Antimicrobial resistance of Helicobacter pylori in Germany, 2015 to 2018.

OBJECTIVES: National and international guidelines recommend empiric first-line treatments of individuals infected with Helicobacter pylori without prior antimicrobial susceptibility testing. For this reason, knowledge of primary resistance to first-line antibiotics such as clarithromycin is essential. We assessed the primary resistance of H. pylori in Germany to key antibiotics by molecular genetic methods and evaluated risk factors for the development of resistance. METHODS: Gastric tissue samples of 1851 yet treatment-naïve H. pylori-positive patients were examined with real-time PCR or PCR and Sanger sequencing for mutations conferring resistance to clarithromycin, levofloxacin and tetracycline. Clinical and epidemiological data were documented and univariable and multivariable logistic regression analyses were conducted. RESULTS: Overall primary resistances were 11.3% (210/1851) to clarithromycin, and 13.4% (201/1497) to levofloxacin; resistance to tetracycline (2.5%, 38/1497) was as low as combined resistance to clarithromycin/levofloxacin (2.6%, 39/1497). Female sex and prior antimicrobial therapies owing to unrelated bacterial infections were risk factors for clarithromycin resistance (adjusted OR (aOR) 2.3, 95% CI 1.6-3.4; and 2.6, 95% CI 1.5-4.5, respectively); older age was associated with levofloxacin resistance (aOR for those ≥65 years compared with those 18-35 years: 6.6, 95% CI 3.1-14.2). CONCLUSIONS: Clarithromycin might still be recommended in first-line eradication therapies in yet untreated patients, but as nearly every tenth patient may carry clarithromycin-resistant H. pylori it may be advisable to rule out resistance ahead of treatment by carrying out susceptibility testing or prescribing an alternative therapy.

[S2k-guideline Helicobacter pylori and gastroduodenal ulcer disease]. / S2k-Leitlinie Helicobacter pylori und gastroduodenale Ulkuskrankheit.

In the line "bismuth-containing quadruple therapy" of Table 7 (p 342), in the column "dosage" incorrectly at the three antibiotics respectively 1-1-1-1. The correct is: 3-3-3-3.

Feasibility and quality development of biomaterials in the pretest studies of the German National Cohort.

BACKGROUND: The German National Cohort (GNC) is designed to address research questions concerning a wide range of possible causes of major chronic diseases (e.g. cancer, diabetes, infectious, allergic, neurologic and cardiovascular diseases) as well as to identify risk factors and prognostic biomarkers for early diagnosis and prevention of these diseases. The collection of biomaterials in combination with extensive information from questionnaires and medical examinations represents one of the central study components. OBJECTIVES: In two pretest studies of the German National Cohort conducted between 2011 and 2013, a range of biomaterials from a defined number of participants was collected. Ten study centres were involved in pretest 1 and 18 study centres were involved in pretest 2. Standard operation procedures (SOP) were developed and evaluated to minimize pre-analytical artefacts during biosample collection. Within the pretest studies different aspects concerning feasibility of sample collection/preparation [pretest 1 (a)] and quality control of biomarkers and proteome analyses were investigated [pretest 1 (b), (c)]. Additionally, recruitment of study participants for specific projects and examination procedures of all study centres in a defined time period according to common standards as well as transportation and decentralized storage of biological samples were tested (pretest 2). These analyses will serve as the basis for the biomaterial collection in the main study of the GNC starting in 2014. MATERIALS AND METHODS: Participants, randomly chosen from the population (n = 1000 subjects recruited at ten study sites in pretest 1) were asked to donate blood, urine, saliva and stool samples. Additionally, nasal and oropharyngeal swabs were collected at the study sites and nasal swabs were collected by the participants at home. SOPs for sample collection, preparation, storage and transportation were developed and adopted for pretest 2. In pretest 2, 18 study sites (n = 599 subjects) collected biomaterials mostly identical to pretest 1. Biomarker analyses to test the quality of the biomaterials were performed. RESULTS: In pretest 1 and 2, it was feasible to collect all biomaterials from nearly all invited participants without major problems. The mean response rate of the subjects was 95 %. As one important result we found for example that after blood draw the cellular fraction should be separated from the plasma and serum fractions during the first hour with no significant variation for up to 6 h at 4 ℃ for all analysed biomarkers. Moreover, quality control of samples using a proteomics approach showed no significant clustering of proteins according to different storage conditions. All developed SOPs were validated for use in the main study after some adaptation and modification. Additionally, electronic and paper documentation sheets were developed and tested to record time stamps, volumes, freezing times, and aliquot numbers of the collected biomaterials. DISCUSSION: The collection of the biomaterials was feasible without major problems at all participating study sites. However, the processing times were in some cases too long. To avoid pre-analytical artefacts in sample collection, appropriate standardisation among the study sites is necessary. To achieve this, blood and urine collection will have to be adapted to specific conditions of usage of liquid handling robots, which will be available at all participating study centres in the main study of the GNC. Strict compliance with the SOPs, thorough training of the staff and accurate documentation are mandatory to obtain high sample quality for later analyses. The so obtained biomaterials represent a valuable resource for research on infectious and other common complex diseases in the GNC.

Presence of virulence genes, adhesion and invasion of Arcobacter butzleri.

AIMS: The pathogenic potential of Arcobacter butzleri isolates was investigated by detecting the presence of putative virulence genes and analysing the adhesive and invasive capabilities in cell cultures of human cell lines. METHODS AND RESULTS: The presence of ten putative virulence genes in 52 A. butzleri isolates was determined by PCR. The genes ciaB, mviN, pldA, tlyA, cj1349 and cadF were detected in all, whilst irgA (15%), iroE (60%), hecB (44%) and hecA (13%) were detected only in few A. butzleri isolates. On HT-29 cells, four of six isolates adhered to and three of them were able to invade, whilst all six isolates adhered to and invaded Caco-2 cells with higher degrees. The genes ciaB, cadF and cj1349 of all six isolates were sequenced, but no considerable changes of the amino acids in putative functional domains were observed. CONCLUSION: Selected A. butzleri isolates adhere to and invade HT-29 and Caco-2 cells, which emphasize their human pathogenic potential. The efficiency of invasion depends on the eukaryotic cell line and individual bacterial strain used. We could not show any functional correlation between the amino acid sequence of CadF, CiaB or Cj1349 and the adhesive and invasive phenotype. SIGNIFICANCE AND IMPACT OF THE STUDY: We have shown that some A. butzleri strains invade various cell lines. This underlines their pathogenic potential and hints at their relevance in human disease.

Is Helicobacter pylori antibiotic resistance surveillance needed and how can it be delivered?

BACKGROUND: Most patients are prescribed Helicobacter pylori treatment without culture and antibiotic susceptibility testing, as current guidance recommends that patients with recurrent dyspepsia should be tested for H. pylori using a non-invasive breath or faecal antigen test. AIMS: To determine the prevalence of H. pylori antibiotic resistance in patients attending endoscopy in England and Wales, and the feasibility of an antibiotic resistance surveillance programme testing. METHODS: We tested the antibiotic susceptibility of H. pylori isolates from biopsy specimens from 2063 of 7791 (26%) patients attending for endoscopy in Gloucester and Bangor, and 339 biopsy specimens sent to the Helicobacter Reference Unit (HRU) in London. Culture and susceptibility testing was undertaken in line with National and European methods. RESULTS: Helicobacter pylori were cultured in 6.4% of 2063 patients attending Gloucester and Bangor hospitals. Resistance to amoxicillin, tetracycline and rifampicin/rifabutin was below 3% at all centres. Clarithromycin, metronidazole and quinolone resistance was significantly higher in HRU (68%, 88%, 17%) and Bangor isolates (18%, 43%, 13%) than Gloucester (3%, 22%, 1%). Each previous course of these antibiotics is associated with an increase in the risk of antibiotic resistance to that agent [clarithromycin: RR = 1.5 (P = 0.12); metronidazole RR = 1.6 (P = 0.002); quinolone RR = 1.8 (P = 0.01)]. CONCLUSIONS: Helicobacter pylori infection is now uncommon in dyspeptic patients at endoscopy. A surveillance system is feasible and necessary to inform dyspepsia management guidance. Clinicians should take a thorough antibiotic history before prescribing metronidazole, clarithromycin or levofloxacin for H. pylori.

[Pathogenesis, diagnostics and treatment of Helicobacter pylori infection]. / Pathogenese, Diagnostik und Therapie der Helicobacter-pylori-Infektion.

More than one-half of the world population is infected with Helicobacter pylori. Of those, approx. 500,000 die from gastric carcinoma every year. Ulcer disease, gastricatrophy and the rare MALT lymphoma are other sequelae of H. pylori infection. H. pylori possesses an array of virulence factors that include urease, flagellar motility, adhesins, the vacuolating cytotoxin VacA and the protein CagA. The gene encoding CagA is located on the cag pathogenicity island, comprising 29 genes the majority of which encodes components of a type IV secretion system capable of translocating CagA into epithelial cells where it interferes with cellular signal transduction processes. A number of diagnostic tests for H. pylori infection require gastroendoscopy. These include the biopsy urease test, histology, culture with susceptibility testing, and molecular detection methods such as fluorescent in situ hybridization. Non-invasive tests that do not require endoscopy include the (13)C urea breath test, H. pylori stool antigen ELISA and serology. The latter is unsuitable for treatment follow-up, since antibody titres persist up to a year after successful treatment. When patients have never been treated for H. pylori infection, biopsy urease test and histology are usually sufficient for diagnosis. In patients where endoscopy is not required, H. pylori infection can be reliably detected by (13)C urea breath test, stool antigen ELISA or serology. Patients who have under gone one or more unsuccessful cycles of eradication therapy in most cases harbour H. pylori resistant to one or several antibiotics. In these patients, culture and antibiotic susceptibility testing are indicated. Patients who have never been treated for H. pylori infection usually harbour susceptible strains. In such patients, classic "Italian" or "French" triple therapies may achieve eradication in >90% of cases. In the case of treatment failure, second-line antibiotic treatment regiments (rescue therapy) are used, optimally guided by susceptibility data.

Linkage of autosomal dominant common variable immunodeficiency to chromosome 5p and evidence for locus heterogeneity.

Common variable immunodeficiency (CVID, OMIM 240500) and selective immunoglobulin A deficiency (IgAD) are the most frequent primary immunodeficiencies in humans. Of the cases with CVID/IgAD, 20%-25% are familial, but the only previous claims of linkage or association are to the HLA region on chromosome 6p. We report the results of a genome-wide scan in three multiplex families with CVID, IgAD, and dysgammaglobulinemia, where affection is inherited in an autosomal dominant pattern. Two of the families are consistent with linkage to the telomeric region of chromosome 5p, whereas the third is consistent with linkage to the HLA region. Using a locus heterogeneity model and a conservative penetrance model, we obtained a LOD score of 3.35 for the 5p region. We sequenced the exons of one promising candidate gene within this region (PDCD6, also known as ALG-2) but found no causative mutation.

Proteins encoded by the cag pathogenicity island of Helicobacter pylori are required for NF-kappaB activation.

Helicobacter pylori is the etiological agent in the development of chronic gastritis, duodenal ulceration, and gastric adenocarcinoma. The difference in virulence between individual strains is reflected in their ability to induce interleukin-8 (IL-8) secretion from gastric epithelial cells. It has been shown that virulence is associated with the presence of a bacterial gene cluster (a pathogenicity island). We have recently demonstrated that H. pylori-mediated IL-8 secretion requires activation of the transcription factor NF-kappaB. Here, we show that NF-kappaB induction requires six membrane proteins encoded within the pathogenicity island.

A secreted/shed product of Helicobacter pylori activates transcription factor nuclear factor-kappa B.

Helicobacter pylori is an etiologic agent in the development of chronic gastritis, duodenal ulceration, and gastric adenocarcinoma. Exposure of gastric epithelial cells to H. pylori induces secretion of the cytokine IL-8, which plays a pivotal role in the immunopathogenesis of H. pylori infections. Isolated Helicobacter strains differ in their virulence and in their ability to induce cytokine production. High degrees of virulence correlate with enhanced IL-8 production. However, the molecular mechanism of this variance in Helicobacter pathogenicity remains poorly understood. Here we show that H. pylori-mediated IL-8 secretion requires activation of the transcription factor nuclear factor-kappaB (NF-kappaB) in a gastric epithelial cell line. Several H. pylori strains which fail to induce IL-8 secretion do not activate NF-kappaB, while all IL-8-inducing strains activate the transcription factor. Moreover, the antioxidant curcumin, which inhibits NF-kappaB activation, also completely suppresses IL-8 induction by H. pylori. NF-kappaB activation is not mediated by LPSs, since purified H. pylori LPS had no effect on gastric epithelial cells. In contrast, both IL-8 secretion and NF-kappaB activation require a secreted H. pylori product, which is not secreted by strains mutated in picB/cagE, a recently identified putative transport protein.