Helicobacter in the developing world

Molecular, pathological and immunohistochemical investigation of Helicobacteraceae in the abomasum of dairy cattle and sheep in Northern Italy

Although several Helicobacter species have been associated with gastric disease in humans and animals, their role in domestic ruminants is still unclear. This study aimed to investigate the prevalence of H. pylori, "Candidatus H. bovis" and other Helicobacteraceae in the abomasum of dairy cattle and sheep reared in Northern Italy, to shed light on their role as potential reservoir of H. pylori for humans and to evaluate the involvement of Helicobacter spp. in the gastric pathology of these animal species. Abomasa from 25 dairy cows and 24 sheep were collected at slaughter. Following macroscopic examination, samples of fundic and pyloric mucosa were analysed by a screening PCR for Helicobacteraceae, followed by specific PCRs (H. pylori, "Candidatus H. bovis", and Wolinella spp.), histological examination, and immunohistochemistry for Helicobacter spp. Overall, 96 % of the bovine and 42 % of the ovine abomasa tested positive for Helicobacteraceae. No samples tested positive for H. pylori, while 68 % of bovine samples tested positive for "Candidatus H. bovis", mostly in the pyloric mucosa. Immunohistochemistry showed colonisation by Helicobacter spp. only in the pyloric glands of 11 bovine abomasa (44 %), while in ovine abomasa colonisation was not detected. Our results confirmed that "Candidatus H. bovis" is the most common Helicobacteraceae in the bovine abomasum and specifically colonises bovine pyloric glands. No association was found between Helicobacter spp. infection status and abomasal inflammation, suggesting a high degree of adaptation to the bovine host. The role of cattle and sheep as potential source of H. pylori for humans appears to be negligible.

The efficacy of removal of animal milk from the diet in functional dyspepsia: A cross-sectional study

BACKGROUND AND STUDY AIMS

We aimed to investigate the effect of removing milk and dairy products from diets on functional dyspepsia (FD) symptoms, as the aetiology remains unclear and new management approaches are needed.

PATIENTS AND METHODS

This cross-sectional cohort study included 120 patients, with a mean age of 42.5 ± 12.3, of whom 77 (64.2 %) were female, with FD diagnosed by the Rome IV criteria. Patients were divided equally into two groups: those who eliminated milk and dairy products from their diet under the advice of a dietician without medical treatment and those who did not. The severity of symptoms was assessed using the gastrointestinal symptom rating scale (GSRS) at the beginning and end of a one-month period.

RESULTS

The restricted and unrestricted diet groups showed no significant differences in age, body mass index, symptom frequency and duration, weight changes, FD subtype, and gastroscopy results (p > 0.05). The diet group had more female patients (p = 0.01) and higher GSRS scores at the beginning (p = 0.01) but similar scores at the end of the study (p = 0.99). After one month, both groups had improved GSRS scores (p = 0.01), but the diet group had a more significant decrease in total symptom scores (p = 0.01) and in 7 of the 15 subsets (p < 0.05).

CONCLUSION

Of the 120 FD patients who followed up for one month, 60 who removed milk products had a more significant reduction in GSRS symptom score and 7 of the 15 symptom subset scores than 60 patients receiving an unrestricted diet.

Characteristic endoscopic findings in Helicobacter pylori diagnosis in clinical practice

INTRODUCTION

Helicobacter pylori is a major risk factor for gastric cancer. In addition to eradication therapy, early-phase detection of gastric cancer through screening programs using high-vision endoscopy is also widely known to reduce mortality. Although European and US guidelines recommend evaluation of atrophy and intestinal metaplasia by high-vision endoscopy and pathological findings, the guideline used in Japan - the Kyoto classification of gastritis - is based on endoscopic evaluation, and recommends the grading of risk factors. This system requires classification into three endoscopic groups: H. pylori-negative, previous H. pylori infection (inactive gastritis), and current H. pylori infection (active gastritis). Major endoscopic findings in active gastritis are diffuse redness, enlarged folds, nodularity, mucosal swelling, and sticky mucus, while those in H pylori-related gastritis - irrespective of active or inactive status - are atrophy, intestinal metaplasia, and xanthoma.

AREAS COVERED

This review describes the endoscopic characteristics of current H. pylori infection, and how characteristic endoscopic findings should be evaluated.

EXPERT OPINION

Although the correct evaluation of endoscopic findings related to H. pylori remains necessary, if findings of possible infection are observed, it is important to diagnose infection by detection methods with high sensitivity and specificity, including the stool antigen test and urea breath test.

Characteristics of Helicobacter pylori Eradication Therapy in Patients 80 Years or Older Living in a Metropolitan Area: A Multicenter Retrospective Study

BACKGROUND

The situation of Helicobacter pylori eradication therapy has been changing over time, owing to increases in antimicrobial-resistant strains, lifestyle improvements, and changes in indications for eradication. In Japan, eradication therapy is now available to all H. pylori-positive patients under the medical insurance system, and the potassium-competitive acid blocker vonoprazan has been used for eradication from 2015. Recently, with the aging of society, opportunities to provide eradication to elderly patients are increasing, but the current status and effectiveness of eradication in elderly patients remains unclear. Therefore, we aimed to investigate the trends of H. pylori eradication in a metropolitan area to determine the factors associated with successful H. pylori eradication in elderly patients older than 80 years.

METHODS

Trends in the eradication rates of patients who received first- or second-line eradication at 20 hospitals in the Tokyo metropolitan area from 2013 to 2023 were investigated.

RESULTS

The eradication rates in the per-protocol analysis were 82.3% (95% confidence interval [CI]: 81.2%-83.2%) for the first-line treatment (n = 6481), and 87.9% (86.9%-88.9%) for the second-line treatment (n = 4899). Multivariate analysis showed that independent factors for successful eradication in the first-line treatment were an age of older than 80 years (OR: 0.606; 95% CI: 0.448-0.822), peptic ulcers (vs. atrophic gastritis: 3.817; 3.286-4.433), and vonoprazan (vs. proton pump inhibiters (PPIs), 3.817; 3.286-4.433), and an age of older than 80 years (0.503; 0.362-0.699) and vonoprazan (1.386; 1.153-1.667) in the second-line treatment.

CONCLUSION

After 2015, the eradication rate of both first- and second-line therapies were maintained at a higher level than before 2015, owing to the use of vonoprazan. As the H. pylori eradication rate in patients older than 80 years was low, an effective strategy for these patients needs to be developed in the future.

Eradication Therapy for Helicobacter pylori Infection in Patients Receiving Hemodialysis: Review

Patients receiving hemodialysis (HD) often develop gastrointestinal diseases. Recently, although in general population, clinical guidelines for Helicobacter pylori have strongly recommended its eradication in patients to prevent gastric cancer, optimal eradication regimen and optimal dosage of drugs for patients receiving HD have not been established, due to possible incidence of adverse events. Some antimicrobial agents used in eradication therapy, particularly amoxicillin, can exacerbate renal dysfunction. Given the delayed pharmacokinetics of drugs in patients receiving HD compared with those in healthy individuals, drug regimen and dosage should be considered to minimize adverse effects. Although previous studies have investigated the benefits of eradication therapy for patients receiving HD, because most studies were small in terms of the number of enrolled patients, it is hard to show evidence. The numbers of eradication in HD patients have recently increased, and it is important to provide an optimal regimen. The consideration of eradication in patients undergoing HD with a reduction in the drug dose by 1/2-1/3 may prevent adverse events. Additionally, another important consideration is whether adverse events can be prevented while maintaining a similar eradication rate with reduced drug dosages. Recent meta-analysis findings indicate comparable eradication rates in patients receiving HD and healthy individuals, both with the same dosage regimen and at a reduced dosage regimen, with no significant differences (relative risk [RR] for successful eradication: 0.85 [95% confidence interval (CI): 0.48-1.50]). Unlike with the same dosage regimen (RR for adverse events: 3.15 [95% CI: 1.93-5.13]), the adverse events in the dosage reduction regimen were similar to those in healthy individuals (RR: 1.26 [95% CI: 0.23-6.99]). From a pharmacological perspective, the eradication regimen in patients receiving HD should consider the dosage (1/2-1/3 dosage), dosing number (bid), dosing timing of drugs (after HD), and susceptibility to antimicrobial agents.

CagA-positive Helicobacter pylori may promote and aggravate scrub typhus

Helicobacter pylori (H. pylori) infection may alter the host's resistance to tsutsugamushi disease pathogens through the Th1 immune response, leading to potential synergistic pathogenic effects. A total of 117 scrub typhus cases at Beihai People's Hospital and affiliated hospitals of Youjiang University for Nationalities and Medical Sciences were studied from January to December 2022, alongside 130 healthy individuals forming the control group. All participants underwent serum H. pylori antibody testing. The prevalence of H. pylori infection was significantly higher among scrub typhus patients (89.7%) compared to healthy individuals (54.6%) (p < 0.05). Moreover, type I H. pylori infection was notably more prevalent in scrub typhus cases (67.5%) compared to healthy individuals (30%) (p < 0.05). Multifactorial analysis demonstrated type I H. pylori infection as an independent risk factor for scrub typhus (adjusted odds ratio: 2.407, 95% confidence interval: 1.249-4.64, p = 0.009). Among scrub typhus patients with multiple organ damage, the prevalence of type I H. pylori infection was significantly higher (50.6%) than type II H. pylori infection (15.4%) (χ2 = 4.735, p = 0.030). These results highlight a higher incidence of H. pylori infection in scrub typhus patients compared to the healthy population. Additionally, type I H. pylori strain emerged as an independent risk factor for scrub typhus development. Moreover, individuals infected with type I H. pylori are more susceptible to multiple organ damage. These findings suggest a potential role of H. pylori carrying the CagA gene in promoting and exacerbating scrub typhus.

The Anti-Oxidant Curcumin Solubilized as Oil-in-Water Nanoemulsions or Chitosan Nanocapsules Effectively Reduces Helicobacter pylori Growth, Bacterial Biofilm Formation, Gastric Cell Adhesion and Internalization

The bacterium Helicobacter pylori (H. pylori) represents a major risk factor associated with the development of gastric cancer. The anti-oxidant curcumin has been ascribed many benefits to human health, including bactericidal effects. However, these effects are poorly reproducible because the molecule is extremely unstable and water insoluble. Here we solubilized curcumin as either nanoemulsions or chitosan nanocapsules and tested the effects on H. pylori. The nanoemulsions were on average 200 nm in diameter with a PdI ≤ 0.16 and a negative zeta potential (-54 mV), while the nanocapsules were 305 nm in diameter with a PdI ≤ 0.29 and a positive zeta potential (+68 mV). Nanocapsules were safer than nanoemulsions when testing effects on the viability of GES-1 gastric cells. Also, nanocapsules were more efficient than nanoemulsions at inhibiting H. pylori growth (minimal inhibitory concentration: 50 and 75 μM, respectively), whereby chitosan contributed to this activity. Importantly, both formulations effectively diminished H. pylori's adherence to and internalization by GES-1 cells, as well as biofilm formation. In summary, the demonstrated activity of the curcumin nanoformulations described here against H. pylori posit them as having great potential to treat or complement other therapies currently in use against H. pylori infection.

Prophylactic immunization to Helicobacter pylori infection using spore vectored vaccines

BACKGROUND

Helicobacter pylori infection remains a major public health threat leading to gastrointestinal illness and increased risk of gastric cancer. Mostly affecting populations in developing countries no vaccines are yet available and the disease is controlled by antimicrobials which, in turn, are driving the emergence of AMR.

MATERIALS AND METHODS

We have engineered spores of Bacillus subtilis to display putative H. pylori protective antigens, urease subunit A (UreA) and subunit B (UreB) on the spore surface. Following oral dosing of mice with these spores, we evaluated immunity and colonization in animals challenged with H. pylori.

RESULTS

Oral immunization with spores expressing either UreA or UreB showed antigen-specific mucosal responses (fecal sIgA) including seroconversion and hyperimmunity. Following challenge, colonization by H. pylori was significantly reduced by up to 1-log.

CONCLUSIONS

This study demonstrates the utility of bacterial spores for mucosal vaccination to H. pylori infection. The heat stability and robustness of Bacillus spores coupled with their existing use as probiotics make them an attractive solution for either protection against H. pylori infection or potentially for therapy and control of active infection.

Anti-Heliobacter pylori and Anti-Inflammatory Potential of Salvia officinalis Metabolites: In Vitro and In Silico Studies

Due to its rising antibiotic resistance and associated inflammations, Helicobacter pylori poses a challenge in modern medicine. Salvia officinalis, a member of the Lamiaceae family, is a promising medicinal herb. In this regard, a phytochemical screening followed by GC-MS and LC-MS was done to evaluate the chemical profile of the total ethanolic extract (TES) and the essential oil, respectively. The anti-H. pylori and the anti-inflammatory activities were evaluated by a micro-well dilution technique and COX-2 inhibition assay. Potential anti-H. pylori inhibitors were determined by an in silico study. The results revealed that the main metabolites were flavonoids, sterols, volatile oil, saponins, and carbohydrates. The LC-MS negative ionization mode demonstrated 12 compounds, while GC-MS showed 21 compounds. Carnosic acid (37.66%), epirosmanol (20.65%), carnosol1 (3.3%), and 12-O-methyl carnosol (6.15%) were predominated, while eucalyptol (50.04%) and camphor (17.75%) were dominant in LC-MS and GC-MS, respectively. TES exhibited the strongest anti-H. pylori activity (3.9 µg/mL) asymptotic to clarithromycin (0.43 µg/mL), followed by the oil (15.63 µg/mL). Carnosic acid has the best-fitting energy to inhibit H. pylori (-46.6769 Kcal/mol). TES showed the highest reduction in Cox-2 expression approaching celecoxib with IC50 = 1.7 ± 0.27 µg/mL, followed by the oil with IC50 = 5.3 ± 0.62 µg/mL. Our findings suggest that S. officinalis metabolites with anti-inflammatory capabilities could be useful in H. pylori management. Further in vivo studies are required to evaluate and assess its promising activity.

A Bioluminescence-Based Drug Screen Identifies Activities of Fexinidazole and Its Metabolites against Helicobacter pylori

Helicobacter pylori is responsible for a wide range of gastric diseases, including gastric cancer and gastritis. With half of the world’s population infected by H. pylori and the current standard of care associated with suboptimal outcomes, a search for more effective drugs is critical. To facilitate drug screening for H. pylori, we developed a microtiter plate-based compound screening method that is faster and can screen multiple compounds. We identified activities of fexinidazole and its sulfoxide and sulfone metabolites against H. pylori. Both fexinidazole and its metabolites exhibited equipotency against SS1, 60190, and G27 strains, which were about 3–6-fold more potent than the currently used metronidazole. We also determined the minimal inhibitory concentration (MIC) of metronidazole, fexinidazole, and its metabolites against these strains by a traditional agar plate-based method. While MIC values of fexinidazole and metronidazole were similar against all the strains, both sulfoxide and sulfone showed lower MIC values than metronidazole against SS1 and 60190. Given the recent FDA approval of fexinidazole, our data on the in vitro antibacterial activities of fexinidazole and its metabolites support further evaluation of this drug with the goal of producing an alternative nitro-based antimicrobial with good safety profiles for the treatment of H. pylori infection.

Effect of Helicobacter pylori Infection on Macromineral and Trace Element Status-Systematic Review and Meta-Analysis

OBJECTIVES

To explore the effect of Helicobacter pylori (Hp ) infection on zinc, copper, calcium, magnesium, phosphorus, and iodine status in the pediatric population.

METHODS

A protocol was registered on PROSPERO. A literature search was conducted on Embase, PubMed MEDLINE, and Web of Science, from inception to September 2020, including all studies in English, Spanish, and Portuguese languages. Reference lists were manually searched. Primary studies describing at least one micronutrient status in Hp -positive and Hp -negative or control children were included. PRISMA recommendations were applied. Pooled mean differences (MDs) and 95% confidence intervals were estimated using a random-effects model. A total of 1011 citations were screened. Six cross- sectional studies were included. No publications regarding phosphorus and iodine were identified.

RESULTS

Included studies in meta-analyses comprised an overall age range of 4-18 years, with Hp positivity ranging between 29.5% and 72.3%. These meta-analyses demonstrated a lack of evidence of an association between Hp -positive and Hp -negative or control children regarding serum zinc (vs Hp -negative: MD -1.36 µg/dL; vs control: MD 326.22 µg/dL), copper (MD -0.83 µg/dL), and calcium (MD 0.09 mg/dL) status. Considerable heterogeneity was recognized, except for calcium analysis (I 2 = 0%). Meta-analysis for magnesium was not performed. Five studies presented a low risk of bias.

CONCLUSIONS

The study demonstrated a lack of evidence of an effect of Hp infection on serum zinc, copper, and calcium status. Studies concerning magnesium, phosphorus, and iodine status are warranted. Furthermore, larger and well-controlled studies are recommended.

GC-MS Profiling, Anti-Helicobacter pylori, and Anti-Inflammatory Activities of Three Apiaceous Fruits' Essential Oils

Eradication of Helicobacter pylori is a challenge due to rising antibiotic resistance and GIT-related disorders. Cuminum cyminum, Pimpinella anisum, and Carum carvi are fruits belonging to the Apiaceae family. Their essential oils were extracted, analyzed using GC-MS, tested for anti-H. pylori activity by a micro-well dilution technique, identified for potential anti-H. pylori inhibitors by an in-silico study, and investigated for anti-inflammatory activity using a COX-2 inhibition assay. Results showed that the main components of C. cyminum, P. anisum, and C. carvi were cumaldehyde (41.26%), anethole (92.41%), and carvone (51.38%), respectively. Essential oil of C. cyminum exhibited the greatest anti-H. pylori activity (3.9 µg/mL) followed by P. anisum (15.63 µg/mL), while C. carvi showed the lowest activity (62.5 µg/mL). The in-silico study showed that cumaldehyde in C. cyminum has the best fitting energy to inhibit H. pylori.C. cyminum essential oil showed the maximum ability to reduce the production of Cox-2 expression approaching celecoxib with IC50 = 1.8 ± 0.41 µg/mL, followed by the C. carvi oil IC50 = 7.3 ± 0.35 µg/mL and then oil of P. anisum IC50 = 10.7±0.63 µg/mL. The investigated phytochemicals in this study can be used as potential adjunct therapies with conventional antibiotics against H. pylori.

Lactobacillus plantarum-derived postbiotics prevent Salmonella-induced neurological dysfunctions by modulating gut-brain axis in mice

Postbiotics are the inactive bacteria and/or metabolites of beneficial microbes which have been recently found to be as effective as their live probiotic. This study aimed to evaluate the benefits of Lactobacillus plantarum (LP)-derived postbiotics on ameliorating Salmonella-induced neurological dysfunctions. Mice were pretreated with LP postbiotics (heat-killed bacteria or the metabolites) or active bacteria, and then challenged with Salmonella enterica Typhimurium (ST). Results showed that LP postbiotics, particularly the metabolites, effectively prevented ST infection in mice, as evidenced by the inhibited weight loss, bacterial translocation, and tissue damages. The LP postbiotics markedly suppressed brain injuries and neuroinflammation (the decreased interleukin (IL)-1β and IL-6, and the increased IL-4 and IL-10). Behavior tests indicated that LP postbiotics, especially the metabolites, protected mice from ST-induced anxiety and depressive-like behaviors and cognitive impairment. A significant modulation of neuroactive molecules (5-hydroxytryptamine, gamma-aminobutyric acid, brain-derived neurotrophic factor, dopamine, acetylcholine, and neuropeptide Y) was also found by LP postbiotic pretreatment. Microbiome analysis revealed that LP postbiotics optimized the cecal microbial composition by increasing Helicobacter, Lactobacillus and Dubosiella, and decreasing Mucispirillum, norank_f_Oscillospiraceae, and Eubacterium_siraeum_group. Moreover, LP postbiotics inhibited the reduction of short-chain fatty acids caused by ST infection. Pearson's correlation assays further confirmed the strong relationship of LP postbiotics-mediated benefits and gut microbiota. This study highlights the effectiveness of postbiotics and provide a promising strategy for preventing infection-induced brain disorders by targeting gut–brain axis.

Evaluation of antibiotic resistance of Helicobacter pylori bacteria obtained from gastric biopsy samples: A cohort study

Objective

Helicobacter pylori infection is associated with a wide range of gastrointestinal diseases and is very common in developing countries. Overuse and self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication of the bacterium. The aim of this study is to evaluate the antibiotic resistance of h. pylori from samples obtained from gastric biopsy.

Methods

In this descriptive-analytical study was performed on 205 patients’ samples positive for h. pylori infection. Following h. pylori testing, the sample were culture with different antibiotics to obtain data regarding the resistance. Demographic information of the patients such as age, sex, employment status, area of residence and patient-related factors such as reason for referral, and previous history of treatment were obtained and evaluated for the correlation with antibiotic resistance.

Results

In this study, the mean age of the subjects was 42.32 ± 16.65 years. The most common reason for referral of patients in the present study was epigastric pain in 49.3% (101 patients). Antibiotic resistance to amoxicillin was 46.8%, tetracycline was 41%, metronidazole was 33.2%, clarithromycin was 70.7%. levofloxacin was 36.1% and bismuth was 19.5%. Sex, age, type of living (rural or urban), employment, reason for referral and history of treatment was not associated with any antibiotic resistance, p > 0.05.

Conclusion

Our study showed that clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline. Excessive use of these antibiotics and self-prescription should be analyzed in future studies and public-awareness programs might be required.

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H.pylori infection is associated with a wide range of gastrointestinal diseases.

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Self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication.

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Clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline.

A comparative whole genome analysis of Helicobacter pylori from a human dense South Asian setting

Helicobacter pylori, a Gram-negative bacterium, is associated with a wide range of gastric diseases such as gastritis, duodenal ulcer, and gastric cancer. The prevalence of H pylori and risk of disease vary in different parts of the world based on the prevailing bacterial lineage. Here, we present a contextual and comparative genomics analysis of 20 clinical isolates of H pylori from patients in Bangladesh. Despite a uniform host ethnicity (Bengali), isolates were classified as being part of the HpAsia2 (50%) or HpEurope (50%) population. Out of twenty isolates, eighteen isolates were cagA positive, with two HpEurope isolates being cagA negative, three EPIYA motif patterns (AB, AB-C, and ABC-C) were observed among the cagA-positive isolates. Three vacA genotypes were observed with the s1m1i1dic1 genotype observed in 75% of isolates; the s1m2i1d1c2 and s2m2i2d2c2 genotypes were found to be 15% and 10% of isolates, respectively. The non-virulent genotypes s2m2i2d2c2 was only observed in HpEurope population isolates. Genotypic analysis of oipA gene, present in all isolates, revealed five different patterns of the CT repeat; all HpAsia2 isolates were in "ON" while 20% of HpEurope isolates were genotypically "OFF." The three blood group antigen binding adhesins encoded genes (bab genes) examined and we observed that the most common genotype was (babA/babB/-) found in eight isolates, notably six were HpAsia2 isolates. The babA gene was found in all HpAsia2 isolates but present in only half of the HpEurope isolates. In silico antibiotic susceptibility analysis revealed that 40% of the strains were multi-drug resistant. Mutations associated with resistance to metronidazole, fluoroquinolone, and clarithromycin were detected 90%, 45%, and 5%, respectively, in H pylori strain. In conclusion, it is evident that two populations of H pylori with similar antibiotic profiles are predominant in Bangladesh, and it appears that genotypically the HpAisa2 isolates are potentially more virulent than the HpEurope isolates.

Helicobacter pylori adhesins: HpaA a potential antigen in experimental vaccines for H. pylori

BACKGROUND

Helicobacter pylori is a gram-negative bacterium involved in many gastric pathologies such as ulcers and cancers. Although the treatment for this infection has existed for several years, the development of a vaccine is nevertheless necessary to reduce the severe forms of the disease. For more than three decades, many advances have been made particularly in the understanding of virulence factors as well as the pathogenesis of gastric diseases caused by H. pylori. Among these key virulence factors, specific antigens have been identified: Urease, Vacuolating cytotoxin A (VacA), Cytotoxin-associated gene A (CagA), Blood group antigen-binding adhesin (BabA), H. pylori adhesin A (HpaA), and others.

OBJECTIVES

This review will focus on H. pylori adhesins, in particular, on HpaA and on the current knowledge of H. pylori vaccines.

METHODS

All of the information included in this review was retrieved from published studies on H. pylori adhesins in H. pylori infections.

RESULTS

These proteins, used in their native or recombinant forms, induce protection against H. pylori in experimental animal models.

CONCLUSION

H. pylori adhesins are known to be promising candidate vaccines against H. pylori. Future research should be carried out on adhesins, in particular, on HpaA.

Live Attenuated Measles Virus Vaccine Expressing Helicobacter pylori Heat Shock Protein A

Measles virus (MV) Edmonston derivative strains are attractive vector platforms in vaccine development and oncolytic virotherapy. Helicobacter pylori heat shock protein A (HspA) is a bacterial heat shock chaperone with essential function as a Ni-ion scavenging protein. We generated and characterized the immunogenicity of an attenuated MV strain encoding the HspA transgene (MV-HspA). MV-HspA showed faster replication within 48 h of infection with >10-fold higher titers and faster accumulation of the MV proteins. It also demonstrated a superior tumor-killing effect in vitro against a variety of human solid tumor cell lines, including sarcoma, ovarian and breast cancer. Two intraperitoneal (i.p.) doses of 10⁶ 50% tissue culture infectious dose (TCID₅₀) MV-HspA significantly improved survival in an ovarian cancer xenograft model: 63.5 days versus 27 days for the control group. The HspA transgene induced a humoral immune response in measles-permissive Ifnarko-CD46Ge transgenic mice. Eight of nine animals developed a long-term anti-HspA antibody response with titers of 1:400 to 1:12,800 without any negative impact on development of protective anti-MV immune memory. MV-HspA triggered an immunogenic cytopathic effect as measured by an HMGB1 assay. The absence of significant elevation of PD-L1 expression indicated that vector-encoded HspA could act as an immunomodulator on the immune check point axis. These data demonstrate that MV-HspA is a potent oncolytic agent and vaccine candidate for clinical translation in cancer treatment and immunoprophylaxis against H. pylori.

Low Serum B12 Concentrations Are Associated with Low B12 Dietary Intake But Not with Helicobacter pylori Infection or Abnormal Gastric Function in Rural Mexican Women

Background: Gastric function, Helicobacter pylori infection, and vitamin B12 (B12) dietary intake were assessed as predictors of serum B12. Methods: H. pylori antibodies, gastric function, B12 dietary intake, and biochemical/hematological parameters were measured in 191 adult women from two rural communities in Querétaro, Mexico. Results: The overall mean serum B12 concentration was 211 ± 117 pmol/L. The prevalences of low (≤ 148 pmol/L), marginal (148 to 221 pmol/L), and adequate (> 221 pmol/L) serum B12 were 28.4%, 31.1%, and 40.5%, respectively. Seventy-one percent of women tested positive for H. pylori antibodies. The prevalence of gastric function categories did not differ by serum B12 categories. The odds ratio for having low serum B12 was 2.7 (p = 0.01) for women with an intake below the estimated average requirement, 3.6 (p = 0.01) for those in the lowest tertile of total B12 intake, and 3.0 (p = 0.02) for those in the lowest tertile of B12 intake from animal source foods. Age and B12 intake were predictors of serum B12 concentrations [serum B12 (pmol/L) = 90.060 + 5.208 (B12 intake, µg/day) + 2.989 (age, years). Conclusions: Low serum B12 concentrations were associated with low B12 dietary intake but not with H. pylori infection or abnormal gastric function in rural Mexican women.

Sex effect on growth faltering in an indigenous ethnic minority population of infants in Israel

OBJECTIVE

We examined sex effects on growth faltering in an indigenous population of Bedouin Arab infants born in Israel, an economically developed country.

DESIGN

Retrospective cohort study. Height-for-age Z-score (HAZ) at age 6, 12, 18 and 24 months was calculated for full-term, normal-birth-weight Bedouin infants born during years 2000-2009 and attending maternal and child health (MCH) clinics. Multivariate linear regression analysis (MLRA) was used to calculate the association between sex and HAZ, controlling for year of birth, birth weight (BW) and residence by type of settlement (established settlement (ES); non-established settlement (NES)).

SETTING

Bedouin are an indigenous poor community of semi-nomadic Arabs, with the highest infant mortality rate in Israel. Fifty per cent of Bedouin infants live in NES with inadequate access to running water, electricity, and rubbish and sewage disposal. All Bedouin receive free well-baby care in community-based MCH clinics.

PARTICIPANTS

Full-term, normal Bedouin infants (n 5426) born during 2000-2009 and attending computerized MCH clinics who had growth measurements at age 6, 12, 18 and 24 months.

RESULTS

At all ages, girls had significantly higher mean HAZ than boys (P < 0·05). Increasing birth year, residence in ES and increasing BW were positively associated with HAZ (P < 0·05) at all ages. In MLRA controlling for birth year, BW and type of settlement, sex still had a significant effect, with lower HAZ among boys at 6, 12, 18 and 24 months of age (P < 0·001 at all ages).

CONCLUSIONS

Our results indicated that sex effects on growth faltering can occur in an indigenous population with low socio-economic status within an economically developed country.

Genetic diversity, inbreeding and cancer

Genetic diversity is essential for adaptive capacities, providing organisms with the potential of successfully responding to intrinsic and extrinsic challenges. Although a clear reciprocal link between genetic diversity and resistance to parasites and pathogens has been established across taxa, the impact of loss of genetic diversity by inbreeding on the emergence and progression of non-communicable diseases, such as cancer, has been overlooked. Here we provide an overview of such associations and show that low genetic diversity and inbreeding associate with an increased risk of cancer in both humans and animals. Cancer being a multifaceted disease, loss of genetic diversity can directly (via accumulation of oncogenic homozygous mutations) and indirectly (via increased susceptibility to oncogenic pathogens) impact abnormal cell emergence and escape of immune surveillance. The observed link between reduced genetic diversity and cancer in wildlife may further imperil the long-term survival of numerous endangered species, highlighting the need to consider the impact of cancer in conservation biology. Finally, the somewhat incongruent data originating from human studies suggest that the association between genetic diversity and cancer development is multifactorial and may be tumour specific. Further studies are therefore crucial in order to elucidate the underpinnings of the interactions between genetic diversity, inbreeding and cancer.

Seroprevalence and determinants of Helicobacter pylori infection among asymptomatic under-five children at a Tertiary Hospital in the South-Western region of Nigeria

Background

The epidemiology of Helicobacter pylori (H. pylori) infection among under-five children in the South West Nigeria remains largely understudied. There is no data on the subject from the study area.

Objectives

This study was conducted to assess the seroprevalence of H. pylori infection among under-five children at a tertiary hospital in the South Western, Nigeria and to determine its associated socio-demographic factors.

Methods

Sera of 360 children were analyzed for anti H. pylori Ig G using enzyme linked immunosorbent assay test kit (BQ ELISA Ig G KIT) and H. pylori infection risk factors were determined. Determinants of H. pylori infection was determined using binary logistic regression analysis and p-values < 0.05 were taken as statistically significant.

Results

H. pylori infection seroprevalence rate was 32.8% and increased with age. Living in one room accommodation, large families, playing with soil, family history of dyspepsia, practice of premastication, sharing of plates and cutlery, and water closet toilet were associated with H. pylori Ig G seropositivity (p<0.05) on binary regression analysis.

Conclusion

The seroprevalence of H. pylori infection in under -five children is high, increasing as the age of the children increased. This may suggest that instituting preventive measures at young age, targeting identified factors may be effective in reducing the burden of H. pylori infection.

[ARTICLE PARTIAL RETRACTION] PREVALENCE OF HELICOBACTER PYLORI INFECTION IN DYSPEPTIC PATIENTS AND ITS ASSOCIATION WITH CLINICAL RISK FACTORS FOR DEVELOPING GASTRIC ADENOCARCINOMA

BACKGROUND

In Brazil, particularly in the underdeveloped localities, the prevalence of Helicobacter pylori (H. pylori) infections can range up to 90%. These rates are higher in older individuals and vary by country region. H. pylori infections are linked to the development of gastric pathologies, namely mild to moderate gastritis, gastroenteritis, peptic ulcer, intestinal metaplasia, and gastric cancer. In 1994, this organism was classified by the International Agency for Research on Cancer (IARC) as pertaining to the Group 1 carcinogen for gastric adenocarcinoma etiology. Gastric cancer represents a significant public health problem, being the fourth most common malignant tumor and the second largest cause of cancer-related deaths.

OBJECTIVE

To investigate the prevalence of H. pylori infection in dyspeptic patients and determine the link between clinical risk factors and gastric adenocarcinoma diagnosis.

METHODS

Polymerase chain reaction (PCR) analysis was employed for molecular diagnosis of gastric tissue biopsies collected from 113 dyspeptic patients at the University Hospital of Federal University of Goiás. Molecular analyses allowed the identification of H. pylori infections. Furthermore, histopathological examinations were performed to determine the clinical risks of developing gastric malignancies.

RESULTS

The test results identified 69 individuals older than 44 years, from 75 (66.4%) positive H. pylori infection samples. The prevalence of gastric adenocarcinoma in this study was 1.3%. Among the infected patients, six (8.2%) had high risk, and 67 (91.8%) had a low risk of developing gastric cancer (P<0.05).

CONCLUSION

This study shows a high prevalence of H. pylori infection and identifies its contribution to gastric inflammations, which in the long term are manifested in high-risk clinical factors for the development of gastric adenocarcinoma.

Correlation between Helicobacter pylori Infection and Gastric Atrophy Examined in the Sera of Mongolian People

Serum specimens obtained from 680 individuals were examined to measure the amounts of pepsinogens 1 and 2, anti-CagA antibodies, and anti-Helicobacter pylori antibodies. We examined sera obtained from 610 Mongolian individuals living in the capital city, Ulaanbaatar. Seventy serum specimens were collected from Japanese people who were health-screened: These were stored at the gastroenterology laboratory of Jichi Medical University. The sera of the Japanese people were used as a control specimen. Two enzyme-linked immunosorbent assay (ELISA) kits, an E-plate ELISA kit from Eiken Chemical Co., Ltd. (Tokyo, Japan), and a Biohit ELISA kit from Biohit Oyj (Helsinki, Finland), were used for the detection of anti-H. pylori IgG antibodies in the sera of the 610 Mongolian people. An ELISA kit EIA-4138 from DRG Instruments GmbH (Germany) was used for the detection of anti-CagA IgG antibodies in the serum specimens. Serum pepsinogens were detected by an ELISA kit from Biohit Oyj. Of the 610 serum specimens, 385 specimens tested positive for the detection of anti-H. pylori antibodies using the two ELISA kits, and 47 tested negative. For the detection of anti-H. pylori antibodies by the Biohit ELISA kit, 560 and 50 specimens were positive and negative, respectively. The ratio of serum pepsinogen 1/2 was statistically lower (p < 0.0001) in the H. pylori-positive (560 specimens) than in the H. pylori-negative (50 specimens) specimens. However, the levels of serum pepsinogen 1 had no statistical significance (p = 0.465) between the specimens of the H. pylori-positive and -negative specimens. The ratio of serum pepsinogen 1/2 was 6.74 ± 0.12 in the H. pylori-positive specimens, whereas the ratio of serum pepsinogen 1/2 was 12.69 ± 1.02 in the H. pylori-negative specimens. This study demonstrated the high prevalence of H. pylori infection in Mongolian people, including young generations, and the people infected with H. pylori possessed low pepsinogen 1/2 ratios, indicating atrophic gastritis. The serological examinations by the two ELISA kits did not consistently reflect the prevalence of H. pylori infection in Mongolian people.

The Interaction of Helicobacter pylori Infection and Type 2 Diabetes Mellitus

Helicobacter pylori is one of the most common human pathogens that can cause gastrointestinal (GI) disorders, including simple gastritis, gastric ulcer, and malignant gastritis. In some cases, such as immunodeficiency and underlying diseases, it can be problematic as opportunistic infections. Diabetes mellitus (type 2) (T2DM) is one of the H. pylori underlying diseases. Since GI problems are observed in diabetic patients, it is necessary to treat H. pylori infection. In this review, we aimed to evaluate the possible relationship between H. pylori and T2DM according to epidemiological surveys of 70 studies retrieved from databases, including Scopus, PubMed, and Google Scholar about the relationship between H. pylori and T2DM, and discuss the reported background mechanisms of this correlation. According to the results of our study, the different studies have shown that H. pylori is more prevalent in Type 2 diabetic patients than healthy individuals or nondiabetic patients. The reason is development of H. pylori infection-induced inflammation and production of inflammatory cytokines as well as different hormonal imbalance by this bacterium, which are associated with diabetes mellitus. On the other hand, by tracing anti-H. pylori antibodies in patients with diabetes mellitus and occurrence of symptoms such as digestive problems in >75% of these patients, it can be concluded that there is a relationship between this bacterium and T2DM. Considering the evidence, it is crucially important that the probability of infection with H. pylori is evaluated in patients with T2DM so that medical process of the patient is followed with higher cautious.

Helicobacter pylori and enteric parasites co-infection among diarrheic and non-diarrheic Egyptian children: seasonality, estimated risks, and predictive factors

Helicobacter pylori (H. pylori) and intestinal parasites are known for their high prevalence in children. Both of them infect the gastrointestinal tract with overlapping clinical pictures. This study was conducted to determine H. pylori prevalence and its association with intestinal parasites in children, moreover to estimate risk and predictive factors for their detection in stool samples. Single fecal samples were collected from 226 Egyptian pediatric patients (125 diarrheic and 101 non-diarrheic) attending gastroenterology outpatients' clinics, from February 2016 to June 2017. All stool specimens were microscopically examined to search for ova and parasites. Copro-DNAs detection of H. pylori and Cryptosporidium were performed using nested-PCR assays. H. pylori was detected molecularly in 36.8% of the total study population, with a higher prevalence in diarrheic than in non-diarrheic children. Intestinal parasites were detected in 27.4% of the total study populations, of these, 43.9% had co-existence with H. pylori colonized patients and was significantly associated with Cryptosporidium spp. and G. intestinalis. Estimated risk of the presence of H. pylori was in January. Our data provide a better understanding of the epidemiology of H. pylori infection when associated with intestinal parasites. H. pylori co-existence with G. intestinals and Cryptosporidium may suggest the association of H. pylori infection with markers of fecal exposure. Whether H. pylori provides favorable conditions for intestinal parasitosis or vice versa, still further investigations are needed with an emphasis upon determining correlation with gut microbiomes.

A review of gastrointestinal protocols for primary care medical service trips (MSTs) in Latin America and the Caribbean

Background

Gastrointestinal disorders are among the most common conditions encountered on short-term, primary care medical service trips (MSTs) in Latin America and the Caribbean (LAC), but their optimal management remains unclear. There have been no previous attempts to describe the protocols that Western volunteer clinicians use in managing these patients.

Methods

A systematic web search was used to identify organizations operating MSTs in LAC. Clinical protocols were downloaded from organizational websites, and organizations were contacted online to obtain those that were not publicly available. Protocols were analysed qualitatively, and content compared with existing international guidelines.

Results

Two hundred and twenty-five organizations were identified and contacted to obtain their clinical protocols, and the content of each protocol was qualitatively analysed. Twenty protocols were obtained, of which 75% (15/20) discussed dyspepsia, 65% (13/20) discussed parasites and 60% (12/20) discussed diarrhoea. The protocols infrequently included literature citations.

Conclusion

Gastrointestinal disorder protocols used by MSTs in LAC sometimes neglected important aspects of clinical management that are emphasized in international guidelines. This study is a first step in context-specific clinical guideline development for MSTs operating in LAC.

Helicobacter pylori: A foodborne pathogen?

Helicobacter pylori (H. pylori) is an organism that is widespread in the human population and is sometimes responsible for some of the most common chronic clinical disorders of the upper gastrointestinal tract in humans, such as chronic-active gastritis, duodenal and gastric ulcer disease, low-grade B-cell mucosa associated lymphoid tissue lymphoma of the stomach, and gastric adenocarcinoma, which is the third leading cause of cancer death worldwide. The routes of infection have not yet been firmly established, and different routes of transmission have been suggested, although the most commonly accepted hypothesis is that infection takes place through the faecal-oral route and that contaminated water and foods might play an important role in transmission of the microorganism to humans. Furthermore, several authors have considered H. pylori to be a foodborne pathogen because of some of its microbiological and epidemiological characteristics. H. pylori has been detected in drinking water, seawater, vegetables and foods of animal origin. H. pylori survives in complex foodstuffs such as milk, vegetables and ready-to-eat foods. This review article presents an overview of the present knowledge on the microbiological aspects in terms of phenotypic characteristics and growth requirements of H. pylori, focusing on the potential role that foodstuffs and water may play in the transmission of the pathogen to humans and the methods successfully used for the detection of this microorganism in foodstuffs and water.

Clinical and Socio- Demographic Risk Factors for Acquisition of Helicobacter pylori Infection in Nigeria

Background: The aim of the study was to assess clinical and socio-demographic characteristics as well as prior drug usage as risk factors for Helicobacter pylori (H. pylori) infection in Nigeria. Methods: A total of 347 respondents were surveyed by assessing their clinical and socio-demographic characteristics in comparison with the non-invasive gold standard for H. pylori diagnosis, the urea breath test (UBT). Chi-square test and odds ratio analyses were conducted in order to assess if variables such as socio-demographic factors, drug intake, and history of ulcer/gastritis/ gastric cancer within the family significantly predicted test results. Results: A total of 130 (37.5%) respondents were positive for H. pylori by the UBT. Living with more than three people in an apartment and a history of ulcer/gastritis within the family were significantly associated with H. pylori (p ≤0.05), as well as current antibiotic intake (p ≤0.05). Nationality, stay outside Nigeria, level of education, main occupation, smoking and drinking habits, sources of drinking water, number of children and history of gastric cancer had no significant association with H. pylori infection (p ≥ 0.05). Conclusion: The results of the questionnaire revealed that most socio-demographic characteristics of the respondents had no significant association with H. pylori. Overcrowding, having siblings/parents with history of ulcer/gastritis as well as prior antibiotic usage had a significant association.

Advances and Opportunities in Nanoparticle- and Nanomaterial-Based Vaccines against Bacterial Infections

As the dawn of the postantibiotic era we approach, antibacterial vaccines are becoming increasingly important for managing bacterial infection and reducing the need for antibiotics. Despite the success of vaccination, vaccines remain unavailable for many pressing microbial diseases, including tuberculosis, chlamydia, and staphylococcus infections. Amid continuing research efforts in antibacterial vaccine development, the advancement of nanomaterial engineering has brought forth new opportunities in vaccine designs. With increasing knowledge in antibacterial immunity and immunologic adjuvants, innovative nanoparticles are designed to elicit the appropriate immune responses for effective antimicrobial defense. Rationally designed nanoparticles are demonstrated to overcome delivery barriers to shape the adaptive immunity. This article reviews the advances in nanoparticle- and nanomaterial-based antibacterial vaccines and summarizes the development of nanoparticulate adjuvants for immune potentiation against microbial pathogens. In addition, challenges and progress in ongoing antibacterial vaccine development are discussed to highlight the opportunities for future vaccine designs.

The magnitude of antibiotic resistance to Helicobacter pylori in Africa and identified mutations which confer resistance to antibiotics: systematic review and meta-analysis

Background

Worldwide Helicobacter pylori (H.pylori) treatment is of great challenge due to increased antibiotic resistance. The burden of H. pylori antibiotic resistance in Africa is high with unclear information regarding the real magnitude. This systematic review and meta-analysis was conducted to investigate the magnitude of H.pylori antibiotic resistance in Africa to gain insight of the extent of the problem among H.pylori naïve treatment patients.

Method

The search was performed in the academic databases, Embase, PubMed, Web of Science and Africa Wide Information. ProQuest Dissertation and Theses, Scopus, Ethos, Africa Index Medicus (WHO), BioMed Central Proceedings, BASE, British Library, Open grey, Library of Congress and the New York Academy of Grey Literature Report were additionally searched for grey literature. Published articles from Africa on H.pylori antibiotic resistance between 1986 and June 2017 were systematically reviewed to estimate the H. pylori extent of resistance to macrolides, quinolones, amoxicillin, tetracycline and metronidazole.

Results

In 26 articles a total of 2085 isolates were tested for metronidazole, 1530 for amoxicillin, 1277 for tetracycline, 1752 for clarithromycin and 823 for quinolones.The overall pooled proportion of H.pylori resistance to quinolones, clarithromycin, tetracycline, metronidazole and amoxicillin were: (17.4%, 95%CI 12.8 - 21.9), (29.2%, 95%CI:26.7-31.8), (48.7%, 95%CI: 44.5-52.9), (75.8%, 95% CI: 74.1-.77.4) and (72.6%, 95% CI: 68.6-76.6), respectively. The commonest mutation detected were A2143G (49/97) for clarithromycin, RdxA (41/56) for metronidazole and D87I (16/40) for quinolones.

Conclusion

Prevalence of metronidazole, clarithromycin, and amoxicillin resistance is high in developing world including Africa. This could impair the first line triple therapy of the H.pylori infection. There is a need of conducting surveillance of H.pylori susceptibility pattern in Africa for dual and triple resistance which can be used for the empirical treatment.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3099-4) contains supplementary material, which is available to authorized users.

A meta-analysis of the association between Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum

BACKGROUND

Hyperemesis gravidarum remains a common, distressing, and significant yet poorly understood disorder during pregnancy. The association between maternal Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum has been increasingly recognized and investigated. This study thus aimed to provide an updated review and meta-analysis of the topic.

METHODS

Using the search terms (H. pyloriOR Helicobacter ORHelicobacter pyloriOR infection) AND (pregnancy OR emesis OR hyperemesis gravidarum OR nausea OR vomiting), a preliminary search on the PubMed, Ovid, Web of Science, Google Scholar, and WanFang database yielded 372 papers published in English between January 1st, 1960 and June 1st, 2017.

RESULTS

A total of 38 cross-sectional and case-control studies, with a total of 10 289 patients were eligible for review. Meta-analysis revealed a significant association between H. pylori infection and hyperemesis gravidarum during pregnancy, with a pooled odds ratio of 1.348 (95% CI: 1.156-1.539, P < .001). Subgroup analysis found that serologic and stool antigen tests were comparable methods of detecting H. pylori as they yielded similar odds ratios.

LIMITATIONS

Although the studies did not have high heterogeneity (I²  = 28%), publication bias was observed, and interstudy discrepancies in the diagnostic criteria adopted for hyperemesis gravidarum limit the reliability of findings. Also, 15 of the included studies were from the same country (Turkey), which could limit the generalizability of current findings. The prevalence of H. pylori infection varies throughout the world, and there may also be pathogenic differences as most strains of H. pylori in East Asia carry the cytotoxin-associated gene A gene.

CONCLUSION

H. pylori infection was associated with an increased likelihood of hyperemesis gravidarum during pregnancy. Given the high prevalence of H. pylori infections worldwide, detecting H. pylori infection and the eradication of maternal H. pylori infection could be part of maternal hyperemesis gravidarum management. Further confirmation with robust longitudinal studies and mechanistic investigations are needed.

Probiotics in 14-day triple therapy for Asian pediatric patients with Helicobacter pylori infection: a network meta-analysis

Although 14-day triple therapy has been widely administrated for eradicating Helicobacter pylori (H. pylori) in Asia, its antibiotic-associated side effects restrict the effectivity of eradication therapy in pediatric patients. Therefore, a network meta-analysis (NMA) was conducted to compare the efficacy and safety of probiotics supplemented in 14-day triple therapy in Asian pediatric patients.

Materials and Methods

Randomized controlled trials (RCTs) were retrieved comprehensively in electronic databases (such as PubMed, Cochrane library, Embase, CNKI, Wan fang database, VIP database and CBM) until April 2017. Additional references were obtained from reviewed articles. NMA was performed using a random-effects model under a frequentist framework.

Results

Seventeen RCTs were included. NMA indicated that Bifidobacterium infantis+Clostridium butyricum was most beneficial for H. pylori eradication rates (P-score = 0.82) and Bacillus mesentericus+Clostridium butyricum+Streptococcus faecalis for total side effects (P-score = 0.77). Taken together, Bacillus mesentericus+Clostridium butyricum+Streptococcus faecalis was the best one to supplement in 14-day triple therapy due to its efficacy (P-score = 0.72) and safety (P-score = 0.77). Additionally, pairwise meta-analysis indicated that probiotics supplemented 14-day triple therapy significantly increased H. pylori eradication rates (RR: 1.16, 95%CI: 1.07–1.26) and reduced the incidence of total side effects (RR: 0.40, 95%CI: 0.34–0.48) compared with placebo.

Conclusions

Bacillus mesentericus+Clostridium butyricum+Streptococcus faecalis is the optimal probiotic regime of reducing total side effects and improving eradication rates when supplemented 14-day triple therapy. Further direct evidence is needed to warrant it.

Review: Prevalence and dynamics of Helicobacter pylori infection during childhood

INTRODUCTION

Long-term persistent Helicobacter pylori infection has been associated with ulceropeptic disease and gastric cancer. Although H. pylori is predominantly acquired early in life, a clear understanding of infection dynamics during childhood has been obfuscated by the diversity of populations evaluated, study designs, and methods used.

AIM

Update understanding of true prevalence of H. pylori infection during childhood, based on a critical analysis of the literature published in the past 5 years.

METHODS

Comprehensive review and meta-analysis of original studies published from 2011 to 2016.

RESULTS

A MEDLINE^® /PubMed^® search on May 1, 2016, using the terms pylori and children, and subsequent exclusion, based on abstract review using predefined criteria, resulted in 261 citations. An Embase^® search with the same criteria added an additional 8 citations. In healthy children, meta-analysis estimated an overall seroprevalence rate of 33% (95% CI: 27%-38%). Seven healthy cohort studies using noninvasive direct detection methods showed infection prevalence estimates ranging from 20% to 50% in children ≤5 and 38% to 79% in children >5 years. The probability of infection persistence after a first positive sample ranged from 49% to 95%. Model estimates of cross-sectional direct detection studies in asymptomatic children indicated a prevalence of 37% (95% CI: 30%-44%). Seroprevalence, but not direct detection rates increased with age; both decreased with increasing income. The model estimate based on cross-sectional studies in symptomatic children was 39% (95% CI: 35%-43%).

CONCLUSIONS

The prevalence of H. pylori infection varied widely in the studies included here; nevertheless, model estimates by detection type were similar, suggesting that overall, one-third of children worldwide are or have been infected. The few cohort and longitudinal studies available show variability, but most studies, show infection rates over 30%. Rather surprisingly, overall infection prevalence in symptomatic children was only slightly higher, around 40%. Studies including only one positive stool sample should be interpreted with caution as spontaneous clearance can occur.

The interaction between smoking, alcohol and the gut microbiome

The gastrointestinal microbiome is a complex echosystem that establishes a symbiotic, mutually beneficial relation with the host, being rather stable in health, but affected by age, drugs, diet, alcohol, and smoking. Alcohol and smoking contribute to changes in the stomach and affect H pylori-related disorders including the risk of gastric cancer. In the small intestine and in the colon alcohol causes depletion of bacteria with anti-inflammatory activity, eventually resulting in intestinal damage with "leaky gut". These changes contribute to hepatic damage in both alcoholic and non-alcoholic liver disease and have been associated with other disorders. Lactobacillus GG and A. muciniphila exert a protective effect in this setting. Smoking leads to modifications of the gut microbiome linked with a protective effect toward ulcerative colitis and deleterious for Crohn's disease. The exact cause-effect relation between alcohol and smoking and changes of the gastrointestinal microbiome needs further exploration with high throughput methodologies, and controlled studies are necessary to define the role of microbiome modulation on the immune response and systemic activation of pro-inflammatory pathways.

Efficacy and safety of probiotic-supplemented triple therapy for eradication of Helicobacter pylori in children: a systematic review and network meta-analysis

AIM

The aim of this study was to identify the best probiotic supplementation in triple therapy for pediatric population with Helicobacter pylori infection.

METHODS

Eligible trials were identified by comprehensive searches. Relative risks with 95% confidence intervals and relative ranks with P scores were assessed.

RESULTS

Twenty-nine trials (3122 participants) involving 17 probiotic regimens were identified. Compared with placebo, probiotic-supplemented triple therapy significantly increased H. pylori eradication rates (relative ratio (RR) 1.19, 95% CI 1.13-1.25) and reduced the incidence of total side effects (RR 0.49, 95% CI 0.38-0.65). Furthermore, to supplemented triple therapy, Lactobacillus casei was identified the best for H. pylori eradication rates (P score = 0.84), and multi-strain of Lactobacillus acidophilus and Lactobacillus rhamnosus for total side effects (P score = 0.93). As for the subtypes of side effects, multi-strain of Bifidobacterium infantis, Bifidobacterium longum, L. acidophilus, L. casei, Lactobacillus plantarum, Lactobacillus reuteri, L. rhamnosus, Lactobacillus salivarius, Lactobacillus sporogenes, and Streptococcus thermophilus was the best to reduce the incidence of diarrhea; multi-strain of Bacillus mesentericus, Clostridium butyricum, and Streptococcus faecalis for loss of appetite; multi-strain of B. longum, Lactobacillus bulgaricus, and S. thermophilus for constipation; multi-strain of Bifidobacterium bifidum, B. infantis, L. acidophilus, L. bulgaricus, L. casei, L. reuteri, and Streptococcus for taste disturbance; Saccharomyces boulardii for bloating; and multi-strain of Bifidobacterium breve, B. infantis, L. acidophilus, L. bulgaricus, L. casei, L. rhamnosus, and S. thermophilus for nausea/vomiting.

CONCLUSIONS

Probiotics are recommended to supplement triple therapy in pediatrics, and the effectiveness of triple therapy is associated with specific probiotic supplementation.

Sex-differences in the prevalence of Helicobacter pylori infection in pediatric and adult populations: Systematic review and meta-analysis of 244 studies

BACKGROUND

The main outcome of Helicobacter pylori infection, i.e. gastric cancer, is more frequent in men, but there is no comprehensive synthesis of the evidence on a potential role of sex in the acquisition and/or persistence of infection.

AIMS

To quantify the association between sex and H. pylori infection in pediatric and adult populations, through systematic review and meta-analysis.

METHODS

PubMed^® was searched, from inception to September 2015, to identify population-based studies reporting the prevalence and/or incidence of H. pylori infection in both sexes. Odds ratios (OR) or data to compute them were extracted; adjusted estimates were preferred, whenever available. The DerSimonian and Laird method was used to compute summary estimates and respective 95% confidence intervals (95%CI), separately for children and adults.

RESULTS

Among a total of 244 studies, mostly cross-sectional, male sex was associated with a greater prevalence of H. pylori infection, both in children (102 studies, OR=1.06, 95%CI: 1.01, 1.12, I²=43.7%) and adults (169 studies, OR=1.12, 95%CI: 1.09, 1.15, I²=68.5%). An underrepresentation of studies showing a negative association between male sex and infection was observed (Egger's test: p=0.006).

CONCLUSIONS

Although further research is needed to understand the mechanisms by which sex may influence the acquisition and/or persistence of infection, our results support a small contribution of sex differences in the prevalence of infection to the male predominance of H. pylori-related outcomes, including gastric cancer.

Epidemiology, Diagnosis, and Risk Factors of Helicobacter pylori Infection in Children

H. pylori infection is a global public health problem associated with some gastrointestinal diseases in children, especially in developing countries, since prevalence of H. pylori is low in the developed world. Both noninvasive (stool antigen test, urea breath test, and blood test) and invasive (histology, rapid urease test, and microbiological culture) tests have been utilized to detect H. pylori infection. However, a single test is not reliable enough and does not provide accurate enough data to determine H. pylori infection among children. Risk factors of H. pylori infection in children were related to ethnicities, household properties, geographic location, living conditions, water sources, type of housing, presence/absence of sewage systems, and garbage collection within the living environment. These risk factors were usually associated with the socioeconomic status of the family. This review article aims to determine the gaps in the knowledge of the epidemiology, risk factors, and diagnostic tests of H. pylori infection among children.

How to cite this article: Ozbey G, Hanafiah A. Epidemiology, Diagnosis, and Risk Factors of Helicobacter pylori Infection in Children. Euroasian J Hepato-Gastroenterol 2017;7(1):34-39.

Surface expression of Helicobacter pylori HpaA adhesion antigen on Vibrio cholerae, enhanced by co-expressed enterotoxigenic Escherichia coli fimbrial antigens

Helicobacter pylori infection can cause peptic ulceration and is associated with gastric adenocarcinoma. This study aimed to construct and characterize a non-virulent Vibrio cholerae O1 strain, which grows more rapidly than H. pylori, as vector for H. pylori antigens for possible use as a vaccine strain against H. pylori. This was done by recombinant expression of the H. pylori adhesion antigen HpaA alone or, as a proof of principle, together with different colonization factor (CF) antigens of enterotoxigenic Escherichia coli (ETEC) which may enhance immune responses against HpaA. A recombinant V. cholerae strain co-expressing HpaA and a fimbrial CF antigens CFA/I or CS5, but not the non-fimbrial CF protein CS6, was shown to express larger amounts of HpaA on the surface when compared with the same V. cholerae strain expressing HpaA alone. Mutations in the CFA/I operon showed that the chaperon, possibly together with the usher, was involved in enhancing the surface expression of HpaA. Oral immunization of mice with formaldehyde-inactivated recombinant V. cholerae expressing HpaA alone or together with CFA/I induced significantly higher serum antibody responses against HpaA than mice similarly immunized with inactivated HpaA-expressing H. pylori bacteria. Our results demonstrate that a non-virulent V. cholerae strain can be engineered to allow strong surface expression of HpaA, and that the expression can be further increased by co-expressing it with ETEC fimbrial antigens. Such recombinant V. cholerae strains expressing HpaA, and possibly also other H. pylori antigens, may have the potential as oral inactivated vaccine candidates against H. pylori.

VacA and CagA Status as Biomarker of Two Opposite End Outcomes of Helicobacter pylori Infection (Gastric Cancer and Duodenal Ulcer) in a Moroccan Population

Helicobacter pylori (H. pylori) infection induces inflammation of the gastric mucosa, which may progress to precancerous lesions leading to gastric cancer. Pathological determinism is associated to some virulence genes of the bacterium, notably the vacA and cagA genes. The present study aimed to determine the H. pylori genotypes distribution and their association with sex, age and gastric diseases in a Moroccan population. Gastric biopsy was taken from 1079 consenting patients. The specimens were processed by PCR to identify H. pylori and to determine the genotypic profile by PCR characterizing vacA s, vacA m and vacA i regions directly from biopsies H. pylori positives. VacA genotyping revealed the predominance of vacA m2 (53.2%), vacA s2 (52.9%) and vacA i2 (52%). The most virulent vacA alleles (s1, i1 and m1) are more predominant in men (47.3%, 41.9% and 46.1% respectively) than in women (38.3%, 33.3% and 37% respectively). However, the association between vacA genotypes and age did not reach a statistical significant value. Logistic regression analysis results show that vacA i1m1 and vacA i1m2 genotypes were strongly associated with the risk of GC, the Odds Ratio (95% confidence interval) was 29.73 [5.08-173.73] and 9.17 [2.06-40.82] respectively, while vacAs1/cagA+ seems to be a risk factor for DU since it is inversely associated with GC (OR was 0.13 [0.02-0.75]. The results of this study suggest that vacA i1 genotype independently to vacAm status may be of a clinical usefulness and will help to identify patients at a high risk of GC development.

The role of environmental tobacco exposure and Helicobacter pylori infection in the risk of chronic tonsillitis in children

CONTEXT AND OBJECTIVE:

Helicobacter pylori (H. pylori) is a chronic infectious pathogen with high prevalence. This study investigated the interaction between environmental tobacco exposure and H. pylori infection on the incidence of chronic tonsillitis in Chinese children.

DESIGN AND SETTING:

Cross-sectional study performed in an outpatient clinic in China.

METHODS:

Pediatric patients with chronic tonsillitis were enrolled. H. pylori infection was determined according to the presence of H. pylori CagA IgG antibodies. Serum cotinine levels and environmental tobacco smoke (ETS) exposure were determined for all participants.

RESULTS:

There was no significant difference in H. pylori infection between the children with chronic tonsillitis and children free of disease, but there was a significant difference in ETS between the two groups (P = 0.011). We next studied the association between ETS and chronic tonsillitis based on H. pylori infection status. In the patients with H. pylori infection, there was a significant difference in ETS distribution between the chronic tonsillitis and control groups (P = 0.022). Taking the participants without ETS as the reference, multivariate logistic regression analysis showed that those with high ETS had higher susceptibility to chronic tonsillitis (adjusted OR = 2.33; 95% CI: 1.67-3.25; adjusted P < 0.001). However, among those without H. pylori infection, ETS did not predispose towards chronic tonsillitis.

CONCLUSION:

Our findings suggest that tobacco exposure should be a putative mediator risk factor to chronic tonsillitis among children with H. pylori infection.

Diversification of the vacAs1m1 and vacAs2m2 Strains of Helicobacter pylori in Meriones unguiculatus

The bacterium Helicobacter pylori exhibits great genetic diversity, and the pathogenic roles of its virulence factors have been widely studied. However, the evolutionary dynamics of H. pylori strains during stomach colonization are not well-characterized. Here, we analyzed the microevolutionary dynamics of the toxigenic strain vacAs1m1, the non-toxigenic strain vacAs2m2, and a combination of both strains in an animal model over time. Meriones unguiculatus were inoculated with the following bacteria: group 1-toxigenic strain vacAs1m1/cagA+/cagE+/babA2+; ST181, group 2-non-toxigenic strain vacAs2m2/cagA+/cagE+/babA2+; ST2901, and group 3-both strains. The gerbils were euthanized at different time points (3, 6, 12, and 18 months). In group 1, genetic alterations were observed at 6 and 12 months. With the combination of both strains, group 3 also exhibited genetic alterations at 3 and 18 months; moreover, a chimera, vacA m1-m2, was detected. Additionally, four new sequence types (STs) were reported in the PubMLST database for H. pylori. Synonymous and non-synonymous mutations were analyzed and associated with alterations in amino acids. Microevolutionary analysis of the STs (PHYLOViZ) identified in each group revealed many mutational changes in the toxigenic (vacAs1m1) and non-toxigenic (vacAs2m2) strains. Phylogenetic assessments (eBURST) did not reveal clonal complexes. Our findings indicate that the toxigenic strain, vacAs1m1, and a combination of toxigenic and non-toxigenic strains acquired genetic material by recombination. The allelic combination, vacAs2m1, displayed the best adaptation in the animal model over time, and a chimera, m1-m2, was also identified, which confirmed previous reports.

Genotyping of Peroxisome Proliferator-Activated Receptor gamma in Iranian Patients with Helicobacter pylori Infection

Helicobacter pylori (H. pylori) infection as a serious problem in both adults and children can induce chronic gastritis, peptic ulcer disease (PUD), and possibly gastric cancer. The aim of the current study was to survey antibiotic resistance and also to determine influence of PPARγ polymorphism in patients with H. pylori infection. During an 11-month-period, 98 H. pylori isolates were collected from 104 biopsy specimens. In vitro susceptibility of H. pylori isolates to 4 antimicrobial agents metronidazole, clarithromycin, amoxicillin and tetracycline were assessed by quantitative method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guideline. PPARγ polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of H. pylori infection in our study was 94.2%. In vitro susceptibility data showed that highest level of resistance was related to metronidazole (66.3%), and the majority of H. pylori isolates were highly susceptible to amoxicillin and tetracycline (94.9% and 96.9%, respectively). Genotypic frequencies were 25.5% for CC (Pro12Pro), 40.8% for GC (Pro12Ala) and 33.7% for GG (Ala12Ala). In our study, CG genotype had highest distributions among infected patients with H. pylori. The study suggests that the PPAR-γ Pro12Ala polymorphism could be evaluated as a potential genetic marker for susceptibility to gastric cancer in the presence of H. pylori infection.

Inefficacy of triple therapy and comparison of two different bismuth-containing quadruple regimens as a firstline treatment option for helicobacter pylori

BACKGROUND/AIM

Increasing resistance of Helicobacter pylori to antimicrobials necessitated the development of new regimens and the modification of existing regimens. The present study aimed to compare the efficacy of two bismuth-containing quadruple regimens-one including clarithromycin (C) instead of metronidazole (M) and triple therapy.

PATIENTS AND METHODS

Patients with H. pylori infection given the following regimens were sequentially enrolled in this retrospective study: (1) Triple therapy: Lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d., and amoxicillin 1 g b.i.d., (2) bismuth group C: Lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d., amoxicillin 1 g b.i.d., and bismuth subsalicylate 524 mg b.i.d., and (3) bismuth group M: Lansoprazole 30 mg b.i.d., amoxicillin 1 g b.i.d., metronidazole 500 mg t.i.d., and bismuth subsalicylate 524 mg b.i.d. for 14 days. Gastroscopy and 14 C-urea breath test were performed before enrollment, and urea breath test was repeated four weeks after the treatment.

RESULTS

At per-protocol analysis, the eradication rates were 64.7% (95% confidence interval 60.4-68.7) with the triple therapy (n = 504), 95.4% (95% confidence interval 91.5-99.4) with the bismuth group C (n = 501), and 93.9% (95% confidence interval 89.7-98.7) with the bismuth group M (n = 505). The eradication rates were similar between the two bismuth groups (P > 0.05) but significantly greater than that of the triple therapy (P < 0.05).

CONCLUSION

In our study, both of the bismuth-containing quadruple therapies reached high eradication rates, whereas triple therapy was shown to be ineffective. Moreover, clarithromycin may also be a component of bismuth-containing quadruple therapy.

Severe gastritis decreases success rate of Helicobacter pylori eradication

BACKGROUND

In several studies, different risk factors other than antibiotic resistance have been documented with Helicobacter pylori eradication failure. We aimed in this study to investigate the relationship of gastric density of H. pylori, the occurrence/degree of gastric atrophy, and intestinal metaplasia (IM) with success rate of H. pylori eradication.

METHODS

Two hundred consecutive treatment naive patients who received bismuth containing standart quadruple treatment due to H. pylori infection documented by histopathological examination of two antral or two corpal biopsies entered this retrospective study. The updated Sydney system was used to grade the activity of gastritis, density of H. pylori colonization, atrophy, and IM. Stages III and IV of operative link for gastritis assessment (OLGA) or the operative link on gastric intestinal metaplasia assessment (OLGIM) stages was considered as severe gastritis. H. pylori eradication was determined via stool H. pylori antigen test performed 4 weeks after the end of therapy.

RESULTS

The presence of gastric atrophy and IM was significantly higher in patients with eradication failure (p = 0.001 and 0.01, respectively). Severe gastritis (OLGA III-IV and OLGIM III-IV) rates were higher in eradication failure group. A multiple linear regression analysis showed that OLGA and OLGIM stages were to be independent risk factors for eradication failure (p = 0.03 and 0.01, respectively).

CONCLUSION

Our results suggested that histopathologically severe gastritis may cause H. pylori eradication failure. In addition, we found that H. pylori density was not a risk factor for treatment failure in patients who receive quadruple treatment.