs mitigated the damaging effects of CCK. The same BAs further enhanced pancreatitis in L-arginine- and PDL-based pancreatitis, whereas they ameliorated pancreatic damage in the caerulein and BPDL models. Mechanistically, the binding affinity of the CCK1 receptor was significantly reduced by hydrophobic BAs. The hydrophobicity of BAs and the involvement of CCK seem to be relevant in the course of AP. Systemic BAs may affect the severity of AP by interfering with the CCK1 receptor.

Simultaneous nitrification-denitrification using baffled osmotic membrane bioreactor-microfiltration hybrid system at different oxic-anoxic conditions for wastewater treatment.

The efficacy of a baffled osmotic membrane bioreactor-microfiltration (OMBR-MF) hybrid system equipped with thin film forward osmosis membrane for wastewater treatment was evaluated at laboratory scale. The novel OMBR-MF hybrid system involved baffles, that separate oxic and anoxic zones in the aerobic reactor for simultaneous nitrification and denitrification (SND), and a bioreactor comprised of thin film composite-forward osmosis (TFC-FO) and polyether sulfone-microfiltration (PES-MF) membranes. The evaluation was conducted under four different oxic-anoxic cycle patterns. Changes in flux, salinity build-up, and microbial activity (e.g., extracellular polymeric substances (EPS) were assessed. Over the course of a 34 d test, the OMBR-MF hybrid system achieved high removal of total organic carbon (TOC) (86-92%), total nitrogen (TN) (63-76%), and PO4-P (57-63%). The oxic-anoxic cycle time of 0.5-1.5 h was identified to be the best operating condition. Incorporation of MF membrane effectively alleviated salinity build-up in the reactor, allowing stable system operation.

Helicobacter pylori cagA, vacA, and iceA genotypes and clinical outcomes: a cross-sectional study in central Vietnam.

Helicobacter pylori is the most common cause of gastroduodenal diseases. The concept that cagA-positive H. pylori is a risk factor for gastric cancer appears to be true only for H. pylori strains from Western countries. Other virulent genes may have a synergistic interaction with cagA during pathogenesis. This study aims to investigate H. pylori cagA, vacA, and iceA prevalence, genotypes, and their association to clinical outcomes in Vietnamese patients. The cagA status and vacA and iceA genotypes were determined using the PCR technique on DNA extracted from gastric biopsies of 141 patients with gastroduodenal diseases. After performing molecular analysis for cagA, vacA, and iceA genes, samples with mixed H. pylori strains, positivity, or negativity for both cagA and cagPAI-empty site, or unidentified genotypes were excluded. Finally, 107 samples were examined. The presence of the cagA, vacA, and iceA genes were detected in 77.6%, 100%, and 80.4% of cases, respectively. Notably, cagA( +) with EPIYA-ABD, vacA s1i1m1, vacA s1i1m2, iceA1, and iceA2 accounted for 73.8%, 44.9%, 33.6%, 48.6%, and 31.8% of cases, respectively. Four iceA2 subtypes (24-aa, 59-aa, 94-aa, and 129-aa variants) were found, with the 59-aa variant the most prevalent (70.6%). The cagA( +)/vacAs1i1m1/iceA1 and cagA( +)/vacAs1i1m2/iceA1 combinations were found in 26.2% and 25.1% of cases, respectively. A multivariable logistic regression analysis was performed, after adjusting for age and gender, with the gastritis group was used as a reference control. Statistically significant associations were found between the vacA s1i1m2 genotype, the iceA1 variant, and the cagA( +)/vacAs1i1m2/iceA1 combination and gastric cancer; the adjusted ORs were estimated as 18.02 (95% CI: 3.39-95.81), 4.09 (95% CI: 1.1-15.08), and 16.19 (95% CI: 3.42-76.66), respectively. Interestingly, for the first time, our study found that vacA s1i1m2, but not vacA s1i1m1, was a risk factor for gastric cancer. This study illustrates the genetic diversity of the H. pylori cagA, vacA, and iceA genes across geographical regions and contributes to understanding the importance of these genotypes for clinical outcomes.

Current status of Helicobacter pylori resistance to clarithromycin and levofloxacin in Vietnam: Results from molecular analysis of gastric biopsy specimens.

OBJECTIVES: The management of Helicobacter pylori in Vietnam is becoming progressively more difficult due to increasing antibiotic resistance, particularly to clarithromycin (CLR) and levofloxaxin (LVX). In Vietnam, the selection of an H. pylori eradication regimen is predominantly based on empirical evidence. However, molecular analysis aimed at identifying H. pylori antibiotic-resistant genotypes is a promising method in antibiotic susceptibility testing. In this study, we aimed to determine the rates of genotypic H. pylori resistance to CLR and LVX by using DNA strip technology in Vietnam. METHODS: We performed DNA-strip technology-based testing on 112 patients with H. pylori-positive gastroduodenal diseases to detect 23S rRNA and gyrA mutations. RESULTS: Helicobacter pylori genotypic resistance to CLR and LVX was evident in 81.3% and 53.6% of the patients, respectively, and dual resistance was observed in 48.2%. The 23S rRNA A2142G and A2143G mutations accounted for 1.8% and 79.5% of cases, respectively. The gyrA N87K, D91N, D91G, and D91Y mutations were present in 37.5%, 11.6%, 5.4%, and 5.4% of patients, respectively. All four gyrA mutations were observed in both the naïve and failure patients. We further found an association between the 23S rRNA A2143G mutation and a history of CLR use as well as between the gyrA N87K mutation and a history of LVX use. CONCLUSIONS: We found a very high prevalence of H. pylori resistance to CLR and LVX and dual resistance to these antibiotics in Vietnam. The application of molecular assays is feasible and may improve the management of H. pylori infection in Vietnam.

Non-cardia early gastric cancer in Central Vietnam: noticeable uncommon background mucosa and results of endoscopic submucosa dissection.

Background and study aims Gastric cancer (GC) is one of the leading causes of malignancy-related death in Vietnam, with increasing incidence of non-cardia early gastric cancer (N-EGC). Data on accurate diagnosis of EGC and treatment by endoscopic submucosal dissection (ESD) in Vietnam are very sparse. The aim of this study was to describe the characteristics of N-EGC and evaluate the effectiveness and the safety of ESD in Central Vietnam. Patients and methods We prospectively enrolled patients with N-EGC detected by magnified chromoendoscopy from December 2013 to August, 2018 in Central Vietnam. Selected cases of N-EGC received standardized ESD technique and have been following up carefully as in protocol. Results Among 606 GC patients, 46 had N-GEC and underwent ESD. The depth of invasion was pT1a in 33 (71.7 %), pT1b1 in 10 (21.7 %), and pT1b2 in three cases (6.6 %). Mild chronic atrophic gastritis, most being C2 (63 %), and gastritis-like EGC that did not appear malignant was the predominant type. ESD achieved a 97.8 % en bloc resection rate; the mean procedure time was 76 ± 22 minutes (range 24-155), and mean endoscopic tumor size was 23 ± 5 mm (range 13-52) and ESD sample size was 28 ± 7 mm (range 16.5-60). Complications consisted of two patients with bleeding and one with a minor perforation, all of which were successfully managed by endoscopy. The longest and the mean follow-up times were 84 and 64 months, respectively, with no recurrence. Conclusions A significant proportion patients with N-EGC have a background mucosa of mild chronic atrophic gastritis. Our results 7 years after starting ESD demonstrate early promising outcomes with the procedure.

Erratum: Non-cardia early gastric cancer in Central Vietnam: noticeable uncommon background mucosa and results of endoscopic submucosal dissection.

[This corrects the article DOI: 10.1055/a-1854-4587.].

Consensus statements and recommendations on the management of mild-to-moderate gastroesophageal reflux disease in the Southeast Asian region.

This paper reports the proceedings from the first consensus meeting on the management of mild-to-moderate gastroesophageal reflux disease (GERD) in the Southeast Asian (SEA) region. Seventeen statements were drawn up by a steering committee that focused on epidemiology, mechanism of action, diagnostic investigations, and treatment. Voting on the recommendations used the Delphi method with two rounds of voting among the 10 panel members. The consensus panel agreed that GERD is mostly a mild disease in the SEA region with predominantly non-erosive reflux disease (NERD). Complicated GERD and Barrett's esophagus are infrequently seen. The panel recommended endoscopy in patients with alarm or refractory symptoms but cautioned that the incidence of gastric cancer is higher in SEA. pH and impedance measurements were not recommended for routine assessment. The acid pocket is recognized as an important pathogenic factor in GERD. Lifestyle measures such as weight reduction, avoidance of smoking, reduction of alcohol intake, and elevation of the head of the bed were recommended but strict avoidance of specific foods or drinks was not. Alginates was recommended as the first-line treatment for patients with mild-to-moderate GERD while recognizing that proton-pump inhibitors (PPIs) remained the mainstay of treatment of GERD. The use of alginates was also recommended as adjunctive therapy when GERD symptoms were only partially responsive to PPIs.

Role of Bile Acids and Bile Salts in Acute Pancreatitis: From the Experimental to Clinical Studies.

ABSTRACT: Acute pancreatitis (AP) is one of the most common gastroenterological disorders leading to hospitalization. It has long been debated whether biliary AP, about 30% to 50% of all cases, is induced by bile acids (BAs) when they reach the pancreas via reflux or via the systemic blood circulation.Besides their classical function in digestion, BAs have become an attractive research target because of their recently discovered property as signaling molecules. The underlying mechanisms of BAs have been investigated in various studies. Bile acids are internalized into acinar cells through specific G-protein-coupled BA receptor 1 and various transporters. They can further act via different receptors: the farnesoid X, ryanodine, and inositol triphosphate receptor. Bile acids induce a sustained Ca2+ influx from the endoplasmic reticulum and release of Ca2+ from acidic stores into the cytosol of acinar cells. The overload of intracellular Ca2+ results in mitochondrial depolarization and subsequent acinar cell necrosis. In addition, BAs have a biphasic effect on pancreatic ductal cells. A more detailed characterization of the mechanisms through which BAs contribute to the disease pathogenesis and severity will greatly improve our understanding of the underlying pathophysiology and may allow for the development of therapeutic and preventive strategies for gallstone-inducedAP.

A case report of anorectal malignant melanoma in the transitional zone.

INTRODUCTION: Anorectal malignant melanoma is an uncommon and highly malignant disease with a greater incidence in females. Many patients were misdiagnosed as hemorrhoids, benign polyps, and rectal cancer. They were often diagnosed in an advanced stage. Wide local excision and abdominoperineal resection are the main treatments of rectal melanoma. PRESENTATION OF CASE: A case report is a 77-year-old man who has blood in the stool for 4 months without clinical examination. He admitted to the emergency room with sudden syndromes that related to bowel perforation. Rectal examination detected a large anorectal polyp. Computer tomography showed free air and fluid in the peritoneal cavity. He was received laparoscopic surgery and found the fishbone penetrated the sigmoid colon without polyp resection. The polyp was treated by local excision a few days later. The histology examination was a primary malignant melanoma. Due to the pigmented lesion that remained from the resected polyp's root, the abdominoperineal resection was performed as a radical treatment. DISCUSSION: Diagnosis of anorectal malignant melanoma is difficult because of atypical signs, that are confused with bleeding hemorrhoids especially an amelanotic melanoma. Treatment is controversial, including surgery, radiotherapy, chemotherapy, and target therapy. A present case is an option in radical surgery. CONCLUSION: Anorectal melanoma is a rare disease with poor results and prognosis. A lack of large-data leads to a missing evidence-based guideline in this disease. Early-staging diagnosis and surgical treatment help patients improve their overall survival.

High rates of clarithromycin and levofloxacin resistance of Helicobacter pylori in patients with chronic gastritis in the south east area of Vietnam.

BACKGROUND: The increasing rates of clarithromycin (CLR)- and levofloxacin (LVX)-resistant Helicobacter pylori are the main causes of the considerable decrease in the eradication rates of triple therapy and LVX-based regimens. The aims of this study were to determine the rates of CLR- and LVX-resistant H. pylori by the Epsilometer test and to assess the risk factors for this antibiotic resistance among patients with chronic gastritis in the south east area of Vietnam. METHODS: Gastric biopsy specimens were obtained from 153 patients with H. pylori-positive chronic gastritis for use in culture and in the Epsilometer test to determine CLR and LVX susceptibilities. RESULTS: The rates of H. pylori resistance to CLR and LVX were 72.6% and 40.5%, respectively. Dual-resistant H. pylori (to both CLR and LVX) accounted for 30.7% of patients. The rates of high-level resistance to CLR and LVX were 18.9% and 83.9%, respectively. Multivariate analysis showed that age older than 30 years (odds ratio [OR] = 3.80, 95% confidence interval [CI] 1.61-8.97) and history of H. pylori treatment (OR = 8.72, 95% CI 1.90-39.91) were independent risk factors for CLR resistance, whereas only age older than 35 years (OR = 2.42, 95% CI 1.23-4.76) was an independent risk factor for LVX resistance. CONCLUSIONS: These results revealed high rates of resistance of H. pylori to CLR and LVX in patients with chronic gastritis in the south east area of Vietnam. This suggests that CLR-based triple therapy should not be used for the eradication treatment of H. pylori, and LVX susceptibility testing of H. pylori strains should be performed before choosing alternative regimens.

Association of TP53 gene codon 72 polymorphism with Helicobacter pylori-positive non-cardia gastric cancer in Vietnam.

INTRODUCTION: This research aimed to determine the association of the combination of H. pylori infection and TP53 codon 72 polymorphism with non-cardia gastric cancer (GC) in Vietnam. METHODOLOGY: A total of 164 patients with non-cardia GC and 164 patients with peptic ulcer disease or functional dyspepsia in controls matched by sex and age were enrolled. H. pylori infection was diagnosed by rapid urease test and polymerase chain reaction (PCR). The cagA gene-positivity and vacA sm subtypes were determined by multiplex PCR. Genotypes of TP53 codon 72 polymorphism were determined by PCR-restriction fragment length polymorphism. RESULTS: The prevalence of H. pylori infection in GC and control group were 61.6% and 55.4%, respectively. The rates of cagA-positive strains in the two H. pylori-positive groups were 80.2% and 71.4%, respectively. There was no statistically significant difference in TP53 codon 72 genotype distribution between GC group (frequencies of Arg/Arg, Arg/Pro and Pro/Pro genotypes were 31.1%, 43.3% and 25.6%, respectively) and controls (29.3%, 52.4% and 18.3%, respectively), p = 0.172. The significant difference in genotype distribution was observed in recessive model (Pro/Pro vs Arg/Arg + Arg/Pro) when stratifying by H. pylori infection (OR = 2.02, 95% CI 1.03-3.96, p = 0.041) and by cagA-positivity (OR = 2.33, 95% CI 1.07-5.07, p = 0.032). CONCLUSIONS: This study suggests a synergistic interaction between H. pylori infection, especially cagA-positive H. pylori, and Pro/Pro genotype of TP53 codon 72 polymorphism might play a significant role in the pathogenesis of GC in the Vietnamese population.

Characterisation of point mutations in domain V of the 23S rRNA gene of clinical Helicobacter pylori strains and clarithromycin-resistant phenotype in central Vietnam.

OBJECTIVES: The prevalence of clarithromycin (CLR)-resistant Helicobacter pylori is increasing worldwide, including in Vietnam. The aims of this study were to determine point mutations in the 23S rRNA domain V of clinical H. pylori strains in central Vietnam, to estimate the prevalence of phenotypic CLR resistance and to assess the association between 23S rRNA domain V genotype and CLR-resistant phenotype. METHODS: Sequencing of the 23S rRNA domain V of H. pylori strains from gastric biopsy specimens was performed for 185 patients with H. pylori-positive chronic gastritis, of which 104 samples were subjected to susceptibility testing to determine CLR resistance. RESULTS: A total of 24 types of point mutation were detected. A2143G and A2142G mutations were observed in 40.5% and 4.3%, respectively. New point mutations were detected (C2041T, C2083T, C2191T, G2220A, G2225A, G2240A, C2273T, T2276C, G2287A, C2399T, A2445G and C2622T). 23S rRNA domain V genotypes were diversified, with combinations of two or more point mutations as well as single point mutations. The rate of phenotypic CLR resistance was 53.8%, increasing from 40.4% in 2012-2014 to 70.2% in 2015-2017 (P=0.0045). A2143G and A2142G accounted for 89.3% of phenotypically CLR-resistant H. pylori isolates. CONCLUSIONS: A diversity of point mutations in the 23S rRNA domain V was observed in clinical H. pylori isolates. The rate of phenotypically CLR-resistant H. pylori is significantly increasing in central Vietnam. Further research is necessary to clarify the role of the combination of 23S rRNA domain V mutations in the molecular mechanism of CLR resistance.

Efficient fouling control using outer-selective hollow fiber thin-film composite membranes for osmotic membrane bioreactor applications.

This paper investigates the efficiency of fouling mitigation methods using a novel outer selective hollow fiber thin-film composite forward osmosis (OSHF TFC FO) membrane for osmosis membrane bioreactor (OMBR) system treating municipal wastewater. Two home-made membrane modules having similar transport properties were used. Two operation regimes with three different fouling mitigation strategies were utilized to test the easiness of membrane for fouling cleaning. These two membrane modules demonstrated high performance with high initial water flux of 14.4 LMH and 14.1 LMH and slow increase rate of mixed liquor's salinity in the bioreactor using 30 g/L NaCl as draw solution. OMBR system showed high removals of total organic carbon and NH4 + -N (>98%). High fouling cleaning efficiency was achieved using OSHF TFC FO membrane with different fouling control methods. These results showed that this membrane is suitable for OMBR applications due to its high performance and its simplicity for fouling mitigation.

Helicobacter pylori 23S rRNA gene mutations associated with clarithromycin resistance in chronic gastritis in Vietnam.

INTRODUCTION: Data about the prevalence of the A2142C, A2142G, and A2143G mutations in 23S rRNA gene is still limited. The aim of this study was to determine the prevalence of these mutations in 23S rRNA gene of H. pylori vietnamese strains. METHODOLOGY: One hundred and sixty-nine patients with H. pylori-positive chronic gastritis were examined. H. pylori was detected by rapid urease test and Polymerase chain reaction (PCR). Total DNA was extracted from gastric biopsy specimens. A2142C, A2142G, and A2143G mutations were detected by DNA sequencing and PCR-restriction fragment length polymorphism (PCR-RFLP). RESULTS: A2143G mutation was detected in 36.1% of samples, A2142G mutation in 3.6%, while A2142C mutation was not found in any case. The mixture of wild-type and mutation strains was found in 50% of specimens with A2142G, in 23% of specimens with A2143G mutation. There was no association of 23S rRNA gene point mutations with gender or age. However, an association between the heterogeneity of mutation and age was evidenced, with mean age of the group of pure A2143G higher than the group of wild-type/A2143G mixture, and rate of the wild-type/A2143G mixture higher in patients under 40 years of age. CONCLUSION: A2143G mutation was prominent, while A2142C mutation was not found in the 23S rRNA gene. PCR-RFLP has revealed a reliable assay allowing a rapid and cost-effective detection of clarithromycin-resistant strains. This is useful in countries as Vietnam with high prevalence of clarithromycin-resistance before choosing optimal therapy for H. pylori eradication.

Genotyping of Helicobacter pylori shows high diversity of strains circulating in central Vietnam.

In Vietnam, the high prevalence of Helicobacter pylori infection represents a serious health problem. Virulence genes of H. pylori have been associated to increased risk of severe gastrointestinal diseases and the genetic background differs in geographical areas. We investigated cagA and vacA genotypes of H. pylori from dyspeptic patients from central Vietnam and the correlation with clinical outcomes; we also performed sequencing analysis of partial cagA gene. Overall, 84% of strains were cagA-positive, 75% were East-Asian type with a prevalence of vacAs1i1m1 and vacAs1i1m2 genotypes (66.7% and 33.3%, respectively) and 9% were Western type vacAs1i1m1 (n=4) and vacAs1i1m2 (n=4); vacAs1i2m2 (n=4) and vacAs2i2m2 (n=2) genotypes were associated to cagA-negative. Strains from gastric ulcer and cancer were of East-Asian type, while cagA-negative or Western strains were from gastritis and duodenal ulcer. H. pylori strains from gastric ulcer patients were predominantly vacAs1i1m1 compared to other vacA genotypes (p<0.05). East-Asian type strains vacAs1i1m1 or vacAs1i1m2 were found in gastric cancer patients and also in less severe disease. Phylogenetic tree analysis of CagA sequences showed the co-circulation of H. pylori of different geographical origins with Western sequences closer related to Cambodia, one of the entry of Western strains in Southeast-Asia through human migrations. Sequence analysis revealed in two Western type strains a chimeric CagA-3' region with identity with East-Asian CagA suggesting recombination event in the process of evolution among East-Asian and Western H. pylori strains. Moreover, polymorphism in CagA multimerization (CM) motif was observed including new East-Asian CM motifs. In conclusion, we have found in central Vietnam a geographically dependent diversity of cagA genotype, with higher rates of cagA-negative and Western-type strains compared with other nation's parts that can partly explain the lower risk of gastric cancer. The polymorphism of CM motifs may explain the variability of disease manifestations of vacAs1i1m1 and s1i1m2 East-Asian isolates.

Effects of lercanidipine versus amlodipine in hypertensive patients with cerebral ischemic stroke.

OBJECTIVE: The aim of this study was to compare the efficacy and safety of lercanidipine and amlodipine in the treatment of hypertensive patients with acute cerebral ischemic stroke. RESEARCH DESIGN AND METHODS: An open label, controlled, randomized, parallel-group study was conducted on 104 hypertensive patients (blood pressure [BP] >130/80 mmHg) diagnosed with ischemic stroke. Enrolled subjects were randomly assigned to a 4 week treatment with lercanidipine 20 mg/day or amlodipine 10 mg/day. The treatment was administered during the acute phase of the stroke, either immediately after the diagnosis or during an observation period of maximum 6 days. RESULTS: Both lercanidipine and amlodipine were able to significantly reduce mean clinical systolic BP (SBP)/diastolic BP (DBP), mean 24 h ambulatory BP and day-time and night-time BP. In particular, mean clinical SBP/DBP was reduced from 168.9 ± 21.6/96.2 ± 13.6 mmHg to 147.1 ± 22.0/87.1 ± 14.0 mmHg in the lercanidipine group (p < 0.001 for SBP and p < 0.01 for DBP) and from 167.1 ± 19.9/97.8 ± 14.5 mmHg to 143.3 ± 21.9/82.8 ± 14.1 mmHg in the amlodipine-treated group (p < 0.001 for both SBP and DBP). No statistical difference was observed between the two treatments in the reduction of clinical BP. The response and normalization rates registered in the two groups of patients were also similar, with no significant difference between the two drugs. In addition, both treatments reported comparable results in terms of early morning BP surge reduction and BP stabilization, measured through trough-peak ratio and smoothness index. However lercanidipine showed a better tolerability profile than amlodipine, with fewer adverse events and a lower percentage of patients suffering from side effects. CONCLUSIONS: Lercanidipine is as effective as amlodipine in the reduction and stabilization of BP in hypertensive patients after a stroke, and presents some advantages in terms of safety. Larger studies are necessary to further evaluate these preliminary findings.

High rate of levofloxacin resistance in a background of clarithromycin- and metronidazole-resistant Helicobacter pylori in Vietnam.

Antimicrobial resistance in Helicobacter pylori has increased worldwide and has become a major cause of treatment failure in many countries, including Vietnam. It is advisable to perform an antibiogram to provide optimal regimens for H. pylori eradication. This study evaluated the rate of antibiotic resistance to the four commonly used antibiotics against H. pylori at a tertiary care hospital in Central Vietnam and analysed point mutations in genes related to clarithromycin (CLA) and levofloxacin (LFX) resistance. A total of 92 H. pylori strains from gastric biopsy specimens were tested; 42.4% were resistant to CLA (primary, 34.2%; secondary, 73.7%), 41.3% to LFX (primary, 35.6%; secondary, 63.2%), 76.1% to metronidazole (MTZ) and 1.1% to amoxicillin. Multidrug resistance was observed in 56.5% (primary, 50.7%; secondary, 78.9%) of isolates (P<0.05). The rate of resistance to LFX was significantly higher in females than males (P<0.05). Most of the CLA- and LFX-resistant strains harboured resistance-associated mutations, with common positions at A2143G and T2182C in the 23S rRNA gene and at Asn-87 or Asp-91 in GyrA. Minimum inhibitory concentrations (MICs) increased in strains carrying quadruple mutations in their 23S rRNA gene and in strains with Asn-87 GyrA mutation (P<0.05). One high-level LFX-resistant strain (MIC=32mg/L) had new mutations with a combination of N87A, A88N and V65I. High resistance rates to CLA, MTZ and LFX discourage standard and LFX-based triple therapies as first-line treatment in Vietnam.

Antimicrobial resistance in Helicobacter pylori: current situation and management strategy in Vietnam.

Increasing antimicrobial resistance to key antibiotics in Helicobacter pylori has become a main cause of treatment failures in many countries, including Vietnam. For this reason it is advisable to perform antimicrobial sensitivity tests to provide more focused regimens for H. pylori eradication. However, this approach is generally unavailable for H. pylori in Vietnam and the selection of treatment regimens is mainly based on the trend of antibiotic use in the population, resistance development in the region, and history of H. pylori eradication of patients. The aim of this review is to examine the current situation of antimicrobial resistance in Vietnam and suggest management strategies for treatment selection.