RESUMO
The porcine Helicobacter suis and canine-feline H. heilmannii are gastric Helicobacter species with zoonotic potential. However, little is known about the pathogenesis of human infections with these Helicobacter species. To gain more insight into the interactions of both zoonotic Helicobacter species with human gastric epithelial cells, we investigated bacterial genes that are differentially expressed in a H. suis and H. heilmannii strain after adhesion to the human gastric epithelial cell line MKN7. In vitro Helicobacter-MKN7 binding assays were performed to obtain bacterial RNA for sequencing analysis. H. suis and H. heilmannii bacteria attached to the gastric epithelial cells (i.e. cases) as well as unbound bacteria (i.e. controls) were isolated, after which prokaryotic RNA was purified and sequenced. Differentially expressed genes were identified using the DESeq2 package and SARTools pipeline in R. A list of 134 (83 up-regulated and 51 down-regulated) and 143 (60 up-regulated and 83 down-regulated) differentially expressed genes (padj ≤ 0.01; fold change ≥ 2) were identified for the adherent H. suis and H. heilmannii strains, respectively. According to BLASTp analyses, only 2 genes were commonly up-regulated and 4 genes commonly down-regulated in both pathogens. Differentially expressed genes of the H. suis and H. heilmannii strains belonged to multiple functional classes, indicating that adhesion of both strains to human gastric epithelial cells evokes pleiotropic adaptive responses. Our results suggest that distinct pathways are involved in human gastric colonization of H. suis and H. heilmannii. Further research is needed to elucidate the clinical significance of these findings.
Assuntos
Aderência Bacteriana , Regulação Bacteriana da Expressão Gênica , Helicobacter heilmannii/fisiologia , Transcriptoma , Linhagem Celular , Células Epiteliais , Expressão Gênica , Helicobacter heilmannii/classificação , Helicobacter heilmannii/genética , Humanos , EstômagoRESUMO
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.
Assuntos
Mucosa Gástrica/microbiologia , Gastrite/microbiologia , Helicobacter heilmannii/genética , Helicobacter heilmannii/patogenicidade , Mucosa Intestinal/microbiologia , Animais , Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Gatos , Linhagem Celular , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Cães , Células Epiteliais/microbiologia , Mucosa Gástrica/citologia , Gerbillinae , Glicosiltransferases/genética , Infecções por Helicobacter/microbiologia , Helicobacter heilmannii/classificação , Humanos , Mucosa Intestinal/citologia , Dados de Sequência Molecular , Filogenia , Estrutura Terciária de Proteína , RNA Ribossômico 16S/genética , Virulência/genética , Zoonoses/microbiologiaRESUMO
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.
Assuntos
Infecções por Helicobacter/microbiologia , Helicobacter heilmannii/patogenicidade , Gastropatias/microbiologia , Estômago/microbiologia , Animais , Antibacterianos/uso terapêutico , Quimioterapia Combinada , Genoma Bacteriano , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/transmissão , Helicobacter heilmannii/classificação , Helicobacter heilmannii/efeitos dos fármacos , Helicobacter heilmannii/genética , Interações Hospedeiro-Patógeno , Humanos , Inibidores da Bomba de Prótons/uso terapêutico , Estômago/efeitos dos fármacos , Estômago/patologia , Gastropatias/diagnóstico , Gastropatias/tratamento farmacológico , Gastropatias/epidemiologia , Resultado do TratamentoRESUMO
Three gram-negative, microaerophilic bacteria, strains ASB1(T), ASB2 and ASB3, with a corkscrew-like morphology isolated from the gastric mucosa of cats were studied using a polyphasic taxonomic approach. The isolates grew on biphasic culture plates under microaerobic conditions at 37 °C and exhibited urease, oxidase and catalase activities. They were also able to grow in colonies on dry agar plates. Based on 16S rRNA gene sequence analysis, ASB1(T), ASB2 and ASB3 were identified as members of the genus Helicobacter and showed 98 to 99â% sequence similarity to strains of Helicobacter felis, Helicobacter bizzozeronii, 'Candidatus Helicobacter heilmannii', Helicobacter cynogastricus, Helicobacter baculiformis and Helicobacter salomonis, six related Helicobacter species previously detected in feline or canine gastric mucosa. Sequencing of the partial hsp60 gene demonstrated that ASB1(T), ASB2 and ASB3 constitute a separate taxon among the feline and canine Helicobacter species. The urease gene sequences of ASB1(T), ASB2 and ASB3 showed approximately 91â% similarity to those of 'Candidatus Helicobacter heilmannii'. Protein profiling, the absence of alkaline phosphatase activity and several other biochemical characteristics also allowed strains ASB1(T), ASB2 and ASB3 to be differentiated from other Helicobacter species of feline or canine gastric origin. The results of this polyphasic taxonomic study show that the cultured isolates constitute a new taxon corresponding to 'Candidatus Helicobacter heilmannii', which was previously demonstrated in the stomach of humans, wild felidae, cats and dogs. The name Helicobacter heilmannii sp. nov. is proposed for these isolates; the type strain is ASB1(T) (=DSM 24751 (T) =LMG 26292(T)) [corrected].
Assuntos
Doenças do Gato/microbiologia , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/veterinária , Helicobacter heilmannii/classificação , Helicobacter heilmannii/isolamento & purificação , Animais , Proteínas de Bactérias/química , Técnicas de Tipagem Bacteriana , Gatos , Chaperonina 60/genética , Chaperonina 60/metabolismo , DNA Bacteriano/análise , DNA Ribossômico/análise , Cães , Eletroforese/métodos , Genes de RNAr , Infecções por Helicobacter/microbiologia , Helicobacter heilmannii/genética , Helicobacter heilmannii/metabolismo , Humanos , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie , Urease/genéticaRESUMO
The involvement of Helicobacter pylori in the pathogenesis of extragastric diseases continues to be an interesting topic in the field of Helicobacter-related pathology. Although conflicting findings have been reported for most of the disorders, a role of H. pylori seems to be important especially for the development of cardiovascular and hematologic disorders. Previously isolated human and animal Helicobacter sp. flexispira and "Helicobacter heilmannii" strains have been validated using polyphasic taxonomy. A novel enterohepatic Helicobacter has been isolated from mastomys and mice, adding to the list of helicobacters that colonize the liver. Genetic targets that may aid the classification of novel Helicobacter species have emerged. Animal models of Helicobacter-induced gastric and hepatobiliary diseases have offered insights to the mechanisms associated with premalignant transformation.
Assuntos
Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter/isolamento & purificação , Animais , Arteriosclerose/microbiologia , Doenças Cardiovasculares/microbiologia , Modelos Animais de Doenças , Gastroenteropatias/microbiologia , Helicobacter/classificação , Infecções por Helicobacter/patologia , Helicobacter heilmannii/classificação , Helicobacter heilmannii/isolamento & purificação , Doenças Hematológicas/microbiologia , Humanos , Hepatopatias/microbiologia , CamundongosRESUMO
BACKGROUND: A small proportion of patients suffering from chronic active gastritis are diagnosed with gastric Helicobacter species other than Helicobacter pylori. Circumstantial evidence has suggested that these bacteria, also referred to as "Helicobacter heilmannii"-like organisms (HHLO), may be transmitted through animals. The isolation of a Helicobacter bizzozeronii strain from a human patient confirmed this hypothesis. It was the aim of the present study to assess the presence of animal Helicobacter species and H. pylori in humans infected with HHLO, as diagnosed by histology. METHODS: Paraffin-embedded gastric biopsy specimens of 108 HHLO-infected patients (42 women and 66 men) from three clinical centers were screened for the presence of animal gastric Helicobacter species by polymerase chain reaction (PCR), using assays targeting the 16S rDNA region of the three known canine and feline helicobacters (H. bizzozeronii, H. salomonis and H. felis), "Candidatus H. suis", and "Candidatus H. bovis". In addition, the presence of H. pylori was evaluated by multiplex PCR analysis. RESULTS: In 63.4% of the stomachs (64/101) classification of the Helicobacter infection into the above mentioned groups was achieved. Non-pylori Helicobacter species commonly colonizing the stomachs of cats and dogs were found in 48.5% (49/101) of the patients. Fourteen (13.9%) samples tested positive for "Candidatus H. suis", and "Candidatus H. bovis" was demonstrated in 1 (0.9%) patient. The presence of H. pylori was established in 13 patients (12.9%). Eleven stomachs (10.9%) were infected with at least two different Helicobacter species. CONCLUSIONS: This study identifies animal Helicobacter species in the stomach of a large series of HHLO-infected patients, which may have clinical implications in a subset of patients with gastric disease.
Assuntos
Animais Domésticos/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter heilmannii/isolamento & purificação , Helicobacter/isolamento & purificação , Zoonoses/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Biópsia , Doenças do Gato/microbiologia , Gatos , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Doenças do Cão/microbiologia , Cães , Feminino , Helicobacter/classificação , Helicobacter/genética , Infecções por Helicobacter/veterinária , Helicobacter heilmannii/classificação , Helicobacter heilmannii/genética , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estômago/microbiologiaRESUMO
While Helicobacter pylori is accepted as the major bacterial agent of gastric disease in humans, some patients and many animals are infected with a larger, tightly helical-shaped bacterium previously referred to as 'Helicobacter heilmannii' or 'Gastrospirillum hominis'. Taxonomic classification of these bacteria has been hampered by the inability to cultivate them in vitro and by the inadequate discriminatory power of 16S rRNA gene sequence analysis. This study describes the detection and phylogenetic analysis of 26 different gastrospirillum isolates from humans and animals, which incorporates sequence data based on the 16S rRNA and urease genes. Fifteen gastrospirilla detected in humans, primates and pigs clustered with 'Candidatus Helicobacter suis', thus expanding the host range for this organism. By comparison, based on 16S rRNA data, the remaining 11 gastrospirilla could not be differentiated from Helicobacter felis, Helicobacter bizzozeronii and Helicobacter salomonis. However, urease gene sequence analysis allowed for the discrimination of this latter group into four discrete clusters, three of which contained the above recognized species. The fourth cluster contained isolates from human and feline hosts, and should provisionally be considered a unique bacterial species, for which the name 'Candidatus Helicobacter heilmannii' is proposed.
Assuntos
Helicobacter heilmannii/classificação , Helicobacter heilmannii/genética , Helicobacter/classificação , RNA Ribossômico 16S/genética , Urease/genética , Adulto , Idoso , Animais , Proteínas de Bactérias/genética , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , Feminino , Mucosa Gástrica/microbiologia , Gastroscopia , Genes de RNAr , Helicobacter/genética , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/veterinária , Humanos , Dados de Sequência Molecular , Filogenia , Primatas/microbiologia , RNA Bacteriano/genética , Análise de Sequência de DNA , Suínos/microbiologiaRESUMO
Infection with candidatus "Helicobacter heilmannii" is associated with gastritis and mucosa-associated lymphoid tissue lymphoma in people. Infection with "H. heilmannii" type 1 predominates (80%) and is thought to be acquired from dogs, cats, or pigs. We further examined the zoonotic potential of dogs and cats by amplifying gastric DNA from cats (n = 45) and dogs (n = 10) with primers against "H. heilmannii" ureB and 16S rRNA genes and sequencing the products. Fluorescence in situ hybridization (FISH) with eubacterial and "H. heilmannii"-specific probes was employed to directly visualize "H. heilmannii" types and their intragastric distribution. ureB sequences of "H. heilmannii" amplicons clustered with human and feline isolates of "H. heilmannii" and were distinct from the "H. heilmannii"-like organisms (HHLO) H. felis, H. salomonis, and H. bizzozeronii. 16S ribosomal DNA sequences in 20 "H. heilmannii"-infected cats and dogs were distinct from "H. heilmannii" type 1 and "H. suis" and clustered with "H. heilmannii" types 2 and 4. FISH confirmed the presence of "H. heilmannii" types 2 and 4 in dogs but failed to definitively characterize the "H. heilmannii" types present in cats. In infected dogs, "H. heilmannii" inhabited the gastric mucus and glands, and in dogs coinfected with other HHLO it shared the same gastric niche. The results indicate that dogs and cats are predominantly colonized by "H. heilmannii" bacteria that are distinct from type 1 and from "H. suis." As "H. heilmannii" type 1 predominates in people, the zoonotic risk posed by dogs and cats is likely small.
Assuntos
Mucosa Gástrica/microbiologia , Helicobacter heilmannii/isolamento & purificação , Animais , Sequência de Bases , Doenças do Gato/microbiologia , Gatos , Primers do DNA/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Doenças do Cão/microbiologia , Cães , Gastrite/microbiologia , Gastrite/veterinária , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/veterinária , Helicobacter heilmannii/classificação , Helicobacter heilmannii/genética , Humanos , Hibridização in Situ Fluorescente , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Zoonoses/microbiologiaRESUMO
Gastric infection with Helicobacter heilmannii (previously known as Gastrospirillum hominis) is invariably linked with the presence of chronic gastritis and the risk of developing low-grade mucosa-associated lymphoid tissue lymphoma in humans. In contrast to Helicobacter pylori, various H. heilmannii species colonize the stomachs of domestic animals, which might be a reservoir for transmission to humans (zoonosis). To identify the number and prevalence of different H. heilmanni types in humans, we analyzed 89 gastric biopsy samples histologically identified as H. heilmannii positive by fluorescence in situ hybridization. Of these gastric specimens, 84 (94.4%) contained a single H. heilmannii type. In five samples, however, two different H. heilmannii types were detected. The most prevalent species in monoinfected samples is H. heilmannii type 1, found in 78.5% (66 of 84) of the specimens, followed by a novel H. heilmannii-like organism (HHLO), HHLO type 4, identified in 9.6% (8 of 84) of tissue sections. H. heilmannii type 2 and a further HHLO type not described before, type 3, were found in 8.3% (7 of 84) and 1.2% (1 of 84) of the monoinfected samples, respectively. Additionally, HHLO type 5 with a 16S ribosomal DNA sequence identical to that of Helicobacter salomonis was found with a prevalence of 2.4% (2 of 89). Thirteen of these biopsy samples were also investigated by a PCR approach developed for this study that allows a Helicobacter-specific amplification of a variable portion of the 16S rRNA gene and subsequent sequencing. In total, five different types of HHLOs could be identified within these samples. We conclude that humans can be infected by at least five different HHLO types, which presumably have their origin in animal species like dogs, cats, and pigs.
Assuntos
Mucosa Gástrica/microbiologia , Infecções por Helicobacter/epidemiologia , Helicobacter heilmannii/isolamento & purificação , Hibridização in Situ Fluorescente , RNA Ribossômico 16S/genética , Biópsia , DNA Bacteriano/análise , DNA Bacteriano/genética , DNA Ribossômico/análise , DNA Ribossômico/genética , Formaldeído , Infecções por Helicobacter/microbiologia , Helicobacter heilmannii/classificação , Helicobacter heilmannii/genética , Humanos , Reação em Cadeia da Polimerase/métodos , Prevalência , Análise de Sequência de DNA , Estômago/microbiologia , Fixação de Tecidos/métodosRESUMO
INTRODUCTION: Helicobacter pylori is one of the most common causes of human gastritis. Recently, a new agent has been isolated, which also causes a gastritis. It has been initially named Gastrospirillum hominis and renamed Helicobacter heilmannii (Hh). Hh is extremely rare. In spite of the rarity it is important to recognize and diagnose it, as it requires a proper therapy, different from Hp therapy. Clinical presentation and serological results of Hh are superimposable to those of HP. Therefore differential diagnosis resides on histological grounds. PURPOSE of the present paper is to report 14 new cases of Hh gastritis, which constitutes the first italian series. RESULTS: Cases constituted 0.01% of all gastric biopsies seen in the period 1994-1998. Nine patients were male and five were female; age ranged from 32 to 76 years (50 years on average). All patients presented a mild to moderate gastritis. Hh is a spiral bacterium, being about 10 micra in length, localized in single or small groups in the glandular mucus. Two cases were associated with Hp. One case was associated with gastric adenocarcinoma. Two cases were diagnosed during the follow-up of duodenal ulcer. In CONCLUSION, the incidence of Hh gastritis in the present series seems consistent with that from other European countries. In all cases the presence of Hh was associated with features of gastritis. This confirms the pathogenetic role of Hh.