overcomes natural immunity in repeated infections.

Repeated experimental reinfection of two subjects indicates that infection does not promote an immune response protective against future reinfection. Our results highlight the importance of preventing reinfection after eradication, through public health initiatives, and possibly treatment of family members. They indicate difficulties for vaccine development, especially therapeutic vaccines.

A mutation burst during the acute phase of Helicobacter pylori infection in humans and rhesus macaques.

The evolution rate and genetic changes that occur during chronic infection with Helicobacter pylori have been analysed, but little is known about the genomic changes during the initial, acute bacterial infection phase. Here we analyse the rate and pattern of genome evolution in H. pylori from the genomes of two input strains isolated from human volunteers with asymptomatic infection, and the genomes of two output strains collected 20 and 44 days after re-infection.

Comparative analysis of the full genome of Helicobacter pylori isolate Sahul64 identifies genes of high divergence.

Isolates of Helicobacter pylori can be classified phylogeographically. High genetic diversity and rapid microevolution are a hallmark of H. pylori genomes, a phenomenon that is proposed to play a functional role in persistence and colonization of diverse human populations.

Helicobacter pylori genomic microevolution during naturally occurring transmission between adults.

The human gastric pathogen Helicobacter pylori is usually acquired during childhood and, in the absence of treatment, chronic infection persists through most of the host's life. However, the frequency and importance of H. pylori transmission between adults is underestimated.

Did transmission of Helicobacter pylori from humans cause a disease outbreak in a colony of Stripe-faced Dunnarts (Sminthopsis macroura)?

Since the discovery that Helicobacter pylori causes a range of pathologies in the stomachs of infected humans, it has become apparent that Helicobacters are found in a diverse range of animal species where they are frequently associated with disease. In 2003 and 2004, there were two outbreaks of increased mortality associated with gastric bleeding and weight-loss in a captive colony of the Australian marsupial, the Stripe-faced Dunnart (Sminthopsis macroura). The presence of gastric pathology led to an investigation of potential Helicobacter pathogenesis in these animals.

The peopling of the Pacific from a bacterial perspective.

Two prehistoric migrations peopled the Pacific. One reached New Guinea and Australia, and a second, more recent, migration extended through Melanesia and from there to the Polynesian islands. These migrations were accompanied by two distinct populations of the specific human pathogen Helicobacter pylori, called hpSahul and hspMaori, respectively.

Methodology and transport medium for collection of Helicobacter pylori on a string test in remote locations.

Background: Helicobacter pylori can be isolated from patients using the string test but contaminating oral and nasopharyngeal microflora need to be suppressed by rapid plating out onto selective culture media. Recently, use of this diagnostic method was enhanced by using a novel transport medium to collect specimens from subjects in a remote Australian clinic over 1300 km from the laboratory.

Methods: Retrieved string tests were transported to the laboratory in chilled polystyrene boxes in 5 ml screw-cap bottles with 3 ml of a brain heart infusion broth plus antibiotics.

Prevalence of Helicobacter pylori in Indigenous Western Australians: comparison between urban and remote rural populations.

Objectives: To determine and compare the prevalence of Helicobacter pylori in an urban and a remote rural Western Australian Indigenous community.

Design: Cross-sectional study of Helicobacter pylori status determined by urea breath tests between mid-January 2003 and the end of June 2004.

Participants: 520 self-selected fasting participants, comprising 270 members of the Martu community at Jigalong, Punmu and Parnngurr in the East Pilbara region (129 men, 141 women; age range, 2-90 years) and 250 people from the Perth Indigenous community (96 men, 154 women; age range, 3-75 years.

The relation of Helicobacter pylori to gastric adenocarcinoma and lymphoma: pathophysiology, epidemiology, screening, clinical presentation, treatment, and prevention.

Helicobacter pylori infection may be the most common chronic bacterial infection worldwide; however, the prevalence varies between countries and is usually linked to socioeconomic conditions. Gastric cancer is one of the most frequent cancers in developing countries and usually about the seventh most common in developed countries. This article explores the relation of H.

Nitazoxanide in treatment of Helicobacter pylori: a clinical and in vitro study.

Nitazoxanide (NTZ) is an antibiotic with microbiological characteristics similar to those of metronidazole but without an apparent problem of resistance. The aim of this study was the prospective evaluation of NTZ given as a single agent in the treatment of Helicobacter pylori infection. Twenty culture-positive patients with dyspepsia who had previously failed at least one course of H.

Evaluation of a new formulation CLOtest.

Background And Aims: The CLOtest and other rapid urease detection kits are widely used in the endoscopic diagnosis of Helicobacter pylori. A new formulation CLOtest has been developed with the goal of obtaining a positive result more rapidly. The aims of this study were to validate the sensitivity and specificity of the new test and compare the time taken for a positive result to be visible in both the new and standard CLOtest.