Epidemiology of Helicobacter pylori infection

Flagellin glycosylation with pseudaminic acid in Campylobacter and Helicobacter: prospects for development of novel therapeutics

Many pathogenic bacteria require flagella-mediated motility to colonise and persist in their hosts. Helicobacter pylori and Campylobacter jejuni are flagellated epsilonproteobacteria associated with several human pathologies, including gastritis, acute diarrhea, gastric carcinoma and neurological disorders. In both species, glycosylation of flagellin with an unusual sugar pseudaminic acid (Pse) plays a crucial role in the biosynthesis of functional flagella, and thereby in bacterial motility and pathogenesis. Pse is found only in pathogenic bacteria. Its biosynthesis via six consecutive enzymatic steps has been extensively studied in H. pylori and C. jejuni. This review highlights the importance of flagella glycosylation and details structural insights into the enzymes in the Pse pathway obtained via a combination of biochemical, crystallographic, and mutagenesis studies of the enzyme-substrate and -inhibitor complexes. It is anticipated that understanding the underlying structural and molecular basis of the catalytic mechanisms of the Pse-synthesising enzymes will pave the way for the development of novel antimicrobials.

Fifth Chinese National Consensus Report on the management of Helicobacter pylori infection

BACKGROUND

Since the 'Fourth Chinese National Consensus Report on the management of H. pylori infection' was published in 2012, three important consensuses (Kyoto global consensus report on H. pylori gastritis, The Toronto Consensus for the Treatment of H. pylori Infection in Adults and Management of H. pylori infection-the Maastricht V/Florence Consensus Report) have been published regarding the management of H. pylori infection.

MATERIALS AND METHODS

A Delphi method was adopted to develop the consensus of relevant 'statements'. First, the established 'statements' were sent to experts via email. Second, after undergoing two rounds of consultation, the initial statements were discussed face to face and revised in the conference item by item on 16 December 2016. Finally, 21 core members of conferees participated in the final vote of statements. Voting for each statement was performed using an electronic system with levels of agreements shown on the screen in real time.

RESULTS

Consensus contents contained a total of 48 "statements" and related 6 parts, including indications for H. pylori eradication, diagnosis, treatment, H. pylori and gastric cancer, H. pylori infection in special populations, H. pylori and gastrointestinal microbiota.

CONCLUSIONS

Recommendations are provided on the basis of the best available evidence.

Can bacterial virulence factors predict antibiotic resistant Helicobacter pylori infection?

AIM

To evaluate the association between virulence factor status and antibiotic resistance in Helicobacter pylori (H. pylori)-infected patients in Ireland.

METHODS

DNA was extracted from antral and corpus biopsies obtained from 165 H. pylori-infected patients. Genotyping for clarithromycin and fluoroquinolone-mediating mutations was performed using the Genotype HelicoDR assay. cagA and vacA genotypes were investigated using PCR.

RESULTS

Primary, secondary and overall resistance rates for clarithromycin were 50.5% (n = 53/105), 78.3% (n = 47/60) and 60.6% (n = 100/165), respectively. Primary, secondary and overall resistance rates for fluoroquinolones were 15.2% (n = 16/105) and 28.3% (n = 17/60) and 20% (n = 33/165), respectively. Resistance to both antibiotics was 12.4% (n = 13/105) in treatment-naïve patients, 25% (n = 15/60) in those previously treated and 17% (n = 28/165) overall. A cagA-positive genotype was detected in 22.4% (n = 37/165) of patient samples. The dominant vacA genotype was S1/M2 at 44.8% (n = 74/165), followed by S2/M2 at 26.7% (n = 44/165), S1/M1 at 23.6% (n = 39/165) and S2/M1 at 4.8% (n = 8/165). Primary clarithromycin resistance was significantly lower in cagA-positive strains than in cagA-negative strains [32% (n = 8/25) vs 56.3% (n = 45/80) P = 0.03]. Similarly, in patients infected with more virulent H. pylori strains bearing the vacA s1 genotype, primary clarithromycin resistance was significantly lower than in those infected with less virulent strains bearing the vacA s2 genotype, [41% (n = 32/78) vs 77.8% (n = 21/27) P = 0.0001]. No statistically significant association was found between primary fluoroquinolone resistance and virulence factor status.

CONCLUSION

Genotypic H. pylori clarithromycin resistance is high and cagA-negative strains are dominant in our population. Less virulent (cagA-negative and vacA S2-containing) strains of H. pylori are associated with primary clarithromycin resistance.

Helicobacter Pylori Serology in Relation to Hepatitis C Virus Infection and IL28B Single Nucleotide Polymorphism

The aim of the study was to evaluate the serological rate of Helicobacter pylori (H. pylori) infection in patients with chronic hepatitis C virus (HCV) infection and determine any correlations with liver damage and IL28B single-nucleotide polymorphism (SNP). One hundred eighty-nine patients with chronic HCV infection were included in the study, and H. pylori status was defined based on anti-H. pylori-IgG or anti-CagA-IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Liver damage was assessed using histology or transient elastography. IL28B C/T polymorphism (rs12979860) was evaluated in circulating blood cells using a PCR-based restriction fragment length polymorphism assay. Overall H. pylori serology was positive in 38.1% of our HCV-infected subjects. Among those, the anti-CagA-IgG positivity rate was 43.1% and was within the range of previously described populations of the same region. Highest prevalence of H. pylori was found in patients between 31 and 40 years compared to other age subgroups. The seropositivity rate was higher in the non-cirrhotic group than the cirrhotic one (45.4% vs. 20.0%, p < 0.05). No difference was found in IL28B genotype between H. pylori-positive and -negative cohorts. However, we observed a trend for the lower anti-CagA-IgG expression level in relation to the IL28B T-allele. Our results do not support an association between HCV and H. pylori infection. Whether IL28B SNP has a functional role in modulation of serological response to H. pylori CagA needs further investigation.

Efficacy and Safety of Wei Bi Mei, a Chinese Herb Compound, as an Alternative to Bismuth for Eradication of Helicobacter pylori

Bismuth-containing quadruple therapy has been recommended as the first line of treatment in areas of high clarithromycin or metronidazole resistance. However, safety concerns of bismuth agents have long been raised. We first assessed the efficacy and safety of Wei Bi Mei granules, which are bismuth compounds consisting of three synthetic drugs and five medicinal herbs, compared to bismuth aluminate and colloidal bismuth subcitrate (CBS) in H. pylori-infected mouse model. We then used atomic fluorescence spectroscopy and autometallography to measure the accumulation of three bismuth agents in the brain, heart, liver, and kidneys in adult Sprague-Dawley rats. We also evaluated the safety of bismuth agents by conducting clinical biochemistry tests in blood samples of experimental animals. Wei Bi Mei granules exhibited the highest efficacy of anti-H. pylori activity and yielded the lowest bismuth accumulation when compared to CBS and bismuth aluminate. Our findings show that Wei Bi Mei granules are a safe Chinese medicinal herb with potent anti-H. pylori activity and can be considered as an alternative to current bismuth compounds. Thus, Wei Bi Mei granules merit further evaluation, particularly with regard to efficacy and safety when they are combined with other H. pylori eradication medications in the clinical setting.

Helicobacter Pylori infection of the gallbladder and the risk of chronic cholecystitis and cholelithiasis: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is coexisted with various diseases, including chronic gastritis, ulcer, and gastric cancer. Besides, chronic cholecystitis and cholelithiasis are extremely widespread over the world, which are considered as high health-care cost burdens of digestive diseases. Epidemiologic evidence on Helicobacter pylori infection in gallbladder increasing the risk of biliary diseases has been contradictory.

AIM

Conduct a meta-analysis of overall studies and investigate an association between Helicobacter pylori infection of the gallbladder with chronic cholecystitis/cholelithiasis.

METHODS

We used PubMed, EMBASE, and Cochrane library databases to identify all published studies before August 2017. Pooled odds ratios (OR) and corresponding 95% confidence intervals (CIs) were obtained using the random effects model. Heterogeneity, sensitivity, and stratified analyses were also performed.

RESULTS

Eighteen studies involving 1544 participants and 1061 biliary cases with chronic cholecystitis/cholelithiasis were included. Helicobacter pylori infection of the gallbladder was significantly associated with an increased risk of chronic cholecystitis and cholecystitis (OR = 3.022; 95% CI, 1.897-4.815; I²  = 20.1%). In addition, country-based subgroup analysis also showed a positive association between Helicobacter pylori positivity and chronic cholecystitis/cholelithiasis risk. The ORs (95% CIs) for Asian and non-Asian region studies were 3.75 (1.83-7.71) and 2.25 (1.29-3.89), respectively.

CONCLUSION

This meta-analysis suggests that infection of the gallbladder with Helicobacter pylori is closely related to an increased risk of chronic cholecystitis and cholelithiasis.

Helicobacter pylori eradication may influence timing of endoscopic surveillance for gastric cancer in patients with gastric precancerous lesions: A retrospective study

Chronic atrophic gastritis and intestinal metaplasia related to Helicobacter pylori infection, are major risk factors for gastric adenocarcinoma. Eradication of H pylori and endoscopy surveillance of precancerous lesions may reduce the risk and/or lead to early detection of gastric cancer improving survival. In this study, the progression of precancerous lesions after H pylori treatment was evaluated.Patients with incomplete or complete intestinal metaplasia and/or gastric atrophy at the index endoscopy, were examined for the extension/histological worsening of precancerous lesions at the endoscopy surveillance for gastric cancer. Progression of lesions was evaluated according to H pylori status, age, and sex. Cox proportional hazard regression model and Kaplan-Meier curves were used to evaluate the strength of predictors for lesions progression.Among 105 patients (61 women) H pylori negative patients showed a milder worsening of gastric lesions between index and surveillance endoscopy compared with patients positive for the infection (log-rank test: P < .0001, P = .012, and P = .032 for antrum, angulus, and corpus, respectively). The Cox regression model showed persistence of H pylori infection (hazard ratio = 4.436; P < .0001) as the only relevant factor for lesion progression, whereas age >65 years and sex were not significant predictors.According to literature our results demonstrate that H pylori eradication is the major factor able to delay gastric precancerous lesions progression. Time interval for endoscopic surveillance in patients negative for H pylori infection and with gastric precancerous lesions may be extended.

Gastric xanthelasma and metabolic disorders: A large retrospective study among Chinese population

AIM

To gain knowledge of xanthelasma, a large population-based study was conducted.

METHODS

Patients who underwent upper gastrointestinal endoscopy at the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China during Jan 2009 to Nov 2016 were included. General characteristics as well as clinical data were collected, including blood routine, serum biochemical analysis, endoscopic findinds, histological evaluation and comorbiditie. Statistical analyses was performed using SPSS 20.0 software for Windows (IBM Inc., Chicago, IL, United States) using Student’s t-test, Mann-Whitney U test, χ² test, univariable and multivariable logistic analysis. 2-tailed P value less than 0.05 was considered to be statistically significant.

RESULTS

A total of 176006 endoscopies were retrieved and we included 1370 xanthelasma participants (703 men, 667 women) in this study. Prevalence of xanthelasma was 0.78% with average age of 56.6 ± 11.2 years. Chief complaint of xanthelasma consisted abdominal pain (24.2%), up-abdominal discomfort (14.1%), abdominal distention (10.1%), dyspepsia (9.1%), et al. Most xanthelasma occurred as single lesion in gastric antrum. Xanthelasma patients witnessed higher Helicobacter pylori (H. pylori) infection rate, more of other gastric lesions including atrophy, intestinal metaplasia and dysplasia (P < 0.01). In xanthelasma patients, serum carcinoembryonic antigen, triglyceride, fasting glucose, neutrophil, neutrophil-to-lymphocyte ratio were significantly higher, and high density lipoprotein-cholesterol, lymphocyte was lower (P < 0.05). Xanthelasma accompanied with more fatty liver disease and hepatic cyst, but fewer gallbladder polyp (P < 0.05). In logistic regression, it revealed that fasting plasma glucose (OR = 3.347, 1.170-9.575, P < 0.05), neutrophil (OR = 1.617, 1.003-2.605, P < 0.05), and carcinoembryonic antigen (OR = 2.011, 1.236-3.271, P < 0.01) were all independent risk factors in xanthelasma.

CONCLUSION

Current study described a large xanthelasma cohort in Chinese population, revealed its relationship with H. pylori infection, carcinogenesis, metabolic dysfunction and inflammation as well.

Systematic review with meta-analysis: the global recurrence rate of Helicobacter pylori

BACKGROUND

Up-to-date information regarding the recurrence rate of Helicobacter pylori (H. pylori) after eradication therapy is not available.

AIM

To evaluate the global recurrence rate following H. pylori eradication therapy and confirm its association with socioeconomic and sanitary conditions.

METHODS

A systematic search of PubMed, EMBASE and the Cochrane library was performed to identify potentially relevant publications using the following keywords: "Helicobacter pylori" or "H. pylori" or "Hp" and "recurrence" or "recrudescence" or "reinfection" or "recurrent" or "recurred" or "re-infect*" or "relapse*."

RESULTS

A total of 132 studies (53 934 patient-years) were analysed. Each study was weighted according to the duration of patient-years. The global annual recurrence, reinfection and recrudescence rate of H. pylori were 4.3% (95% CI, 4-5), 3.1% (95% CI, 2-5) and 2.2% (95% CI, 1-3), respectively. The H. pylori recurrence rate was inversely related to the human development index (HDI) (ie, 3.1% [95% CI, 2-4], 6.2% [95% CI, 4-8] and 10.9% [95% CI, 6-18] in countries with a very high, high and medium or low HDI) (P <.01) and directly related to H. pylori prevalence (10.9% [95% CI, 7-16], 3.7% [95% CI, 3-5], 3.4% [95% CI, 2-5] and 1.6% [95% CI, 0.5-3] in countries with a very high, high, medium or low local H. pylori prevalence) (P <.01). Global recurrence rates remained relatively stable between 1990s, 2000s and 2010s but varied across different regions (P <.05).

CONCLUSIONS

H. pylori recurrence remains a problem closely associated with socioeconomic and sanitary conditions. Methods to reduce recurrence in developing countries are needed.

Limited effectiveness with a 10-day bismuth-containing quadruple therapy (Pylera® ) in third-line recue treatment for Helicobacter pylori infection. A real-life multicenter study

BACKGROUND

Helicobacter pylori antibiotic resistance is an increasing problem worldwide. Pylera^® may be an option as salvage therapy.

AIM

To assess the effectiveness, safety, and tolerance of Pylera^® as a third-line in clinical practice.

MATERIALS AND METHODS

This was a multicenter, observational, prospective database study in four Spanish hospitals. Consecutive H. pylori-infected individuals treated with Pylera^® and a proton-pump inhibitor (PPI) were invited to participate if they had failed to respond to PPI-clarithromycin-amoxicillin as first-line and to levofloxacin-amoxicillin-PPI as second-line therapy. Eradication was tested 4-8 weeks after Pylera^® using a C¹³ -urea breath test. Treatment-related adverse effects (TRAEs) were assessed through a questionnaire and by reviewing databases. A questionnaire on patient satisfaction was completed in the last visit.

RESULTS

Of 103 subjects fulfilling the selection criteria, 101 were included in the intention-to-treat (ITT) analysis and 97 in the per-protocol (PP) analysis. A 10 day course was prescribed in all patients. Esomeprazole 40 mg b.i.d. was the most used PPI regimen (ITT=94.1%). Ninety-seven individuals (ITT=96.04%) completed more than 90% of the treatment. Overall eradication rates were ITT=80.2% (95% confidence interval [CI]: 72.3%-88.1%) and PP=84.4% (95% CI: 76.8%-91.8%). One or more TRAEs were experienced by 67.3% (95% CI: 57.7%-75.7%), all mild or moderate. TRAEs and the number of pills were the main complaints.

CONCLUSION

In an area of high antibiotic resistance to H. pylori, 10-day Pylera^® plus double-dose PPI emerged as an alternative as third-line therapy, although not achieving optimal eradication rates. TRAEs were common but were neither severe nor did they condition compliance.

Detection of viable Helicobacter pylori inside free-living amoebae in wastewater and drinking water samples from Eastern Spain

Helicobacter pylori is one of the most concerning emerging waterborne pathogens. It has been suggested that it could survive in water inside free-living amoebae (FLA), but nobody has studied this relationship in the environment yet. Thus, we aimed to detect viable H. pylori cells from inside FLA in water samples. Sixty-nine wastewater and 31 drinking water samples were collected. FLA were purified and identified by PCR and sequencing. For exclusively detecting H. pylori inside FLA, samples were exposed to sodium hypochlorite and assayed by specific PMA-qPCR, DVC-FISH and culture. FLA were detected in 38.7% of drinking water and 79.7% of wastewater samples, even after disinfection. In wastewater, Acanthamoeba spp. and members of the family Vahlkampfiidae were identified. In drinking water, Acanthamoeba spp. and Echinamoeba and/or Vermamoeba were present. In 39 (58.2%) FLA-positive samples, H. pylori was detected by PMA-qPCR. After DVC-FISH, 21 (31.3%) samples harboured viable H. pylori internalized cells. H. pylori was cultured from 10 wastewater samples. To our knowledge, this is the first report that demonstrates that H. pylori can survive inside FLA in drinking water and wastewater, strongly supporting the hypothesis that FLA could play an important role in the transmission of H. pylori to humans.

Prevalence and characteristics of Epstein-Barr virus-associated gastric carcinomas in Portugal

Background

Gastric cancer (GC) is one of the most common malignant tumors of the digestive tract and is the third leading cause of cancer death worldwide. Epstein–Barr virus (EBV) has been associated with approximately 10% of the total cases of gastric carcinomas. No previous study has analyzed the prevalence of EBV infection in gastric cancer of the Portuguese population.

Methods

In the present study, we have analyzed 82 gastric carcinoma cases and 33 healthy individuals (control group) from Coimbra region for the presence of EBV by polymerase chain reaction (PCR) and by in situ hybridization (ISH) for EBV-encoded small RNAs (EBERs). The status of H. pylori infection was assessed by serology and by PCR.

Results

EBV was detected by PCR in 90.2% of stomach cancer cases, whereas EBERs were detected in 11%. In our series, EBV-associated gastric carcinoma (EBVaGC) were significantly associated with gender and the majority of them presented lymph node metastasis. These cases were generally graded in more advanced pTNM stages and, non-surprisingly, showed worse survival. H. pylori infection was detected in 62.2% of the gastric cancers and 64.7% of these patients were CagA+. On the other hand, the H. pylori prevalence was higher in the EBV-negative gastric carcinomas (64.4%) than in those carcinoma cases with EBV+ (44.4%).

Conclusions

The present study shows that prevalence of EBVaGC among Portuguese population is in accordance with the worldwide prevalence. EBV infection seems to be associated to poorer prognostic and no relation to H. pylori infection has been found. Conversely, the presence of H. pylori seems to have a favourable impact on patient’s survival. Our results emphasize that geographic variation can contribute with new epidemiological data on the association of EBV with gastric cancer.

Linked colour imaging benefits the endoscopic diagnosis of distal gastric diseases

Gastric diseases are common in China, and gastroduodenoscopy could provide accurate diagnoses. Our previous study verified that linked colour imaging (LCI) can improve endoscopic diagnostic accuracy. This study aimed for the first time to establish an LCI-based endoscopic model called colour-microstructure-vessel (CMV) criteria and validated its clinical feasibility for detecting distal gastric diseases manifested as red mucosal lesions under endoscopy in a cohort of 62 patients. Colour features were extracted from the endoscopic images and categorized into 3 types. Colour type 1 was a typical red; Colour type 2 was red ringed with purple and Colour type 3 was red with yellow in the centre and purple around the periphery, allowing for predicting chronic nonatrophic gastritis, chronic atrophic gastritis and gastric cancer. The sensitivity, specificity and Youden index of Colour type 3 with abnormal M or V for gastric cancer were 100.0%, 98.2% and 98.2%. The kappa values for intra-observer and inter-observer agreement for predicting the pathology were 0.834 and 0.791 for experienced endoscopists and 0.788 and 0.732 for endoscopy learners, and these values were comparable regardless of the experience of the endoscopists (P > 0.05). These findings support that the CMV criteria are a promising model for accurate endoscopic diagnosis.

Helicobacter, Hygiene, Atopy, and Asthma

The hygiene hypothesis links environmental and microbial exposures in early life to the prevalence of atopy, allergy, and asthma. Helicobacter pylori infection is typically acquired in childhood and acquisition of the infection is associated with poor household hygiene. Some population surveys have shown an inverse association between H. pylori infection and atopy, allergy, and asthma leading to the suggestion that H. pylori infection may be protective against disease; others consider it simply a biomarker for poor household hygiene. We review the relevant surveys, cohort studies, meta-analyses, and studies testing the protective hypothesis. Overall, the results of surveys and cohort studies are inconsistent, whereas meta-analyses show a significant but weak inverse correlation. In contrast, studies directly testing the protection hypothesis in relation to asthma in populations with poor hygiene and low H. pylori prevalence failed to confirm a protective effect. H. pylori is a major cause of human disease including chronic gastritis, peptic ulcer, and gastric malignancies. H. pylori infections most likely serve as a biomarker for poor hygienic conditions in childhood. We conclude that while synergistic interactions between environmental factors in childhood are important determinants of the pathogenesis of atopy, allergy, and asthma; H. pylori is inversely related to good hygiene and thus it's presence serves as a biomarker rather than for a specific prevention role for H. pylori or H. pylori antigens.

幽门螺杆菌根除治疗在胃癌预防中的现状及前景

幽门螺杆菌(Helicobacter pylori, H. pylori)与胃癌(gastric cancer, GC)发生发展密切相关, 根除H. pylori可降低GC发生率. 经济学分析表明, 在高危人群中根除治疗H. pylori作为预防GC的策略是成本效益较好的. 即使在GC低风险人群中, H. pylori筛查和治疗也能使上消化道其他非恶性疾病获益. 然而, 广泛开展H. pylori根除治疗可能带来其他问题, 包括抗生素耐药增加和与H. pylori负相关疾病(如胃食管反流病、Barrett食管、哮喘和肥胖等)的患病率升高. 本文将结合近年最新研究, 就上述问题展开论述, 进一步提出H. pylori根除治疗预防GC所面临的挑战以及将来可能的进展方向.

Primary Antibiotic Resistance of Helicobacter pylori in China

BACKGROUND AND AIMS

Antibiotic resistance is the most important factor leading to the failure of eradication regimens; thus, it is important to obtain regional antibiotic resistance information. This review focuses on the prevalence of Helicobacter pylori primary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone in China.

METHODS

We searched the PubMed, EMBASE, the China National Knowledge Infrastructure, and Chinese Biomedical databases from the earliest date of each database to October 2016. The search terms included the following: H. pylori, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone) resistance with or without China or different regions of China. The data analysis was performed using MedCalc 15.2.2. Each article was weighted according to the number of isolated H. pylori strains. A pooled proportion analysis was performed.

RESULTS

Twenty-three studies (14 studies in English and 9 in Chinese) were included in this review. A total of 6274, 6418, 3921, 5468, 2802, and 275 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone, respectively. Overall, the primary resistance rates of clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone were 28.9, 63.8, 28.0, 3.1, 3.9, and 1.7%, respectively.

CONCLUSIONS

In China, the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, and levofloxacin was high and increased over time, whereas the resistance rates to amoxicillin, tetracycline, and furazolidone were low and stable over time.

Gastrointestinal Organoids: Understanding the Molecular Basis of the Host-Microbe Interface

In recent years, increasing attention has been devoted to the concept that microorganisms play an integral role in human physiology and pathophysiology. Despite this, the molecular basis of host-pathogen and host-symbiont interactions in the human intestine remains poorly understood owing to the limited availability of human tissue, and the biological complexity of host-microbe interactions. Over the past decade, technological advances have enabled long-term culture of organotypic intestinal tissue derived from human subjects and from human pluripotent stem cells, and these in vitro culture systems already have shown the potential to inform our understanding significantly of host-microbe interactions. Gastrointestinal organoids represent a substantial advance in structural and functional complexity over traditional in vitro cell culture models of the human gastrointestinal epithelium while retaining much of the genetic and molecular tractability that makes in vitro experimentation so appealing. The opportunity to model epithelial barrier dynamics, cellular differentiation, and proliferation more accurately in specific intestinal segments and in tissue containing a proportional representation of the diverse epithelial subtypes found in the native gut greatly enhances the translational potential of organotypic gastrointestinal culture systems. By using these tools, researchers have uncovered novel aspects of host-pathogen and host-symbiont interactions with the intestinal epithelium. Application of these tools promises to reveal new insights into the pathogenesis of infectious disease, inflammation, cancer, and the role of microorganisms in intestinal development. This review summarizes research on the use of gastrointestinal organoids as a model of the host-microbe interface.

[Molecular genetic predictors of resistance to anti-Helicobacter pylori therapy]

In current clinical practice, there is no optimal empirical therapy for Helicobacter pylori (H. pylori) infection and there is a progressive decrease in the efficiency of classical eradication therapy (ET) regimens. The variability in the efficiency of ET in a specific patient is largely due to the heterogeneous molecular genetic mechanisms underlying the resistance of the microorganism to the components of the treatment regimens. The basis of the mechanisms for antibiotic resistance in H. pylori is mainly the point mutations in some genes, which determine alterations in the mechanisms of action of drugs, such as clarithromycin (domain V of 23S rRNA), metronidazole (rdxA, frxA), amoxicillin (pbp1A), tetracycline (16S rRNA), and levofloxacin (gyrA). The predictors of resistance to ET are also the CagA-negative status of the microorganism and the presence of the vacA s2 allele. There are a number of host genetic determinants (the CYP2C19 genotype (*1/*1, *1/*17, *17/*17) and the MDR1 3435 T/T genotype (in an Asian population)) that reduce the efficiency of ET, by altering the pharmacokinetics of proton pump inhibitors. In addition, the IL-1β-511 C/C polymorphism that affects gastric acid secretion is a predictor of the inefficiency of ET.