Gastric and Enterohepatic Helicobacters other than Helicobacter pylori

Abstract

During the past year, research on non-Helicobacter pylori species has intensified. H. valdiviensis was isolated from wild birds, and putative novel species have been isolated from Bengal tigers and Australian marsupials. Various genomes have been sequenced: H. bilis, H. canis, H. macacae, H. fennelliae, H. cetorum, and H. suis. Several studies highlighted the virulence of non-H. pylori species including H. cinaedi in humans and hyperlipidemic mice or H. macacae in geriatric rhesus monkeys with intestinal adenocarcinoma. Not surprisingly, increased attention has been paid to the position of Helicobacter species in the microbiota of children and animal species (mice, chickens, penguins, and migrating birds). A large number of experimental studies have been performed in animal models of Helicobacter induced typhlocolitis, showing that the gastrointestinal microbial community is involved in modulation of host pathways leading to chronic inflammation. Animal models of H. suis, H. heilmannii, and H. felis infection have been used to study the development of severe inflammation-related pathologies, including gastric MALT lymphoma and adenocarcinoma.

<b><i>Helicobacter pylori</i></b> and Other Gastric Microbiota in Gastroduodenal Pathologies

“…The family of Helicobacteraceae contains few species with human pathogenic potential besides H. pylori including H. heilmannii , and H. fennelliae and there are furthermore roughly 40 zoonotic species [3]. H. pylori is a gram-negative, spiral-shaped, motile and curved flagellated ε-Proteobacterium with the exclusive property to survive in the acidic environment of the stomach and causing chronic active gastritis in all infected subjects.…”

Genomic and clinical evidence uncovers the enterohepatic species Helicobacter valdiviensis as a potential human intestinal pathogen

“…In 2014, we described the species Helicobacter valdiviensis , a novel EHH isolated from wild bird fecal samples in the south of Chile (South America), and since then other putative new non‐ H. pylori species have been isolated from several wild animals . However, the zoonotic potential, pathogenicity, and clinical relevance of most of these emerging species remain to be investigated.…”

“…However, the zoonotic potential, pathogenicity, and clinical relevance of most of these emerging species remain to be investigated. A fundamental achievement has been the generation of whole‐genome sequences for many non‐ H. pylori species, whose comparison allowed to identify novel markers for molecular diagnostics and genetic variations putatively involved in virulence and antimicrobial resistance …”

Outer membrane phospholipase A’s roles in Helicobacter pylori acid adaptation

“…The Helicobacter genus comprises a versatile group of species that is found in different hosts, usually colonizing the intestine, liver, or stomach [4]. They can be divided into gastric- and enterohepatic- Helicobacters , with different morphology and genetic diverse lineages [5].…”