A mixed population of Helicobacter pylori, Helicobacter bizzozeronii and "Helicobacter heilmannii" in the gastric mucosa of a domestic cat

Clinical presentation and outcomes of Helicobacter heilmannii gastritis in children in the New England region of the United States

OBJECTIVE

To describe the clinical, endoscopic, histologic, and treatment outcomes of Helicobacter heilmannii (H. heilmannii) associated gastritis in children in the New England region of the United States.

METHODS

Retrospective study of children (1-18 years) with H. heilmannii identified on gastric mucosal biopsies from two pediatric centers over a 21-year period, January 2000-December 2021. Cases were identified by querying pathology databases at each institution. Demographic and clinical data were obtained from the medical record. Endoscopic and histologic findings were extracted from endoscopy and pathology reports, respectively.

RESULTS

Thirty-eight children were diagnosed with H. heilmannii-associated gastritis during the study period. The mean age at diagnosis was 10.1 ± 5.3 years, and 25/38 (66%) cases were male. Abdominal pain (32%) and nausea with or without vomiting (26%) were the most common symptoms. Thirty-two children (84%) had endoscopic findings including gastric nodularity (55%) and erythema (26%). All children had histologic signs of chronic gastritis, including those with normal endoscopic exams. Antibiotic regimens used for treating Helicobacter pylori were frequently prescribed. Of the 17 children who underwent a follow-up endoscopy (range 2-68 months), 15 (88%) did not have H. heilmannii identified on gastric biopsies.

CONCLUSION

H. heilmannii was an infrequent but potential cause of epigastric abdominal pain and nausea in our cohort of New England children. While morphologically distinct from H. pylori, the bacteria can result in similar endoscopic and histologic findings of nodularity and chronic gastritis, respectively. The rate of eradication, as assessed by histology following treatment with H. pylori therapies, was below the 90% recommended goal for antimicrobial therapies.

An investigative study on the zoonotic potential of Helicobacter pylori

BACKGROUND

Helicobacter pylori is one of the most common bacterial infections and is widespread globally. It causes a variety of gastrointestinal disorders, though a great proportion of infections are asymptomatic. A total of 143 fresh stool samples were collected from apparently healthy farm and pet animals (43 cattle, 50 buffaloes, 50 sheep, 50 dogs, and 50 cats), in addition to 768 human stool samples. The samples were examined using stool antigen and rapid antibody tests, and further confirmation of glmM "human antigen-positive samples and animal milk samples" was conducted by polymerase chain reaction (PCR).

RESULTS

The prevalence rates of H. pylori infection in animals were 22.2% and 16% in antibody and stool antigen tests, respectively. The detection rates were 28%, 24%, 12%, 10%, and 4.7% in cats, dogs, buffaloes, sheep, and cattle, respectively. On the other hand, the prevalence rate of H. pylori infection in human stool samples was 74.8%, and a statistically significant association was observed between prevalence and several factors, such as sex, age, and locality. PCR was performed to detect the glmM gene of H. pylori, and this gene was found in 21 of 27 human antigen-positive samples and 5 of 13 animal milk samples.

CONCLUSIONS

H. pylori was detected in both human and animal samples. Furthermore, glmM was found in milk and human samples. Our findings suggest that pet and farm animals could transmit H. pylori infection to humans.

Helicobacter spp. in the Stomach of Cats: Successful Colonization and Absence of Relevant Histopathological Alterations Reveals High Adaptation to the Host Gastric Niche

In addition to Helicobacter pylori, many non-Helicobacter pylori Helicobacters (NHPH) are able to cause gastric disease in humans. Cats are a natural reservoir for many of these species. Accordingly, living in close and intimate contact with animals has been identified as a risk factor, and an important zoonotic significance has therefore been attributed to NHPH. To determine the prevalence and associated gastric histopathological changes of Helicobacter species, the gastric mucosa of 71 cats were evaluated. Only four presented normal histopathological mucosa with the absence of spiral-shaped organisms. Normal gastric mucosa and the presence of spiral-shaped bacteria were observed in 13 cats. The remaining animals presented histopathological changes representative of gastritis. Helicobacter species were detected in 53 cats (74.6%) by at least one detection method. None of the animals were positive for H. pylori or for H. ailurogastricus. Helicobacter heilmannii organisms were identified in 20 animals, predominantly in the body gastric region. Helicobacter salomonis was the second most prevalent species (57.1%), although it was mainly found in association with other NHPH. Helicobacter felis and H. bizzozeronii were less frequently detected. The great majority of the Helicobacter spp. PCR-positive animals presented normal features regarding fibrosis/mucosal atrophy, neutrophils, eosinophils, or other inflammatory cells and lymphofollicular hyperplasia. Given the controversy and the strong evidence of absence of significant histopathological alterations associated with the presence of Helicobacter spp. in cats, it is possible to hypothesize that these bacteria may be able to adapt to the feline gastric microenvironment or even to comprise part of the gastric microbiome of this animal species. Thus, prudency must be taken when prescribing an antibiotic therapy based solely on the presence of these bacteria in the feline stomach.

Helicobacter genus in the intestine and liver of stray cats: the molecular, histopathological, and immunohistochemical study

OBJECTIVES

The study was designed to determine the presence of Helicobacter genus and three species of H. pylori, H. bilis, and H. canis, in the duodenum, ileum, colon, and liver of stray cats. Moreover, the histopathological and immunohistochemical analyses have been performed.

METHODS

Samples were taken from the duodenum, ileum, colon, and liver of 30 cats for molecular and histopathological evaluations. Polymerase chain reaction was carried out for the detection of the Helicobacter genus in the mentioned samples. Then, species-specific primers were used in Helicobacter-positive samples.

RESULTS

Helicobacter genus prevalence rates in the duodenum, ileum, colon, and liver samples were 50%, 60%, 50%, and 43.3%, respectively. Helicobacter pylori, H. canis, and H. bilis were isolated from at least one tissue of 18 (60%), 13 (43.3%), and 8 (26.7%) of the cats, respectively. Immunohistochemical findings confirmed the presence of bacteria in the intestinal crypt or the mucosal layer of duodenum, ileum, colon, and hepatic sinusoids.

CONCLUSION

In the present study, the concurrent infection of duodenum and liver was noticeable. Furthermore, the high prevalence of H. pylori in cats, as a well-known human pathogen, should be considered. High incidence of Helicobacter in gut and liver of Ahvaz stray cats is noticeable. According to the zoonotic importance of Helicobacter, more studies in the field of treatment and prevention are highly recommended.

Helicobacter pylori-induced gastric pathology: insights from in vivo and ex vivo models

Gastric colonization with Helicobacter pylori induces diverse human pathological conditions, including superficial gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric adenocarcinoma and its precursors. The treatment of these conditions often relies on the eradication of H. pylori, an intervention that is increasingly difficult to achieve and that does not prevent disease progression in some contexts. There is, therefore, a pressing need to develop new experimental models of H. pylori-associated gastric pathology to support novel drug development in this field. Here, we review the current status of in vivo and ex vivo models of gastric H. pylori colonization, and of Helicobacter-induced gastric pathology, focusing on models of gastric pathology induced by H. pylori, Helicobacter felis and Helicobacter suis in rodents and large animals. We also discuss the more recent development of gastric organoid cultures from murine and human gastric tissue, as well as from human pluripotent stem cells, and the outcomes of H. pylori infection in these systems.

Epidemiological study on feline gastric Helicobacter spp. in Japan

Epidemiological and pathological studies on Helicobacter spp. in feline stomachs in Japan were conducted using genus- and species-specific (H. felis, H. bizzozeronii, H. heilmannii sensu stricto [s.s.] and H. pylori) polymerase chain reactions (PCRs), ureAB gene sequencing and histopathology. PCR results showed that 28 of 56 cats were infected with Helicobacter spp., and H. heilmannii s.s. was the most prevalent species by both PCR (28/28) and ureAB gene sequencing (26/28). Some of the sequences showed high similarities with those from human patients with gastric diseases (99%). There were no significant differences between Helicobacter spp.-positive and -negative cats in the severity of chronic gastritis (P=0.69). This is the first extensive epidemiological study on feline gastric Helicobacter spp. in Japan.

The Other Helicobacters

In the past year, a substantial number of (putative) novel Helicobacter species have been described, including Helicobacter himalayensis colonizing the Himalayan marmot and Helicobacter apodemus, colonizing the Korean striped field mouse. In addition, a putative novel gastric Helicobacter species was identified in wild gorillas and chimpanzees, for which the name "Candidatus H. homininae" was proposed. A high incidence of gastric non-H. pylori Helicobacter infection was described in China and multiple case reports have described the involvement of enterohepatic Helicobacter species, especially Helicobacter cinaedi, in a wide range of diseases. Several studies in rodent models further elucidated the mechanisms underlying the development of gastric mucosa-associated lymphoid tissue lymphoma during infection with gastric non-H. pylori Helicobacters. The effects of infection with gastric Helicobacters on the development of neuroinflammation were investigated and several enterohepatic Helicobacter species were shown to affect the composition of the gut microbiota, to influence vaccine efficiency as well as the progression of cancer in distant sites of the body.