Helicobacter suis induces changes in gastric inflammation and acid secretion markers in pigs of different ages

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

Helicobacter suis is the most common non-Helicobacter 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 Hybridization (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.

The prevalence of porcine gastric ulcer and Helicobacter suis in Taiwan

Gastric ulcer is a common disease affecting pigs worldwide, with a prevalence reported as high as 93%. The cause of porcine gastric ulcer is multifactorial, with Helicobacter suis (H. suis) being considered as the primary pathogenic factor. To date, prevalence of H. suis resulting in porcine gastric ulcer in Taiwan has not been investigated. In this study, we collected 360 pig stomachs from the slaughterhouses. In addition, stomach tissues from the 88 diseased pigs submitted for necropsy were divided into symptomatic and asymptomatic groups. Gastric lesions were scored, and polymerase chain reaction was used to determine the occurrence of gastric ulcer and the prevalence of H. suis. The positive rate of H. suis in the samples from slaughtered pigs was 49.7%, and both infection of H. suis and the presence of gastric lesions were prone to occur in autumn. The positive rates of H. suis infection in the symptomatic and asymptomatic groups were 59.1% and 31.8%, respectively. Moreover, the proportion of the samples with gastroesophageal ulcer in the symptomatic group was 68.2%, predominantly observed in growing pigs. The incidence of the samples from the slaughterhouses with gastroesophageal erosion to ulceration revealed a significant difference between H. suis -infected and H. suis -uninfected pigs; however, there is no significant difference in the samples of diseased pigs. In conclusion, H. suis infection was associated with gastric ulcer in slaughtered pigs, but it was not the primary cause of gastroesophageal ulcer in diseased pigs with clinical symptoms.

Incidences of Helicobacter infection in pigs and tracing occupational hazard in pig farmers

Helicobacter species (spp.) is a gram-negative spiral-shaped motile bacterium that causes gastritis in pigs and also colonizes in the human stomach. The present study assessed the prevalence of Helicobacter spp. in pig gastric mucosa and the stool of pig farmers in Assam, India. A total of 403 stomach samples from pig slaughter points, 74 necropsy samples of pigs from pig farms, and 97 stool samples from pig farmers were collected. Among the pig stomach samples, 43 (20.09%) of those with gastritis showed the presence of Gram-negative, spiral-shaped organisms, while only 3.04% of stomach samples without lesions had these organisms. Scanning Electron Microscopy (SEM) of urease-positive stomach samples revealed tightly coiled Helicobacter bacteria in the mucus lining. Histopathological examination showed chronic gastritis with hemorrhagic necrosis, leucocytic infiltration, and lymphoid aggregates. PCR confirmed the presence of Helicobacter suis in 19.63% of pig stomach samples and 2.08% of pig farmer stool samples. Additionally, 3.12% of the stool samples from pig farmers were positive for Helicobacter pylori. Phylogenetic analysis revealed distinct clusters of Helicobacter suis with other Helicobacter spp. These findings highlight the prevalence of Helicobacter in both pig gastric mucosa and pig farmer stool. The findings highlight the need for improved sanitation and hygiene practices among pig farmers to minimize the risk of Helicobacter infection in humans.

The role of Helicobacter suis, Fusobacterium gastrosuis, and the pars oesophageal microbiota in gastric ulceration in slaughter pigs receiving meal or pelleted feed

This study investigated the role of causative infectious agents in ulceration of the non-glandular part of the porcine stomach (pars oesophagea). In total, 150 stomachs from slaughter pigs were included, 75 from pigs that received a meal feed, 75 from pigs that received an equivalent pelleted feed with a smaller particle size. The pars oesophagea was macroscopically examined after slaughter. (q)PCR assays for H. suis, F. gastrosuis and H. pylori-like organisms were performed, as well as 16S rRNA sequencing for pars oesophagea microbiome analyses. All 150 pig stomachs showed lesions. F. gastrosuis was detected in 115 cases (77%) and H. suis in 117 cases (78%), with 92 cases (61%) of co-infection; H. pylori-like organisms were detected in one case. Higher infectious loads of H. suis increased the odds of severe gastric lesions (OR = 1.14, p = 0.038), while the presence of H. suis infection in the pyloric gland zone increased the probability of pars oesophageal erosions [16.4% (95% CI 0.6-32.2%)]. The causal effect of H. suis was mediated by decreased pars oesophageal microbiome diversity [-1.9% (95% CI - 5.0-1.2%)], increased abundances of Veillonella and Campylobacter spp., and decreased abundances of Lactobacillus, Escherichia-Shigella, and Enterobacteriaceae spp. Higher infectious loads of F. gastrosuis in the pars oesophagea decreased the odds of severe gastric lesions (OR = 0.8, p = 0.0014). Feed pelleting had no significant impact on the prevalence of severe gastric lesions (OR = 1.72, p = 0.28). H. suis infections are a risk factor for ulceration of the porcine pars oesophagea, probably mediated through alterations in pars oesophageal microbiome diversity and composition.

Molecular detection of Helicobacter spp. and Fusobacterium gastrosuis in pigs and wild boars and its association with gastric histopathological alterations

Besides Helicobacter pylori, a Gram-negative bacterium that may cause gastric disorders in humans, non-Helicobacter pylori helicobacters (NHPH) may also colonize the stomach of humans and animals. In pigs, H. suis can induce gastritis and may play a role in gastric ulcer disease, possibly in association with Fusobacterium gastrosuis. In the present study, gastric samples from 71 slaughtered pigs and 14 hunted free range wild boars were tested for the presence of DNA of F. gastrosuis and gastric Helicobacter species associated with pigs, dogs cats and humans, using species-specific PCR assays, followed by sequencing of the amplicon. These gastric samples were also histopathologically evaluated. Almost all the pigs presented gastritis (95.8%). Helicobacter spp. were detected in 78.9% and F. gastrosuis in 35.2% of the animals. H. suis was the most frequently identified Helicobacter species (57.7% of the animals), followed by a H. pylori-like species (50.7%) and less often H. salomonis and H. felis (each in 2.8% of the animals). H. suis was most often detected in the glandular (distal) part of the stomach (pars oesophagea 9.9%, oxyntic mucosa 35.2%, antral mucosa 40.8%), while the H. pylori-like species was mainly found in the non-glandular (proximal) part of the stomach (pars oesophagea 39.4%, oxyntic mucosa 14.1%, antral mucosa 4.2%). The great majority of wild boars were also affected with gastritis (71.4%) and Helicobacter spp. and F. gastrosuis were detected in 64.3% and 42.9% of the animals, respectively. H. bizzozeronii and H. salomonis were the most frequently detected Helicobacter species, while a H. pylori-like species and H. suis were only occasionally identified. These findings suggest that these microorganisms can colonize the stomach of both porcine species and may be associated with gastric pathology. This should, however, be confirmed through bacterial isolation. This is the first description of the presence of F. gastrosuis DNA in the stomach of wild boars and a H. pylori-like species in the pars oesophagea of the porcine stomach.

Gastric Helicobacter species associated with dogs, cats and pigs: significance for public and animal health

This article focuses on the pathogenic significance of Helicobacter species naturally colonizing the stomach of dogs, cats and pigs. These gastric "non-Helicobacter (H.) pylori Helicobacter species" (NHPH) are less well-known than the human adapted H. pylori. Helicobacter suis has been associated with gastritis and decreased daily weight gain in pigs. Several studies also attribute a role to this pathogen in the development of hyperkeratosis and ulceration of the non-glandular stratified squamous epithelium of the pars oesophagea of the porcine stomach. The stomach of dogs and cats can be colonized by several Helicobacter species but their pathogenic significance for these animals is probably low. Helicobacter suis as well as several canine and feline gastric Helicobacter species may also infect humans, resulting in gastritis, peptic and duodenal ulcers, and low-grade mucosa-associated lymphoid tissue lymphoma. These agents may be transmitted to humans most likely through direct or indirect contact with dogs, cats and pigs. Additional possible transmission routes include consumption of water and, for H. suis, also consumption of contaminated pork. It has been described that standard H. pylori eradication therapy is usually also effective to eradicate the NHPH in human patients, although acquired antimicrobial resistance may occasionally occur and porcine H. suis strains are intrinsically less susceptible to aminopenicillins than non-human primate H. suis strains and other gastric Helicobacter species. Virulence factors of H. suis and the canine and feline gastric Helicobacter species include urease activity, motility, chemotaxis, adhesins and gamma-glutamyl transpeptidase. These NHPH, however, lack orthologs of cytotoxin-associated gene pathogenicity island and vacuolating cytotoxin A, which are major virulence factors in H. pylori. It can be concluded that besides H. pylori, gastric Helicobacter species associated with dogs, cats and pigs are also clinically relevant in humans. Although recent research has provided better insights regarding pathogenic mechanisms and treatment strategies, a lot remains to be investigated, including true prevalence rates, exact modes of transmission and molecular pathways underlying disease development and progression.

Linking Animal Welfare and Antibiotic Use in Pig Farming-A Review

Preventative measures, such as biosecurity and vaccinations, are essential but not sufficient to ensure high standards of health in pig production systems. Restrictive, barren housing and many widely used management practices that cause pain and stress predispose high-performance pigs reared in intensive systems to disease. In this context, antibiotics are used as part of the infrastructure that sustains health and high levels of production in pig farms. Antimicrobial resistance (AMR) is a global emergency affecting human and animal health, and the use of antibiotics (AMU) in intensive livestock farming is considered an important risk factor for the emergence and spread of resistant bacteria from animals to humans. Tackling the issue of AMR demands profound changes in AMU, e.g., reducing their use for prophylaxis and ending it for growth promotion. In support of such recommendations, we revise the link between animal welfare and AMU and argue that it is crucial to sustainably reduce AMU while ensuring that pigs can live happy lives. In support of such recommendations, we aimed to revise the link between animal welfare and AMU in pigs by analysing stress factors related to housing and management and their impact on pig welfare. In particular, we reviewed critical management practices that increase stress and, therefore, pigs' susceptibility to disease and reduce the quality of life of pigs. We also reviewed some alternatives that can be adopted in pig farms to improve animal welfare and that go beyond the reduction in stress. By minimising environmental and management stressors, pigs can become more immunocompetent and prepared to overcome pathogenic challenges. This outcome can contribute to reducing AMU and the risk of AMR while simultaneously improving the quality of life of pigs and, ultimately, maintaining the pig industry's social license.

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Nonproliferative and Proliferative Lesions of the Minipig

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions) Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in most tissues and organs from the minipig used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. Relevant infectious and parasitic lesions are included as well. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

Links between fecal microbiota and the response to vaccination against influenza A virus in pigs

This study describes the associations between fecal microbiota and vaccine response variability in pigs, using 98 piglets vaccinated against the influenza A virus at 28 days of age (D28) with a booster at D49. Immune response to the vaccine is measured at D49, D56, D63, and D146 by serum levels of IAV-specific IgG and assays of hemagglutination inhibition (HAI). Analysis of the pre-vaccination microbiota characterized by 16S rRNA gene sequencing of fecal DNA reveals a higher vaccine response in piglets with a richer microbiota, and shows that 23 operational taxonomic units (OTUs) are differentially abundant between high and low IAV-specific IgG producers at D63. A stronger immune response is linked with OTUs assigned to the genus Prevotella and family Muribaculaceae, and a weaker response is linked with OTUs assigned to the genera Helicobacter and Escherichia-Shigella. A set of 81 OTUs accurately predicts IAV-specific IgG and HAI titer levels at all time points, highlighting early and late associations between pre-vaccination fecal microbiota composition and immune response to the vaccine.

Replacing dietary antibiotics with 0.20% l-glutamine in swine nursery diets: impact on intestinal physiology and the microbiome following weaning and transport

Previous research demonstrates that supplementing 0.20% l-glutamine (GLN) in the diets of newly weaned and transported pigs improves growth rate to a similar extent as providing dietary antibiotics (AB). However, research comparing the effects of GLN vs. AB on intestinal physiology and the microbiome is limited. Therefore, the study objective was to compare the effects of supplementing nursery diets with GLN, AB, or no dietary antibiotics (NA) on intestinal physiology and the microbiome of pigs in a production environment following weaning and transport. Mixed-sex piglets (N = 480; 5.62 ± 0.06 kg body weight [BW]) were weaned (18.4 ± 0.2 d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pens were blocked by BW and allotted to one of the three dietary treatments (n = 10 pens/dietary treatment/replicate [8 pigs/pen]): AB (chlortetracycline [441 ppm] + tiamulin [38.6 ppm]), GLN (0.20% as-fed), or NA fed for 14 d. From day 14 to 34, pigs were fed common AB-free diets in two phases. On day 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and AB pigs vs. NA pigs. On day 33, glucagon-like peptide 2 (GLP-2) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. AB pigs. Crypt depth was increased overall on day 33 (P = 0.01; 16.2%) during the spring replicate compared with the summer replicate. Villus height:crypt depth was reduced (P = 0.01; 9.6%) during the spring replicate compared with the summer replicate on day 33. On day 13, tumor necrosis factor-alpha and occludin mRNA abundance was increased (P ≤ 0.04; 45.9% and 106.5%, respectively) and zonula occludens-1 mRNA abundance tended to be greater (P = 0.10; 19.2%) in the spring replicate compared with the summer replicate. In addition, AB pigs had increased (P = 0.01; 101.3%) GLP-2 mRNA abundance compared with GLN and NA pigs. Microbiome analysis indicated that on day 13, dietary treatment altered the microbiota community structure (P = 0.03). Specifically, the AB pigs tended to be distinct from both the NA and GLN pigs (P = 0.08), and Lactobacillus was increased nearly 2-fold in AB compared with NA pigs (q = 0.04) and GLN pigs (q = 0.22). In conclusion, GLN supplementation tended to improve some morphological markers of intestinal health similarly to AB pigs, while the microbiome composition in GLN pigs was more similar to NA pigs than AB pigs.

Presence of Helicobacter pylori and H. suis DNA in Free-Range Wild Boars

Simple Summary

Helicobacter pylori and H. suis are associated with gastric pathologies in humans. To obtain better insights into the potential role of wild boars as reservoirs of these pathogens, gastric samples of 14 animals were tested for the presence of H. pylori and H. suis DNA. Two wild boars were found PCR-positive for H. pylori and one for H. suis. This indicates that these microorganisms may colonize the stomach of wild boars.

Abstract

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that infects half of the human population worldwide, causing gastric disorders, such as chronic gastritis, gastric or duodenal ulcers, and gastric malignancies. Helicobacter suis (H. suis) is mainly associated with pigs, but can also colonize the stomach of humans, resulting in gastric pathologies. In pigs, H. suis can induce gastritis and seems to play a role in gastric ulcer disease, seriously affecting animal production and welfare. Since close interactions between domestic animals, wildlife, and humans can increase bacterial transmission risk between species, samples of gastric tissue of 14 free range wild boars (Sus scrofa) were evaluated for the presence of H. pylori and H. suis using PCR. Samples from the antral gastric mucosa from two animals were PCR-positive for H. pylori and another one for H. suis. These findings indicate that these microorganisms were able to colonize the stomach of wild boars and raise awareness for their putative intervention in Helicobacter spp. transmission cycle.

Sudden death associated with bleeding into digestive system of finishing pigs – a review

Sudden deaths of finishing pigs in modern pig herds cause economic losses and therefore draw constant attention worldwide. In the case of peracute mortality associated with gastrointestinal bleeding, pigs usually die during a short period without clinical manifestations. Necropsy can detect bleeding into various parts of the digestive system. Determining the exact aetiology of the sudden death can be difficult in many cases. Diseases and conditions such as gastric ulcers, abdominal torsion, haemorrhagic bowel syndrome and infectious diseases should be taken into account in the differential diagnosis. Because some of these diseases still have an unclear aetiology and pathogenesis, the aim of our work was to provide a summary of existing knowledge as well as to describe related pathognomonic pathological changes.

Risk factors for gastric ulceration in nursery pigs

Pars oesophageal gastric ulceration is a prevalent condition in swine production and often observed in finisher pigs at slaughter, with reported prevalence ranging from 32 % to 65 %. Although feeding practices in nursery and finisher pigs are similar, little is known about the prevalence and risk factors associated with this condition in nursery pigs. This prospective cohort study aimed to identify risk factors for gastric ulceration in nursery pigs. The objectives were: (1) to estimate the association of inherent pig characteristics (birth weight, sex, parity of sow, litter size, and pen fouling behavior) and management characteristics (antibiotic treatment during suckling and post weaning, piglet rotation during lactation, weaning age and weight) with pars oesophageal lesions; (2) to assess differences in gastric dry matter content, pH, and percentage of solid particles in the sediment in relation to pars oesophageal lesions. A total of 58 piglets tracked from birth to 20 days of age and 210 nursery pigs from birth to 10 weeks of age were euthanized and assessed for pars oesophageal gastric lesions. All nursery pigs were fed finely ground pelleted feed ad libitum. Based on a macroscopic assessment, the pigs' stomachs were categorized as either LPO "lesions in the Pars oesophagea" or NLPO "no lesions in the Pars oesophagea". We observed an overall prevalence of 26.2 % (CI 95 % 0.67 - 0.79) for LPO in nursery pigs at 10 weeks of age, while no lesion were observed in piglets at 20 days of age. A mixed multivariable logistic regression model showed that piglets with a birthweight ≤ 1.11 kg had a 2.11 times higher odds of LPO (CI 95 % 1.02-4.37, p = 0.04) than their heavier counterparts. There was a weak association of LPO in nursery pigs from pens with pen fouling with a 2.14 times higher odds (CI 95 % 0.97-4.72 p = 0.05). Nursery pigs with LPO presented an increased gastric content fluidity with a reduced (p ≤ 0.01) gastric dry matter content (18.7 %), solid phase (74.7 %), and pH (3.22) compared to NLPO nursery pigs (20.5 %, 85.09 %, 3.56, respectively). We have demonstrated that LPO are present in nursery pigs as early as 10 weeks of age. We observed that low birth weight is associated with higher odds for LPO in nursery pigs. These observations might help explain differences between individual pigs in terms of LPO development when groups are exposed to similar environments, management, and feeding conditions.

Helicobacter and the Potential Role in Neurological Disorders: There Is More Than Helicobacter pylori

Trillions of symbiotic microbial cells colonize our body, of which the larger part is present in the human gut. These microbes play an essential role in our health and a shift in the microbiome is linked to several diseases. Recent studies also suggest a link between changes in gut microbiota and neurological disorders. Gut microbiota can communicate with the brain via several routes, together called the microbiome–gut–brain axis: the neuronal route, the endocrine route, the metabolic route and the immunological route. Helicobacter is a genus of Gram-negative bacteria colonizing the stomach, intestine and liver. Several papers show the role of H. pylori in the development and progression of neurological disorders, while hardly anything is known about other Helicobacter species and the brain. We recently reported a high prevalence of H. suis in patients with Parkinson’s disease and showed an effect of a gastric H. suis infection on the mouse brain homeostasis. Here, we discuss the potential role of H. suis in neurological disorders and how it may affect the brain via the microbiome–gut–brain axis.

Abattoir-Based Measures to Assess Swine Welfare: Analysis of the Methods Adopted in European Slaughterhouses

The assessment of swine welfare requires feasible, reliable, and reasonable indicators. On-farm evaluation of pig welfare can provide valuable information to veterinarians and farmers. However, such protocols can result expensive and time-consuming. With this regard, an interest in the appraisal of swine welfare at abattoir has grown over the recent years. In particular, the use of certain lesions collected directly from slaughtered animals to determine the welfare status of pigs has been evaluated by several authors. In the present review, the different methods developed to score lesions collected directly from the body and the viscera of animals slaughtered in European abattoirs ("abattoir-based measures") are presented. The text specifically focuses on the methods currently available in the literature for the scoring of body, pluck and gastric lesions during post-mortem activities. Moreover, the strengths and weaknesses of abattoir-based measures schemes are discussed. To conclude, the future perspectives of the assessment of pig welfare at the slaughterhouse are described, appealing for a benchmarking system that can be systematically used by veterinarians and other professional figures involved in the process.

A novel method for isolation and culture of primary swine gastric epithelial cells

BACKGROUND

Culturing primary epithelial cells has a major advantage over tumor-derived or immortalized cell lines as long as their functional phenotype and genetic makeup are mainly maintained. The swine model has shown to be helpful and reliable when used as a surrogate model for human diseases. Several porcine cell lines have been established based on a variety of tissues, which have shown to extensively contribute to the current understanding of several pathologies, especially cancer. However, protocols for the isolation and culture of swine gastric epithelial cells that preserve cell phenotype are rather limited. We aimed to develop a new method for establishing a primary epithelial cell culture from the fundic gland region of the pig stomach.

RESULTS

Mechanical and enzymatic dissociation of gastric tissue was possible by combining collagenase type I and dispase II, protease inhibitors and antioxidants, which allowed the isolation of epithelial cells from the porcine fundic glands showing cell viability > 90% during the incubation period. Gastric epithelial cells cultured in RPMI 1640, DMEM-HG and DMEM/F12 media did not contribute enough to cell adhesion, cluster formation and cell proliferation. By contrast, William's E medium supplemented with growth factors supports confluency and proliferation of a pure epithelial cell monolayer after 10 days of incubation at 37 °C, 5% CO2. Mucin-producing cell phenotype of primary isolates was confirmed by PAS staining, MUC1 by immunohistochemistry, as well as the expression of MUC1 and MUC20 genes by RT-PCR and cDNA sequencing. Swine gastric epithelial cells also showed origin-specific markers such as cytokeratin cocktail (AE1/AE3) and cytokeratin 18 (CK-18) using immunohistochemical and immunofluorescence methods, respectively.

CONCLUSIONS

A new method was successfully established for the isolation of primary gastric epithelial cells from the fundic gland zone through a swine model based on a combination of tissue-specific proteases, protease inhibitors and antioxidants after mechanical cell dissociation. The formulation of William's E medium with growth factors for epithelial cells contributes to cell adhesion and preserves functional primary cells phenotype, which is confirmed by mucin production and expression of typical epithelial markers over time.

Helicobacter suis infection is associated with nodular gastritis-like appearance of gastric mucosa-associated lymphoid tissue lymphoma

Most patients with gastric mucosa‐associated lymphoid tissue (MALT) lymphoma are infected with Helicobacter pylori, and eradication therapy is the first‐line treatment for localized disease with H pylori infection. However, there were several reports showing effectiveness of eradication therapy in even H pylori negative cases. Gastric MALT lymphomas are endoscopically classified into three common types: superficial, ulcerative, and elevated types. For the past 20 years, we have encountered 200 cases of localized gastric MALT lymphoma. Among them, only 4 cases (2%) showed similar macroscopic findings to those of nodular gastritis (gastric MALT lymphoma with nodular gastritis‐like appearance; M‐NGA). Here, we compared clinicopathological characteristics and prevalence of non‐H pylori Helicobacter (NHPH) infection between M‐NGA and other common types of gastric MALT lymphoma. To examine the prevalence of NHPH infection, DNA was extracted from formalin‐fixed paraffin‐embedded biopsy tissues from four cases of M‐NGA, 20 cases of common endoscopic types of gastric MALT lymphoma, and 10 cases of nodular gastritis. We used a highly sensitive polymerase chain reaction assay to detect the presence of five species of NHPH (Helicobacter suis, H felis, H bizzozeronii, H salomonis, and H heilmannii). H suis infection was detected in 4, 2, and 0 of the 4, 20, and 10 cases of M‐NGA, other types of gastric MALT lymphoma, and nodular gastritis, respectively. Other NHPH species were not detected in any cases. Complete response rate by eradication therapy was 4/4 in M‐NGA cases. Therefore, nodular gastritis‐like MALT lymphoma, which shows a very rare phenotype, is closely associated with NHPH infection, and eradication therapy may be the first‐choice treatment.

Characterization of the non-glandular gastric region microbiota in Helicobacter suis-infected versus non-infected pigs identifies a potential role for Fusobacterium gastrosuis in gastric ulceration

Helicobacter suis has been associated with development of gastric ulcers in the non-glandular part of the porcine stomach, possibly by affecting gastric acid secretion and altering the gastric microbiota. Fusobacterium gastrosuis is highly abundant in the gastric microbiota of H. suis-infected pigs and it was hypothesized that this micro-organism could play a role in the development of gastric ulceration. The aim of this study was to obtain further insights in the influence of a naturally acquired H. suis infection on the microbiota of the non-glandular part of the porcine stomach and in the pathogenic potential of F. gastrosuis. Infection with H. suis influenced the relative abundance of several taxa at phylum, family, genus and species level. H. suis-infected pigs showed a significantly higher colonization rate of F. gastrosuis in the non-glandular gastric region compared to non-infected pigs. In vitro, viable F. gastrosuis strains as well as their lysate induced death of both gastric and oesophageal epithelial cell lines. These gastric cell death inducing bacterial components were heat-labile. Genomic analysis revealed that genes are present in the F. gastrosuis genome with sequence similarity to genes described in other Fusobacterium spp. that encode factors involved in adhesion, invasion and induction of cell death as well as in immune evasion. We hypothesize that, in a gastric environment altered by H. suis, colonization and invasion of the non-glandular porcine stomach region and production of epithelial cell death inducing metabolites by F. gastrosuis, play a role in gastric ulceration.

Systems Immunology Characterization of Novel Vaccine Formulations for Mycoplasma hyopneumoniae Bacterins

We characterized five different vaccine candidates and a commercial vaccine in terms of safety, immunogenicity and using a systems vaccinology approach, with the aim to select novel vaccine candidates against Mycoplasma hyopneumoniae. Seven groups of six M. hyopneumoniae-free piglets were primo- and booster vaccinated with the different experimental bacterin formulations, the commercial vaccine Hyogen® as a positive control or PBS as a negative control. The experimental bacterin was formulated with cationic liposomes + c-di-AMP (Lipo_AMP), cationic liposomes + Toll-like receptor (TLR) 2/1, TLR7, and TLR9 ligands (TLR ligands; Lipo_TLR), micro-particles + TLR ligands (PLGA_TLR), squalene-in-water emulsion + TLR ligands (SWE_TLR), or DDA:TDB liposomes (Lipo_DDA:TDB). Lipo_DDA:TDB and Lipo_AMP were the most potent in terms of serum antibody induction, and Lipo_DDA:TDB, Lipo_AMP, and SWE_TLR significantly induced Th1 cytokine-secreting T-cells. Only PLGA_TLR appeared to induce Th17 cells, but was unable to induce serum antibodies. The transcriptomic analyses demonstrated that the induction of inflammatory and myeloid cell blood transcriptional modules (BTM) in the first 24 h after vaccination correlated well with serum antibodies, while negative correlations with the same modules were found 7 days post-vaccination. Furthermore, many cell cycle and T-cell BTM upregulated at day seven correlated positively with adaptive immune responses. When comparing the delivery of the identical TLR ligands with the three formulations, we found SWE_TLR to be more potent in the induction of an early innate immune response, while the liposomal formulation more strongly promoted late cell cycle and T-cell BTM. For the PLGA formulation we found signs of a delayed and weak perturbation of these BTM. Lipo_AMP was found to be the most potent vaccine at inducing a BTM profile similar to that correlating with adaptive immune response in this and other studies. Taken together, we identified four promising vaccine candidates able to induce M. hyopneumoniae-specific antibody and T-cell responses. In addition, we have adapted a systems vaccinology approach developed for human to pigs and demonstrated its capacity in identifying early immune signatures in the blood relating to adaptive immune responses. This approach represents an important step in a more rational design of efficacious vaccines for pigs.

Helicobacter suis infection alters glycosylation and decreases the pathogen growth inhibiting effect and binding avidity of gastric mucins

Helicobacter suis is the most prevalent non-Helicobacter pylori Helicobacter species in the human stomach and is associated with chronic gastritis, peptic ulcer disease, and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. H. suis colonizes the gastric mucosa of 60-95% of pigs at slaughter age, and is associated with chronic gastritis, decreased weight gain, and ulcers. Here, we show that experimental H. suis infection changes the mucin composition and glycosylation, decreasing the amount of H. suis-binding glycan structures in the pig gastric mucus niche. Similarly, the H. suis-binding ability of mucins from H. pylori-infected humans is lower than that of noninfected individuals. Furthermore, the H. suis growth-inhibiting effect of mucins from both noninfected humans and pigs is replaced by a growth-enhancing effect by mucins from infected individuals/pigs. Thus, Helicobacter spp. infections impair the mucus barrier by decreasing the H. suis-binding ability of the mucins and by decreasing the antiprolific activity that mucins can have on H. suis. Inhibition of these mucus-based defenses creates a more stable and inhabitable niche for H. suis. This is likely of importance for long-term colonization and outcome of infection, and reversing these impairments may have therapeutic benefits.

Epidermal growth factor receptor 2 immunoexpression in gastric cells of domestic cats with H. heilmannii infection

The aim of this study was to evaluate the immunoexpression of HER-2 in gastric cells of cats infected with Non H. pylori Helicobacter (NHPH) and to investigate an association with the presence of inflammatory infiltrate. Forty-eight paraffin-embedded gastric samples were retrieved from the archives of the Veterinary Anatomic Pathology Laboratory that had previously been shown to be positive for NHPH with the rapid urease test and cytology. Infection by NHPH was confirmed by histopathology using the Warthin-Starry staining. Hematoxylin-eosin stained sections were reviewed to evaluate inflammatory cell infiltrates. Immunohistochemical analysis was done using anti- H. pylori antibody and anti-HER-2 antibody. Molecular analysis was performed by PCR to confirm the presence of Helicobacter. Statistical analysis was performed to determine whether there was an association between the presence of H. Heilmannii and HER-2 expression in gastric samples. All samples were positive for NHPH, by immunohistochemistry, and confirmed by PCR as H. Heilmannii. On histopathologic analysis, 56,3% of the samples had lymphocytes and plasma cells infiltrates, 52,1% of which were mild and 4,2% moderate. The intensity of the inflammatory infiltrate in the gastric mucosa was significantly greater in the complete plasma membrane of parietal cells of gastric glands that had greater HER-2 immunoexpression (p = 0.0001). A statistically significant association (p = 0.007) between the H. Heilmannii infection score and the expression of HER-2 in the lateral membrane of gastric surface cells was observed. HER-2 expression may be increased in feline gastric cells infected by H. Heilmannii and in parietal cells of gastric glands with an increased inflammatory infiltrate.

Helicobacter suis binding to carbohydrates on human and porcine gastric mucins and glycolipids occurs via two modes

Helicobacter suis colonizes the stomach of most pigs and is the most prevalent non-Helicobacter pylori Helicobacter species found in the human stomach. In the human host, H. suis contributes to the development of chronic gastritis, peptic ulcer disease and MALT lymphoma, whereas in pigs it is associated with gastritis, decreased growth and ulcers. Here, we demonstrate that the level of H. pylori and H. suis binding to human and pig gastric mucins varies between individuals with species dependent specificity. The binding optimum of H. pylori is at neutral pH whereas that of H. suis has an acidic pH optimum, and the mucins that H. pylori bind to are different than those that H. suis bind to. Mass spectrometric analysis of mucin O-glycans from the porcine mucin showed that individual variation in binding is reflected by a difference in glycosylation; of 109 oligosaccharide structures identified, only 14 were present in all examined samples. H. suis binding to mucins correlated with glycans containing sulfate, sialic acid and terminal galactose. Among the glycolipids present in pig stomach, binding to lactotetraosylceramide (Galβ3GlcNAcβ3Galβ4Glcβ1Cer) was identified, and adhesion to Galβ3GlcNAcβ3Galβ4Glc at both acidic and neutral pH was confirmed using other glycoconjugates. Together with that H. suis bound to DNA (used as a proxy for acidic charge), we conclude that H. suis has two binding modes: one to glycans terminating with Galβ3GlcNAc, and one to negatively charged structures. Identification of the glycan structures H. suis interacts with can contribute to development of therapeutic strategies alternative to antibiotics.

Macroevolution of gastric Helicobacter species unveils interspecies admixture and time of divergence

Since the discovery of the human pathogen Helicobacter pylori, various other Helicobacter species have been identified in the stomach of domesticated and wild mammals. To better understand the evolutionary history of these ecologically similar but genetically distinct species, we analyzed 108 gastric Helicobacter genomes and included 54 enterohepatic Helicobacter genomes for comparison purposes. An admixture analysis supported the presence of an ecological barrier, preventing the genetic exchange between the gastric and enterohepatic Helicobacter species, and unraveled many gene flow events within and across species residing in the stomach. As pets can be colonized by multiple gastric Helicobacter species, the genetic exchange between the canine and feline strains was evident, with H. heilmannii and H. bizzozeronii showing the highest interspecies recombination. An admixture between H. pylori (in particular, the ancestral African strains), H. acinonychis from wild felines and H. cetorum from marine mammals was also identified. Because these latter species do not share the same host, this phenomenon is most likely a remaining signal of shared ancestry. A reconstruction of the time of divergence of the gastric Helicobacter spp. revealed that the domestic animal-related Helicobacter species evolved in parallel with H. pylori and its two closest relatives (H. acinonychis and H. cetorum), rather than together.

Other Helicobacters and the gastric microbiome

The current article is a review of the most important, accessible, and relevant literature published between April 2017 and March 2018 on other Helicobacters and the gastric microbiome. The first part of the review focuses on literature describing non-Helicobacter pylori-Helicobacter (NHPH) infections in humans and animals whilst the subsequent section focuses specifically on the human gastric microbiome. Novel diagnostic methods as well as new NHPHs species have been identified in recent studies. Furthermore, our knowledge about the pathogenesis of NHPH infections has been further enhanced by important fundamental studies in cell lines and animal models. Over the last year, additional insights over the prevalence and potential prevention strategies of NHPHs have also been reported. With regard to understanding the gastric microbiome, new information detailing the structure of the gastric microbiota at different stages of H. pylori infection, within different patient geographical locations, was documented. There was also a study detailing the impact of proton-pump inhibitor usage and the effect on the gastric microbiome. Newer analysis approaches including defining the active microbiome through analysis of RNA rather than DNA-based sequencing were also published allowing the first assessments of the functional capabilities of the gastric microbiome.

Mucus-Pathogen Interactions in the Gastrointestinal Tract of Farmed Animals

Gastrointestinal infections cause significant challenges and economic losses in animal husbandry. As pathogens becoming resistant to antibiotics are a growing concern worldwide, alternative strategies to treat infections in farmed animals are necessary in order to decrease the risk to human health and increase animal health and productivity. Mucosal surfaces are the most common route used by pathogens to enter the body. The mucosal surface that lines the gastrointestinal tract is covered by a continuously secreted mucus layer that protects the epithelial surface. The mucus layer is the first barrier the pathogen must overcome for successful colonization, and is mainly composed of densely glycosylated proteins called mucins. The vast array of carbohydrate structures present on the mucins provide an important setting for host-pathogen interactions. This review summarizes the current knowledge on gastrointestinal mucins and their role during infections in farmed animals. We examine the interactions between mucins and animal pathogens, with a focus on how pathogenic bacteria can modify the mucin environment in the gut, and how this in turn affects pathogen adhesion and growth. Finally, we discuss analytical challenges and complexities of the mucus-based defense, as well as its potential to control infections in farmed animals.

The role of infectious agents in the development of porcine gastric ulceration

Ulceration of the non-glandular part of the stomach is a common disease entity of pigs worldwide, with prevalences of up to 93%. It may result in decreased daily weight gain, decreased feed intake and sudden death, thus leading to significant economic losses, as well as animal welfare issues. The aetiology is multifactorial. Diet particle size, management and infectious agents have been hypothesised to be involved. The exact mechanism behind porcine gastric ulceration is, however, not completely clear. The aim of this article is to provide an overview of the role of infectious agents in the development of porcine gastric ulceration. Results of recent studies indicate that Helicobacter suis infection plays an important role in gastric ulceration, probably by affecting gastric acid secretion through alteration of the number and/or function of parietal, D and G cells. In a gastric environment altered by H. suis, higher numbers of Fusobacterium gastrosuis are present and this novel pathogen has a potential role in the development of porcine gastric ulceration. Inoculation of pigs with Lactobacillus sp., Bacillus sp. or Helicobacter pylori-like bacteria in combination with a carbohydrate-rich diet may induce gastric lesions. It has been hypothesised that production of short chain fatty acids by some of these bacteria might be involved in the pathogenesis of porcine gastric ulceration, but the lack of taxonomic characterisation hampers the interpretation of these studies. Severe infectious diseases have also been associated with gastric lesions, probably due to interruption in feed intake and/or histamine release. Other agents, including fungi and parasites such as Hyostrongylus rubidus and Ascaris suum, have occasionally been associated with gastric lesions in pigs.

In-feed bambermycin medication induces anti-inflammatory effects and prevents parietal cell loss without influencing Helicobacter suis colonization in the stomach of mice

The minimum inhibitory concentration of bambermycin on three porcine Helicobacter suis strains was shown to be 8 μg/mL. The effect of in-feed medication with this antibiotic on the course of a gastric infection with one of these strains, the host response and the gastric microbiota was determined in mice, as all of these parameters may be involved in gastric pathology. In H. suis infected mice which were not treated with bambermycin, an increased number of infiltrating B-cells, T-cells and macrophages in combination with a Th2 response was demonstrated, as well as a decreased parietal cell mass. Compared to this non-treated, infected group, in H. suis infected mice medicated with bambermycin, gastric H. suis colonization was not altered, but a decreased number of infiltrating T-cells, B-cells and macrophages as well as downregulated expressions of IL-1β, IL-8M, IL-10 and IFN-γ were demonstrated and the parietal cell mass was not affected. In bambermycin treated mice that were not infected with H. suis, the number of infiltrating T-cells and expression of IL-1β were lower than in non-infected mice that did not receive bambermycin. Gastric microbiota analysis indicated that the relative abundance of bacteria that might exert unfavorable effects on the host was decreased during bambermycin supplementation. In conclusion, bambermycin did not affect H. suis colonization, but decreased gastric inflammation and inhibited the effects of a H. suis infection on parietal cell loss. Not only direct interaction of H. suis with parietal cells, but also inflammation may play a role in death of these gastric acid producing cells.