Helicobacter Species Research Articles

Helicobacter cappadocius sp. nov., from lizards: The first psychrotrophic Helicobacter species

It was aimed to determine the prevalence of Helicobacter in some reptilian and amphibian species in Türkiye and to describe the bacteria. For this purpose, 73 cloacal swab samples were used as material. The description of the isolates was performed by detailed phenotypic tests, whole genome analyses, and MALDI-TOF MS. As a result of the phenotypic analysis, two helical, curved Gram-negative, motile isolates were recovered. It was determined through the analysis of 16S rRNA gene sequences that two isolates belonged to the genus Helicobacter. These isolates were found to be in a distinct group from other Helicobacter species. However, the 16S rRNA sequence did not match any identified species, with the closest match being Helicobacter mustelae strain R85-13-6T, which had an identity level of 96.2 %. Additionally, it was found that strains faydin-H75T and faydin-H76 had a 99.3 % identity level for their 16S rRNA genes. After conducting dDDH and ANI analyses, it was found that strains faydin-H75T and their close neighbors H.anseris ATCC BAA-1299T shared 13.5 % and 68.8 % similarity, respectively. The genome size of the strains was 1.7 Mb while G + C contents were 33.5 %. Metagenomic analyses using IMNGS and Protologger tools revealed the presence of faydin-H75T in various lizard species with high similarity, confirming its broad distribution and host specificity. The results indicated that these two strains represent a novel species, for which we propose the name Helicobacter cappadocius with faydin-H75T (=NCTC014972 = LMG 33382 = DSM117062) as the respective type strain. The current novel species is the first Helicobacter species to exhibit a psychrotrophic feature.

Detection, isolation and virulence characterization of Helicobacter suis from pork products aimed to human consumption

Helicobacter suis is the most common non-H. pylori gastric Helicobacter species found in humans. Infection is associated with gastritis, peptic ulcer, gastric MALT lymphoma and neurodegenerative disorders, particularly Parkinson's disease. However, the pathogenicity of this species is still a matter of research, and results of virulence studies and antibiotic susceptibility tests tend to vary between strains. Cholesterol α-glucosyltransferase (αCgT), a known H. pylori virulence factor, appears to be present in most clinical H. suis isolates. The ability to form biofilms also plays a crucial role in the pathogenesis of H. pylori. However, no reports have been published on this ability in H. suis.H. suis is considered an emerging zoonotic pathogen, with pigs being the main source of human infection. However, there is very little information on its presence in pork, mainly due to the difficulties of its culture. Therefore, our aim was to determine the prevalence of H. suis in pork products from our geographical area by PCR and fluorescence in situ hybridisation (FISH), as well as to isolate the bacteria and determine the antibiotic susceptibility patterns, the presence of the αCGT gene and the ability of the isolates to form biofilms.Overall, H. suis was detected in 20 of the 70 (28.6 %) samples analyzed. In 3 of them, H. suis was isolated. The αCGT gene was detected in all isolates and two of them showed a multiresistance pattern. The H. suis reference strain and two of the isolates showed “strong” to “moderate” in vitro biofilm formation ability under optimal growth conditions.Our results seem to indicate that H. suis is significantly prevalent in pork products. The combination of culture with FISH and/or mPCR proved to be a rapid and specific method for the detection, identification and direct visualization of cultivable H. suis cells from pork food products.

Helicobacter Pylori and Metaplastic Changes in Chronic Cholecystitis: A Correlation Study

Abstract Introduction: Various types of metaplastic changes, such as gastric metaplasia (foveolar type or antral type) and intestinal metaplasia, are observed in chronic cholecystitis but not in normal mucosa. Helicobacter species can be detected in the bile and gallbladder tissue of patients with benign gallbladder disease. Objective: The present study aimed to observe the correlation between chronic cholecystitis and the presence of Helicobacter pylori as well as the different types of metaplastic changes in gallbladder mucosa. Materials and Methods: This descriptive, observational study was conducted at the Departments of Pathology and Surgery at a tertiary care medical college and hospital from April 2021 to March 2022, using a cross-sectional design. All confirmed cases of chronic cholecystitis, with or without cholelithiasis, were included in the study. Results: Intestinal metaplasia was the most common type of metaplastic change in the gallbladder epithelium in chronic cholecystitis in this region. PAS and Alcian Blue positivity were significantly higher in cases with metaplasia compared to those without metaplasia. H. pylori was detected in 3 cases (1.55%) of chronic cholecystitis in this study population. Conclusion: Mucin histochemistry may help identify early metaplastic changes in gallbladder epithelium. The use of a combination of methods for the detection of H. pylori in gallbladder tissue may increase the detection of positive cases.

Helicobacter pylori HP0018 Has a Potential Role in the Maintenance of the Cell Envelope.

Helicobacter pylori is a bacterial pathogen that colonizes the human stomach, where it can cause a variety of diseases. H. pylori uses a cluster of sheathed flagella for motility, which is required for host colonization in animal models. The flagellar sheath is continuous with the outer membrane and is found in most Helicobacter species identified to date. HP0018 is a predicted lipoprotein of unknown function that is conserved in Helicobacter species that have flagellar sheaths but is absent in Helicobacter species that have sheath-less flagella. Deletion of hp0018 in H. pylori B128 resulted in the formation of long chains of outer membrane vesicles, which were most evident in an aflagellated variant of the Δhp0018 mutant that had a frameshift mutation in fliP. Flagellated cells of the Δhp0018 mutant possessed what appeared to be a normal flagellar sheath, suggesting that HP0018 is not required for sheath formation. Cells of the Δhp0018 mutant were also less helical in shape compared to wild-type cells. A HP0018-superfolder green fluorescent fusion protein expressed in the H. pylori Δhp0018 mutant formed fluorescent foci at the cell poles and lateral sites. Co-immunoprecipitation assays with HP0018 identified two enzymes involved in the modification of the cell wall peptidoglycan, AmiA and MltD, as potential HP0018 interaction partners. HP0018 may modulate the activity of AmiA or MltD, and in the absence of HP0018, the unregulated activity of these enzymes may alter the peptidoglycan layer in a manner that results in an altered cell shape and hypervesiculation.

Prevalence and diversity of enteric Helicobacter spp. in healthy and diarrheic cats.

Helicobacters are gastric and enterohepatic and live in the gut. The role of enterohepatic Helicobacters as intestinal pathogens is uncertain, while stomach Helicobacters are well-known. The prevalence of Helicobacter species in cat feces helps us understand their impact on cat health and human disease transmission. This study used PCR to identify Helicobacter spp. in feces samples from healthy and diarrhoeic cats, independent of the reason. The study also compared intestinal and stomach Helicobacter species. PCR analysis was performed on fecal samples from 40 cats, with 20 cats having diarrhea and 20 cats showing no symptoms. The PCR analysis aimed to detect Helicobacter's presence using a method that identifies the bacteria through the 16S rRNA gene. The diarrhoeic group had a greater prevalence of infection (17:9 ratio), with an overall 65% infection rate detected. Cats that were older than 2 years showed a higher incidence of disease. H. canis had the highest occurrence rate (69.2%), followed by H. bilis, H. bizzozeronii, and H. salomonis. Significantly, H. pylori, H. felis, and H. heilmannii were not reported. H. canis was the predominant species found in both healthy and diarrheic cats, indicating the need for more investigation. The detection of the gastric species H. salomonis and H. bizzozeronii further complicates the classification. This highlights the complex nature of Helicobacter infections in cats, emphasizing the need for further investigation to guide the development of preventative measures and treatment techniques for both veterinary and public health purposes.

Chronic PM2.5 exposure disrupts intestinal barrier integrity via microbial dysbiosis-triggered TLR2/5-MyD88-NLRP3 inflammasome activation

BackgroundPM2.5, a known public health risk, is increasingly linked to intestinal disorders, however, the mechanisms of its impact are not fully understood. PurposeThis study aimed to explore the impact of chronic PM2.5 exposure on intestinal barrier integrity and to uncover the underlying molecular mechanisms. MethodsC57BL/6 J mice were exposed to either concentrated ambient PM2.5 (CPM) or filtered air (FA) for six months to simulate urban pollution conditions. We evaluated intestinal barrier damage, microbial shifts, and metabolic changes through histopathology, metagenomics, and metabolomics. Analysis of the TLR signaling pathway was also conducted. ResultsThe mean concentration of PM2.5 in the CPM exposure chamber was consistently measured at 70.9 ± 26.8 μg/m³ throughout the study period. Our findings show that chronic CPM exposure significantly compromises intestinal barrier integrity, as indicated by reduced expression of the key tight junction proteins Occludin and Tjp1/Zo-1. Metagenomic sequencing revealed significant shifts in the microbial landscape, identifying 35 differentially abundant species. Notably, there was an increase in pro-inflammatory nongastric Helicobacter species and a decrease in beneficial bacteria, such as Lactobacillus intestinalis, Lactobacillus sp. ASF360, and Eubacterium rectale. Metabolomic analysis further identified 26 significantly altered metabolites commonly associated with intestinal diseases. A strong correlation between altered bacterial species and metabolites was also observed. For example, 4 Helicobacter species all showed positive correlations with 13 metabolites, including Lactate, Bile acids, Pyruvate and Glutamate. Additionally, increased expression levels of TLR2, TLR5, Myd88, and NLRP3 proteins were noted, and their expression patterns showed a strong correlation, suggesting a possible involvement of the TLR2/5-MyD88-NLRP3 signaling pathway. ConclusionsChronic CPM exposure induces intestinal barrier dysfunction, microbial dysbiosis, metabolic imbalance, and activation of the TLR2/5-MyD88-NLRP3 inflammasome. These findings highlight the urgent need for intervention strategies to mitigate the detrimental effects of air pollution on intestinal health and identify potential therapeutic targets.

Use of Deep-Amplicon Sequencing (DAS), Real-Time PCR and In Situ Hybridization to Detect H. pylori and Other Pathogenic Helicobacter Species in Feces from Children.

Detecting Helicobacter pylori in fecal samples is easier and more comfortable than invasive techniques, especially in children. Thus, the objective of the present work was to detect H. pylori in feces from children by molecular methods as an alternative for diagnostic and epidemiological studies. Forty-five fecal samples were taken from pediatric patients who presented symptoms compatible with H. pylori infection. HpSA test, culture, real-time quantitative PCR (qPCR), fluorescence in situ hybridization (FISH), direct viable count associated with FISH (DVC-FISH), and Illumina-based deep-amplicon sequencing (DAS) were applied. No H. pylori colonies were isolated from the samples. qPCR analysis detected H. pylori in the feces of 24.4% of the patients. In comparison, DVC-FISH analysis showed the presence of viable H. pylori cells in 53.3% of the samples, 37% of which carried 23S rRNA mutations that confer resistance to clarithromycin. After DAS, H. pylori-specific 16S rDNA sequences were detected in 26 samples. In addition, DNA from H. hepaticus was identified in 10 samples, and H. pullorum DNA was detected in one sample. The results of this study show the presence of H. pylori, H. hepaticus, and H. pullorum in children's stools, demonstrating the coexistence of more than one Helicobacter species in the same patient. The DVC-FISH method showed the presence of viable, potentially infective H. pylori cells in a high percentage of the children's stools. These results support the idea that fecal-oral transmission is probably a common route for H. pylori and suggest possible fecal-oral transmission of other pathogenic Helicobacter species.

Assessing the Prevalence and Dynamics of Emerging Campylobacterales in Human Stool Samples in Brussels by Filtration Culture.

Thermophilic C. jejuni/coli is reported to be the first bacterial cause of gastroenteritis worldwide and the most common zoonosis in Europe. Although non-jejuni/coli Campylobacter sp. are increasingly suspected to be responsible for diarrhoea or to be involved in inflammatory bowel disease, they remain poorly isolated due to their fastidious and non-thermophilic nature. Additionally, they are not targeted by commercial syndromic PCR assays. In this study, we present routine diagnostic results over 6 years (2017-2019 and 2021-2023) of Campylobacter sp. and related species, obtained by optimised culture from 51,065 stools by both 0.65 µm pore filtration on antibiotic-free agar, incubated in an H2-enriched atmosphere at 37 °C (also known as the Cape Town protocol), and the use of selective inhibitory Butzler medium incubated at 42 °C. This allowed the isolation of 16 Campylobacter species, 2 Aliarcobacter species, and 2 Helicobacter species, providing a completely different view of the epidemiology of Campylobacterales, in which C. jejuni/coli represents only 30.0% of all isolates, while C. concisus represents 44.4%. C. ureolyticus, representing only 5.5% of all Campylobacterales pre-COVID-19, represented 20.6% of all strains post-COVID-19 (218% increase; p < 0.05). At the same time, the proportions of C. jejuni, C. coli, and C. concisus decreased by 37, 53, and 28%, respectively (p < 0.05).

Molecular surveillance of Helicobacter species with high prevalence from two streams with various wastewater pollution in Taiwan

Helicobacter species are potential zoonotic pathogens classified as either enterohepatic or gastric. Helicobacter infection can be transmitted through wastewater from households and livestock and through water from irrigation and streams. In this study, the distribution and source of Helicobacter species in the Donggang and Yenshui rivers, two natural water bodies with different characteristics, were analyzed. A total of 44 water samples were collected over the four seasons. The samples were subjected to Helicobacter 16 s rRNA gene PCR, followed by sequencing and comparison for identification and analysis. The detection rate of Helicobacter species in both rivers was 79.55%, with H. kayseriensis (10/35, 28.57%) being the most common species. Analysis of the environment around the sampling sites showed a high detection rate in the livestock-rich area, and the results of BLAST for species identification and comparison indicated feces as the contamination source. The area around the Donggang River was developed for animal husbandry, led to a high detection rate of Helicobacter species. Many Helicobacter species were identified to have a risk of zoonotic transmission, especially if the stream is used as a source of drinking, agricultural, or even aquacultural water. The high presence of Helicobacter species in natural water bodies suggests that wastewater treatment is an effective strategy to control pathogen spread. Therefore, investigation and monitoring of pathogens in wastewater are highly important. However, methods for the isolation and culture of Helicobacter species in natural waters have yet to be developed. Hence, future research should focus on developing such methods.

Bibliometric analysis and evaluation of publications on non-Helicobacter pylori helicobacters from 1993 to 2023.

Aim: A bibliometric analysis and evaluation of research on non-Helicobacter pylori Helicobacter species (NHPHs) is essential to determining future research directions. Materials & methods: A comprehensive search was carried out using predetermined search terms within the Web of Science Core Collection (WoSCC) to gather publications spanning from 1993 to 2023. VOSviewer and Citespace were employed for data analysis and visualization. Results: 308 publications on NHPHs were included. Among these, gastric NHPHs received more publications and attention compared with enterohepatic NHPHs. Key findings included the identification of most productive countries, institutions, journals, authors, keywords, research trends and notable perspectives in the field. Conclusion: The article guides further research and clinical applications on NHPHs.

Comparison of Plenum and Cage-level Filter Exhaust Dust PCR Testing to Soiled Bedding Sentinel Mice (Mus musculus) on an IVC Rack.

The use of soiled-bedded sentinels (SBSs) has historically been the standard for colony health surveillance monitoring at our institution. With the advent of newer technologies in which dust collected from filters is tested by PCR, we compared traditional SBS with PCR testing of both exhaust air dust collected from a filter in the downstream vertical plenum (exhaust dust test [EDT]) and the SBS cage-level exhaust filter (SCEF). Our hypothesis was that both methods of filter testing would identify more pathogens than SBS testing. Twenty-five individually ventilated mouse racks that used disposable caging were sanitized and placed into rotation. Rack plenums were tested by PCR to verify negative results before the study start. Exhaust dust collection media were placed in the exhaust plenum (n = 25). SBS cages were placed on each side of the rack with 2 mice per cage (n = 42 mice), with the remaining cage slots occupied by research animals. At each triweekly cage change, the exhaust air filters were carefully removed from the cage top, placed in sterile 50-mL conical tubes, and pooled for submission. After 3mo, the SBS mice were tested via serology for bacterial and viral agents and by PCR for Helicobacter species, pinworms, and ectoparasites. In addition, the EDT filter and SCEF were collected for PCR to evaluate for the same agents. Our results indicate that the SCEF consistently detected agents more frequently than the EDT filter placed in the plenum and that the EDT filter media detected agents more frequently than did the SBS mice. Our data suggest that both PCR methods of detection are superior to SBS for individually ventilated disposable rodent cages and that the SCEF is superior to EDT. These data supported our movement of institution toward environmental monitoring as a method of rodent colony health surveillance.

Comparison of gastric inflammation and metaplasia induced by Helicobacter pylori or Helicobacter felis colonization in mice.

Mouse infection models with Helicobacter species are widely used to study Helicobacter pathogenesis and gastric cancer initiation. However, Helicobacter pylori is not a natural mouse pathogen, and mouse-adapted H. pylori strains are poorly immunogenic. In contrast, Helicobacter felis is a natural mouse pathogen that induces robust gastric inflammation and is often used in mice to investigate gastric cancer initiation. Although both bacterial strains are widely used, their disease pathogenesis in mice differs dramatically. However, few studies have directly compared the pathogenesis of these bacterial species in mice, and the contrasting features of these two models are not clearly defined. This study directly compares the gastric inflammation, atrophy, and metaplasia development triggered by the widely used PMSS1 H. pylori and CS1 H. felis strains in mice. It serves as a useful resource for researchers to select the experimental model best suited for their studies.

Anti-Helicobacter pylori Effects of Thymus caramanicus Jalas Essential Oils: A New Antimicrobial Approach.

Helicobacter pylori are the principal causative factor in the etiological factors of chronic, active, or type B gastritis; peptic and duodenal ulcers; stomach carcinoma; and epithelial tissue lymphoid malignancies. It infects more than half of the population worldwide. To reduce H. pylori production, pharmacological therapy of H. pylori diseases typically involves using threefold treatment methods. However, as a result of such therapy, antimicrobial resistance is commonly developed. Alternative therapeutics for H. pylori diseases are thus of particular interest. Thyme essential oils (EOs) obtained from T. caramanicus Jalas plants in Iran were tested for antibacterial activity against H. pylori obtained from 320 poultry specimens in this investigation. Antibacterial activity was measured using inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs). The impact of T. caramanicus Jalas essential oils on H. pylori isolate cagA, vacA, and babA2 gene expression was evaluated using a quantitative real-time PCR method (p < 0.05). The chemical content of these EOs varied significantly according to chromatographic examination. Thymol, carvacrol, and terpinene-4-ol are the most abundant components in these EOs. H. pylori was recognized as a Helicobacter species with a 175-bp PCR product of 16S rRNA in 20/20 (100%). According to PCR results, all 20 (100%) isolates belonged to H. pylori. The EOs inhibited H. pylori in a dose-dependent manner, with T. caramanicus Jalas being the most effective, followed by pterygium EOs in decreasing order. At 8 mg/mL of T. caramanicus Jalas EOs, IZs against H. pylori were 27.4 ± 0.42 mm, and at 8 mg/mL of pterygium, IZs against H. pylori were 1 ± 0.02. T. caramanicus Jalas essential oils were used to treat all bacteria, and the findings showed that T. caramanicus Jalas had a substantial inhibitory impact on the expression of cagA, vacA, and babA2 virulence-related genes (p < 0.05). In a dose-dependent manner, the EOs of T. caramanicus Jalas EO demonstrated a high degree of antimicrobial property against H. pylori bacteria. The most efficient EOs were those from T. caramanicus Jalas with relative concentrations of thymol and carvacrol, followed by the coumarin-dominated pterygium EO with reduced antibacterial activity.

Polymerase Chain Reaction on In-cage Filter Paper at Different Time Points to Detect Helicobacter spp.

Helicobacter spp. infections in mice can have broad-ranging effects on gastrointestinal, reproductive, and immune systems. This can introduce significant confounding variables for research and may reduce scientific rigor. Screening mouse colonies for Helicobacter species can be accomplished via noninvasive PCR testing on filter paper placed in animal-free dirty bedding sentinel cages. In our facility, one tablespoon of dirty bedding from each cage on a rack is added to a designated sentinel cage every 3 wk at cage change, and PCR testing is performed on in-cage filter paper quarterly. We hypothesized that cages that received Helicobacter spp.-positive bedding at later time points would have a lower detection rate of Helicobacter spp. with PCR testing compared with cages that received positive bedding at earlier time points due to the filter paper becoming saturated. To determine if screening would be able to detect one positive row of cages on a rack, 9 tablespoons of Helicobacter- positive bedding and 71 tablespoons of negative bedding were added at the 3-, 6-, or 9-wk time points to 14 empty sentinel cages per time point. Negative bedding was added every 3 wk to cages not scheduled to receive positive bedding. Negative controls received 80 tablespoons of negative bedding and positive controls received 80 tablespoons of positive bedding at each time point. Filter paper was tested via PCR for Helicobacter spp. at 12 wk. All positive controls tested positive, and all negative controls tested negative. Two 3-wk cages, two 6-wk cages, and three 9-wk cages were positive, indicating no difference between time points. This resulted in a 16.7% Helicobacter spp. detection rate. These results indicate that PCR on in-cage filter paper may not be reliable in detecting low levels of Helicobacter spp. nucleic acid in dirty bedding.

Helicobacter fennelliae Localization to Diffuse Areas of Human Intestine, Japan.

The site of enterohepatic Helicobacter colonization/infection in humans is still unknown. We report microbiologically and histopathologically confirmed H. fennelliae localization in the large intestine in an immunocompromised patient in Japan. This case contributes to better understanding of the life cycle of enterohepatic Helicobacter species.

Helicobacter ibis sp. nov., isolated from faecal droppings of black-faced ibis (Theristicus melanopis).

As part of a larger study on Epsilonproteobacteria carried by wild birds in the city of Valdivia (southern Chile), two curved rod-shaped Gram-stain-negative strains (A82T and WB-40) were recovered from faecal samples and subjected to a taxonomic study. Results of a genus-specific PCR showed that these isolates belonged to the genus Helicobacter. Further identification by 16S rRNA and hsp60 (60 kDa heat-shock protein) gene sequence analysis revealed that they formed a separate phylogenetic clade, different from other known Helicobacter species with 'Helicobacter burdigaliensis' CNRCH 2005/566HT and Helicobacter valdiviensis WBE14T being the most closely related species. This was confirmed by core-genome phylogeny as well as digital DNA-DNA hybridization and average nucleotide identity analyses between the genomes of strains A82T and WB-40 and all other Helicobacter species. The draft genome sequences of A82T and WB-40, obtained by Illumina NextSeq 2000 sequencing, consisted of 1.6 Mb with a G+C content of 31.9-32.0 mol%. The results obtained from the phylogenetic and genomic characterization, together with their different morphological and biochemical features, revealed that these two strains represent a novel species, for which we propose the name Helicobacter ibis sp. nov. with A82T (=LMG 32718T=CCCT 22.04T) as the type strain.

Characterization of HcaA, a novel autotransporter protein in Helicobacter cinaedi, and its role in host cell adhesion.

Helicobacter species are classified as gastric or enterohepatic according to their habitat. Among enterohepatic Helicobacter species, which inhabit the intestine, colon, and liver, Helicobacter cinaedi has been most frequently isolated from humans. H. cinaedi often causes bacteremia and cellulitis in immunocompromised hosts. Here, we focused on the H. cinaedi autotransporter protein A (HcaA), a novel virulence factor in H. cinaedi. We discovered that HcaA contributes to cell adhesion via its Arg-Gly-Asp motif. Furthermore, in animal experiments, bacterial colonization was reduced in mice infected with HcaA-knockout strains, supporting the hypothesis that HcaA contributes to H. cinaedi adhesion to host cells. Our study provides a novel mechanism for the establishment of H. cinaedi infections and provides new insights into the role of autotransporter proteins in the establishment of Helicobacter infection.

Presence of potentially novel Helicobacter pylori-like organisms in gastric samples from cats and dogs

While seven gastric non-Helicobacter pylori Helicobacter (NHPH) species are known to commonly colonize the stomach of cats and dogs, the potential of H. pylori and H. pylori-like organisms to infect animals remains controversial and was investigated in this study using gastric samples of 20 cats and 27 dogs. A Helicobacter genus-specific 16 S rRNA PCR assay, H. pylori-specific ureAB and glmM PCR assays and a nested PCR detecting 23 S rRNA in a Helicobacter genus-specific manner in a first round of PCR and a H. pylori-specific manner in a second round, were performed in combination with sequencing. Histopathological and anti-Helicobacter immunohistochemical evaluations were also performed. Based on 16 S rRNA sequence analysis, 39/47 animals (83%) appeared infected with canine/feline gastric NHPHs in the corpus and/or antrum. H. pylori-specific ureAB amplicons were obtained in samples of 22 stomachs (47%). One canine antrum sample positive in the ureAB assay was also positive in the H. pylori-specific glmM assay. While 36/47 (77%) animals had a positive sample in the first round of the nested 23 S rRNA PCR assay, all samples were negative in the second round. Sequence analysis of obtained amplicons and immunohistochemistry point towards the presence of unidentified H. pylori-like organisms in cats and dogs. Histopathological examination suggests a low pathogenic significance of the gastric Helicobacter spp. present in these animals. In conclusion, cats and dogs may be (co-)infected with gastric Helicobacter organisms other than the known gastric NHPHs. Culture and isolation should be performed to confirm this hypothesis.

Detection of Helicobacter species in humans and their dog

Helicobacter is a genus of Gram-negative bacteria that colonizes the stomach of humans and dogs, among other mammals. The most frequent species found in the gastric mucosa of man is H. pylori, however, there are other species of Helicobacter in the stomach of humans, such as H. suis, H. bizzozeronii, H. felis, H. salomonis and H. heilmannii sensu stricto, named non H. pylori Helicobacter (NHPH) some of which also colonize the dog's stomach. The detection of NHPH in the stomach mucosa of humans with gastric disease, and in a high percentage of dogs, suggests the possibility that these animals play an important role in the pathogenesis and transmission of infection to man, postulating the path of transmission oral-oral or fecal-oral. The aim of this study was to determine whether people with signs of chronic gastritis who have Helicobacter spp. and who own dogs as pets, share the same species with them. The presence of Helicobacter spp. in gastric samples of 30 people with clinical signs of chronic gastritis and histopathological diagnosis of gastric infection with Helicobacter spp. was analyzed by PCR. The presence of Helicobacter spp. was also studied in the dogs of these people. Then, the species of Helicobacter presented was determined in both. In human gastric samples, H. pylori was the only species found, while in dogs, samples were H. bizzozeronii, H. felis, H. salomonis and H. heilmannii. In this work the same species were not found in dogs and their owners.

Determination of Helicobacter heilmannii in cats by real time polymerase chain reaction and histopathology

Helicobacter species such as Helicobacter heilmannii, Helicobacter pylori, Helicobacter felis, Helicobacter bizzozeronii, Helicobacter salomonis have been identified in cats and dogs, and research suggesting that these species may be zoonotic agents have increased in recent years. The aim of this study is to reveal the presence of H. heilmannii in stomach and liver tissues taken during necropsies of domestic, stray and shelter cats by real-time PCR and histopathology and to compare histopathological findings and real-time PCR results. The material of the study consisted of stomach and liver tissues taken from 41 cats who died from different causes and were necropsied. DNA of H. heilmannii was determined in the stomach tissues of 36 cats and the liver tissues of 24 cats in the study conducted with real-time PCR using specific primers of H. heilmannii. Epithelial degeneration in the stomach, fibrosis and oedema in the lamina propria and lymphoplasmacytic cell infiltration were detected histopathologically in the cats diagnosed with gastritis. Eight cats were positive in Hematoxylin-Eosin staining and nineteen cats were positive in the staining with Warthin Starry of the sections, in terms of Helicobacter-like microorganisms. Microscopically, dissociation of the remark cords and hydropic degeneration in hepatocytes and mononuclear cell infiltrations in some sections were determined in the livers. In conclusion, with this study, it was understood that real-time PCR analyses are very useful in determining H. heilmannii in cats. However, histopathological examinations are necessary to associate the presence of bacteria with the development of the disease.