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.

Gastric Helicobacter species associated with dogs, cats and pigs: significance for public and animal health

This article focuses on the pathogenic significance of Helicobacter species naturally colonizing the stomach of dogs, cats and pigs. These gastric "non-Helicobacter (H.) pylori Helicobacter species" (NHPH) are less well-known than the human adapted H. pylori. Helicobacter suis has been associated with gastritis and decreased daily weight gain in pigs. Several studies also attribute a role to this pathogen in the development of hyperkeratosis and ulceration of the non-glandular stratified squamous epithelium of the pars oesophagea of the porcine stomach. The stomach of dogs and cats can be colonized by several Helicobacter species but their pathogenic significance for these animals is probably low. Helicobacter suis as well as several canine and feline gastric Helicobacter species may also infect humans, resulting in gastritis, peptic and duodenal ulcers, and low-grade mucosa-associated lymphoid tissue lymphoma. These agents may be transmitted to humans most likely through direct or indirect contact with dogs, cats and pigs. Additional possible transmission routes include consumption of water and, for H. suis, also consumption of contaminated pork. It has been described that standard H. pylori eradication therapy is usually also effective to eradicate the NHPH in human patients, although acquired antimicrobial resistance may occasionally occur and porcine H. suis strains are intrinsically less susceptible to aminopenicillins than non-human primate H. suis strains and other gastric Helicobacter species. Virulence factors of H. suis and the canine and feline gastric Helicobacter species include urease activity, motility, chemotaxis, adhesins and gamma-glutamyl transpeptidase. These NHPH, however, lack orthologs of cytotoxin-associated gene pathogenicity island and vacuolating cytotoxin A, which are major virulence factors in H. pylori. It can be concluded that besides H. pylori, gastric Helicobacter species associated with dogs, cats and pigs are also clinically relevant in humans. Although recent research has provided better insights regarding pathogenic mechanisms and treatment strategies, a lot remains to be investigated, including true prevalence rates, exact modes of transmission and molecular pathways underlying disease development and progression.

An exploratory study on the presence of Helicobacter heilmannii and Helicobacter billis in the faces of companion dogs

Background

Companion animals like dogs play an important role in the lives of many people and are often considered to be members of families, but definitely, any contact with them poses an inherent risk of transmitting zoonotic pathogens. One of these pathogens is the genus Helicobacter which is linked to many disorders in human and animal.

Objectives

The aim of this study was to investigate the presence of some zoonotic species of genus Helicobacter in companion dogs.

Results

Through culturing in a special medium, nine samples (9%) were detected as infected (two pure and seven mixed culture). Based on multiplex‐PCR, 13 samples (13%) were infected by Helicobacter spp. although none of them were infected by H. pylori. Species‐specific PCR indicated that 38.5% or 5/13 of the samples were infected with H. heilmannii, while 15.45% or 2/13 of the samples were infected by H. billis. Multivariate logistic regression analysis showed that the age factor had a significant effect on Helicobacter spp. infection (odds ratio [OR] = 2.42, p = 0.01).

Conclusion

This study revealed the negligible faecal transmission of H. pylori. Moreover, due to the detection of H. Heilmannii and H. billis in feces and their association with human gastric diseases, dog owners should be educated about the risks and transmission modes of zoonotic bacterial infections of dogs.

Evidence of Helicobacter spp. in Saliva and Gastric Mucosa of Domestic Dogs in the Central Region of Rio Grande do Sul, Brazil

Helicobacter pylori is a spiral-shaped bacterium, which plays a role in the aetiology of gastric diseases in humans. Non-H. pylori Helicobacter (NHPH) species naturally colonise the stomach of animals and also induce gastric lesions in humans, highlighting their zoonotic importance. We evaluated the gastric bacterial colonisation density and gastric lesions and sought to identify the main phylogenetic groups of the Helicobacter spp. obtained from dogs in the central region of Rio Grande do Sul, Brazil, with this study aiming to investigate the occurrence of Helicobacter spp. in saliva and gastric samples from these dogs. This study included 35 dogs and used analysis such as cytology, histopathology, PCR, rapid urease testing, and phylogenetic analysis. Of the dogs, 94.3% were positive for Helicobacter spp., and these bacteria were present in the stomach of 32 dogs and saliva of eight. Respectively, eight, 15, and nine dogs had mild, moderate, and severe colonisation. Lymphocytic-plasmacytic infiltrate was the main gastric lesion. However, the presence of Helicobacter and the density appeared to be unrelated to the gastric lesions. The samples possessed a high nucleotide identity with remarkably similar sequences among some of the species of NHPH such as H. heilmannii s.s., H. salomonis, H. felis, and H. bizzozeronii. The saliva of domestic dogs, even of those who appear clinically healthy, can cause Helicobacter infection in humans and other animals, with, in these dogs, increased density, occurrence rate, and predominance of NHPH of zoonotic importance being found in the stomach with a lower occurrence of Helicobacter spp. in the saliva.

Diagnostic reliability of nested PCR depends on the primer design and threshold abundance of Helicobacter pylori in biopsy, stool, and saliva samples

BACKGROUND

The aim of this work was to find a reliable nested PCR for the detection of Helicobacter pylori in biopsy, stool, and saliva specimens.

MATERIALS AND METHODS

Novel nested PCR was elaborated and validated on 81 clinical biopsy, stool, and saliva samples from the same individual and compared to available H pylori assays: histology, rapid urease test (RUT), stool antigen test (SAT), ¹³ C-urea breath test (UBT).

RESULTS

The efficiency and selectivity of 17 published nested polymerase chain reactions (PCR) available for Helicobacter pylori detection were re-evaluated. Most of them had serious limitations and mistakes in primer design. Hence, we elaborated a nested PCR for the unambiguous identification of H pylori in biopsy, stool, and saliva, using primers targeted to variable regions of the 16S ribosomal RNA (rRNA) gene. Moreover, we determined the detection limit by adding a known number of cells. This number was as low as 0.5 cells in a PCR vial, but due to the DNA isolation procedures, it required 1-5 × 10³ cells/g or ml of specimen. The sensitivity for nested PCR from stomach biopsies was on the same scale as ¹³ C-UBT (93.8%), but it was much lower in amplifications from stool (31.3%). Sequencing of all obtained PCR products exclusively confirmed H pylori-specific DNA sequences.

CONCLUSIONS

Elaborated nested PCR assay can serve as an auxiliary method for controversial samples (patients with bleeding or taking proton-pump inhibitor) in laboratories with basic equipment. The sensitivity and specificity for the amplification from gastric biopsies was almost like ¹³ C-UBT. Despite the good sensitivity, the threshold occurrence and the ability to survive in the oral cavity aside from and independent of the stomach is the reason why H pylori DNA cannot be reliably detected in saliva, stool, and some biopsy samples.

Epidermal growth factor receptor 2 immunoexpression in gastric cells of domestic cats with H. heilmannii infection

The aim of this study was to evaluate the immunoexpression of HER-2 in gastric cells of cats infected with Non H. pylori Helicobacter (NHPH) and to investigate an association with the presence of inflammatory infiltrate. Forty-eight paraffin-embedded gastric samples were retrieved from the archives of the Veterinary Anatomic Pathology Laboratory that had previously been shown to be positive for NHPH with the rapid urease test and cytology. Infection by NHPH was confirmed by histopathology using the Warthin-Starry staining. Hematoxylin-eosin stained sections were reviewed to evaluate inflammatory cell infiltrates. Immunohistochemical analysis was done using anti- H. pylori antibody and anti-HER-2 antibody. Molecular analysis was performed by PCR to confirm the presence of Helicobacter. Statistical analysis was performed to determine whether there was an association between the presence of H. Heilmannii and HER-2 expression in gastric samples. All samples were positive for NHPH, by immunohistochemistry, and confirmed by PCR as H. Heilmannii. On histopathologic analysis, 56,3% of the samples had lymphocytes and plasma cells infiltrates, 52,1% of which were mild and 4,2% moderate. The intensity of the inflammatory infiltrate in the gastric mucosa was significantly greater in the complete plasma membrane of parietal cells of gastric glands that had greater HER-2 immunoexpression (p = 0.0001). A statistically significant association (p = 0.007) between the H. Heilmannii infection score and the expression of HER-2 in the lateral membrane of gastric surface cells was observed. HER-2 expression may be increased in feline gastric cells infected by H. Heilmannii and in parietal cells of gastric glands with an increased inflammatory infiltrate.

An evaluation of the usefulness of invasive and non-invasive methods used to diagnose Helicobacter spp. infections in dogs

The aim of this study was to assess the suitability of invasive and non-invasive methods used to diagnose Helicobacter spp. in the stomachs of dogs. The study was carried out on 30 dogs of both sexes and different breeds, between one and 15 years old. A histopathologic examination, a microbiological culture, a rapid urease test, a direct bacteriological preparation and a nested PCR assay were carried out. Gastric Helicobacter spp. was identified in gastric biopsy specimens from 16 (53.3%) dogs using direct bacteriological preparation, in four (13.3%) dogs based on a culture, in 23 (76.6%) dogs using the rapid urease test and in 21 (70,0%) dogs based on a histopathological assessment of the biopsy specimens. The nested PCR of the gastric biopsy specimens revealed gastric Helicobacter spp. in all the dogs (100%). A saliva PCR assay revealed gastric Helicobacter spp. in 23 (76.6%) dogs, while stool PCR revealed the bacterium in seven (23.3%) dogs. We found that invasive methods were more accurate than non-invasive methods in detecting a Helicobacter spp. infection in dogs. In addition, the nested PCR method used to evaluate the gastric mucosal biopsy specimens was the most accurate test for detecting Helicobacter spp. It was further found that the PCR-based saliva assay was the best non-invasive method for detecting Helicobacter spp. However, taking into consideration that most of the diagnostic methods used to detect this bacterium have drawbacks, at least two diagnostic methods should be used to detect Helicobacter spp. as is done in human medicine.

IDENTIFICAÇÃO DE Helicobacter spp. EM MUCOSAS GÁSTRICA E DUODENAL DE CÃES (Canis familiaris) UTILIZANDO A TÉCNICA DE WARTHIN-STARRY

Resumo Bactérias do gênero Helicobacter spp. têm sido identificadas na mucosa gástrica de diferentes espécies de mamíferos, inclusive em caninos. Pacientes infectados têm gastrite histológica; no entanto, não são todos os portadores que apresentam sinais clínicos. O objetivo deste trabalho foi identificar as bactérias sugestivas de Helicobacter spp. pela impregnação pela prata e caracterizar as lesões histopatológicas observadas. Foram analisadas amostras de mucosas gástrica e entérica de 26 caninos. Para avaliação histopatológica, foi realizada avaliação qualitativa, na qual foram atribuídos escores de ausente (-) a acentuada (+++), considerando a densidade de bactérias espiraladas por campo (400x), presença de células inflamatórias e aglomerados linfoides. Dos 26 animais avaliados, 34,6% apresentaram positividade para helicobacteriose. A gastrite foi observada em 15,38% dos animais e a maior ocorrência de bactérias do gênero Helicobacter spp. foi observada em região de corpo/fundo gástrico (23%). Em nove amostras, seis de corpo/fundo gástrico e três de antro pilórico, foram observados aglomerados linfóides associados a Helicobacter spp. Por meio de Teste de Fisher, verificou-se associação positiva entre a presença de Helicobacter spp. e agregados linfoides (p<0,001). A infecção por Helicobacter spp. está associada com a presença de aglomerados linfóides em caninos.