Helicobacter pylori Infection Does Not Impact on Lung Transplant Outcome.

BACKGROUND: Helicobacter pylori (HP) is a spiral, gram-negative, microaerophilic bacterium that colonises the human gastric mucosa and is associated with gastrointestinal and extragastrointestinal disorders. Since no data are yet available on HP infection in lung transplant patients, we evaluated the prevalence and impact of HP infection in a population of such patients. METHODS: Sixty-seven lung transplant patients were enrolled in the study (35 females and 32 males, age 48.4 ± 13.3 years), 54 underwent bilateral and 13 single lung transplant. Serum antibodies against HP and CagA were assayed in all subjects. RESULTS: The prevalence of HP infection in lung transplant patients was similar to that in the general population (49.25% vs. 51.4%), whereas HP-positive patients showed lower CagA positivity (9% vs. 50.2%, p < 0.0001). There was a higher prevalence of HP infection in patients who underwent lung transplant because of pulmonary fibrosis (p = 0.049), and a lower prevalence in COPD patients (p = 0.011). No correlation was found between HP infection in lung transplant patients and graft outcome. No differences in primary graft dysfunction, acute rejection or bronchiolitis obliterans syndrome-free survival were found. However, more patients who required three or more post-transplant re-hospitalisations were observed among HP-positive patients. CONCLUSIONS: The prevalence of HP infection in lung transplant patients was comparable to that of the general population and to that reported in heart and kidney transplant recipients. It did not seem to impact short-, mid- or long-term lung allograft outcome. H. pylori infection did not prove to be clinically relevant in lung transplant patients.

Application of proteomics to the study of Helicobacter pylori and implications for the clinic.

INTRODUCTION: Helicobacter pylori (H. pylori) is a gram-negative bacterium that colonizes the gastric epithelium and mucous layer of more than half the world's population. H. pylori is a primary human pathogen, responsible for the development of chronic gastritis, peptic ulceration and gastric cancer. Proteomics is impacting several aspects of medical research: understanding the molecular basis of infection and disease manifestation, identification of therapeutic targets and discovery of clinically relevant biomarkers. Areas covered: The main aim of the present review is to provide a comprehensive overview of the contribution of proteomics to the study of H. pylori infection pathophysiology. In particular, we focused on the role of the bacterium and its most important virulence factor, CagA, in the progression of gastric cells transformation and cancer progression. We also discussed the proteomic approaches aimed at the investigation of the host response to bacterial infection. Expert commentary: In the field of proteomics of H. pylori, comprehensive analysis of clinically relevant proteins (functional proteomics) rather than entire proteomes will result in important medical outcomes. Finally, we provided an outlook on the potential development of proteomics in H. pylori research.

Polysorbate 80 and Helicobacter pylori: a microbiological and ultrastructural study.

BACKGROUND: The frequent occurrence of chemoresistant strains reduces the chances of eradication of H. pylori infection and prompted the investigation of non-antibiotic substances active against this organism. Some surfactants enhance the effectiveness of antibiotics for their permeabilizing properties towards bacteria. We examined the antimicrobial activity to H. pylori of the surfactant polysorbate 80, used alone and in association with amoxicillin, clarithromycin, metronidazole, levofloxacin and tetracycline. We also aimed to study the ultrastructural alterations caused upon H. pylori by polysorbate 80, alone and in combination with antibiotics. Twenty-two H. pylori strains were tested using the broth dilution method. After incubation, broth from each dilution was subcultured onto agar enriched with foetal bovine serum to determine the minimum bactericidal concentration (MBC). Synergistic effect of polysorbate 80 with antibiotics was investigated by the broth dilution and disc diffusion techniques. Ultrastructural alterations of organisms treated with polysorbate 80, alone and in association with antibiotics were analyzed by transmission electron microscopy. RESULTS: MBCs of polysorbate 80 ranged from 2.6 (1.1) µg/ml to 32 (0) µg/ml. Polysorbate 80 exerted a synergistic effect when associated with metronidazole and clarithromycin: polysorbate 80 and metronidazole MBCs decreased by ≥ 4 fold; clarithromycin MBCs for two resistant strains decreased by 20 and 1000 times. The principal alteration caused by polysorbate 80 consisted in the detachment of the outer membrane of bacteria. CONCLUSIONS: The bactericidal activity of polysorbate 80 and the synergistic effect of the association with metronidazole and clarithromycin could be useful in the treatment of H. pylori infection.

Factors modulating the outcome of treatment for the eradication of Helicobacter pylori infection.

A group of 180 H. pylori culture positive dyspeptic patients (64 patients with peptic ulcer, PU) completed a 2-week treatment with omeprazole, amoxicillin and metronidazole and underwent endoscopy again 6-8 weeks after the end of therapy. One hundred and twenty-four patients (68.8%) were successfully treated. Factors increasing the rates of eradication were the presence of PU (p=0.007) and anti-CagA serum antibodies (p=0.003). Factors negatively modulating eradication were the presence of coccoid forms (p=0.0008) and metronidazole-resistant strains (p=0.001); degrees of histological gastritis had no significant effect on eradication rates. Microscopic examination of smeared biopsies for the detection of the coccoid morphoytpe of H. pylori may help avoiding therapeutic failures.