Spatial distribution of Helicobacter spp. in the gastrointestinal tract of dogs

Fluorescent In Situ Hybridization for the Detection of Intracellular Bacteria in Companion Animals

FISH techniques have been applied for the visualization and identification of intracellular bacteria in companion animal species. Most frequently, these techniques have focused on the identification of adhesive-invasive Escherichia coli in gastrointestinal disease, although various other organisms have been identified in inflammatory or neoplastic gastrointestinal disease. Previous studies have investigated a potential role of Helicobacter spp. in inflammatory gastrointestinal and hepatic conditions. Other studies evaluating the role of infectious organisms in hepatopathies have received some attention with mixed results. FISH techniques using both eubacterial and species-specific probes have been applied in inflammatory cardiovascular, urinary, and cutaneous diseases to screen for intracellular bacteria. This review summarizes the results of these studies.

Detection of invasive Escherichia coli in dogs with granulomatous colitis using immunohistochemistry

Granulomatous colitis in dogs can be associated with infection of the colonic mucosa by invasive strains of Escherichia coli. To date, fluorescence in situ hybridization (FISH) is the gold-standard method to assess intramucosal and intracellular bacterial invasion. However, FISH requires expensive fluorescence microscopy equipment and is therefore not widely available. We investigated the use of immunohistochemistry (IHC) as an alternative method to detect invasive E. coli in dogs with granulomatous colitis. Archived paraffin-embedded blocks were selected from 26 dogs with colitis, in which FISH had been performed by an outside laboratory. Using a polyclonal antibody, IHC for E. coli was performed on sections cut from the same blocks, and the presence of invasive E. coli was recorded. All 11 specimens in which FISH had detected E. coli were also positive on IHC, with strong immunolabeling in the cytoplasm of macrophages and extracellularly in the lamina propria; all 15 specimens that were negative for invasive bacteria on FISH were also negative on IHC. We found that IHC is a sensitive technique for the detection of invasive E. coli in dogs with granulomatous colitis.

Prevalence, diversity and public health implications of Helicobacter species in pet and stray dogs

Background

It is probable that humans can acquire H. pylori and non—H. pylori Helicobacter infections via domestic animals. The prevalence and risk factors of infections of Helicobacter species in canines of Taipei city were therefore analysed in this study.

Materials and methods

A total of 95 canine faecal samples were collected from different animal shelters and hospitals in Taipei city. Total DNA was extracted for semi-nested PCR detection of Helicobacter species. The PCR products were sequenced for further comparative database and phylogenetic analyses.

Results

The overall prevalence of Helicobacter species in canines of Taipei city was 75.79% (72/95). Two gastric, seven enterohepatic and two unclassified Helicobacter species were identified, all of which have been implicated in the aetiology of human diseases. The predominant species detected included H. canis (27.78%), H. pylori (26.39%), H. canicola (18.06%), and H. bilis (13.89%) in decreasing order, while H. canadensis and H. typhlonius were identified for the first time in canines. The genotypes in H. pylori and H. canicola clusters grouped together, with their respective reference strains, showed a close evolutionary distance in the phylogenetic tree, indicating a common ancestry may have existed in these clusters respectively. The residential region of canines, dog living status (pet or stray) and breed (purebred or mixed-breed) are the risk factors associated with Helicobacter infections in the canines examined.

Conclusion

The high prevalence of Helicobacter infections in canines highlights a potential public health risk of zoonotic transmission among dogs, humans and other animals, and therefore, the need for proper methods in controlling the transmission routes. In addition, the 16S rRNA gene amplification method was found to be useful for bacterial identification and phylogenetic analysis.

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The prevalence of Helicobacter infection in dogs of Taipei city was found to be 75.79%.

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Species detected included H. canis, H. pylori, H. canicola, H. bilis and others, including 2 unclassified species.

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Almost all the species detected are identical with those reported to be found in humans in some other studies, suggesting possible cross-transmission between humans and canines.

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Residential region, living status (pet or stray) and breed type of canines are risk factors associated with Helicobacter infections in the canines.

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Phylogenetic analysis indicated an evolutionary pattern in H. pylori and H. canicola clusters, suggesting a common ancestry may have existed in these clusters respectively.

The validity evaluation of different 16srRNA gene primers for helicobacter detection urgently requesting to design new specific primers

Molecular diagnosis of helicobacters by PCR is simpler, more accurate, and feasible compared to other diagnostic methods. Validity and accuracy are highly dependent on the PCR primer design, diffusion time, and mutation rate of helicobacters. This study aimed to design 16srRNA -specific primers for Helicobacter spp. and H. pylori. Application of comparative statistical analysis of the diagnostic utility of the most available 16srRNA genus-specific primers. The new primers were designed using bioinformatics tools (MAFFT MSA and Gblocks command line). A comparative study was applied on nine genus-specific 16srRNA primers in comparison to the ConsH using in silico and laboratory evaluation. The results demonstrated that the best specificity and sensitivity of the primers designed for this study compared to other primers. The comparative study revealed that the heminested outer/inner primers were the worst. Although H276, 16srRNA(a), HeliS/Heli-nest, and Hcom had acceptable diagnostic utility, false positive and false negative results were obtained. Specificity testing on clinical samples indicated a surprising result; that H. pylori was not the sole enemy that we were looking for, but the Non-Helicobacter pylori Helicobacters should be considered as a real risk prognostic for gastric diseases, consequently, a specific diagnosis and treatment should be developed. This study concluded that our designed primers were the most specific and sensitive in comparison with other primers. In addition, in silico evaluation is not accurate enough for primer assessment and that the laboratory evaluation is mandatory.

IL-1R8 as Pathoimmunological Marker for Severity of Canine Chronic Enteropathy

Chronic enteropathy (CE) is a severe multifactorial gastrointestinal disease that affects dogs and is driven by poorly characterized inflammatory pathways. Imbalance of pro-inflammatory response regulators, including IL-1R8, may be due to different factors, among which the infection with Helicobacteraceae is known to lead to a vicious circle in which excessive pro-inflammatory signaling and gastrointestinal injury reinforce each other and boost the disease. We investigated the expression of IL-1R8 in large intestine biopsies of dogs with or without clinical signs of CE and with previously assessed enterohepatic Helicobacter spp. colonization status by mean of quantitative real-time PCR. Our study revealed that IL-1R8 is downregulated in both acutely (p = 0.0074) and chronically (p = 0.0159) CE affected dogs compared to healthy controls. The data also showed that IL-1R8 expression tends to decrease with colonization by Helicobacter spp. Interestingly, a negative correlation was detected between the level of expression of IL-1R8 and the severity of macroscopic lesions identified by endoscopy and the crypt hyperplasia score. We further compared the expression levels between males and females and found no statistically significant difference between the two groups. No significant difference was observed in IL-1R8 expression profiles with the age of the animals either. Interestingly, an association was uncovered between IL-1R8 expression level and dog breed. Together, our data advance knowledge on gastrointestinal pathoimmunology in dogs and highlight the potential utilization of IL-1R8 as a diagnostic, prognostic and therapeutic biomarker for canine chronic enteropathy.

Helicobacter Species and Their Association with Gastric Pathology in a Cohort of Dogs with Chronic Gastrointestinal Signs

Prevalence of individual Helicobacter species, data evaluating their association with gastric pathology and comparison of accuracy of diagnostic techniques are limited. The aims of this study were to determine the prevalence of gastric Helicobacter species, their association with gastric pathology, and to compare diagnostic techniques. Gastric biopsies from 84 privately-owned dogs with chronic gastrointestinal signs were obtained endoscopically. Helicobacters were detected using PCR, cytology, urease test, and histopathology. PCR detected helicobacters in 71.4% of dogs. Helicobacter heilmannii sensu stricto (s.s.) was the predominant species. Mixed infection was detected in 40% of PCR positive dogs. Gastritis was diagnosed in 38.5% of Helicobacter positive and 47.4% of Helicobacter negative dogs. Mono-infection was associated with 2.4 times increased odds of having more severe inflammation compared to mixed infection. Erosions and ulcers were common endoscopic lesions. Cytology had sensitivity/specificity of 88.3/91.7%. Association between infection and lymphoid follicular hyperplasia was demonstrated.

Association of gastric lymphofollicular hyperplasia with Helicobacter-like organisms in dogs

Background

The relationships among gastric lymphoid follicular hyperplasia (GLFH), Helicobacter‐like organisms (HLOs), and clinical signs have not been established in dogs.

Objectives

To evaluate the epidemiologic, clinical, endoscopic, and histopathologic findings associated with GLFH in dogs, and determine the association of GLFH with HLOs and the French Bulldog (FB) breed.

Animals

Two hundred eighty‐eight dogs that underwent gastroscopy between 2013 and 2016.

Methods

Retrospective, cross‐sectional study. Gastric biopsy samples were reviewed and scored for inflammation and HLOs. Dogs were divided into 3 groups: group 1 (63 FBs), group 2 (45 non‐FB brachycephalic dogs), and group 3 (180 nonbrachycephalic dogs). Variables were evaluated for their association with GLFH.

Results

Univariate analysis determined that intact males, young age, vomiting, gastroscopic findings (discoloration, hemorrhage, and ulcers), and histopathologic findings (gastric lamina propria lymphocytic infiltration and HLO score) were associated with GLFH (P ≤ .03). In the multivariate analysis, GLFH was associated with the HLO score (odds ratio [OR] > 5 for HLO scores 1‐2 and >15 for HLO score of 3; P < .001), with vomiting (OR > 4; P = .01) but not with FB breed (P = .76) and age (P = .1). The HLO score was associated with younger age (P < .001).

Conclusion and Clinical Importance

The HLO score was associated with a high GLFH score. Vomiting was associated with GLFH. Helicobacter‐like organisms are highly prevalent in young dogs and GLFH is indirectly associated with this factor. Clinical relevance of the identification of GLFH and HLO remains to be determined.

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.

Enterohepatic Helicobacter species - clinical importance, host range, and zoonotic potential

The genus Helicobacter defined just over 30 years ago, is a highly diverse and fast-growing group of bacteria that are able to persistently colonize a wide range of animals. The members of this genus are subdivided into two groups with different ecological niches, associated pathologies, and phylogenetic relationships: the gastric Helicobacter (GH) and the enterohepatic Helicobacter (EHH) species. Although GH have been mostly studied, EHH species have become increasingly important as emerging human pathogens and potential zoonotic agents in the last years. This group of bacteria has been associated with the development of several diseases in humans from acute pathologies like gastroenteritis to chronic pathologies that include inflammatory bowel disease, and liver and gallbladder diseases. However, their reservoirs, as well as their routes of transmission, have not been well established yet. Therefore, this review summarizes the current knowledge of taxonomy, epidemiology, and clinical role of the EHH group.

Research Relevant Background Lesions and Conditions: Ferrets, Dogs, Swine, Sheep, and Goats

Animal models provide a valuable tool and resource for biomedical researchers as they investigate biological processes, disease pathogenesis, novel therapies, and toxicologic studies. Interpretation of animal model data requires knowledge not only of the processes/diseases being studied but also awareness of spontaneous conditions and background lesions in the model that can influence or even confound the study results. Species, breed/stock, sex, age, anatomy, physiology, diseases (noninfectious and infectious), and neoplastic processes are model features that can impact the results as well as study interpretation. Here, we review these features in several common laboratory animal species, including ferret, dog (beagle), pig, sheep, and goats.

Ménétrier-like disease in a Pointer with concurrent granulomatous gastritis, helicobacteriosis and leishmaniosis: a case report

Background

Ménétrier-like disease is a rare hypertrophic canine gastropathy, reported in only seven dogs. Clinical signs are vomiting, anorexia and weight loss. Macroscopically, giant cerebriform gastric mucosal folds are typically seen in the corpus and fundus of the stomach. Histopathologically, fundic mucous cell hyperplasia and loss of parietal and chief cells are typical.

Case presentation

A nine-year-old spayed female Pointer had a history of intermittent vomiting, marked weight loss and hypoalbuminaemia. A gastroduodenoscopy was performed three times within three months with macroscopic changes remaining the same. The gastric mucosa of the corpus, fundus and proximal antrum was markedly irregular, with cerebriform mucosal folds. In the first gastric biopsies, histopathology revealed a moderate granulomatous gastritis, with a severe manifestation of Helicobacter-like organisms. Treatment for Helicobacter spp. decreased the vomiting slightly. The dog was diagnosed with concurrent leishmaniosis; the conventional anti-Leishmania treatment decreased the vomiting moderately, the hypoalbuminaemia resolved and the dog gained weight back to a normal body condition. Granulomatous gastritis was not present in the gastric biopsies after these treatments. The dog increased vomiting when palliative treatment (maropitant citrate, ondansetron and esomeprazole) was discontinued, and thus, full-thickness biopsies of the stomach were taken and Ménétrier-like disease was diagnosed. The affected area was too large to be surgically removed; thus, palliative treatment was reinstated. The dog remained clinically well 39 months after the first clinical presentation.

Conclusions

This is the first report of Ménétrier-like disease in a dog with a simultaneous manifestation of granulomatous gastritis, helicobacteriosis and leishmaniosis. The clinical signs decreased after treatment of helicobacteriosis and leishmaniosis, but vomiting remained probably as a sign of Ménétrier-like disease. Treatment options for dogs are surgical removal of the abnormal area or palliative treatment. In humans, promising results for a cure have been shown with cetuximab treatment, a human monoclonal antibody, but no canine antibody is commercially available yet. The dog here was doing well 39 months after first presentation, which is the longest reported survival time for Ménétrier-like disease with only palliative treatment in dogs. Full-thickness biopsies are preferred in macroscopic hypertrophic lesions of the stomach for better assessment of Ménétrier-like disease.

Exploring the role of healthy dogs as hosts of enterohepatic Helicobacter species using cultivation-dependent and -independent approaches

Enterohepatic Helicobacter (EHH) species have been increasingly associated with acute gastroenteritis, inflammatory bowel disease and hepatobiliary diseases in humans. However, their host range and transmission routes are poorly understood. Therefore, the aim of this study was to determine the presence of EHH in healthy dogs using both cultivation-dependent and -independent methods. Three hundred and ninety faecal samples from domestic dogs without gastrointestinal symptoms were analysed between June 2018 and July 2019 in Valdivia (South of Chile). Samples were inoculated on selective medium and in parallel were filtrated over an antibiotic-free blood agar. Both media were incubated in a microaerobic atmosphere at 37°C for 7 days. Colonies were identified by PCR and phylogenetic analysis. A subset of 50 samples (half of them positive for EHH by cultivation and the remaining half negative) was analysed by PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) for direct detection. Cultivation method detected EHH in 15.4% (60/390) of the samples, being the most prevalent species H. canis (5.8%, 23/390) and H. canicola (5.1%, 20/390), followed by H. bilis (3.6%, 14/390) and 'H. winghamensis' (1.3%, 5/390). In contrast, PCR-DGGE method detected Helicobacter DNA in almost all (96%, 48/50) tested samples. On the other hand, the method used also allowed to isolate other Campylobacterales, in fact 44.3% (173/390) of the samples were positive for Campylobacter upsaliensis (43.3%, 169/390) followed by C. jejuni (2.0%, 8/390). Moreover, two strains that presented Campylobacter-like morphology were finally identified as Anaerobiospirillum succiniciproducens. Our results indicate that healthy domestic dogs commonly carry EHH and other Campylobacter species. However, further studies are needed to determine whether and how these Helicobacter and Campylobacter species can be transmitted to humans.

Gut Helicobacter presentation by multiple dendritic cell subsets enables context-specific regulatory T cell generation

Generation of tolerogenic peripheral regulatory T (pTreg) cells is commonly thought to involve CD103⁺ gut dendritic cells (DCs), yet their role in commensal-reactive pTreg development is unclear. Using two Helicobacter-specific T cell receptor (TCR) transgenic mouse lines, we found that both CD103⁺ and CD103^- migratory, but not resident, DCs from the colon-draining mesenteric lymph node presented Helicobacter antigens to T cells ex vivo. Loss of most CD103⁺ migratory DCs in vivo using murine genetic models did not affect the frequency of Helicobacter-specific pTreg cell generation or induce compensatory tolerogenic changes in the remaining CD103^- DCs. By contrast, activation in a Th1-promoting niche in vivo blocked Helicobacter-specific pTreg generation. Thus, these data suggest a model where DC-mediated effector T cell differentiation is 'dominant', necessitating that all DC subsets presenting antigen are permissive for pTreg cell induction to maintain gut tolerance.

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.

Bacterial Biogeography of the Colon in Dogs With Chronic Inflammatory Enteropathy

The intestinal microbiota is believed to play a role in the pathogenesis of inflammatory bowel disease in humans and chronic inflammatory enteropathy (CIE) in dogs. While most previous studies have described the gut microbiota using sequencing methods, it is fundamental to assess the spatial distribution of the bacteria for a better understanding of their relationship with the host. The microbiota in the colonic mucosa of 22 dogs with CIE and 11 control dogs was investigated using fluorescence in situ hybridization (FISH) with a universal eubacterial probe (EUB338) and specific probes for select bacterial groups. The number of total bacteria labeled with EUB338 probe was lower within the colonic crypts of dogs with CIE compared to controls. Helicobacter spp. and Akkermansia spp. were decreased on the colonic surface and in the crypts of dogs with CIE. Dogs with CIE had increased number of Escherichia coli/Shigella spp. on the colonic surface and within the crypts compared to control dogs. In conclusion, the bacterial microbiota in the colonic mucosa differed between dogs with and without CIE, with depletion of the crypt bacteria in dogs with CIE. The crypt bacterial species that was intimately associated with the host mucosa in control dogs was composed mainly of Helicobacter spp.

Canine Idiopathic Chronic Hepatitis

The World Small Animal Veterinary Association's Liver Standardization Group produced standardized criteria for the histologic diagnosis of canine chronic hepatitis (CH). They define CH by the presence of hepatocellular apoptosis or necrosis, a variable mononuclear or mixed inflammatory cell infiltrate, regeneration, and fibrosis. There are variations in histologic appearance between breeds. Hepatic copper accumulation is an important cause of canine CH. However, where copper accumulation has been ruled out, dogs are said to have idiopathic CH. This article reviews theories regarding the etiopathogenesis of canine CH other than copper accumulation, and its clinical features, diagnostic findings, and management.

Gastroduodenal Ulceration in Small Animals: Part 1. Pathophysiology and Epidemiology

Gastroduodenal ulceration in small animals is a complex and important comorbidity that occurs when the physiological homeostasis of the gastrointestinal tract is disrupted secondary to administration of medications or the presence of local or systemic diseases. The aim of this article is to provide a comprehensive review of the veterinary literature regarding the pathophysiology, epidemiology, and risk factors associated with gastroduodenal ulceration in small animals. Pertinent concepts from the human literature will be integrated into the discussion. This article serves as an introduction to the second part of this series, which will review current evidence regarding the use of H2-receptor antagonists and proton pump inhibitors in small animals.

Helicobacter Species Identified in Captive Sooty Mangabeys (Cercocebus atys) with Metastatic Gastric Adenocarcinoma

BACKGROUND

Of all human cancers, gastric carcinoma is the one of the leading causes of death. Helicobacter pylori is considered a major etiologic agent of this disease. Spontaneously occurring gastric carcinoma is a rare diagnosis in nonhuman primates. A 2011 case report documented a high incidence of gastric adenocarcinoma in a closed colony of captive sooty mangabeys (Cercebus atys). However, H. pylori infection was not detected in these animals.

MATERIALS AND METHODS

In this study, using archived formalin-fixed, paraffin-embedded stomach sections of these animals alternative methodologies were used to identify H. pylori and other non-H. pylori Helicobacter species. In addition, two additional cases of sooty mangabeys with metastatic gastric carcinoma are characterized.

RESULTS

Using fluorescent in situ hybridization, we identified gastric H. suis in 75% of archived and new gastric carcinoma cases. In the two newly reported cases, H. suis and a novel Helicobacter species were detected via PCR and sequence analysis of the 16S rRNA gene. H. pylori was not identified in any of the gastric carcinoma cases via FISH and/or PCR and sequence analysis of Helicobacter spp. in DNA from of available tissues.

CONCLUSIONS

This report is the first to characterize Helicobacter species infection in spontaneous gastric carcinoma with metastatic potential in nonhuman primates.

Diagnosis of Genus Helicobacter through a hemi-nested PCR assay of 16S rRNA

The present study aimed to establish a genus-specific PCR-based assay to detect helicobacters using 16S rRNA gene as the target template. We designed the hemi-nested primers based on sequences of 16S rRNA gene of 34 types of Helicobacter species. The inclusivity, sensitivity, and specificity of the PCR assay using these primers were examined in three different models, comprising feces simulated samples, BLAB/c mice infection model and clinic patients samples. The detection sensitivity of Helicobacter pylori, Helicobacter hepaticus and Helicobacter bilis strains from feces simulated samples was all 102 CFU/ml. We successfully detected H. hepaticus and H. bilis in the liver, cecum and feces of experimentally infected mice. H. pylori was successfully detected in the feces samples from 3 patients infected with H. pylori while not in the feces samples from 3 healthy human. However, the C97/C05–C97/C98 PCR assay detected H. pylori in the 2 positive samples. Due to the PCR assay’s excellent inclusivity, high sensitivity and specificity it may be used to detect the presence of Helicobacters.

Comparison of in vivo confocal endomicroscopy with other diagnostic modalities to detect intracellular helicobacters

Intracellular colonisation may serve as a protected niche where Helicobacter spp. organisms evade effective treatment. In dogs, non-Helicobacter pylori-helicobacters are frequently intracellular. Confocal endomicroscopy allows in vivo gastrointestinal imaging and has aided real-time identification of Helicobacter pylori and other intracellular and mucosally associated bacteria. The objectives of this study were: (1) to determine the utility of confocal endomicroscopy to identify non-Helicobacter pylori-helicobacters compared with other diagnostic modalities, and (2) to assess its ability to identify intracellular organisms. Fourteen clinically healthy dogs underwent standard gastroduodenoscopy followed by confocal endomicroscopy using topical acriflavine. Confocal images were obtained from at least five gastric sites. Endoscopic biopsies were obtained for histopathology, PCR and fluorescence in situ hybridisation (FISH). Methodologies were compared for their ability to determine the presence and spatial distribution of gastric helicobacters in dogs. Confocal endomicroscopy provided high quality images allowing in vivo identification of non-Helicobacter pylori-helicobacters in 13 dogs. Histopathology identified helicobacters in 11 dogs. Organisms were identified within the superficial gastric mucus and within gastric pits, and distribution throughout the stomach was diffuse and multi-focal. Confocal endomicroscopy findings correlated with PCR and FISH post-procedure analysis. Only FISH identified intracellular organisms, which were present in 13/14 dogs. Confocal endomicroscopy provided in vivo histology images and was capable of identifying non-Helicobacter pylori-helicobacters during gastroscopy, but was unable to identify intracellular organisms using the current fluorophore protocol.

Canine Gastric Pathology: A Review

Gastric disorders are common in dogs and are a major reason for veterinary consultation. In human medicine, the classification of gastric diseases based on histological features, genotypes and molecular phenotypes helps to better understand the characteristics of each subtype, and to improve early diagnosis, prevention and treatment. Canine gastric lesions often show strong histological similarities to their human counterparts. However, such conditions in the canine stomach are poorly studied and their cellular and molecular features are largely unknown. This article reviews the histopathological classification of inflammatory and neoplastic lesions of the canine stomach and provides an update on the application of molecular techniques within the field of canine gastric pathology. The canine disorders are compared with current knowledge of the equivalent human diseases.

The pathogenic potential of Helicobacter cinaedi isolated from non-human sources: adherence, invasion and translocation ability in polarized intestinal epithelial Caco-2 cells in vitro

Helicobacter cinaedi infection has been recognized as an increasingly important emerging disease in humans. Infection with H. cinaedi causes bacteremia, cellulitis and enteritis. H. cinaedi has been isolated from non-human sources, including dogs, cats and rodents; however, it remains unclear whether animal strains are pathogenic in humans and as zoonotic pathogens. In this study, H. cinaedi isolates were recovered from a dog and a hamster, and the ability of these isolates to adhere to, invade and translocate across polarized human intestinal epithelial Caco-2 cells was examined in vitro. To better understand the pathogenic potential of animal H. cinaedi isolates, these results were compared with those for a human strain that was isolated from a patient with bacteremia. The animal and human strains adhered to and invaded Caco-2 cells, but to a lesser degree than the C. jejuni 81–176 strain, which was used as a control. The integrity of tight junctions was monitored by measuring transepithelial electrical resistance (TER) with a membrane insert system. The TER values for all H. cinaedi strains did not change during the experimental periods compared with those of the controls; however, translocation of H. cinaedi from the apical side to the basolateral side was confirmed by cultivation and H. cinaedi-specific PCR, suggesting that the H. cinaedi strains translocated by transcellular route. This study demonstrated that H. cinaedi strains of animal origin might have a pathogenic potential in human epithelial cells as observed in a translocation assay in vitro with a human isolate.

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.

Pararenal Lymphatic Cyst Infection Caused by Helicobacter cinaedi

A 43-year-old man was referred to our hospital for an acute-onset fever and left flank pain. He had been previously diagnosed with lymphangioma, and abdominal computed tomography showed pararenal cysts with fat stranding around the left kidney, of which infection was subsequently confirmed on magnetic resonance imaging. Gram-negative spiral bacilli were isolated from two sets of blood cultures, and Helicobacter cinaedi was identified using 16S rRNA sequencing. The patient was successfully treated with ceftriaxone therapy without recurrence. A multilocus sequence typing analysis indicated the current H. cinaedi strain differed from previous strains isolated in Japan.

Helicobacter cinaedi-associated Vertebral Osteomyelitis in an Immunocompetent Patient

A 56-year-old previously healthy man was hospitalized due to a 10-day history of neck pain and an elevated C-reactive protein level. Gram-negative spiral bacilli were isolated from his blood, and Helicobacter cinaedi was confirmed using 16S rRNA sequencing. The infectious focus was not identified by initial cervical magnetic resonance imaging (MRI); however, repeated MRI demonstrated prominent high signal intensity in the entire region of the C6-C7 vertebrae and C6/C7 disc space. Furthermore, fluorodeoxyglucose-positron emission tomography/computed tomography showed no significant uptake, other than in the C6-C7 region. The patient was successfully treated with ceftriaxone for six weeks without sequelae.

A comparison of Helicobacter pylori and non-Helicobacter pylori Helicobacter spp. Binding to canine gastric mucosa with defined gastric glycophenotype

BACKGROUND

The gastric mucosa of dogs is often colonized by non-Helicobacter pylori helicobacters (NHPH), while H. pylori is the predominant gastric Helicobacter species in humans. The colonization of the human gastric mucosa by H. pylori is highly dependent on the recognition of host glycan receptors. Our goal was to define the canine gastric mucosa glycophenotype and to evaluate the capacity of different gastric Helicobacter species to adhere to the canine gastric mucosa.

MATERIALS AND METHODS

The glycosylation profile in body and antral compartments of the canine gastric mucosa, with focus on the expression of histo-blood group antigens was evaluated. The in vitro binding capacity of FITC-labeled H. pylori and NHPH to the canine gastric mucosa was assessed in cases representative of the canine glycosylation pattern.

RESULTS

The canine gastric mucosa lacks expression of type 1 Lewis antigens and presents a broad expression of type 2 structures and A antigen, both in the surface and glandular epithelium. Regarding the canine antral mucosa, H. heilmannii s.s. presented the highest adhesion score whereas in the body region the SabA-positive H. pylori strain was the strain that adhered more.

CONCLUSIONS

The canine gastric mucosa showed a glycosylation profile different from the human gastric mucosa suggesting that alternative glycan receptors may be involved in Helicobacter spp. binding. Helicobacter pylori and NHPH strains differ in their ability to adhere to canine gastric mucosa. Among the NHPH, H. heilmannii s.s. presented the highest adhesion capacity in agreement with its reported colonization of the canine stomach.

Clinical and bacteriological characteristics of Helicobacter cinaedi infection

Helicobacter cinaedi was first isolated from rectal cultures from homosexual men in 1984. In the 1980s to mid 1990s, the microorganism was mainly isolated from samples from homosexual men or immunocompromised patients; however, during the last two decades, H. cinaedi has been isolated from immunocompromised and from immunocompetent individuals worldwide. In Japan, the isolation of this microorganism was first reported in 2003. Since then, many cases have been reported in hospitals across the country. Despite many reports, the etiological properties and pathogenicity of H. cinaedi remain elusive; however, we are increasingly able to recognize some of the features and the clinical relevance of infection. In particular, a long incubation period is essential for detection in an automatic blood culture system and many of the recent isolates are resistant to both macrolides and quinolones. Furthermore, there is an association between infection and severe or chronic illnesses, such as meningitis or arteriosclerosis, in addition to mild diseases such as fever, abdominal pain, gastroenteritis, proctitis, diarrhea, erysipelas, cellulitis, arthritis, and bacteremia. In this review, we introduce the current knowledge and our latest findings relating to H. cinaedi.

Detection of Helicobacter spp. DNA in the colonic biopsies of stray dogs: molecular and histopathological investigations

Abstract

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1957989294118782.

Rapid identification and subtyping of Helicobacter cinaedi strains by intact-cell mass spectrometry profiling with the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry

Helicobacter cinaedi infection is recognized as an increasingly important emerging disease in humans. Although H. cinaedi-like strains have been isolated from a variety of animals, it is difficult to identify particular isolates due to their unusual phenotypic profiles and the limited number of biochemical tests for detecting helicobacters. Moreover, analyses of the 16S rRNA gene sequences are also limited due to the high levels of similarity among closely related helicobacters. This study was conducted to evaluate intact-cell mass spectrometry (ICMS) profiling using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) as a tool for the identification of H. cinaedi. A total of 68 strains of H. cinaedi isolated from humans, dogs, a cat, and hamsters were examined in addition to other Helicobacter species. The major ICMS profiles of H. cinaedi were identical and differed from those of Helicobacter bilis, which show >98% sequence similarity at the 16S rRNA sequence level. A phyloproteomic analysis of the H. cinaedi strains examined in this work revealed that human isolates formed a single cluster that was distinct from that of the animal isolates, with the exception of two strains from dogs. These phyloproteomic results agreed with those of the phylogenetic analysis based on the nucleotide sequences of the hsp60 gene. Because they formed a distinct cluster in both analyses, our data suggest that animal strains may not be a major source of infection in humans. In conclusion, the ICMS profiles obtained using a MALDI-TOF MS approach may be useful for the identification and subtyping of H. cinaedi.

Helicobacter spp. in the saliva, stomach, duodenum and faeces of colony dogs

The role of Helicobacter spp. infection in canine gastrointestinal disease is unclear and routes of transmission are of epidemiological and zoonotic importance. The aim of this study was to identify Helicobacter spp. in the saliva, stomach, duodenum and faeces of dogs using a multiplex PCR, and to evaluate any attendant histopathological changes. Helicobacter canis was the most common species detected in saliva and faeces and no correlation between the presence of Helicobacter spp. and histopathological changes in either the stomach or duodenum was observed. All dogs examined were co-infected with up to four species of the organism. This is the first time these bacteria have been studied at species level at multiple sites within the canine alimentary tract.

Successful culture techniques for Helicobacter species: verification of Helicobacter identity using 16S rRNA gene sequence analysis

This chapter describes protocols for the verification of putative Helicobacter species' identities using 16S rRNA gene sequence analysis.

Localization of Helicobacter spp. in the fundic mucosa of laboratory Beagle dogs: an ultrastructural study

In dogs Helicobacter spp. are found in all gastric regions usually localized in the surface mucus, gastric glands and parietal cells. The aim of this study was to detail the distribution of Helicobacter spp. in the fundic mucosa of asymptomatic Beagle dogs and their intracellular localization within parietal cells, in order to evaluate species-specific pathogenetic effects on gastric cells. The presence of Helicobacter spp. was investigated by immunohistochemistry, TEM, and PCR in the fundic mucosa of six Beagle dogs. Helicobacter spp. were found in all dogs examined, and H. bizzozeronii and H. felis were identified by PCR and confirmed by TEM. In the lumen of the fundic glands, co-localization was common. H. bizzozeronii was present in larger numbers than H. felis in both intraluminal and intraparietal localization. The amounts of H. bizzozeronii were similar in superficial and basal portions of the glands. H. felis was predominantly localized in the superficial portions of gastric glands but almost absent from the base. Within parietal cells, most Helicobacter organisms were intracanalicular, but intact and degenerate Helicobacter organisms were also visualized free in the cytoplasm or in secondary lysosomes. No specific degenerative lesions were found in infected parietal cells. Helicobacter organisms were also observed within macrophages in the lamina propria. In conclusion, there is a differential distribution of H. bizzozeronii and H. felis in the fundic mucosa of Beagle dogs, and their intracellular localization in parietal cells and macrophages suggests novel pathogenic scenarios for the development of immune response and maintenance of chronic gastritis in dogs.

Helicobacter spp. other than Helicobacter pylori

Over the last 12 months, new insights into the association of non-Helicobacter pylori Helicobacters with a range of human diseases in children and adults, including hepatobiliary disease, Crohn's disease, sepsis, and gastric disease were published. Studies investigating the presence of non-H. pylori Helicobacters in domestic animals reinforce previous findings that cats and dogs harbor gastric Helicobacter species and thus may be an important source of these organisms in humans. The confounding effect of enterohepatic Helicobacters on the outcome of biomedical research was investigated in several studies and led to recommendations that animals should be screened prior to performing experiments. A number of important and novel investigations regarding pathogenic mechanisms and immune responses to enterohepatic Helicobacters were conducted. Genomic advances in non-H. pylori Helicobacters included description of the complete genome of Helicobacter canadensis, delineation of two Helicobacter bilis genomospecies, and identification of a novel cis-regulatory RNA. New insights concerning growth conditions, biochemical characterization, and the effect of certain dietary compounds on Helicobacter spp. have also been reported.

Examination of equine glandular stomach lesions for bacteria, including Helicobacter spp by fluorescence in situ hybridisation

Background

The equine glandular stomach is commonly affected by erosion and ulceration. The aim of this study was to assess whether bacteria, including Helicobacter, could be involved in the aetiology of gastric glandular lesions seen in horses.

Results

Stomach lesions, as well as normal appearing mucosa were obtained from horses slaughtered for human consumption. All samples were tested for urease activity using the Pyloritek^® assay, while mucosal bacterial content was evaluated using Fluorescence In Situ Hybridisation. In selected sub samples, bacteria characterisation was pursued further by cloning and sequencing. Mucosal lesions were found in 36/63 stomachs and included hyperplastic rugae, polypoid structures and focal erosions. None of the samples were tested positive for urease activity or for FISH using the Helicobacter genus specific probe. In samples of lesions, as well as normal samples, clones with 99% similarities to Lactobacillus salivarius and Sarcina ventriculi were found. Escherichia like bacterium clones and Enterococcus clones were demonstrated in one focal erosion. Based on a phylogenetic tree these clones had 100% similarity to Escherichia fergusonii and Enterococcus faecium. The Enterococcus were found colonising the mucosal surface, while E. fergusonii organisms were also demonstrated intraepithelial.

Conclusion

Gastric Helicobacter spp. could not be verified as being involved in lesions of the glandular stomach of the horse. Since E. fergusonii has been described as an emerging pathogen in both humans and animals, the finding of this bacterium in gastric erosion warrants further clarification to whether gastric infection with this type bacterium is important for horses.

Delineation of two Helicobacter bilis genomospecies: implications for systematics and evolution

The evolution and taxonomy of Helicobacter bilis strains isolated in Italy and Finland were studied by phylogenetic analysis of different genes, comparative analysis of small rRNA gene intervening sequence (IVS), amplified fragment length polymorphism analysis and DNA-DNA hybridization. The results of this study divided the H. bilis strains into two distinct and divergent genomic groups. In the absence of a specific phenotype or pathotype to distinguish these groups, however, they may be referred to as two genomospecies: H. bilis sensu stricto and Helicobacter sp. FL56. The phylogenetic network of gyrB and ureB gene sequences, as well as the comparative analysis of small rRNA gene IVS, suggests independent evolution of the two genomospecies. In particular, Helicobacter sp. FL56 seems to be the result of adaptation of an ancestral H. bilis strain in a new host. The phenomenon of adaptation to different hosts, or different intestinal niches in the same host, associated with high mutation and recombination rates could explain the evolution and the complex taxonomy of the genus Helicobacter. A comprehensive phylogenomics study of this genus would be useful to properly investigate this hypothesis.