Pathogenesis of Helicobacter pylori in Humans

Abstract

The Old World arenaviruses: taxonomic and zoonotic introduction Arenaviruses represent a fast-growing group of rodent-borne viruses (see Notes in the Proofs) which are an example of how environmental changes disrupt the natural animal virus-host balance and result in unexpected diseases. In the wild, arenaviruses exist as chronic infections in specific rodent hosts. This provides ideal conditions for competition within viral quasispecies for improved adaptation to the host. Analysis of arenavirus phylogeny and rodent cytochrome-b sequences provides examples of coevolution of arenaviruses with their rodent hosts. Based on their antigenic properties and geographic distribution approximately two dozen arenaviruses discovered so far are placed into two groups: the Old World (OW) or Lassa-LCMV complex and the New World (NW) or Tacaribe complex (Salvato et al., 2012). In general, the OW viruses are hosted by rodents of the family Muridae, subfamily Murinae. The NW arenaviruses are associated with rodents of the subfamily Sigmodontinae which are divided into the North and South American lineages. Phylogenetically the NW arenaviruses are further divided into clades A, B, C, and a recombinant A/B clade. Lymphocytic choriomeningitis virus (LCMV), the prototypic arenavirus that belongs to the OW group, is hosted by the house mouse (Mus musculus). The virus is distributed worldwide and can cause aseptic meningitis or meningoencephalitis in immunocompetent children and adults. Recent studies indicate that LCMV is also an under-recognized cause of congenital infection and neurological disease in the fetus and newborns (Bonthius, 2012; Laposova

Advances in diagnosis and treatment of Helicobacter pylori infection

“…The unipolar flagellum makes the bacterium highly motile for quick movements and attachments to gastric mucosa. According to some studies, H. pylori is naturally able to colonize on the surface of gastroduodenal mucosa of human beings, a relationship with a background of near 60,000 years old [1][2][3][4][5][6][7][8][9][10][11].…”