Relating Phage Genomes to Helicobacter pylori Population Structure: General Steps Using Whole-Genome Sequencing Data.

The review uses the Helicobacter pylori, the gastric bacterium that colonizes the human stomach, to address how to obtain information from bacterial genomes about prophage biology. In a time of continuous growing number of genomes available, this review provides tools to explore genomes for prophage presence, or other mobile genetic elements and virulence factors. The review starts by covering the genetic diversity of H. pylori and then moves to the biologic basis and the bioinformatics approaches used for studding the H. pylori phage biology from their genomes and how this is related with the bacterial population structure. Aspects concerning H. pylori prophage biology, evolution and phylogeography are discussed.

Natural history of Helicobacter pylori infection in Mexican schoolchildren: incidence and spontaneous clearance.

OBJECTIVES: The aim of the present study was to estimate the incidence and spontaneous clearance rate of Helicobacter pylori infection and the effect of some variables on these outcomes in schoolchildren. METHODS: From May 2005 to December 2010, 718 schoolchildren enrolled in 3 public boarding schools in Mexico City participated in the follow-up. At the beginning of the study and every 6 months thereafter, breath samples were taken to detect H pylori infection; blood samples and anthropometric measurements were taken to evaluate nutritional status. Data on sociodemographic characteristics were collected. RESULTS: The prevalence of H pylori infection was 38%. The incidence rate was 6.36%/year. Schoolchildren with anemia or iron deficiency at the beginning of the study (who received iron supplements) showed a higher infection acquisition rate than those with normal iron nutritional status, hazard ratio (HR) 12.52 (95% confidence interval [CI] 4.01%-39.12%), P < 0.001 and HR 2.05 (95% CI 1.09%-3.87%), P = 0.027, respectively. The spontaneous clearance rate of the infection was 4.74%/year. The spontaneous clearance rate was higher in children who had iron deficiency (who received iron supplements), HR 5.02 (95% CI 1.33%-18.99%), P = 0.017, compared with those with normal nutritional iron status. It was lower in schoolchildren with ≥ 2 siblings compared with schoolchildren with 1 or no siblings, HR 0.23 (95% CI 0.08%-0.63%), P = 0.004. CONCLUSIONS: H pylori infection status is dynamic in schoolchildren. Variables related to health status and infection transmission, such as iron status and number of siblings, are important for the incidence and spontaneous clearance of H pylori infection.

Europe, the bull and the Minotaur: the biological legacy of a Neolithic love story.

The European cattle was domesticated 10 000 years ago in eastern Turkey, 1000 years later pottery-associated milk fats identify cattle-based dairy activity in western Turkey. Subsequently, the Indo-European language, domesticated animals and plants travel as a Neolithic package along two major routes across Europe. A striking south-east to north-west gradient of a mutation in the current European population (lactase persistence into adulthood) documents the expansion of a Neolithic dairy culture into a Mesolithic hunter society. Using oral tradition (myths), archaeological and written historical evidence and biological data, it is asked whether highly transmissible viral diseases like measles and smallpox entered during the Neolithic from domesticated animals into the human population. The bovine origin of paramyxovirus infections is likely; smallpox comes from camels or from rodents via cattle while mycobacteria and Helicobacter infected humans already before the Neolithic. Microbes adapt constantly and quickly to changing ecological situations. The current global environmental changes will lead to another highly dynamic phase of viral transmissions into the human population.

Helicobacter: a paradigm shift in peptic ulcer disease and more?

There are many diseases where the cause is unknown and this makes a specific treatment difficult. In many cases all that can be achieved is amelioration of the illness. Peptic ulcer disease was one such condition no more that 20 years ago. The management was drastic--either an operation or life-long medication in order to reduce the acid secreted by the stomach. However, the cause of this condition was discovered in 1983. Although initially sceptical, the medical fraternity now almost universally endorse Helicobacter pylori as the cause of the majority of stomach ulcers. Peptic ulcers can now be cured by antibiotics. This is a major shift in medical practice. Continued investigations on Helicobacter pylori are bringing to light other possible associations with disease as well as delineating plausible biological mechanisms for disease pathogenesis.

Use of a mouse model to examine anti-Helicobacter pylori agents.

A mouse model of Helicobacter infection of the gastric mucosa was evaluated for in vivo screening of new anti-Helicobacter pylori therapies. The aim of the study was to test antimicrobial agents with known anti-H. pylori effects in humans to validate that similar results were obtained in the mouse model. Specific pathogen-free mice were colonized with H. felis, a cat stomach isolate that has been shown to induce chronic gastritis in gnotobiotic mice. In H. felis-inoculated mice 4 weeks after treatment, only 25% were cleared with erythromycin, 47% with metronidazole, 0% with tetracycline, 70% with amoxycillin, and 25% with bismuth subcitrate. In contrast, triple therapy with metronidazole, amoxycillin, and bismuth subcitrate resulted in 80% eradication, whereas triple therapy with metronidazole, tetracycline, and bismuth subcitrate eradicated the Helicobacter from all the animals. We believe the similarities of these treatments to those reported in the literature for humans warrant the use of this model for the early screening of possible anti-H. pylori therapies, especially as in vitro testing has been found to be so non-predictive of therapeutic success.