Isolation and characterization of Helicobacter suis from human stomach.

Helicobacter suis, a bacterial species naturally hosted by pigs, can colonize the human stomach in the context of gastric diseases such as gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Because H. suis has been successfully isolated from pigs, but not from humans, evidence linking human H. suis infection to gastric diseases has remained incomplete. In this study, we successfully in vitro cultured H. suis directly from human stomachs. Unlike Helicobacter pylori, the viability of H. suis decreases significantly on neutral pH; therefore, we achieved this using a low-pH medium for transport of gastric biopsies. Ultimately, we isolated H. suis from three patients with gastric diseases, including gastric MALT lymphoma. Successful eradication of H. suis yielded significant improvements in endoscopic and histopathological findings. Oral infection of mice with H. suis clinical isolates elicited gastric and systemic inflammatory responses; in addition, progression of gastric mucosal metaplasia was observed 4 mo postinfection. Because H. suis could be isolated from the stomachs of infected mice, our findings satisfied Koch's postulates. Although further prospective clinical studies are needed, H. suis, like H. pylori, is likely a gastric pathogen in humans. Furthermore, comparative genomic analysis of H. suis using complete genomes of clinical isolates revealed that the genome of each H. suis isolate contained highly plastic genomic regions encoding putative strain-specific virulence factors, including type IV secretion system-associated genes, and that H. suis isolates from humans and pigs were genetically very similar, suggesting possible pig-to-human transmission.

Helicobacter heilmannii Colonization Is Associated with High Risk for Gastritis.

INTRODUCTION: We aimed to study potential associations between colonization by four common non-pylori Helicobacter species and gastroduodenal diseases by comparing samples from patients infected with H. pylori with samples from non-infected subjects. MATERIALS AND METHODS: Patients (n = 190) who were subjected to upper gastrointestinal endoscopy because of gastroduodenal conditions were enrolled in this cross-sectional study. Antral biopsy samples were taken from patients in two major hospitals (Mehrad and Imam-Hossein) in Tehran, Iran, during 2017-2018. DNA was isolated from the biopsy specimens, and PCR amplification was used to identify the Helicobacter species by using their corresponding specific primer sets. RESULTS: Out of 120 cases positive for H. pylori, 46 (38%) were patients with gastritis, 23 (19%) with duodenal ulcer, 11 (9%) with gastric cancer, and 40 (33.3%) with gastric ulcer. Overall, 70 (36%) patients were negative for H. pylori. H. pylori cases were uninfected by any of the other tested Helicobacter species. Among the 70 patients without H. pylori, 34 had gastritis-31 (94%) of these were positive also for H. heilmannii (p = 0.001, Odds Ratio: 51.6; 95% Confidence Intervals: 11.8-225.6). We did not find any patient carrying mixed Helicobacter infections with any non-pylori Helicobacter species in this cohort. CONCLUSIONS: Given our evidence about the possibility of involvement of H. heilmannii in patients suffering from gastritis and nonexistence of mixed non-pylori Helicobacter infections, bacteriological testing of subjects negative for H. pylori becomes clinically relevant and important.

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.

Presence of gastric Helicobacter species in children suffering from gastric disorders in Southern Turkey.

BACKGROUND: Infections with gastric Helicobacter spp. are associated with gastritis, peptic ulceration, and malignancies. Helicobacter pylori is the most prevalent Helicobacter species colonizing the human stomach. Other gastric non-H. pylori helicobacters (NHPHs) have been described in 0.2%-6% of human patients with gastric disorders. Nevertheless, due to difficulties in the diagnosis of NHPH infections and lack of routine screening, this is most likely an underestimation of their true prevalence. To the best of our knowledge, no studies have been performed in the presence of Helicobacter spp. in children suffering from gastric disorders in Southern Turkey. MATERIALS AND METHODS: In total, 110 children with gastric complaints were examined at the Cukurova University Balcali hospital, Turkey. Gastroscopy was performed to evaluate the presence of gastric mucosal lesions. Biopsies of the pyloric gland zone were taken for histopathological analysis, rapid urease testing, and presence of Helicobacter spp. DNA by PCR. RESULTS: Based on the PCR results, the prevalence of Helicobacter spp. was 32.7% (36/110). H. pylori was found in 30.9% (34/110), H. suis in 1.8% (2/110), and H. heilmannii/H. ailurogastricus in 0.9% (1/110) of the human patients. A mixed infection with H. pylori and H. suis was present in one patient. The presence of mucosal abnormalities, such as nodular inflammation, ulceration, and hyperemia, as well as gastritis, was significantly higher in Helicobacter spp. positive patients. CONCLUSION: Helicobacter pylori, H. suis, and H. heilmannii/H. ailurogastricus were present in children with gastric complaints. Infection with these pathogens may be involved in the development of gastritis and ulceration.

Epidemiological study of gastric Helicobacter spp. in dogs with gastrointestinal disease in Japan and diversity of Helicobacter heilmannii sensu stricto.

Epidemiological and pathological studies of Helicobacter spp. in canine stomachs in Japan were performed to investigate strain specific pathogenicity. Gastric biopsies from 144 dogs with gastrointestinal diseases were evaluated for the presence of Helicobacter spp. using genus and species specific PCRs for Helicobacter felis, Helicobacter bizzozeronii, Helicobacter heilmannii sensu stricto (s.s.) and Helicobacter pylori. PCR indicated that 50/144 (34.7%) dogs were infected with Helicobacter spp. Of the genus positive samples, 21/50 could not be amplified by any of the species specific PCRs. To investigate Helicobacter at the species level, partial ureAB gene sequences from 48/50 genus positive samples were determined; 47 strains were identified. Thirty-five strains from 45 cases were closely related to H. heilmannii s.s. (89-99% sequence similarity), seven strains from seven cases were closely related to H. bizzozeronii (95-99% sequence similarity), three strains from three cases were closely related to Helicobacter felis (86%, 98% and 99% sequence similarity), one strain from one case was closely related to Helicobacter salomonis (99% sequence similarity) and one strain from one case was closely related to H. pylori (99% sequence similarity). Dogs infected with Helicobacter spp. most similar to H. heilmannii s.s. had a higher frequency of moderate to severe gastritis than dogs negative for Helicobacter spp. (P=0.044). In conclusion, the predominant Helicobacter spp. detected in canine stomachs in our study were most closely related to H. heilmannii s.s. and displayed substantial genetic diversity. Infection with Helicobacter spp. may be associated with more severe gastritis in dogs.

Divergence between the Highly Virulent Zoonotic Pathogen Helicobacter heilmannii and Its Closest Relative, the Low-Virulence "Helicobacter ailurogastricus" sp. nov.

Helicobacter heilmannii naturally colonizes the stomachs of dogs and cats and has been associated with gastric disorders in humans. Nine feline Helicobacter strains, classified as H. heilmannii based on ureAB and 16S rRNA gene sequences, were divided into a highly virulent and a low-virulence group. The genomes of these strains were sequenced to investigate their phylogenetic relationships, to define their gene content and diversity, and to determine if the differences in pathogenicity were associated with the presence or absence of potential virulence genes. The capacities of these helicobacters to bind to the gastric mucosa were investigated as well. Our analyses revealed that the low-virulence strains do not belong to the species H. heilmannii but to a novel, closely related species for which we propose the name Helicobacter ailurogastricus. Several homologs of H. pylori virulence factors, such as IceA1, HrgA, and jhp0562-like glycosyltransferase, are present in H. heilmannii but absent in H. ailurogastricus. Both species contain a VacA-like autotransporter, for which the passenger domain is remarkably larger in H. ailurogastricus than in H. heilmannii. In addition, H. ailurogastricus shows clear differences in binding to the gastric mucosa compared to H. heilmannii. These findings highlight the low-virulence character of this novel Helicobacter species.

Mouse Models for Assessing the Protective Efficacy of Lactobacillus gasseri SBT2055 against Helicobacter suis Infection Associated with the Development of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma.

BACKGROUND: Helicobacter suis strain TKY infection has been strongly associated with the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma in a C57BL/6J mouse model. MATERIALS AND METHODS: 1. C57BL/6J mice were intragastrically administered Lactobacillus strains once daily with 10(8)-10(9) colony-forming units (CFU), starting 2 days before intragastric infection with H. suis TKY (approximately 1 × 10(4) copies of 16S rRNA genes) or H. pylori Sydney strain 1 (SS1; 3 × 10(8) CFU) and continuing for 14 days after infection. 2. C57BL/6J mice were given powdered feed mixed with lyophilized L. gasseri SBT2055 (LG2055) cells (5 × 10(8) CFU/g), starting 2 weeks before intragastric infection with H. suis TKY and continuing 12 months after infection. RESULTS: 1. Among the 5 Lactobacillus strains that we examined, only LG2055 exhibited significantly preventive efficacy against both H. suis TKY and H. pylori SS1 at day 15 after infection. 2. Dietary supplementation with LG2055 protected mice from the formation of round protrusive lesions in the gastric fundus 12 months after infection with H. suis TKY, whereas such lesions had developed in the gastric fundus of nonsupplemented mice 12 months after infection. In addition, the formation of lymphoid follicles in gastric mucus layers was suppressed by dietary LG2055 at 3 months after infection. CONCLUSIONS: LG2055 administration is effective for suppressing the progression of gastric MALT lymphoma by reducing H. suis colonization.

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.

Helicobacter heilmannii sensu lato: an overview of the infection in humans.

Helicobacter heilmannii sensu lato (H. heilmannii s.l.) is a group of gastric non-Helicobacter pylori Helicobacter species that are morphologically indistinguishable from each other. H. heilmannii s.l. infect the stomach of several animals and may have zoonotic potential. Although the prevalence of these infections in humans is low, they are associated with gastric pathology, including mucosa-associated lymphoid tissue lymphoma, making them a significant health issue. Here, the taxonomy, epidemiology, microbiology, diagnosis, and treatment of these infections will be reviewed. The gastric pathology associated with H. heilmannii s.l. infections in humans will also be addressed. Finally, the features of the complete bacterial genomes available and studies on species-specific pathogenesis will be reviewed. The understanding of the mechanisms that underlie gastric disease development mediated by the different bacterial species that constitute H. heilmannii s.l. is essential for developing strategies for prevention and treatment of these infections.

Genome sequence of Helicobacter suis supports its role in gastric pathology.

Helicobacter (H.) suis has been associated with chronic gastritis and ulcers of the pars oesophagea in pigs, and with gastritis, peptic ulcer disease and gastric mucosa-associated lymphoid tissue lymphoma in humans. In order to obtain better insight into the genes involved in pathogenicity and in the specific adaptation to the gastric environment of H. suis, a genome analysis was performed of two H. suis strains isolated from the gastric mucosa of swine. Homologs of the vast majority of genes shown to be important for gastric colonization of the human pathogen H. pylori were detected in the H. suis genome. H. suis encodes several putative outer membrane proteins, of which two similar to the H. pylori adhesins HpaA and HorB. H. suis harbours an almost complete comB type IV secretion system and members of the type IV secretion system 3, but lacks most of the genes present in the cag pathogenicity island of H. pylori. Homologs of genes encoding the H. pylori neutrophil-activating protein and γ-glutamyl transpeptidase were identified in H. suis. H. suis also possesses several other presumptive virulence-associated genes, including homologs for mviN, the H. pylori flavodoxin gene, and a homolog of the H. pylori vacuolating cytotoxin A gene. It was concluded that although genes coding for some important virulence factors in H. pylori, such as the cytotoxin-associated protein (CagA), are not detected in the H. suis genome, homologs of other genes associated with colonization and virulence of H. pylori and other bacteria are present.

Suppression of lymphangiogenesis induced by Flt-4 antibody in gastric low-grade mucosa-associated lymphoid tissue lymphoma by Helicobacter heilmannii infection.

BACKGROUND AND AIMS: Our recent study revealed that per oral infection with Helicobacter heilmannii induced low-grade mucosa-associated lymphoid tissue (MALT) lymphoma in the gastric fundus of C57BL/6 mice after a period of 6 months, although the pathophysiological mechanism of lymphoma expansion remains to be clarified. The present study was undertaken to elucidate the interaction of this tumor with angiogenesis and lymphangiogenesis. In addition, the effect of Flt-4 antibodies on lymphoma expansion was investigated. METHODS: C57BL/6 female mice infected with H. heilmannii for 3 months were used in the experiments. Localization of vascular endothelial growth factor C (VEGF-C) and Flt-4 immunoreactivity were detected by indirect immunohistochemical methods. Localization of lymphatic and vascular endothelial cells was investigated by localization of prox-1. In addition, Flt-4 antibody with and without Flt-1 or Flk-1 antibodies was administered i.p. to clarify their effects on tumor size. RESULTS: MALT lymphoma has a rich microvascular network consisting of immature capillaries, lymphatics and venules. By immunohistochemical analysis, prox-1 immunoreactivity was observed mostly in the marginal area of the lymphoma, where VEGF-C and Flt-4 immunoreactivities were also seen. Stereomicroscopic study revealed that administration of Flt-4 and Flt-1 antibodies significantly reduced the surface area of the lymphoma in the mouse stomach. CONCLUSION: A VEGF-C-mediated mechanism plays an important role in the expansion of MALT lymphoma and the administration of VEGF receptor antibodies had a suppressive effect on tumor growth.

Microcirculatory alteration in low-grade gastric mucosa-associated lymphoma by Helicobacter heilmannii infection: its relation to vascular endothelial growth factor and cyclooxygenase-2.

BACKGROUND: There are clinical reports that Helicobacter heilmannii, as well as Helicobacter pylori, has been clinically reported to cause gastric low-grade mucosa-associated lymphoid tissue-type (MALT) lymphoma, although its precise mechanism remains to be clarified. Thus, the present study was undertaken to elucidate the alteration of the microcirculatory structure and the relation to angiogenetic factors in mice infected with H. heilmannii for 3 and 6 months. METHODS: Immunohistochemical studies have been performed by FITC-dextran intra-aortic infusion or CD31, vascular endothelial growth factor-A, cyclooxygenase 2 antibodies using our recently established model of gastric mucosa-associated lymphoid tissue-type gastric B-cell lymphoma in C57BL/6 mice. RESULTS: Increased microcirculatory network was recognized surrounding the MALT lymphoma tissues by both the FITC-dextran infusion method and CD31 immunoreactivity. Vascular endothelial growth factor-A immunoreactivity was recognized within the lymphoma tissues as well as in the marginal area, while cyclooxygenase-2 immunoreactivity was localized in the area surrounding the MALT lymphoma tissues. CONCLUSION: Increased microvascular network as well as enhanced VEGF-A immunoreactivity was shown to be related to expansion of the MALT lymphoma formed by Helicobacter heilmannii infection.

Gastrospirillum hominis and Helicobacter pylori infection in Thai individuals: comparison of histopathological changes of gastric mucosa.

The presence of Helicobacter pylori (H. pylori) in the stomach is closely associated with histological signs of chronic active gastritis and peptic ulcer. Another spiral organism named Gastrospirillum hominis (G. hominis) has led to further interest in the bacterial pathogenesis of gastritis. Due to the low prevalence of G. hominis, it is difficult to evaluate its biological behavior. Recently 16 cases of G. hominis-associated gastritis were found in 257 Thai individuals, which made it possible to study the biological characteristics of G. hominis and its relationship with gastric mucosal inflammation. The results showed that H. pylori and G. hominis could be easily observed in the lower third of the mucous layer and in the mucosa of the gastric pits by means of toluidine blue staining. Both bacteria immunostained positive. Helicobacter pylori were usually in the shape of curved bacillary while G. hominis often appeared in spiral configuration. In 257 cases of Thai subjects, 169 cases were found to be H. pylori positive, the detection rate was 65.7%, and 16 cases were G. hominis positive, with a 6.2% detection rate. In G. hominis infection, 43.6% of cases had normal gastric mucosa. Superficial, erosive and atrophic gastritis cases were 13.2, 10.9 and 12.5%, respectively. Mucosal inflammation was usually severe in H. pylori, but neutrophil polymorph infiltration was often mild and focal in G. hominis infection. Although no G. hominis infection with carcinoma was shown in our cases, the occurrence of mucosal atrophy, metaplasia and dysplasia was higher in both bacterial infections compared with H. pylori- and G. hominis-negative cases. It is suggested that G. hominis may be partly responsible for the mucosal inflammation and some malignant-associated lesions.

Gastrite crônica associada a infecçäo "Gastrospirillum hominis" / Chronic gastritis associated with infection by \"Gastrospirillum hominis\"

Além da reconhecida gastrite infecciosa causada pelo Helicobacter pylori, outras bactérias podem colonizar a mucosa gástrica e induzir resposta inflamatória. Sao apresentados os dados clínicos, endoscópicos e histopatológicos de um paciente portador de gastrite crônica associada à infecçao por Gastrospirillum hominis.

Spiral bacteria in the human stomach: the gastric helicobacters.

During the past decade, Helicobacter pylori has become recognized as one of the most common human pathogens, colonizing the gastric mucosa of almost all persons exposed to poor hygienic conditions from childhood. It also is often found, albeit with a lower frequency, in groups of high socioeconomic status. H. pylori causes chronic active gastritis and is a major factor in the pathogenesis of duodenal ulcers and, to a lesser extent, gastric ulcers. In addition, the presence of this bacterium is now recognized as a risk factor for gastric adenocarcinoma and lymphoma. Nevertheless, most infections appear without clinical consequences. In this second decade of intensive research, it is important to understand why H. pylori is sometimes a dangerous pathogen, and to determine how it can be eradicated in those at highest risk for severe disease.