Serological discrimination of dogs infected with gastric Helicobacter spp. and uninfected dogs

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.

Evaluation of the Helicobacteraceae in the oral cavity of dogs

OBJECTIVE

To determine the Helicobacter spp present in the oral cavity of dogs and the relationship of those organisms with gastric Helicobacter spp to better define the potential for dog-human and dog-dog transmission.

SAMPLE

Saliva and dental plaque from 28 dogs and gastric biopsy specimens from a subset of 8 dogs.

PROCEDURES

PCR-based screening for Helicobacter spp was conducted on samples obtained from the oral cavity of 28 dogs. Comparative analysis was conducted on Helicobacteraceae 16S rDNA clone libraries from the oral cavity and stomach of a subset of 8 dogs (5 vomiting and 3 healthy) that had positive PCR results for Helicobacter spp.

RESULTS

Helicobacteraceae DNA was identified in the oral cavity of 24 of 28 dogs. Analysis of cloned 16S rDNA amplicons from 8 dogs revealed that Wolinella spp was the most common (8/8 dogs) and abundant (52/57 [91%] clones) member of the Helicobacteraceae family in the oral cavity. Only 2 of 8 dogs harbored Helicobacter spp in the oral cavity, and 1 of those was coinfected with Helicobacter heilmannii and Helicobacter felis in samples obtained from the stomach and saliva. Evaluation of oral cavity DNA with Wolinella-specific PCR primers yielded positive results for 16 of 20 other dogs (24/28 samples were positive for Wolinella spp).

CONCLUSIONS AND CLINICAL RELEVANCE

Wolinella spp rather than Helicobacter spp were the predominant Helicobacteraceae in the oral cavity of dogs. The oral cavity of dogs was apparently not a zoonotically important reservoir of Helicobacter spp that were non-Helicobacter pylori organisms.

Helicobacter species detection and histopathological changes in stray cats from Niterói, Brazil

Tightly coiled bacteria are common inhabitants of the gastric mucosae of cats and there is considerable debate whether feline helicobacters are commensal or pathogenic organisms. To determine the prevalence of Helicobacter species and gastric histopathological findings, gastric mucosa samples of 56 stray cats were collected from cardia, fundus, body, antrum and pylorus at necropsy. The samples were examined by urease test, cytology, histopathology and culture. Helicobacter species were detected in 53 cats (94.6%) by at least one detection method. Urease test results were positive in gastric samples from 50 (89.3%) cats. Cytological and histological evaluations revealed Helicobacter species in 52 (92.8%) and 50 (89.2%) cats, respectively. Helicobacter species organisms were not cultured from any cat. Regardless of the presence of gastric bacteria, most of the cats had mild to moderate gastritis. These data reveal a high prevalence of Helicobacter species in stray cats from Niterói, Brazil.

Helicobacter heilmannii infection: clinical, endoscopic and histopathological features in Japanese patients

Gastric biopsy materials of 4074 consecutive Japanese patients undergoing esophagogastroduodenoscopy were reviewed, along with those of 15 patients with Helicobacter heilmannii infection (11, chronic gastritis; four, mucosa-associated lymphoid tissue (MALT) lymphoma). In four patients with H. heilmannii infection, the materials were examined by transmission electronmicroscopy. Urea breath test (three patients) and antibody test (five patients) were performed in patients with H. heilmannii infection. In two patients with MALT lymphoma, H. heilmannii was eradicated. The prevalence of H. heilmannii was 0.1% in the consecutive series. In chronic gastritis, the gastric mucosa was endoscopically normal (13.3%), had erythema (33.3%), or had erosions (53.3%); histologically, it showed no epithelial change, mild mononuclear cell infiltration, and slight and focal neutrophil infiltration; Helicobacter heilmannii was positive with anti-H. pylori antibody, and was detected in the mucous gel layer and in foveolae. In MALT lymphoma, the gastric mucosa was coarsely granular with enlarged mucosal folds without ulcers (two cases), with small ulcers (one case), or with multiple erosions (one case). Urea breath test and antibody test were both negative. Eradication of H. heilmannii resulted in remission of MALT lymphoma. Helicobacter heilmannii infection is therefore uncommon in Japanese adults, but is associated with chronic gastritis and gastric MALT lymphoma.

Cloning and sequencing of the canine and feline cardiac troponin I genes

OBJECTIVE

To determine the gene sequences of canine and feline cardiac troponin I (cTnI), express the protein from the cloned gene in vitro, and validate the use of a commercial cTnI serum analyzer in these species via detection of the expressed protein or comparison of sequence homology.

SAMPLE POPULATION

Samples of ventricular myocardium from 5 healthy adult mixed-breed dogs and 5 healthy adult domestic shorthair cats.

PROCEDURE

The RNA was extracted from myocardial samples, and cDNA was synthesized via reverse transcriptase polymerase chain reaction and sequenced. The canine cDNA for the coding region was expressed in cell culture and analyzed by western blot and sandwich enzyme-linked immunosorbent assays.

RESULTS

Canine and feline cTnI genes were cloned and sequenced. Homology of the nucleotide and amino acid sequences of the canine and feline cTnI genes with human and rodent cTnI genes were high; the greatest homology was detected between canine and feline genes (95% and 96%, respectively). Recombinant canine cTnI protein was detected by a commercial serum cTnI analyzer and by western blot analysis.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that commercial cTnI analyzers can be used to measure serum cTnI concentration from dogs and cats. Additionally, our preliminary characterization of the feline cTnI gene may facilitate further investigation of cTnI and its role in familial hypertrophic cardiomyopathy in cats.

Canine gastritis

Gastritis--inflammation of the stomach--is a frequently cited differential yet rarely characterized diagnosis in cases of canine anorexia and vomiting. Although the list of rule-outs for acute or chronic gastritis is extensive, a review of the veterinary literature reveals fewer than 15 articles that have focused on clinical cases of canine gastritis over the last 25 years. The dog frequently appears in the human literature as an experimentally manipulated model for the study of endoscopic techniques or the effect of medications on gastric mucosa. In the veterinary patient, cases of acute gastritis are rarely pursued with the complete diagnostic armamentarium, and cases of chronic gastritis are rarely found to occur as an entity isolated from the rest of the gastrointestinal tract. This article focuses on those findings most clinically relevant to cases of canine gastritis in veterinary medicine.

Helicobacter spp. infection in cats: evaluation of the humoral immune response and prevalence of gastric Helicobacter spp

The principal aims of this study were to evaluate the humoral immune response (IgG) of cats with gastric Helicobacter spp. infection, and to determine the prevalence of different types of Helicobacter spp. in the stomachs of cats. The Helicobacter infection status of 45 cats (12 healthy spay/neuter cats, 9 sick cats, 24 colony cats) was determined by evaluating endoscopic gastric biopsies for urease activity, presence of Helicobacter-like organisms (HLO) on histopathology, and genus and species-specific PCR. Serum samples were evaluated with a kinetic enzyme linked immunosorbent assay (ELISA) utilizing the high molecular cell-associated protein (HM-CAP) fraction of H. felis ATCC 49179.Seventeen of 45 cats were infected with Helicobacter spp.: "H. heilmannii" 9/17, H. felis 4/17, mixed "H. heilmannii" and H. felis 3/17, unclassified-Helicobacter spp. 7/17. H. pylori was not detected in any cat. Kinetic ELISA results were significantly higher for infected cats, than for uninfected cats. Cats infected with different Helicobacter spp. showed similar distribution of OD/min values. There were no effects of age or clinical signs on the results of kinetic ELISA. No correlation between colonization density and seroconversion was observed. There were statistically significant, but weak correlations between the degree of seroconversion and the degree of inflammation, and the number of lymphoid follicles. Infected cats had more severe inflammation in the pylorus and fundus than uninfected cats. Infected sick cats had a higher degree of pyloric, but not fundic inflammation, than healthy infected cats and uninfected sick cats. The results indicate that naturally acquired infection with gastric Helicobacter spp. is associated with seroconversion (IgG) in cats. The similar ELISA values in cats infected with a variety of Helicobacter spp. suggests substantial antigenic homology between different Helicobacter spp. The higher degree of inflammation in infected than uninfected cats, supports a role for Helicobacter as a cause of gastritis in cats.

Emergence of diverse Helicobacter species in the pathogenesis of gastric and enterohepatic diseases

Since Helicobacter pylori was first cultivated from human gastric biopsy specimens in 1982, it has become apparent that many related species can often be found colonizing the mucosal surfaces of humans and other animals. These other Helicobacter species can be broadly grouped according to whether they colonize the gastric or enterohepatic niche. Gastric Helicobacter species are widely distributed in mammalian hosts and are often nearly universally prevalent. In many cases they cause an inflammatory response resembling that seen with H. pylori in humans. Although usually not pathogenic in their natural host, these organisms serve as models of human disease. Enterohepatic Helicobacter species are an equally diverse group of organisms that have been identified in the intestinal tract and the liver of humans, other mammals, and birds. In many cases they have been linked with inflammation or malignant transformation in immunocompetent hosts and with more severe clinical disease in immunocompromised humans and animals. The purpose of this review is to describe these other Helicobacter species, characterize their role in the pathogenesis of gastrointestinal and enterohepatic disease, and discuss their implications for our understanding of H. pylori infection in humans.