Helicobacter spp. Other Than Helicobacter pylori

Abstract

Non-H. pylori Helicobacter species (NHPHS) are associated with several important human and animal diseases. In the past year research into this group of bacteria has continued to gain attention, and novel species have been described in new niches owing to improvements in detection methods. Polymerase chain reaction and/or sequencing remain the gold standard for the detection of this genus. New insights into the pathogenesis of the NHPHS in hepatobiliary, gastric, and intestinal diseases were gained. In particular, data revealed interaction between hepatic steatosis and infectious hepatitis in the development of hepatocellular carcinoma. Evidence of an association between hepatitis C virus and Helicobacter spp. in hepatocarcinoma development was also provided; and male sex hormone signaling appeared to influence infectious hepatitis induced by Helicobacter hepaticus. More findings support an association between Helicobacter heilmannii and gastric adenocarcinoma; and in mice, mucins MUC4 and MUC5 but not MUC1 influence the colonization and pathogenesis of Helicobacter felis. Data indicated that the roles of the adaptive immune system in H. hepaticus-induced intestinal tumorigenesis are different in the small and large intestines, and environmental factors, such as bile acids may modulate H. hepaticus carcinogenic potential. New reports in the prevention and eradication of NHPHS showed a protective response against Helicobacter suis induced by vaccine administration, and a successful cross-foster rederivation method successfully eradicated Helicobacter spp. from contaminated mice litters. Overall, the studies provided insights into the pathophysiology of Helicobacter species other than Helicobacter pylori.

Prevalence of an Unidentified <i>Helicobacter</i> Species in Laboratory Mice and its Distribution in the Hepatobiliary System and Gastrointestinal Tract

“…enterohepatic Helicobacter species also known to cause diseases, such as H. hepaticus and H. bilis, have been associated with hepatitis and intestinal diseases in certain strains of mice and rats [1,5,10,17,18,22,28]. Furthermore, some other Helicobacter species including H. felis, classified in the gastric group, and H. pullorum, classified in the enterohepatic group, have been detected in both humans and animals and are recognized as zoo-notic pathogens [5,22]. However, in contrast to the abundant reports of cases of these Helicobacter species, there are many species that have not yet been studied in detail with regard to the mechanisms of pathogenesis.…”

“…One of the best-characterized gastric species, H. pylori, is a pathogen of the gastric mucosa, causing inflammation, ulcers, and neoplasia in humans [15,20]. enterohepatic Helicobacter species also known to cause diseases, such as H. hepaticus and H. bilis, have been associated with hepatitis and intestinal diseases in certain strains of mice and rats [1,5,10,17,18,22,28]. Furthermore, some other Helicobacter species including H. felis, classified in the gastric group, and H. pullorum, classified in the enterohepatic group, have been detected in both humans and animals and are recognized as zoo-notic pathogens [5,22].…”

Campylobacter and helicobacter in the etiology of gastrointestinal diseases

“…H. heilmannii and H. felis have been rarely found in human stomach infections (Okoli et al, 2009) Intestinal Helicobacter species can enter the bloodstream, and it would therefore be expected that it could enter the liver. Despite detection of helicobacter 16s rDNA in liver tissues by PCR, there have been no published data of helicobacter cultivation or ultrastructural identification.…”

Refractory Chronic Pleurisy Caused by Helicobacter equorum-Like Bacterium in a Patient with X-Linked Agammaglobulinemia

“…In general, Helicobacter pylori is associated with gastritis, peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma (3). Also, non-H. pylori Helicobacter species are associated with gastric, intesti- nal, and hepatobiliary diseases in humans (3,10,14). This understanding is attributed to molecular diagnosis based on the sequencing of bacterial 16S and 23S rRNA genes, an analytical technique that has already proved useful for various bacterial infections during antimicrobial treatment (11), for rare or unexpected pathogens (11), and particularly for difficult-to-culture bacteria such as non-H. pylori Helicobacter species (3).…”

“…Since the discovery of Helicobacter pylori in 1984 (7), various Helicobacter species have been described in a wide variety of animal hosts, and transmission to humans has been suggested (3,10,14). In general, Helicobacter pylori is associated with gastritis, peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma (3).…”