Peptic ulcer disease associated with Helicobacter felis in a dog owner

[Detection of Helicobacter species in humans and their dog]

Helicobacter is a genus of Gram-negative bacteria that colonizes the stomach of humans and dogs, among other mammals. The most frequent species found in the gastric mucosa of man is H. pylori, however, there are other species of Helicobacter in the stomach of humans, such as H. suis, H. bizzozeronii, H. felis, H. salomonis and H. heilmannii sensu stricto, named non H. pylori Helicobacter (NHPH) some of which also colonize the dog's stomach. The detection of NHPH in the stomach mucosa of humans with gastric disease, and in a high percentage of dogs, suggests the possibility that these animals play an important role in the pathogenesis and transmission of infection to man, postulating the path of transmission oral-oral or fecal-oral. The aim of this study was to determine whether people with signs of chronic gastritis who have Helicobacter spp. and who own dogs as pets, share the same species with them. The presence of Helicobacter spp. in gastric samples of 30 people with clinical signs of chronic gastritis and histopathological diagnosis of gastric infection with Helicobacter spp. was analyzed by PCR. The presence of Helicobacter spp. was also studied in the dogs of these people. Then, the species of Helicobacter presented was determined in both. In human gastric samples, H. pylori was the only species found, while in dogs, samples were H. bizzozeronii, H. felis, H. salomonis and H. heilmannii. In this work the same species were not found in dogs and their owners.

Helicobacter bizzozeronii infection in a girl with severe gastric disorders in México: case report

BACKGROUND

Gastric non-Helicobacter pylori helicobacters (NHPH) naturally colonize the stomach of animals. In humans, infection with these bacteria is associated with chronic active gastritis, peptic ulceration and MALT-lymphoma. H. bizzozeronii belongs to these NHPH and its prevalence in children is unknown.

CASE PRESENTATION

This case report describes for the first time a NHPH infection in a 20-month-old girl with severe gastric disorders in Mexico. The patient suffered from melena, epigastric pain, and bloating. Gastroscopy showed presence of a Hiatus Hill grade I, a hemorrhagic gastropathy in the fundus and gastric body, and a Forrest class III ulcer in the fundus. Histopathologic examination revealed a chronic active gastritis with presence of long, spiral-shaped bacilli in the glandular lumen. Biopsies from antrum, body and incisure were negative for presence of H. pylori by culture and PCR, while all biopsies were positive for presence of H. bizzozeronii by PCR. Most likely, infection occurred through intense contact with the family dog. The patient received a triple therapy consisting of a proton pump inhibitor, clarithromycin, and amoxicillin for 14 days, completed with sucralfate for 6 weeks, resulting in the disappearance of her complaints.

CONCLUSION

The eradication could not be confirmed, although it was suggested by clear improvement of symptoms. This case report further emphasizes the zoonotic importance of NHPH. It can be advised to routinely check for presence of both H. pylori and NHPH in human patients with gastric complains.

Helicobacters and cancer, not only gastric cancer?

The Helicobacter genus actually comprises 46 validly published species divided into two main clades: gastric and enterohepatic Helicobacters. These bacteria colonize alternative sites of the digestive system in animals and humans, and contribute to inflammation and cancers. In humans, Helicobacter infection is mainly related to H. pylori, a gastric pathogen infecting more than half of the world's population, leading to chronic inflammation of the gastric mucosa that can evolve into two types of gastric cancers: gastric adenocarcinomas and gastric MALT lymphoma. In addition, H. pylori but also non-H. pylori Helicobacter infection has been associated with many extra-gastric malignancies. This review focuses on H. pylori and its role in gastric cancers and extra-gastric diseases, as well as malignancies induced by non-H. pylori Helicobacters. Their different virulence factors and their involvement in carcinogenesis is discussed. This review highlights the importance of both gastric and enterohepatic Helicobacters in gastrointestinal and liver cancers.

Zoonotic potential of Helicobacter spp

The genus Helicobacter contains more than 35 species. Helicobacter pylori is the most important in terms of human health. Discovery of these helicobacters gives opportunity to understand the relationship between these bacteria which colonise the animal and human gut and their effect on the host. Infection with Helicobacter spp. and the associated diseases in their hosts allow us to study the pathogenic mechanisms. The potential zoonotic pathway for the transmission of Helicobacter spp. and epidemiology of this genus, deserve more attention to these emerging pathogens.

Prevalence of Coinfection with Gastric Non-Helicobacter pylori Helicobacter (NHPH) Species in Helicobacter pylori-infected Patients Suffering from Gastric Disease in Beijing, China

BACKGROUND

The Helicobacter heilmannii sensu lato (H. heilmannii s.l.) group consists of long, spiral-shaped bacteria naturally colonizing the stomach of animals. Moreover, bacteria belonging to this group have been observed in 0.2-6% of human gastric biopsy specimens, and associations have been made with the development of chronic gastritis, peptic ulceration, and gastric MALT lymphoma in humans.

MATERIALS AND METHODS

To gain insight into the prevalence of H. heilmannii s.l. infections in patients suffering from gastric disease in China, H. heilmannii s.l. species-specific PCRs were performed on DNA extracts from rapid urease test (RUT)-positive gastric biopsies from 1517 patients followed by nucleotide sequencing. At the same time, Helicobacter pylori cultivation and specific PCR was performed to assess H. pylori infection in these patients.

RESULTS

In total, H. heilmannii s.l. infection was detected in 11.87% (178/1499) of H. pylori-positive patients. The prevalence of H. suis, H. felis, H. bizzozeronii, H. heilmannii sensu stricto (s.s.), and H. salomonis in the patients was 6.94%, 2.20%, 0.13%, 0.07%, and 2.54%, respectively. Results revealed that all patients with H. heilmannii s.l. infection were co-infected with H. pylori, and some patients were co-infected with more than two different Helicobacter species.

CONCLUSIONS

Helicobacter heilmannii s.l. infections are fairly common in Chinese patients. This should be kept in mind when diagnosing the cause of gastric pathologies in patients. Helicobacter suis was shown to be by far the most prevalent H. heilmannii s.l.species.

[Role of animal gastric Helicobacter species in human gastric pathology]

Animal Helicobacter species other than Helicobacter pylori are also able to cause human gastritis, gastric ulcers, and MALT lymphomas. Animal Helicobacter species are presented with typical spiral fastidious microorganisms colonizing the gastric mucosa of different animals. Bacteria initially received their provisional name Helicobacter heilmannii, and out of them at least five species colonizing the gastric mucosa of pigs, cats, and dogs were isolated later on. A high proportion of these diseases are shown to be zoonotic. Transmission of pathogens occurs by contact. The factors of bacterial pathogenicity remain little studied.

Presence and significance of Helicobacter spp. in the gastric mucosa of Portuguese dogs

BACKGROUND

Non-Helicobacter pylori Helicobacters (NHPH) are also able to cause disease in humans. Dogs are a natural reservoir for many of these species. Close and intense human contact with animals has been identified as a risk factor and therefore, an important zoonotic significance has been attributed to NHPH.

METHODS

To determine the prevalence of Helicobacter species and the gastric histopathological changes associated, gastric mucosa samples of 69 dogs were evaluated.

RESULTS

Only one dog presented a normal histopathological mucosa with absence of spiral-shaped organisms. A normal gastric mucosa and the presence of spiral-shaped bacteria was observed in two dogs. All remaining animals presented histopathological changes representative of gastritis. Helicobacter species were detected in 60 dogs (87.0%) by at least one detection method. Histological, histochemical and immunohistochemical evaluations revealed that Helicobacter spp. were present in 45 (65.2%), 52 (75.4%) and 57 (82.6%) dogs, respectively. Spiral-shaped bacteria were detected by qPCR analysis in 33 (47.8%) dogs. H. heilmannii-like organisms were identified in 22 animals (66.7%) and predominantly in the antral gastric region. H. salomonis was the second most prevalent species (51.5%) although it was mainly found in association with other Helicobacter spp. and in the body gastric region. H. bizzozeronii and H. felis were less frequently detected.

CONCLUSIONS

It was concluded that, despite the high incidence and worldwide distribution of gastric NHPH in dogs, the presence of specific Helicobacter species may vary between geographic regions. NHPH infections were significantly accompanied by mild to moderate intraepithelial lymphocyte infiltration and mild to moderate gastric epithelial injury, but a clear relationship between gastritis and Helicobacter infection could not be established.

Helicobacter heilmannii sensu stricto-related gastric ulcers: A case report

A spiral bacterium (SH9), morphologically different from Helicobacter pylori (H. pylori), was found in a 62-year-old woman’s gastric mucosa. Gastroscopic examination revealed multiple gastric ulcers near the pyloric ring; mapping gastric biopsy showed mild mononuclear infiltration with large lymphoid follicles in the antrum, without corpus atrophy. Urea breath test and H. pylori culture were negative, but Giemsa staining of biopsies revealed tightly coiled bacteria that immunostained with anti-H. pylori antibody. Sequencing of SH9 16S rRNA and the partial urease A and B subunit genes showed that the former sequence had highest similarity (99%; 1302/1315 bp) to Helicobacter heilmannii (H. heilmannii) sensu stricto (H. heilmannii s.s.) BC1 obtained from a bobcat, while the latter sequence confirmed highest similarity (98.3%; 1467/1493 bp) to H. heilmannii s.s. HU2 obtained from a human. The patient was diagnosed with multiple gastric ulcers associated with H. heilmannii s.s. infection. After triple therapy (amoxicillin, clarithromycin, and lansoprazole) with regimen for eradicating H. pylori, gastroscopy showed ulcer improvement and no H. heilmannii s.s. upon biopsy.

Gastric helicobacters in domestic animals and nonhuman primates and their significance for human health

Helicobacters other than Helicobacter pylori have been associated with gastritis, gastric ulcers, and gastric mucosa-associated lymphoid tissue lymphoma in humans. These very fastidious microorganisms with a typical large spiral-shaped morphology were provisionally designated "H. heilmannii," but in fact they comprise at least five different Helicobacter species, all of which are known to colonize the gastric mucosa of animals. H. suis, which has been isolated from the stomachs of pigs, is the most prevalent gastric non-H. pylori Helicobacter species in humans. Other gastric non-H. pylori helicobacters colonizing the human stomach are H. felis, H. salomonis, H. bizzozeronii, and the still-uncultivable "Candidatus Helicobacter heilmannii." These microorganisms are often detected in the stomachs of dogs and cats. "Candidatus Helicobacter bovis" is highly prevalent in the abomasums of cattle but has only occasionally been detected in the stomachs of humans. There are clear indications that gastric non-H. pylori Helicobacter infections in humans originate from animals, and it is likely that transmission to humans occurs through direct contact. Little is known about the virulence factors of these microorganisms. The recent successes with in vitro isolation of non-H. pylori helicobacters from domestic animals open new perspectives for studying these microorganisms and their interactions with the host.

Laboratory appraisal of optimal gaseous conditions for growth of zoonotic Helicobacter felis ATCC 49179

An attempt was made to assess the hitherto undescribed optimal gaseous conditions for growth of zoonotic Helicobacter felis, focusing on the ratio of spiral-forms amongst the whole cells examined. The largest mean colony diameter was obtained under the gaseous condition of O(2) 12% and CO(2) 10%. In analyzing the five day old colonies, the highest percentage of spiral forms (85.5%) was observed under the condition of O(2) 18% and CO(2) 5%. In contrast, the lowest percentage of spiral forms (2.3%) was demonstrated under the condition of O(2) 1% and CO(2) 10%. The condition of O(2) 12% and CO(2) 10% was concluded to be optimal for obtaining cells with the largest colony sizes, although colonies proliferated under such conditions definitely contain many more coccoid cells than spiral forms. In culturing H. felis strains, optimal gaseous conditions should be employed according to the purposes or preferences of study designs.

Phylogeny of a novel "Helicobacter heilmannii" organism from a Japanese patient with chronic gastritis based on DNA sequence analysis of 16S rRNA and urease genes

"Helicobacter heilmannii" is an uncultivable spiral-shaped bacterium inhabiting the human gastric mucosa. It is larger and more tightly-coiled than H. pylori. We encountered a patient with chronic gastritis infected a "H. heilmannii"-like organism (HHLO), designated as SH6. Gastric mucosa derived from the patient was orally ingested by specific pathogen free mice. Colonization of the mice by SH6 was confirmed by electron microscopy of gastric tissue specimens. In an attempt to characterize SH6, 16S rRNA and urease genes were sequenced. The 16S rRNA gene sequence was most similar (99.4%; 1,437/1,445 bp) to HHLO C4E from a cheetah. However, the urease gene sequence displayed low similarity (81.7%; 1,240/1,516 bp) with HHLO C4E. Taxonomic analysis disclosed that SH6 represents a novel strain and should constitute a novel taxon in the phylogenetic trees, being discriminated from any other taxon, with the ability of infecting human gastric mucosa.

Non-Helicobacter pylori helicobacters detected in the stomach of humans comprise several naturally occurring Helicobacter species in animals

Besides the well-known gastric pathogen Helicobacter pylori, other Helicobacter species with a spiral morphology have been detected in a minority of human patients who have undergone gastroscopy. The very fastidious nature of these non-Helicobacter pylori helicobacters (NHPH) makes their in vitro isolation difficult. These organisms have been designated 'Helicobacter heilmannii'. However, sequencing of several genes detected in NHPH-infected tissues has shown that the 'H. heilmannii' group comprises at least five different Helicobacter species, all of them known to colonize the stomach of animals. Recent investigations have indicated that Helicobacter suis is the most prevalent NHPH species in human. This species has only recently been isolated in vitro from porcine stomach mucosa. Other NHPH that colonize the human stomach are Helicobacter felis, Helicobacter bizzozeronii, Helicobacter salomonis and 'Candidatus Helicobacter heilmannii'. In numerous case reports of human gastric NHPH infections, no substantial information is available about the species status of the infecting strain, making it difficult to link the species with certain pathologies. This review aims to clarify the complex nomenclature of NHPH species associated with human gastric disease and their possible animal origin. It is proposed to use the term 'gastric NHPH' to designate gastric spirals that are morphologically different from H. pylori when no identification is available at the species level. Species designations should be reserved for those situations in which the species is defined.

Immunogenicity and pathogenicity of Helicobacter infections of veterinary animals

The initial discovery that the human stomach is commonly infected by the bacterium Helicobacter pylori subsequently resulted in the identification of a whole new family of pathogenic bacteria. In less than 25 years, the Helicobacter genus has grown from obscurity to number at least 38 different species with many more awaiting classifications. These bacteria, many of which are either direct or opportunistic pathogens, are present in virtually every mammalian species examined, and have also now been identified in a number of birds. The pathogenesis associated with these infections is predominantly the result of a chronic inflammatory response mounted by the host against the infection. This is typically a Th1-driven response which can result in a range of conditions from hepatitis, through gallstones to cancer. In some cases the inflammatory response to these infections is normally well managed by the host and disease only results when there is a breakdown or misbalance in the immunoregulatory process, which for example can result in inflammatory bowel disease in experimental models. Understanding the disease association and pathogenic mechanisms of the different Helicobacter infections is clearly of potential significance not only from an animal welfare point of view but also from the growing realisation of how commonly transmission of Helicobacter occurs between different mammals, including pathogenic zoonotic infections of humans.

Extragastric manifestations of Helicobacter pylori infection -- other Helicobacters

Today there is evidence that Helicobacter pylori has a critical role in different extragastric diseases. The discovery of a number of other novel Helicobacter species has stimulated the research in different extragastric diseases, in which an infectious hypothesis is plausible. Enterohepatic Helicobacter species have been hypothesized to play a role in different disorders, including hepatocellular carcinoma, gallstones formation and cholangiocellular carcinoma, as well as enteric diseases and inflammatory bowel diseases. Concerning the extragastric manifestations of H. pylori infection, idiopathic thrombocytopenic purpura, and sideropenic anemia represent, based on the current data, the diseases in which the pathogenic link appears to be strongest. There is also an increasing evidence for a possible association of H. pylori with cardiovascular disease.