Helicobacter pylori: Survival in cultivable and non-cultivable form in artificially contaminated Mytilus galloprovincialis

Helicobacter pylori in the Oral Cavity: Current Evidence and Potential Survival Strategies

Helicobacter pylori (H. pylori) is transmitted primarily through the oral–oral route and fecal–oral route. The oral cavity had therefore been hypothesized as an extragastric reservoir of H. pylori, owing to the presence of H. pylori DNA and particular antigens in distinct niches of the oral cavity. This bacterium in the oral cavity may contribute to the progression of periodontitis and is associated with a variety of oral diseases, gastric eradication failure, and reinfection. However, the conditions in the oral cavity do not appear to be ideal for H. pylori survival, and little is known about its biological function in the oral cavity. It is critical to clarify the survival strategies of H. pylori to better comprehend the role and function of this bacterium in the oral cavity. In this review, we attempt to analyze the evidence indicating the existence of living oral H. pylori, as well as potential survival strategies, including the formation of a favorable microenvironment, the interaction between H. pylori and oral microorganisms, and the transition to a non-growing state. Further research on oral H. pylori is necessary to develop improved therapies for the prevention and treatment of H. pylori infection.

Milk and dairy products as a possible source of environmental transmission of Helicobacter pylori

Helicobacter pylori (H. pylori) is found worldwide, and it is estimated that more than 50% of the population is infected. The presence of H. pylori in the gastrointestinal tract is associated with the occurrence of serious human diseases such as chronic gastritis, duodenal ulcer or gastric cancer. Therefore, the International Agency for Research on Cancer classified H. pylori as a Group 1 carcinogen in 1994. The routes of H. pylori transmission are not yet precisely known. Many authors agree that humans may become infected by H. pylori through foodstuffs. Milk is one of the basic foods of people of all age categories. Helicobacter pylori has been isolated from milk derived from various livestock, such as cows, sheep, goat, camel or buffalo milk. This review research paper indicates that H. pylori may be present in different types of foods and suggests that consumption of milk and selected dairy products may be a source of H. pylori infection for humans.

Review: Epidemiology of Helicobacter pylori

This review summarizes the recent knowledge on the epidemiology of Helicobacter pylori and the potential modes of transmission. In addition to English language publications, the authors have included original full-text publications from Russia and Latin America published in the original languages. High H pylori prevalence has been reported in Russia, Jordan, Iran, China, and Latin American countries as well as in Arctic populations in Canada. Indigenous inhabitants in the Arctic were found to be infected substantially more frequently than non-indigenous inhabitants. In Amsterdam, the Netherlands, the ethnic minority groups were at a significantly higher risk of being H pylori seropositive compared to the Dutch population. For the first time, data on the prevalence from Armenia have been published indicating 41.5% H pylori prevalence. Convincing evidence on the decline of H pylori prevalence in Southeast Hungary and Taiwan was published. A study from Chile suggested high infection rates in newborns during the first month after birth. Two meta-analyses covered the potential correlation between H pylori and periodontal diseases, therefore addressing the potential oro-oral transmission rates. Periodontal disease was found to be more prevalent in H pylori-infected subjects. Other studies addressed the potential role of drinking water and food products as well as socioeconomic factors in transmitting the infection. Several studies in Asia addressed annual reinfection rates of H pylori, ranging from 1.5% in China to 3.1% in Korea. Finally, a review was published on the current evidence and future perspective of analysing H pylori in ancient human remains by a metagenomic approach.