Abstract Background & aims Helicobacter pylori infection is increasingly difficult to treat. The purpose of these consensus statements is to review the literature and provide specific, updated ...recommendations for eradication therapy in adults. Methods A systematic literature search identified studies on H. pylori treatment. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Statements were developed through an online platform, finalized and voted on by an international working group of specialists chosen by the Canadian Association of Gastroenterology. Results Because of increasing failure of therapy, the consensus group strongly recommended that all H. pylori eradication regimens now be given for 14 days. Recommended first-line strategies include concomitant non-bismuth quadruple therapy (proton pump inhibitor, PPI + amoxicillin + metronidazole + clarithromycin, PAMC), and traditional bismuth quadruple therapy (PPI + bismuth + metronidazole + tetracycline, PBMT). PPI triple therapy (PPI + clarithromycin and either amoxicillin or metronidazole) was restricted to areas with known low clarithromycin resistance or high eradication success with these regimens. Recommended rescue therapies include PBMT and levofloxacin-containing therapy (PPI + amoxicillin + levofloxacin, PAL). Rifabutin regimens should be restricted to patients who fail at least 3 prior options. Conclusions Optimal treatment of H. pylori requires careful attention to local antibiotic resistance and eradication patterns. Quadruple therapies PAMC or PBMT should play a more prominent role in H. pylori eradication and all treatments should be given for 14 days.
The peptidoglycan sensor Nod2 and the autophagy protein ATG16L1 have been linked to Crohn’s disease (CD). Although Nod2 and the related sensor, Nod1, direct ATG16L1 to initiate anti-bacterial ...autophagy, whether ATG16L1 affects Nod-driven inflammation has not been examined. Here, we uncover an unanticipated autophagy-independent role for ATG16L1 in negatively regulating Nod-driven inflammatory responses. Knockdown of ATG16L1 expression, but not that of ATG5 or ATG9a, specifically enhanced Nod-driven cytokine production. In addition, autophagy-incompetent truncated forms of ATG16L1 regulated Nod-driven cytokine responses. Mechanistically, we demonstrated that ATG16L1 interfered with poly-ubiquitination of the Rip2 adaptor and recruitment of Rip2 into large signaling complexes. The CD-associated allele of ATG16L1 was impaired in its ability to regulate Nod-driven inflammatory responses. Overall, these results suggest that ATG16L1 is critical for Nod-dependent regulation of cytokine responses and that disruption of this Nod1- or Nod2-ATG16L1 signaling axis could contribute to the chronic inflammation associated with CD.
•ATG16L1 suppresses Nod1- and Nod2-driven cytokine responses•ATG16L1’s regulatory function is independent of its role in autophagosome formation•ATG16L1 negatively regulates Nod1 and Nod2 signaling via Rip2 activation•Crohn’s-disease-associated ATG16L1 allele is defective in Nod1 and Nod2 regulation
ABSTRACT
Background:
Because of the changing epidemiology of Helicobacter pylori infection and low efficacy of currently recommended therapies, an update of the European Society for Paediatric ...Gastroenterology Hepatology and Nutrition/North American Society for Pediatric Gastroenterology, Hepatology and Nutrition recommendations for the diagnosis and management of H pylori infection in children and adolescents is required.
Methods:
A systematic review of the literature (time period: 2009–2014) was performed. Representatives of both societies evaluated the quality of evidence using GRADE (Grading of Recommendation Assessment, Development, and Evaluation) to formulate recommendations, which were voted upon and finalized using a Delphi process and face‐to‐face meeting.
Results:
The consensus group recommended that invasive diagnostic testing for H pylori be performed only when treatment will be offered if tests are positive. To reach the aim of a 90% eradication rate with initial therapy, antibiotics should be tailored according to susceptibility testing. Therapy should be administered for 14 days, emphasizing strict adherence. Clarithromycin‐containing regimens should be restricted to children infected with susceptible strains. When antibiotic susceptibility profiles are not known, high‐dose triple therapy with proton pump inhibitor, amoxicillin, and metronidazole for 14 days or bismuth‐based quadruple therapy is recommended. Success of therapy should be monitored after 4 to 8 weeks by reliable noninvasive tests.
Conclusions:
The primary goal of clinical investigation is to identify the cause of upper gastrointestinal symptoms rather than H pylori infection. Therefore, we recommend against a test and treat strategy. Decreasing eradication rates with previously recommended treatments call for changes to first‐line therapies and broader availability of culture or molecular‐based testing to tailor treatment to the individual child.
Supergenes are tight clusters of loci that facilitate the co-segregation of adaptive variation, providing integrated control of complex adaptive phenotypes. Polymorphic supergenes, in which specific ...combinations of traits are maintained within a single population, were first described for 'pin' and 'thrum' floral types in Primula and Fagopyrum, but classic examples are also found in insect mimicry and snail morphology. Understanding the evolutionary mechanisms that generate these co-adapted gene sets, as well as the mode of limiting the production of unfit recombinant forms, remains a substantial challenge. Here we show that individual wing-pattern morphs in the polymorphic mimetic butterfly Heliconius numata are associated with different genomic rearrangements at the supergene locus P. These rearrangements tighten the genetic linkage between at least two colour-pattern loci that are known to recombine in closely related species, with complete suppression of recombination being observed in experimental crosses across a 400-kilobase interval containing at least 18 genes. In natural populations, notable patterns of linkage disequilibrium (LD) are observed across the entire P region. The resulting divergent haplotype clades and inversion breakpoints are found in complete association with wing-pattern morphs. Our results indicate that allelic combinations at known wing-patterning loci have become locked together in a polymorphic rearrangement at the P locus, forming a supergene that acts as a simple switch between complex adaptive phenotypes found in sympatry. These findings highlight how genomic rearrangements can have a central role in the coexistence of adaptive phenotypes involving several genes acting in concert, by locally limiting recombination and gene flow.
Highlights • Helicobacter pylori infection is strongly associated with gastric cancer. • H. pylori can manipulate the autophagy pathway of its host through the VacA virulence factor. • Altered ...autophagy can influence intracellular survival and persistence of H. pylori. • H. pylori -disrupted autophagy may promote an environment favoring gastric carcinogenesis.
Autophagy is emerging as a crucial defense mechanism against bacteria, but the host intracellular sensors responsible for inducing autophagy in response to bacterial infection remain unknown. Here we ...demonstrated that the intracellular sensors Nod1 and Nod2 are critical for the autophagic response to invasive bacteria. By a mechanism independent of the adaptor RIP2 and transcription factor NF-kappaB, Nod1 and Nod2 recruited the autophagy protein ATG16L1 to the plasma membrane at the bacterial entry site. In cells homozygous for the Crohn's disease-associated NOD2 frameshift mutation, mutant Nod2 failed to recruit ATG16L1 to the plasma membrane and wrapping of invading bacteria by autophagosomes was impaired. Our results link bacterial sensing by Nod proteins to the induction of autophagy and provide a functional link between Nod2 and ATG16L1, which are encoded by two of the most important genes associated with Crohn's disease.
ABSTRACT
Objective:
As the clinical implications of Helicobacter pylori infection in children and adolescents continue to evolve, ESPGHAN and NASPGHAN jointly renewed clinical guidelines using a ...standardized evidence‐based approach to develop updated recommendations for children and adolescents in North America and Europe.
Methods:
An international panel of 11 pediatric gastroenterologists, 2 epidemiologists, 1 microbiologist, and 1 pathologist was selected by societies that developed evidence‐based guidelines based on the Delphi process with anonymous voting in a final face‐to‐face meeting. A systematic literature search was performed on 8 databases of relevance including publications from January 2000 to December 2009. After excluding nonrelevant publications, tables of evidence were constructed for different focus areas according to the Oxford classification. Statements and recommendations were formulated in the following areas: whom to test, how to test, whom to treat, and how to treat. Grades of evidence were assigned to each recommendation based on the GRADE system.
Results:
A total of 2290 publications were identified, from which 738 were finally reviewed. A total of 21 recommendations were generated, and an algorithm was proposed by the joint committee providing evidence‐based guidelines on the diagnostic workup and treatment of children with H pylori infection.
Conclusions:
These clinical practice guidelines represent updated, best‐available evidence and are meant for children and adolescents living in Europe and North America, but they may not apply to those living on other continents, particularly in developing countries with a high H pylori infection rate and limited health care resources.
The body depends on its physical barriers and innate and adaptive immune responses to defend against the constant assault of potentially harmful microbes. In turn, successful pathogens have evolved ...unique mechanisms to adapt to the host environment and manipulate host defenses.
(
), a human gastric pathogen that is acquired in childhood and persists throughout life, is an example of a bacterium that is very successful at remodeling the host-pathogen interface to promote a long-term persistent infection. Using a combination of secreted virulence factors, immune subversion, and manipulation of cellular mechanisms,
can colonize and persist in the hostile environment of the human stomach. Here, we review the most recent and relevant information regarding how this successful pathogen overcomes gastric epithelial host defense responses to facilitate its own survival and establish a chronic infection.
Inhibition of host macroautophagy/autophagy is one of the strategies used by several intracellular pathogens, including H. pylori, to escape killing. Here we discuss our recent work that revealed the ...novel mechanism by which the vacuolating cytotoxin A (VacA) produced by H. pylori inhibits lysosomal and autophagic killing. We discovered that VacA impairs the activity of the lysosomal calcium channel MCOLN1/TRPML1 leading to the formation of enlarged, dysfunctional lysosomes and autophagosomes that serve as an intracellular niche, which allows the bacteria to escape eradication therapy.
PDF
