Helicobacter Species Research Articles

Expansion of nickel binding- and histidine-rich proteins during gastric adaptation of Helicobacter species.

Acquisition and homeostasis of essential metals during host colonization by bacterial pathogens rely on metal uptake, trafficking, and storage proteins. How these factors have evolved within bacterial pathogens is poorly defined. Urease, a nickel enzyme, is essential for Helicobacter pylori to colonize the acidic stomach. Our previous data suggest that acquisition of nickel transporters and a histidine-rich protein (HRP) involved in nickel storage in H. pylori and gastric Helicobacter spp. have been essential evolutionary events for gastric colonization. Using bioinformatics, proteomics, and phylogenetics, we extended this analysis to determine how evolution has framed the repertoire of HRPs among 39 Epsilonproteobacteria; 18 gastric and 11 non-gastric enterohepatic (EH) Helicobacter spp., as well as 10 other Epsilonproteobacteria. We identified a total of 213 HRPs distributed in 22 protein families named orthologous groups (OGs) with His-rich domains, including 15 newly described OGs. Gastric Helicobacter spp. are enriched in HRPs (7.7±1.9HRPs/strain) as compared to EH Helicobacter spp. (1.9±1.0HRPs/strain) with a particular prevalence of HRPs with C-terminal histidine-rich domains in gastric species. The expression and nickel-binding capacity of several HRPs was validated in five gastric Helicobacter spp. We established the evolutionary history of new HRP families, such as the periplasmic HP0721-like proteins and the HugZ-type heme oxygenases. The expansion of histidine-rich extensions in gastric Helicobacter spp. proteins is intriguing but can tentatively be associated with the presence of the urease nickel enzyme. We conclude that this HRP expansion is associated with unique properties of organisms that rely on large intracellular nickel amounts for their survival.

Methylation-Independent Chemotaxis Systems Are the Norm for Gastric-Colonizing Helicobacter Species.

Many bacteria and archaea rely on chemotaxis signal transduction systems for optimal fitness. These complex, multiprotein signaling systems have core components found in all chemotactic microbes, as well as variable proteins found in only some species. We do not yet understand why these variations exist or whether there are specific niches that favor particular chemotaxis signaling organization. One variation is in the presence/absence of the chemotaxis methylation adaptation enzymes CheB and CheR. Genes for CheB and CheR are missing in the gastric pathogen Helicobacter pylori but present in related Helicobacter that colonize the liver or intestine. In this work, we asked whether there was a general pattern of CheB/CheR across multiple Helicobacter species. Helicobacter spp. all possess chemotactic behavior, based on the presence of genes for core signaling proteins CheA, CheW, and chemoreceptors. Genes for the CheB and CheR proteins, in contrast, were variably present. Niche mapping supported the idea that these genes were present in enterohepatic Helicobacter species and absent in gastric ones. We then analyzed whether there were differences between gastric and enterohepatic species in the CheB/CheR chemoreceptor target methylation sites. Indeed, these sites were less conserved in gastric species that lack CheB/CheR. Lastly, we determined that cheB and cheR could serve as markers to indicate whether an unknown Helicobacter species was of enterohepatic or gastric origin. Overall, these findings suggest the interesting idea that methylation-based adaptation is not required in specific environments, particularly the stomach. IMPORTANCE Chemotaxis signal transduction systems are common in the archaeal and bacterial world, but not all systems contain the same components. The rationale for this system variation remains unknown. In this report, comparative genomics analysis showed that the presence/absence of CheR and CheB is one main variation within the Helicobacter genus, and it is strongly associated with the niche of Helicobacter species: gastric Helicobacter species, which infect animal stomachs, have lost their CheB and CheR, while enterohepatic Helicobacter species, which infect the liver and intestine, retain them. This study not only provides an example that a chemotaxis system variant is associated with particular niches but also proposes that CheB and CheR are new markers distinguishing gastric from enterohepatic Helicobacter species.

Molecular screening of gastric Helicobacter pullorum recovered from different avian species in Egypt.

Helicobacter pullorum (H. pullorum) is a bacterium that colonizes the intestines of poultry and causes gastroenteritis. Because these species are known as human and/or animal pathogens, identification of H. pullorum is becoming increasingly necessary. The bacterium has been linked to colitis and hepatitis in humans after being transmitted by infected meat consumption. Misdiagnosis of other enteric zoonotic pathogens such as Campylobacter and other Helicobacter species makes the diagnosis of H. pullorum extremely difficult. This study focused on the molecular detection of H. pullorum from the stomach (proventriculus and gizzard) of different avian species as new target organs for detection and transmission between avian species. Proventriculus and gizzards were obtained from 40 freshly dead chickens and resident wild birds (n=40). Diarrhea was found in the farms that were surveyed. DNA was extracted from all collected samples to conduct PCR amplification. The samples were screened for Helicobacter genus-specific 16s using C97 and C05 primers. To confirm the existence of H. pullorum, the positive samples were sequenced. H. pullorum was recorded in two out of 40 chicken samples. In addition, H. pullorum was recorded in one out of 40 resident wild birds. The 16S rRNA gene sequence for Helicobacter genus-specific in poultry and wild birds showed a 100% homology. In conclusion, broiler chickens and resident wild birds are possible reservoirs for H. pullorum, according to this report, and possibly act as a source of infection for humans via the food supply.

Prevalence, Virulence Genes, Phylogenetic Analysis, and Antimicrobial Resistance Profile of Helicobacter Species in Chicken Meat and Their Associated Environment at Retail Shops in Egypt.

Helicobacter pylori (H. pylori) and Helicobacter pullorum (H. pullorum) are frequently reported pathogens in humans and poultry, respectively. Nevertheless, the source of H. pylori is still unclear. This study aimed to detect Helicobacter spp. in chicken carcasses and to assess the antibiogram and the virulence genes of Helicobacter isolates. Three hundred chicken meat samples (100 each of chicken breast, liver, and gizzard), besides 60 swab samples from chicken processing surfaces, were collected from retail shops in Qalyubia Governorate, Egypt, and examined for the prevalence of H. pylori and H. pullorum. The 16S rRNA of three H. pylori and two H. pullorum isolates were sequenced to determine the genetic relationship between these two Helicobacter spp. Of the 300 chicken samples tested, 16 (5.33%) and 14 (4.67%) were positive for H. pylori and H. pullorum, respectively. Multiplex PCR revealed that the virulence genes vacuolating cytotoxin A (vacA)s1, cytotoxin-associated gene A (cagA), and restriction endonuclease-replacing gene A (hrgA) were detected in 66.7%, 77.8%, and 100% of H. pylori strains tested, respectively. H. pylori showed the highest resistance for clarithromycin, while H. pullorum exhibited the highest resistance towards erythromycin and ciprofloxacin. The study concluded that the chicken meat and giblets are potential sources of the virulent and antimicrobial-resistant strains of H. pylori of human origin.

#67 Treatment of Campylobacter upsaliensis and Helicobacter canis in twin brothers with XLA

Abstract Background X-linked agammaglobulinemia (XLA) is a primary immunodeficiency associated with mutations in the B cell tyrosine kinase gene leading to failure in B cell maturation, resulting in antibody deficiency and increased susceptibility to infections. Patients with XLA are at risk of severe disease with infections with Campylobacter and closely related Helicobacter species and warrant treatment with close follow up given risk of recurrence. Method We present follow up of two 5-year-old fraternal twins with XLA who were diagnosed with C. upsaliensis and H. canis respectively via microbial cell-free DNA (mcfDNA) and underwent successful treatment with multi-drug antimicrobial therapy with 12 months of follow-up. Results Patient #1 was diagnosed with XLA at 11 months of age. At 3 years of age, he presented with fever and diarrhea, with stool cultures that grew C. jejuni. Despite treatment with azithromycin, his symptoms persisted and repeat stool cultures grew C. upsaliensis. Testing via mcfDNA confirmed C. upsaliensis. Patient #2 was diagnosed with XLA at 12 months of age. He developed fever, erythema nodosum (EN) like lesions and arthritis at 3.5 years old. Given his twin’s diagnosis of Campylobacter sp. enteritis, he was given a presumptive diagnosis of Campylobacter reactive arthritis and EN. Despite treatment with Naprosyn and 14 days of azithromycin, his symptoms persisted and stool PCR was positive for Campylobacter sp. mcfDNA testing confirmed C. upsaliensis and H.canis. Given failure of initial antimicrobial therapy, both boys were treated with a 4-week course of IV ertapenem, and oral ciprofloxacin and amoxicillin, and both developed neutropenia and concern for drug toxicity. Therapy was transitioned to triple drug therapy with oral doxycycline, ciprofloxacin and amoxicillin. Doxycycline was discontinued after 3 weeks due to patients’ young age. Ciprofloxacin and amoxicillin were continued for 12 months. Both boys had complete resolution of symptoms after 12 months of therapy and remain without recurrence 10 weeks after discontinuation of antimicrobial therapy. Conclusion Physicians should be aware of the treatment challenges of chronic Campylobacter and Helicobacter infection in boys with XLA and other immunocompromised hosts. Successful treatment may require prolonged multi-drug antimicrobial therapy, with monitoring for drug toxicities.

Helicobacter bilis infection induces oxidative stress in and enhances the proliferation of human cholangiocytes.

Helicobacter bilis, an enterohepatic Helicobacter species, represents a carcinogenic risk factor for cholangiocytes owing to the prevalence of infections in patients with biliary tract cancer, cholecystitis, and pancreaticobiliary maljunction. However, the effect of H.bilis infection on cholangiocytes and the process and mechanism of carcinogenesis are not known. We aimed to determine the effects of H.bilis on cholangiocytes, focusing on inflammation and oxidative stress. Helicobacter bilis and MMNK-1 cells were cocultured for 24 h and inflammatory cytokine secretion was evaluated. Furthermore, MMNK-1 cell proliferation, intracellular reactive oxidant species (ROS) production, and DNA damage caused by ROS were investigated. All factors were compared with and without H.bilis infection. Interleukin (IL)-6 and IL-8 secretion were significantly increased in MMNK-1 cocultures with H.bilis (IL-6, 24.3 ± 12.2 vs. 271.1 ± 286.4pg/ml; IL-8, 167.6 ± 78.7 vs. 1085.1 ± 1047.1 pg/ml, p < .05). MMNK-1 proliferation was also significantly higher in H.bilis cocultures (1.05 ± 0.02 vs. 1.00-fold, respectively; p < .05). Coculturing enhanced the production of ROS in MMNK-1 cells depending on the cell concentration of H.bilis (1.0 vs. 1.17 ± 0.06, p < .05); however, DNA injury was not observed in cocultures with H.bilis (5.35 ± 0.87 vs. 6.08 ± 0.55 pg/μl, p=.06). Helicobacter bilis infection induced ROS production in and enhanced the proliferation of cholangiocytes.

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

Simple SummaryHelicobacter spp. represent spiral-shaped Gram-negative bacteria that can live in the acidic environment of the stomach. While their association with peptic ulcers and gastric neoplasia in people has been clearly documented, their pathogenic potential in dogs is less well defined. Helicobacter pylori, the most prevalent Helicobacter infecting people, does not seem to represent a significant problem in small animals. The aims of this study were to determine the prevalence of individual gastric Helicobacter species in dogs with chronic gastrointestinal signs, their association with gastric lesions, and to compare diagnostic techniques used to detect Helicobacter infection in dogs.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.

Helicobacter spp. in the Stomach of Cats: Successful Colonization and Absence of Relevant Histopathological Alterations Reveals High Adaptation to the Host Gastric Niche.

In addition to Helicobacter pylori, many non-Helicobacter pylori Helicobacters (NHPH) are able to cause gastric disease in humans. Cats are a natural reservoir for many of these species. Accordingly, living in close and intimate contact with animals has been identified as a risk factor, and an important zoonotic significance has therefore been attributed to NHPH. To determine the prevalence and associated gastric histopathological changes of Helicobacter species, the gastric mucosa of 71 cats were evaluated. Only four presented normal histopathological mucosa with the absence of spiral-shaped organisms. Normal gastric mucosa and the presence of spiral-shaped bacteria were observed in 13 cats. The remaining animals presented histopathological changes representative of gastritis. Helicobacter species were detected in 53 cats (74.6%) by at least one detection method. None of the animals were positive for H. pylori or for H. ailurogastricus. Helicobacter heilmannii organisms were identified in 20 animals, predominantly in the body gastric region. Helicobacter salomonis was the second most prevalent species (57.1%), although it was mainly found in association with other NHPH. Helicobacter felis and H. bizzozeronii were less frequently detected. The great majority of the Helicobacter spp. PCR-positive animals presented normal features regarding fibrosis/mucosal atrophy, neutrophils, eosinophils, or other inflammatory cells and lymphofollicular hyperplasia. Given the controversy and the strong evidence of absence of significant histopathological alterations associated with the presence of Helicobacter spp. in cats, it is possible to hypothesize that these bacteria may be able to adapt to the feline gastric microenvironment or even to comprise part of the gastric microbiome of this animal species. Thus, prudency must be taken when prescribing an antibiotic therapy based solely on the presence of these bacteria in the feline stomach.

Description of the two novel species of the genus Helicobacter: Helicobacter anatolicus sp. nov., and Helicobacter kayseriensis sp. nov., isolated from feces of urban wild birds

A total of 26 Gram-negative, motile, gently curved, and rod-shaped isolates were recovered, during a study to determine the faeco-prevalence of Helicobacter spp. in urban wild birds. Pairwise comparisons of the 16S rRNA gene sequences indicated that these isolates belonged to the genus Helicobacter and phylogenetic analysis based on the 16S rRNA gene sequences showed that the isolates were separated into two divergent groups. The first group consisted of 20 urease-positive isolates sharing the highest 16S rRNA gene sequence identity levels of 98.5–98.6% to H. mustelae ATCC 43772T, while the second group contained six urease-negative isolates with the sequence identity level of 98.5% to the type strain of H. pametensis ATCC 51478T. Five isolates were chosen and subjected to comparative whole-genome analysis. The phylogenetic analysis of the 16S rRNA, gyrA and atpA gene sequences showed that Helicobacter isolates formed two separate phylogenetic clades, differentiating the isolates from the other Helicobacter species. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses between strains faydin-H8T, faydin-H23T and their close neighbors H. anseris MIT 04-9362T and H. pametensis ATCC 51478T, respectively, confirmed that both strains represent novel species in the genus Helicobacter. The DNA G+C contents of the strains faydin-H8T and faydin-H23T are 32.0% and 37.6%, respectively. The results obtained for the characterization of the wild bird isolates indicate that they represent two novel species, for which the names Helicobacter anatolicus sp. nov., and Helicobacter kayseriensis sp. nov., are proposed, with faydin-H8T(=LMG 32237T = DSM 112312T) and faydin-H23T(=LMG 32236T = CECT 30508T) as respective type strains.

Myeloperoxidase deficiency impacts the composition of the gut microbiome: a case for variable disease penetrance?

Abstract The most abundant proteolytic enzyme found in neutrophilic granules, myeloperoxidase (MPO) is a heme peroxidase with microbicidal activity. While MPO inhibition has therapeutic promise for treatment of inflammatory illness, differential disease penetrance has been observed in MPO-deficient mice during various disease models. In our studies using the DSS-colitis mouse model, MPO-deficient mice under conventional specific pathogen-free (SPF) conditions experienced similar disease penetrance to co-housed, wildtype controls. In contrast, when housed in restricted SPF conditions lacking norovirus and Helicobacter species, MPO-deficient mice experienced more severe colitis while wildtype mice were unchanged. From these data, we hypothesized that an interplay between MPO (microbicidal activity) and the composition of the gut microbiome impacts disease penetrance of colitis. To investigate, we performed 16S rRNA-sequencing on the intestines of MPO-deficient and wildtype mice housed in restricted SPF conditions and found a proportionate increase in Ruminococcus gnavus, which is associated with intestinal dysbiosis. Correspondingly, we found proportionate decreases in the gut beneficial bacteria Akkermansia muciniphilia and Prevotella sp. These data show that MPO does affect the composition of the gut bacteria, and supports an interplay between inflammatory mediators, the microbiome, and altered disease penetrance.

Validation and improvement of a multiplex PCR method to detect murine Helicobacter species in feces samples of mice.

Murine Helicobacter species have gained increasing awareness in mouse facilities over the last years. Infections with Helicobacter species may have an impact effect on the health of mice and might pose a zoonotic risk to researchers. To minimize the interference with experiments and hence contribute to the 3Rs, a reliable method of monitoring Helicobacter infections in animal facilities needs to be available. The aim of this study was to improve and validate the detection of the most common murine Helicobacter species. A multiplex PCR assay was developed for identification of Helicobacter hepaticus, H.bilis, H.muridarum, H.rodentium, and H.typhlonius that could simultaneously detect these five strains in fecal samples. To ensure the quality of the results, the method was validated based on recommendations for in-house developed tests. The method established was highly sensitive and specific. All five strains were detectable with a detection limit of 102 bacteria. Eight different mouse facilities were tested with the validated assay, and the following prevalence were found: H.rodentium 57%, H.hepaticus 46%, H.typhlonius 17%, H.bilis 12%, and H.muridarum 0%. The multiplex PCR is a reliable, economic, and time-saving diagnostic tool for routine health monitoring. Further prevalence studies are needed to confirm the high prevalence and hence importance of H.rodentium, as until now this agent is not yet listed in FELASA recommendations.

An exploratory study on the presence of Helicobacter heilmannii and Helicobacter billis in the feces of companion dogs.

BackgroundCompanion animals like dogs play an important role in the lives of many people and are often considered to be members of families, but definitely, any contact with them poses an inherent risk of transmitting zoonotic pathogens. One of these pathogens is the genus Helicobacter which is linked to many disorders in human and animal.ObjectivesThe aim of this study was to investigate the presence of some zoonotic species of genus Helicobacter in companion dogs.ResultsThrough culturing in a special medium, nine samples (9%) were detected as infected (two pure and seven mixed culture). Based on multiplex‐PCR, 13 samples (13%) were infected by Helicobacter spp. although none of them were infected by H. pylori. Species‐specific PCR indicated that 38.5% or 5/13 of the samples were infected with H. heilmannii, while 15.45% or 2/13 of the samples were infected by H. billis. Multivariate logistic regression analysis showed that the age factor had a significant effect on Helicobacter spp. infection (odds ratio [OR] = 2.42, p = 0.01).ConclusionThis study revealed the negligible faecal transmission of H. pylori. Moreover, due to the detection of H. Heilmannii and H. billis in feces and their association with human gastric diseases, dog owners should be educated about the risks and transmission modes of zoonotic bacterial infections of dogs.

Presence of Helicobacter Species in Gastric Mucosa of Human Patients and Outcome of Helicobacter Eradication Treatment.

The genus Helicobacter is composed of bacteria that colonize both the human and animal gastrointestinal tract. Helicobacter pylori infects half of the world’s population, causing various disorders, such as gastritis, duodenitis and gastric cancer. Additionally, non-Helicobacter pylori Helicobacter species (NHPH) are commonly found in the stomach of pigs, dogs and cats. Most of these species have zoonotic potential and prevalence rates of 0.2–6.0%, and have been described in human patients suffering from gastric disorders undergoing a gastric biopsy. The aim of this study was to determine the occurrence of Helicobacter spp. in the stomach of patients with gastric cancer (n = 17) and obese (n = 63) patients. Furthermore, the outcome of the Helicobacter eradication treatment and the current infection status was evaluated. Overall, based on the genus-specific PCR followed by sequencing, DNA from Helicobacter spp. was detected in 46.3% of the patients, including single infections with H. pylori in 43.8% of the patients and mixed infections with H. pylori and canine- or feline-associated H. felis in 2.5%. About 32.5% of the patients had been subjected to previous Helicobacter eradication therapy and the triple standard therapy was the most frequent scheme (42.3%). In 48.0% of the patients who received eradication treatment, bacteria were still detected, including one mixed infection. In 23.1% of the patients who reported that a subsequent test had been performed to confirm the elimination of the bacteria, Helicobacter were still detected. In conclusion, although in a smaller percentage, NHPH may also be present in the human stomach. Thus, specific NHPH screening should be included in the diagnostic routine. The continued presence of H. pylori in the stomach of patients recently subjected to eradication schemes raises questions about the efficacy of the current Helicobacter treatments.

Prevalence estimates of Helicobacter species infection in pancreatic and biliary tract cancers.

Background Helicobacter pylori infection is a well‐established risk factor for gastric cancer and has been linked to other gastrointestinal diseases, including pancreatic and biliary tract cancers; however, the relevance of enterohepatic non‐H. pylori helicobacters to the pathophysiology of these diseases remains unclear.Materials and MethodsWe estimated the prevalence of two enterohepatic non‐H. pylori helicobacters (Helicobacter hepaticus and Helicobacter bilis) in the framework of a hospital‐based case‐control study involving 121 patients with biliary tract cancer, pancreatic cancer, or other gastrointestinal diseases. Bile and blood samples were collected from the patients undergoing endoscopic retrograde cholangiopancreatography. The presence of H. bilis, H. hepaticus, and other Helicobacter spp. was examined using bacterial culture, PCR‐based detection, and serological tests.ResultsCulture of Helicobacter spp. from biliary brush samples was unsuccessful. Approximately 13.0% (15/115) of the bile samples collected from patients with a variety of gastrointestinal cancers, including pancreatic and biliary tract cancers, tested positive for one of the enterohepatic non‐H. pylori helicobacter species as determined by PCR. Specifically, H. bilis and H. hepaticus DNA were detected in 11 and 4 bile samples, respectively. Approximately 20%–40% of the patients tested positive for serum non‐H. pylori helicobacter IgG antibodies. The seroprevalence of H. bilis and H. hepaticus in the patients without evidence of H. pylori infection appeared to be higher in the pancreatic cancer group than in the control group.ConclusionOur findings suggest a role for Helicobacter spp., especially H. bilis and H. hepaticus, in the etiology of pancreatic and biliary tract cancers.

Ginger Extract Decreases Susceptibility to Dextran Sulfate Sodium-Induced Colitis in Mice Following Early Antibiotic Exposure.

Background: Intestinal microbial colonization in early life plays a crucial role in immune development and mucosal homeostasis in later years. Antibiotic exposure in early life increases the risk of inflammatory bowel disease (IBD). Ginger acts like a prebiotic and has been used in traditional Chinese medicine for colitis. We investigated the protective effect of ginger against dextran sulfate sodium (DSS)-induced colitis in mice exposed to antibiotic in their early years.Methods: A weaned mouse model exposed to azithromycin (AZT) for 2 weeks was used to mimic antibiotic exposure in childhood among humans. A diet containing ginger extract was administered to mice for 4 weeks after antibiotic exposure. The susceptibility to DSS-induced colitis was evaluated in terms of weight loss, disease activity index (DAI) score, colon length, colitis biomarkers, and intestinal barrier function. The gut microbiota was analyzed in terms of 16S rRNA levels.Results: Ginger extract prevented weight loss, colon shortening, inflammation, and intestinal barrier dysfunction in mice exposed to antibiotics in early life. Ginger increased the bacterial diversity and changed the abundance of bacterial belonging to family Peptococcaceae and Helicobacter species to modulate microbiota structure and composition adversely affected by early antibiotic exposure.Conclusion: Ginger has a protective effect in potentially decreasing the susceptibility to colitis in mice exposed to antibiotics early in life.

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.

Study of association of H. pylori infection of the gall bladder and calculous cholecystitis

Background: Helicobacter pylori infection of the gallbladder has been shown to increase the precipitation of cholesterol to form stones. Also it has been shown that urease induced calcium precipitation by Helicobacter species may initiate gallstone formation. This has raised a question about the possible role of Helicobacter species in the aetiology of gallbladder diseases especially cholelithiasis. Owing to conflicting results on the topic in the studies presently available and more so, only a few studies being reported in Northern India regarding this aspect and additionally having discordant findings. Our study was conceptualized in the Southern India scenario. Methods: During 18 months study period those diagnosed with calculous cholecystitis with USG, patients underwent Laparoscopic Cholecystectomy, the gall bladder specimen sent for histopathological examination for the presence of H. pylori and the mucosal changes associated with infection of the gallbladder with Helicobacter pylori. Results: No statistical significance was seen between H. pylori and gender. Among those having H. pylori majority were females. (p=0.23). No statistical significance was seen between H. pylori and type of stone. Among those having H. pylori majority were pigmented type. (p=0.67) High statistical significance was seen between H. pylori and Inflammatory mononuclear infiltrate. P

Nickel, an essential virulence determinant of Helicobacter pylori: Transport and trafficking pathways and their targeting by bismuth.

Metal acquisition and intracellular trafficking are crucial for all cells and metal ions have been recognized as virulence determinants in bacterial pathogens. Nickel is required for the pathogenicity of H. pylori. This bacterial pathogen colonizes the stomach of about half of the human population worldwide and is associated with gastric cancer that is responsible for 800,000 deaths per year. H. pylori possesses two nickel-enzymes that are essential for in vivo colonization, a [NiFe] hydrogenase and an abundant urease responsible for resistance to gastric acidity. Because of these two enzymes, survival of H. pylori relies on an important supply of nickel, implying tight control strategies to avoid its toxic accumulation or deprivation. H. pylori possesses original mechanisms for nickel uptake, distribution, storage and trafficking that will be discussed in this review. During evolution, acquisition of nickel transporters and specific nickel-binding proteins has been a decisive event to allow Helicobacter species to become able to colonize the stomach. Accordingly, many of the factors involved in these mechanisms are required for mouse colonization by H. pylori. These mechanisms are controlled at different levels including protein interaction networks, transcriptional, post-transcriptional and post-translational regulation. Bismuth is another metal used in combination with antibiotics to efficiently treat H. pylori infections. Although the precise mode of action of bismuth is unknown, many targets have been identified in H. pylori and there is growing evidence that bismuth interferes with the essential nickel pathways. Understanding the metal pathways will help improve treatments against H. pylori and other pathogens.

Helicobacter species binding to the human gastric mucosa.

Helicobacter pylori infects half of the world population, being associated with several gastric disorders, such as chronic gastritis and gastric carcinoma. The Helicobacter genus also includes other gastric helicobacters, such as H. heilmannii¸ H. ailurogastricus, H. suis, H. felis, H. bizzozeronii, and H. salomonis. These gastric helicobacters colonize both the human and animal stomach. The prevalence of gastric non-Helicobacter pylori Helicobacter (NHPH) species in humans has been described as low, and the in vitro binding to the human gastric mucosa was never assessed. Herein, human gastric tissue sections were used for the evaluation of the tissue glycophenotype and for the binding of gastric NHPH strains belonging to different species. Histopathological evaluation showed that 37.5% of the patients enrolled in our cohort presented chronic gastritis, while the presence of neutrophil or eosinophilic activity (chronic active gastritis) was observed in 62.5% of the patients. The secretor phenotype was observed in 68.8% of the individuals, based on the expression of Lewis B antigen and binding of the UleX lectin. The in vitro binding assay showed that all the NHPH strains evaluated were able to bind, albeit in low frequency, to the human gastric mucosa. The H. heilmannii, H. bizzozeronii, and H. salomonis strains displayed the highest binding ability both to the gastric superficial epithelium and to the deep glands. Interestingly, we observed binding of NHPH to the gastric mucosa of individuals with severe chronic inflammation and intestinal metaplasia, suggesting that NHPH binding may not be restricted to the healthy gastric mucosa or slight chronic gastritis. Furthermore, the in vitro binding of NHPH strains was observed both in secretor and non-secretor individuals in a similar frequency. In conclusion, this study is the first report of the in vitro binding ability of gastric NHPH species to the human gastric mucosa. The results suggest that other glycans, besides the Lewis antigens, could be involved in the bacterial adhesion mechanism; however, the molecular intervenients remain unknown.

Molecular Detection of Human Pathogenic Gastric Helicobacter Species in Wild Rabbits (Oryctolagus cuniculus) and Wild Quails (Coturnix coturnix)

Wildlife plays a major role in the maintenance and transmission of multihost pathogens. Several Helicobacter spp. have been described to have zoonotic potential; thus, human, domestic and wild animal interactions deserve more attention. In this study, the presence of the DNA of human pathogenic gastric Helicobacter species was determined in gastric samples collected from wild rabbits and wild quails during the national hunting campaigns in Portugal. Eleven out of the 12 wild rabbits (91.7%) and all six wild quails tested (100%) were PCR positive for one or more gastric Helicobacter species. In both animal species, H. felis, H. bizzozeronii and H. salomonis DNA were detected. In addition to these non-Helicobacter pylori Helicobacter spp. (NHPH), H. pylori DNA was also identified in gizzard samples of wild quails. These findings might indicate that wild rabbits and wild quails may act as reservoirs and contribute to the H. pylori and NHPH environment dissemination, causing both Public Health and One health concerns to arise.