Helicobacter infection and cirrhosis in hepatitis C virus carriage: is it an innocent bystander or a troublemaker?

Helicobacter pullorum and Helicobacter canadensis: Etiology, pathogenicity, epidemiology, identification, and antibiotic resistance implicating food and public health

Nowadays, it is well-established that the consumption of poultry meat, especially chicken meat products has been drastically increasing. Even though more attentions are being paid to the major foodborne pathogens, it seems that scientists in the area of food safety and public health would prefer tackling the minor food borne zoonotic emerging or reemerging pathogens, namely Helicobacter species. Recently, understanding the novel aspects of zoonotic Enterohepatic Helicobacter species, including pathogenesis, isolation, identification, and genomic features is regarded as a serious challenge. In this regard, considerable attention is given to emerging elusive zoonotic Enterohepatic Helicobacter species, comprising Helicobacter pullorum and Helicobacter canadensis. In conclusion, the current review paper would attempt to elaborately summarize and somewhat compare the etiology, pathogenesis, cultivation process, identification, genotyping, and antimicrobial resistance profile of both H. pullorum and H. Canadensis. Further, H. pullorum has been introduced as the most significant food borne pathogen in chicken meat products.

Helicobacter pylori and non-alcoholic fatty liver disease

Helicobacter pylori is the most prevalent infection worldwide, while non-alcoholic fatty liver disease emerged as the most frequent liver disease. The common occurrence can be either by chance or due to certain pathogenetic factors. Epidemiologic studies revealed that the risk of non-alcoholic liver disease is increased in patients infected with Helicobacter pylori. DNA fragments of Helicobacter pylori were rarely identified in human samples of liver carcinoma and fatty liver. Helicobacter pylori could influence the development of non-alcoholic fatty liver either by hormonal (ghrelin? gastrin? insulin?), or by effect of pro-inflammatory cytokines (interleukin 1 and 8, tumor necrosis factor ɑ, interferon ɣ) and by changes of gut microbiome as well. Probiotic supplementation could improve some clinical parameters of non-alcoholic fatty liver disease and eradication rates of Helicobacter pylori. Regimens used for eradication can be safely administered, although non-alcoholic fatty liver increases the risk of drug-induced liver damage. Controlled studies of the effect of eradication on the development and progression of non-alcoholic fatty liver are warranted.

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

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

Helicobacter pullorum: An Emerging Zoonotic Pathogen

Helicobacter pullorum (H.pullorum) commonly colonizes the gastrointestinal tract of poultry causing gastroenteritis. The bacterium may be transmitted to humans through contaminated meat where it has been associated with colitis and hepatitis. Despite the high prevalence of H. pullorum observed in poultry, little is known about the mechanisms by which this bacterium establishes infection in host and its virulence determinants. In this article we aim to provide an overview of this emerging zoonotic pathogen; its general characteristics, hosts, prevalence, and transmission as well as its pathogenic potential. We also discuss possible control strategies and risk of disease emergence.

Genome Dynamics and Molecular Infection Epidemiology of Multidrug-Resistant Helicobacter pullorum Isolates Obtained from Broiler and Free-Range Chickens in India

Some life-threatening, foodborne, and zoonotic infections are transmitted through poultry birds. Inappropriate and indiscriminate use of antimicrobials in the livestock industry has led to an increased prevalence of multidrug-resistant bacteria with epidemic potential. Here, we present a functional molecular epidemiological analysis entailing the phenotypic and whole-genome sequence-based characterization of 11 H. pullorum isolates from broiler and free-range chickens sampled from retail wet markets in Hyderabad City, India. Antimicrobial susceptibility tests revealed all of the isolates to be resistant to multiple antibiotic classes such as fluoroquinolones, cephalosporins, sulfonamides, and macrolides. The isolates were also found to be extended-spectrum β-lactamase producers and were even resistant to clavulanic acid. Whole-genome sequencing and comparative genomic analysis of these isolates revealed the presence of five or six well-characterized antimicrobial resistance genes, including those encoding a resistance-nodulation-division efflux pump(s). Phylogenetic analysis combined with pan-genome analysis revealed a remarkable degree of genetic diversity among the isolates from free-range chickens; in contrast, a high degree of genetic similarity was observed among broiler chicken isolates. Comparative genomic analysis of all publicly available H. pullorum genomes, including our isolates (n = 16), together with the genomes of 17 other Helicobacter species, revealed a high number (8,560) of H. pullorum-specific protein-encoding genes, with an average of 535 such genes per isolate. In silico virulence screening identified 182 important virulence genes and also revealed high strain-specific gene content in isolates from free-range chickens (average, 34) compared to broiler chicken isolates. A significant prevalence of prophages (ranging from 1 to 9) and a significant presence of genomic islands (0 to 4) were observed in free-range and broiler chicken isolates. Taken together, these observations provide significant baseline data for functional molecular infection epidemiology of nonpyloric Helicobacter species such as H. pullorum by unraveling their evolution in chickens and their possible zoonotic transmission to humans.

IMPORTANCE

Globally, the poultry industry is expanding with an ever-growing consumer base for chicken meat. Given this, food-associated transmission of multidrug-resistant bacteria represents an important health care issue. Our study involves a critical baseline approach directed at genome sequence-based epidemiology and transmission dynamics of H. pullorum, a poultry pathogen having established zoonotic potential. We believe our studies would facilitate the development of surveillance systems that ensure the safety of food for humans and guide public health policies related to the use of antibiotics in animal feed in countries such as India. We sequenced 11 new genomes of H. pullorum as a part of this study. These genomes would provide much value in addition to the ongoing comparative genomic studies of helicobacters.

Hepatic Temporal Gene Expression Profiling in Helicobacter hepaticus-Infected A/JCr Mice

Helicobacter hepaticus infection of A/JCr mice is a model of infectious liver cancer. We monitored hepatic global gene expression profiles in H. hepaticus infected and control male A/JCr mice at 3 months, 6 months, and 1 year of age using an Affymetrix-based oligonucleotide microarray platform on the premise that a specific genetic expression signature at isolated time points would be indicative of disease status. Model based expression index comparisons generated by dChip yielded consistent profiles of differential gene expression for H. hepaticus infected male mice with progressive liver disease versus uninfected control mice within each age group. Linear discriminant analysis and principal component analysis allowed segregation of mice based on combined age and lesion status, or age alone. Up-regulation of putative tumor markers correlated with advancing hepatocellular dysplasia. Transcriptionally down-regulated genes in mice with liver lesions included those related to peroxisome proliferator, fatty acid, and steroid metabolism pathways. In conclusion, transcriptional profiling of hepatic genes documented gene expression signatures in the livers of H. hepaticus infected male A/JCr mice with chronic progressive hepatitis and preneoplastic liver lesions, complemented the histopathological diagnosis, and suggested molecular targets for the monitoring and intervention of disease progression prior to the onset of hepatocellular neoplasia.

Impact of Helicobacter pylori eradication on refractory thrombocytopenia in patients with chronic HCV awaiting antiviral therapy

The possibility of delaying treatment of HCV due to severe thrombocytopenia is challenging. This study aimed to detect the prevalence of active helicobacter infection as a claimed cause of thrombocytopenia in a cohort of Egyptian patients with chronic active HCV awaiting combined anti-viral therapy. The study included 400 chronic HCV patients with thrombocytopenia. Laboratory investigations included liver function tests, real time quantitative PCR, reticulocytic count, ESR, ANA, bone marrow aspiration, measurement of anti-helicobacter antibodies, and helicobacter stool antigen. Positive cases for active H. pylori were given the standard triple therapy for 2 weeks. Helicobacter stool antigen was detected 4 weeks after termination of therapy and the change in platelet count was detected 1 month after eradication. A total of 248 out of 281 seropositive patients for H. pylori (88.3 %) showed positive stool antigen (p = 0.01). Eradication was achieved in 169 (68.1 %) patients with platelet mean count 114.9 ± 18.8 × 10(3)/μl with highly significant statistical difference from pretreatment value (49.7 ± 9.2 × 10(3)/μl, p = 0.000). Seventy-nine patients were resistant to conventional triple therapy and given a 7-day course of moxifloxacin-based therapy; 61 patients responded (77.1 %) with mean platelet improvement from 76.4 ± 17.4 × 10(3)/μl to 104.2 ± 15.2 × 10(3)/μl (p = 0.000). The non-responders showed no improvement in their platelet count (74.6 ± 20.5 vs. 73.6 ± 15.3 × 10(3)/ul, P = 0.5). Eradication of active H. pylori in HCV augments platelet count and enhances the early start of antiviral therapy.

The Association between Helicobacter pylori Infection and Chronic Hepatitis C: A Meta-Analysis and Trial Sequential Analysis

Purpose. Helicobacter pylori is a common gastric disease-inducing pathogen. Although an increasing number of recent studies have shown that H. pylori is a risk factor for liver disease, the potential association between H. pylori infection and chronic hepatitis C still remains controversial. The aim of our meta-analysis was to evaluate a potential association between H. pylori infection and chronic hepatitis C. Methods. We searched the PubMed, Embase, CNKI, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases between January 1, 1994, and May 1, 2015. Results. This study included a total of 1449 patients with chronic hepatitis C and 2377 control cases. The prevalence of H. pylori was significantly higher in patients with chronic hepatitis C than in those without chronic hepatitis C. The pooled odds ratio was 2.93. In a subgroup analysis, the odds ratios were 4.48 for hepatitis C virus- (HCV-) related cirrhosis and 5.45 for hepatocellular carcinoma. Conclusion. Our study found a strong association between H. pylori and chronic hepatitis C, particularly during the HCV progression stage; thus, we recommend active screening for H. pylori in patients with chronic hepatitis C.

Impact of Helicobacter pylori on the growth of hepatic orthotopic graft tumors in mice

Helicobacter pylori is a well-known causative organism of chronic gastric diseases and has been found in many hepatic carcinoma samples. To explore the expression of apoptosis-related proteins and carcinoma development in H. pylori-infected livers, we utilized BALB/cAnSlac mice to establish an H. pylori-infected model by oral inoculation and orthotopic grafts of hepatic tumors by H22 cells, respectively. We found that H. pylori colonies could not be cultured from all liver and tumor samples. However, its 16S rRNA was detectable in 85.3% of livers and 66.7% of tumors in the infected mice. Inflammatory cells were observed and thinly distributed in the lobule portions of the liver, and H. pylori mainly existed in the infected hepatic sinusoids and the necrotic areas of the infected tumors. No significant difference was found in liver to body weight ratio between the infected and uninfected. Moreover, the pathological tumor difference was unremarkable between the two. The proliferating cell nuclear antigen (PCNA) and Bcl-2-associated X protein (Bax) expression in the infected tumors was significantly higher and lower, respectively, than those of the uninfected tumors. However, no significant difference in Bcl-2 (B-cell lymphoma 2) expression existed. The results indicate that H. pylori found in the livers which were infected by H. pylori oral inoculation could contribute to the infiltration of inflammatory cells in livers. Although H. pylori has no significant impact on the liver to body weight ratio or tumor Bcl-2 expression, it may upregulate PCNA expression and downregulate Bax expression, respectively. All our findings show that H. pylori may promote proliferation and inhibit apoptosis of tumor cells.

The effect of helicobacter pylori eradication on liver fat content in subjects with non-alcoholic Fatty liver disease: a randomized open-label clinical trial

BACKGROUND

The role of Helicobacter pylori (HP) in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is unclear.

OBJECTIVES

The aim of this study was to evaluate the effect of HP eradication on liver fat content (LFC), liver function tests (LFT), lipid profile, and homeostasis model assessment-IR (HOMA-IR) index in NAFLD.

PATIENTS AND METHODS

Dyspeptic patients with increased serum aminotransferase levels were enrolled in the study. The exclusion criteria were factors affecting serum aminotransferase or HP treatment strategy. Participants with persistent elevated serum aminotransferase level and ultrasound criteria for identification of fatty liver were presumed to have NAFLD. "NAFLD liver fat score" was used to classify NAFLD. Those with "NAFLD liver fat score" greater than -0.64 and positive results for urea breath test (UBT), were included. Lifestyle modification was provided to all participants. HP eradication was performed in intervention arm. LFC, fasting serum glucose (FSG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglyceride (TG), cholesterol (CHOL), high and low-density lipoprotein (HDL, LDL), and HOMA-IR were checked at baseline and after that, at intervals of eight weeks and twenty four weeks.

RESULTS

One hundred (49 males) patients with the mean age of 43.46 (± 11.52) were studied. Repeated measure ANOVA showed a significant reduction in LFC, anthropometric measurements, and laboratory parameters (except for HDL) in the both groups during the study; however, no significant difference was observed between the groups.

CONCLUSIONS

It seems that HP eradication per se might not affect LFC, LFT, lipid profile, and insulin resistance in dyspeptic NAFLD patients.

Helicobacter pylori infection does not promote hepatocellular cancer in a transgenic mouse model of hepatitis C virus pathogenesis

Helicobacter pylori (H. pylori) and hepatitis C virus (HCV) infect millions of people and can induce cancer. We investigated if H. pylori infection promoted HCV-associated liver cancer. Helicobacter-free C3B6F1 wild-type (WT) and C3B6F1-Tg(Alb1-HCVN)35Sml (HT) male and female mice were orally inoculated with H. pylori SS1 or sterile media. Mice were euthanized at ~12 mo postinoculation and samples were collected for analyses. There were no significant differences in hepatocellular tumor promotion between WT and HT mice; however, HT female mice developed significantly larger livers with more hepatic steatosis than WT female mice. H. pylori did not colonize the liver nor promote hepatocellular tumors in WT or HT mice. In the stomach, H. pylori induced more corpus lesions in WT and HT female mice than in WT and HT male mice, respectively. The increased corpus pathology in WT and HT female mice was associated with decreased gastric H. pylori colonization, increased gastric and hepatic interferon gamma expression, and increased serum Th1 immune responses against H. pylori. HT male mice appeared to be protected from H. pylori-induced corpus lesions. Furthermore, during gastric H. pylori infection, HT male mice were protected from gastric antral lesions and hepatic steatosis relative to WT male mice and these effects were associated with increased serum TNF-α. Our findings indicate that H. pylori is a gastric pathogen that does not promote hepatocellular cancer and suggest that the HCV transgene is associated with amelioration of specific liver and gastric lesions observed during concurrent H. pylori infection in mice.

Role of Helicobacter pylori in patients with HCV-related chronic hepatitis and cirrhosis with or without hepatocellular carcinoma: possible association with disease progression

The discovery of Helicobacter hepaticus as a causal agent of hepatitis and hepatocellular carcinoma (HCC) in mice has stimulated interest in looking for Helicobacter species in human liver samples. In this study, we searched for association between H. pylori and HCV-related liver disease. Liver specimens were collected from eighty-five patients; they were divided into five different groups according to liver pathology (METAVIR system). Group I (the 1st control group) consisted of 16 patients with chronic hepatitis C without histological activity. Group II consisted of 25 patients with chronic active hepatitis C, Group III, 17 patients with HCV-related cirrhosis and Group IV, 16 patients with HCV-related cirrhosis and HCC. Group V (2nd control group) consisted of 11 patients suffering from gastro duodenal and gall bladder diseases but negative for HCV. All cases were tested by polymerase chain reaction on liver samples for the presence of H. pylori DNA Cag A gene. Routine biochemical, radiological and RT-PCR for HCV RNA were also performed for all cases. The positivity of H. pylori PCR CagA gene in liver tissue was directly proportional to the severity of liver pathology, this being 75%, 52.9% and 32% in groups IV, III and II, respectively, which was more significant than the 1st and 2nd control groups (P < 0.001). There was a significant difference between H. pylori PCR values when compared to METAVIR staging (F) in different groups (P = 0.001). Helicobacter pylori PCR (Cag A gene) was positive in about 28.2% cases of late fibrosis (F3 + F4) while positivity was (5.9%) in early fibrosis (F1 + F2) (P = 0.0001). There was significant difference between H. pylori PCR (Cag A gene) in liver tissue and METAVIR activity in different groups (P = 0.002) as most of H. pylori PCR-positive cases were METAVIR activity A1 and A2 (15.3% and 12.9%, respectively). There was no association between H. pylori PCR and quantitative HCV RNA (P = 0.531). Also there was no significant difference of Child-Pugh staging in the H. pylori PCR-positive group when compared to the negative group (P = 0.996). There may be an association between the presence of H. pylori (Cag A gene) in the liver and disease progression in HCV-related chronic hepatitis and cirrhosis with and without HCC.

Comparison of Helicobacter bilis-Associated Protein Expression in Huh7 Cells Harbouring HCV Replicon and in Replicon-Cured Cells

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Hepatitis B or C infections are the main causes of HCC with hepatitis C being the major risk factor for liver cancer in the developed countries. Recently, complications with bacteria of the genus Helicobacter have been associated with HCV-induced HCC. To further understand the mechanisms leading to the development of HCC in the presence of HCV and/or Helicobacter spp., investigation of the differential protein expression in Huh7 cells harbouring HCV-replicon, and replicon cured-Huh7 cells cocultured with H. bilis was done employing two-dimensional gel electrophoresis and mass spectrometry. In the transfected-Huh7 cells exposed to sublethal inoculum densities of H. bilis, 53 different proteins were identified comprising of 28 upregulated and 16 downregulated proteins including 9 potential protein isoforms; in the cured Huh7 cells, 45 different proteins were identified including 33 upregulated, 8 downregulated and, 9 potential protein isoforms. H. bilis affected the modulation of proteins involved in different pathways of Huh7-derived cells physiology including proteins involved in the progression from dysplasia to neoplasm. The result also indicated that the response of the Huh7-derived cells to the presence of H. bilis depended on whether or not HCV replicon was present.

Helicobacter Pylori DNA in Liver Tissues From Chronic Hepatitis C Egyptian Patients

Background

Hepatitis C virus (HCV) is considered the most common etiology of chronic liver disease in Egypt, which may progress to cirrhosis and hepatocellular carcinoma (HCC). Previous studies have documented an association between Helicobacter pylori (H. pylori) infection and liver cirrhosis with or without HCC. This study aimed to investigate the presence of H. pylori DNA in the liver tissue of Egyptian patients with chronic hepatitis C (CHC).

Methods

Fifty-two CHC Egyptian patients were enrolled in this study. Plasma anti-H. pylori IgG was assessed with ELISA. Liver biopsies were tested for presence of Helicobacter DNA using genus specific nested polymerase chain reaction (PCR) and species was identified by sequencing.

Results

Anti-H. pylori IgG was detected in 31/52 (59.6%) CHC patients while Helicobacter DNA was detected in 6 (11.5%) patients, all were H. Pylori by sequencing. Helicobacter DNA was more frequent in patients with high stage liver fibrosis (33.3%) than in those with low stage fibrosis (2.7%) (P = 0.006). There was no association between the presence of H. pylori DNA in the liver and age, gender of patients, liver function tests, AFP levels or viral load.

Conclusions

These data confirm the presence of H. pylori DNA in liver of some CHC Egyptian patients and suggest an association of this bacterium with progression of liver fibrosis.

Distance burning: how gut microbes promote extraintestinal cancers

Gut microbes play a major role in carcinogenesis of the gastrointestinal tract. We and others have shown in mouse models that colonic bacteria also influence the development of extraintestinal cancers including hepatocellular and mammary carcinomas. Microbes such as Helicobacter hepaticus invoke a proinflammatory microenvironment in the lower bowel that may extend to distant organs, often in the absence of histologically evident inflammation. Innate immunity plays a crucial role in the promotion of liver cancer and other systemic diseases by gut microbes. Additional mechanisms include type 1 adaptive immunity, altered metabolism, and oxidative stress. Emerging links between host genetics, gut microbes, inflammatory bowel disease and colorectal cancer also may prove useful for the correlation of specific bacterial populations with extraintestinal neoplasms. Interruption of deleterious host-microbe networks through judicious use of antibiotics and targeted molecular therapies may help reduce the incidence of liver, breast, and other human cancers.

Prevalence of Helicobacter pullorum in conventional, organic, and free-range broilers and typing of isolates

Helicobacter pullorum represents a potential food-borne pathogen, and avian species appear to be a relevant reservoir of this organism. In this study, the prevalence of H. pullorum was investigated at 30 conventional farms where 169 ceca from 34 flocks were tested, at eight organic farms where 39 ceca from eight flocks were tested, and at seven free-range farms where 40 ceca from eight flocks were tested. All of the ceca were obtained from healthy broiler chickens. Moreover, amplified fragment length polymorphism, pulsed-field gel electrophoresis, and automated ribotyping were employed to estimate the levels of genetic variability of H. pullorum broiler isolates within and between flocks. Overall, Gram-negative, slender, curved rods, identified as H. pullorum by PCR, were isolated at 93.3% of the farms tested. The percentage of positive free-range farms (54.2%) was significantly lower than that of conventional (100%) or organic (100%) farms (P < 0.001). The level of within-flock genetic variability, calculated as the number of flocks colonized by isolates genetically different by all of the typing methods, was 34.9%. Isolates showing identical profiles by each typing method were observed in 11.6% of the flocks, but they were never detected between flocks. However, groups of isolates clustered together with an overall similarity level of ≥85%. Our results suggest that even though a high level of genetic variability is attributable to H. pullorum broiler isolates, their hierarchical genotyping produces data useful for epidemiological investigations.

Helicobacter pylori accelerates hepatic fibrosis by sensitizing transforming growth factor-β1-induced inflammatory signaling

Our earlier report has shown that Helicobacter pylori promoted hepatic fibrosis in a murine model. Herein, in order to elucidate the mechanism by which H. pylori accelerate liver fibrosis, the authors investigated the changes in expression levels of mitogen-activated protein kinases (MAPKs), p53-related proteins, antioxidants, and proinflammatory cytokines in liver samples. H. pylori infection enhanced CCl4-induced MAP kinase activation and p53 signaling pathway as well as Bax- and proliferating-cell nuclear antigen expressions, whereas H. pylori alone induced neither of these expressions nor hepatic fibrosis. Moreover, mRNA expressions of inflammatory cytokines, glutathione peroxidase expression, and the proliferative index were strongly augmented in livers of the H. pylori with CCl4 treatment group compared with those of the CCl4-alone treatment group, whereas there was no difference in apoptotic index between the two groups. Interestingly, H. pylori treatment increased the number of α-fetoprotein-expressing hepatocytes independently of CCl4 intoxication. In vitro analyses, using an immortalized rat hepatic stellate cell (HSC) line, revealed that H. pylori lysates increased the proliferation of HSCs, which was boosted by the addition of transforming growth factor-beta1 (TGF-β1). Furthermore, the treatment of H. pylori lysates promoted the translocation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) into the nucleus based on an increase in the degradation of NF-κB inhibitor alpha, in the presence of TGF-β1, as did H2O2 treatment. In conclusion, H. pylori infection along with an elevated TGF-β1 may accelerate hepatic fibrosis through increased TGF-β1-induced pro-inflammatory signaling pathways in HSCs. Moreover, H. pylori infection might increase the risk of TGF-β1-mediated tumorigenesis by disturbing the balance between apoptosis and proliferation of hepatocytes.

Helicobacter pylori and Hepatitis C Virus Coinfection in Egyptian Patients

INTRODUCTION

Chronic hepatitis C virus (HCV) infection is a leading cause of end-stage liver disease worldwide. It has been shown that Helicobacter pylori (H. pylori) plays an important role in chronic gastritis, peptic ulcer disease and gastric malignancies, and its eradication has been advocated. The association between H. pylori infection and liver cirrhosis in patients with hepatitis C virus has been documented in different parts of the world; nevertheless, no conclusive data is available in Egypt.

MATERIALS AND METHODS

In the present study, the status of H. pylori infection was sought in 90 patients with chronic HCV infection and in 66 HCV-free healthy controls.

RESULTS

The study showed that the H. pylori positivity was increased significantly (P = 0.03) in the HCV-infected patients when compared to that in healthy controls, where H. pylori infection was found in 50 (55.6%) out of 90 of the HCV-infected patients versus 26 (39.4%) out of 66 of the healthy controls. In HCV-infected patients, the prevalence of H. pylori infection was increased significantly (P = 0.04) from chronic active hepatitis to cirrhosis. H. pylori infection was present in 6/18 (33.3%), 10/21 (47.6%), 16/27 (59.3%), 18/24 (75.0%) patients with chronic active hepatitis, Child-Pugh score A, Child-Pugh score B and Child-Pugh score C, respectively. More importantly, the prevalence of H. pylori infection in HCV-infected patients was increased very significantly (P = 0.003) with increasing Meld (model for end-stage liver disease) score. The prevalence of H. pylori was documented in 9/28 (32.1%) patients with Meld score >10 and in 41/62 (66.1%) patients with Meld score >10.

CONCLUSION

It may be stated that our results collectively reflect a remarkable increase in H. pylori prevalence with advancing hepatic lesions, and the eradication treatment may prove beneficial in those patients with chronic hepatitis C.

Hepatocellular carcinoma: prevalence and molecular pathogenesis of Helicobacter spp

Helicobacter pylori infection is one of the most common chronic bacterial infections in humans. The association of other Helicobacter spp. with extragastric diseases in animals is well established, and a role of these bacteria in human liver disease is becoming clearer. Several case-control studies have reported possible associations of Helicobacter spp. with various liver diseases, including hepatocellular carcinoma, which is the fifth most common type of carcinoma among men worldwide, and the eighth most common among women. Thus, it is important to understand molecular mechanisms that may lead to hepatotoxicity or hepatocellular dysfunction in which Helicobacter spp. may play a role in inducing malignant transformation of liver cells.

Helicobacter pylori infection in patients with chronic hepatitis C and its related factors

AIM: To study the role of H. pylori in chronic hepatitis C.

METHODS: Serum anti-H. pylori-IgG was detected by ELISA to determine whether there is H. pylori infection according to the diagnostic criteria of H. pylori epidemiology. Serum HCV RNA level was detected by real time fluorescence quantitative polymerase chain reaction (FQ-PCR). HCV genotypes were identified by polymerase chain reaction-microplate hybridization-enzyme linked immunosorbent assay (PCR-MPH-ELISA).

RESULTS: H. pylori infection was more prevalent in patients with chronic hepatitis C, cirrhosis due to chronic hepatitis C and HCC than in healthy controls (55.5%, 76.5%, 78.6% vs 43.4%, P < 0.05). H. pylori infection aggravated with the extent of hepatic lesions and the load of hepatitis C virus. H. pylori infection was 59.5%, 66.7%, 65.0% and 59.2% in patients with genotypes 1a, 1b, 2a and 2b, respectively. However, there was no significant difference in these genotypes.

CONCLUSION: H. pylori infection is higher in patients with chronic hepatitis C than in healthy controls. H. pylori might play a role in the progress from chronic hepatitis C to cirrhosis and hepatocellular carcinoma.

TaqMan real-time PCR assay for specific detection of Opisthorchis viverrini DNA in Thai patients with hepatocellular carcinoma and cholangiocarcinoma

The aim of this study was to develop TaqMan real-time PCR assay that detected Opisthorchis viverrini DNA from 18 normal and 18 tumor tissue specimens from Thai patients with hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), who underwent liver resection from October 2005 to May 2006. Control liver specimens were seven non-primary liver cancers. A conserved probe representing 100% sequence homology was used as a reference for O. viverrini-specific probe. Five of six tumors (83%) and all six normal tissues from CCA group; and seven of twelve tumors (58%) and ten of twelve normal tissues (83%) from HCC group were found to have O. viverrini DNA. The O. viverrini DNA detection among HCC and CCA patients were not associated (p=0.193; 90%CI). This RT-PCR will be a useful tool for investigating the relationship between cancer type and presence of the parasite and also for conducting epidemiological surveys.

Low frequency of Helicobacter DNA in benign and malignant liver tissues from Baltimore, United States

Helicobacter DNA has been reported in hepatocellular carcinoma tissues in several studies from varying geographic locations, raising the possibility that Helicobacter infection may contribute to the pathogenesis of hepatocellular carcinoma. Other known risk factors for hepatocellular carcinoma show significant geographic variability, but whether the same holds for Helicobacter is unknown. We studied the prevalence of Helicobacter DNA in a US cohort of hepatocellular carcinoma, where the prevalence of Helicobacter infection is low in the general population. Liver tissues from 57 individuals were examined. Thirty-five individuals had paired tumor/nontumor samples, including 21 cases of hepatocellular carcinoma, for a total of 92 samples studied. Both Helicobacter genus and Helicobacter pylori species-specific polymerase chain reaction was performed. Helicobacter DNA was detected in 5 (9%) of 57 cases, all in nonneoplastic cirrhotic liver tissues from individuals with hepatitis C infection (n = 4) or alcohol liver disease (n = 1). Tissues from 22 hepatocellular carcinomas and 10 cholangiocarcinomas were all negative as were tissues from 8 benign primary hepatic tumors. In conclusion, Helicobacter DNA was detectable in 9% of liver tissues in this cohort but was not found in primary benign or malignant liver tumors. These findings indicate that Helicobacter infection is unlikely to be etiologically associated with hepatocellular carcinoma in this cohort. If Helicobacter infection does contribute to the development of hepatocellular carcinoma in general, then significant regional variability must exist.

Complete nucleotide sequence of the gyrA gene of Helicobacter pullorum and identification of a point mutation leading to ciprofloxacin resistance in poultry isolates

To assess the molecular basis of nalidixic acid and ciprofloxacin resistance in Helicobacter pullorum, the gyrA gene of H. pullorum CIP 104787T was sequenced. In addition, 9 isolates (2 susceptible to ciprofloxacin and resistant to nalidixic acid, 3 susceptible and 4 resistant to both antibiotics) were selected from 44 poultry isolates and the nucleotide sequences of their quinolone resistance-determining regions (QRDRs) were compared. The 2490 bp gyrA gene showed an open reading frame encoding a polypeptide of 829 amino acids. The deduced amino acid sequence of gyrA showed>or=72% identity to Helicobacter hepaticus, Helicobacter pylori and Wolinella succinogenes. Moreover, >or=98% amino acid sequence identity was found comparing the QRDR of the H. pullorum type strain with the QRDRs of the aforementioned bacterial species. All ciprofloxacin-resistant poultry isolates showed an ACA-->ATA (Thr-->Ile) substitution at codon 84 of gyrA, corresponding to codons 86, 87 and 83 of Campylobacter jejuni, H. pylori and Escherichia coli gyrA genes, respectively. This substitution was functionally confirmed to be associated with the ciprofloxacin-resistant phenotype of poultry isolates. This is the first report describing the complete 2490 bp nucleotide sequence of H. pullorum gyrA and confirming the involvement of the Thr84Ile substitution of GyrA in ciprofloxacin resistance of H. pullorum.

Occurrence and antibiotic susceptibility of Helicobacter pullorum from broiler chickens and commercial laying hens in Italy

In 2005, in order to investigate the occurrence of Helicobacter pullorum in poultry, the caecal contents collected from a total of 60 animals intensively reared in Italy on 15 different farms (9 farms of broiler chicken and 6 of laying hens) were examined at the slaughterhouse. A modified Steele-McDermott membrane filter method was used. Small, greyish-white colonies of Gram-negative, gently curved, slender rod bacteria were preliminarily identified as H. pullorum by a Polymerase Chain Reaction (PCR) assay based on 16S rRNA and were then subjected to an ApaLI digestion assay to distinguish H. pullorum from Helicobacter canadensis. One isolate from each farm was phenotypically characterized by biochemical methods and 1D SDS-PAGE analysis of whole cell proteins; antibiotic susceptibility was also tested. According to the PCR and PCR-RFLP results, all the animals examined were positive for H. pullorum. The 1D SDS-PAGE whole protein profile analysis showed high similarity among the 15 isolates tested. A monomodal distribution for the Minimum Inhibitory Concentrations (MICs) was found for ampicillin, chloramphenicol, gentamicin and tetracycline. For erythromycin and ciprofloxacin, a bimodal trend having a second peak at >128 micro(-1) and 32 micro(-1) was found. The isolation method used in this study seems to be highly suitable for isolating H. pullorum from chicken caecal contents. Moreover, the detection of a high number of colonies phenotypically similar to H. pullorum suggests that this microorganism, when present, colonizes the caecum at high concentration.

Relationship between the severity of hepatitis C virus-related liver disease and the presence of Helicobacter species in the liver: A prospective study

AIM: To determine the presence of Helicobacter species DNA in the liver of chronic hepatitis C (CHC) patients with and without cirrhosis as compared to controls, and to identify the bacterial species involved.

METHODS: Seventy-nine consecutive patients (HBV and HIV negative) with a liver sample obtained after liver biopsy or hepatic resection were studied: 41 with CHC without cirrhosis, 12 with CHC and cirrhosis, and 26 controls (HCV negative). Polymerase chain reactions (PCRs) targeting Helicobacter 16S rDNA and species-specific were performed on DNA extracted from the liver. A gastric infection with H pylori was determined by serology and confirmed by ¹³C-urea breath test.

RESULTS: Overall, Helicobacter 16S rDNA was found in 16 patients (20.2%). Although positive cases tended to be higher in CHC patients with cirrhosis (41.6%) than in those without cirrhosis (17.0%) or in controls (15.4%), the difference was not statistically significant (P = 0.08). H pylori-like DNA was identified in 12 cases and H. pullorum DNA in 2, while 2 cases remained unidenti-fied. Gastric infection with H pylori was found in only 2 of these patients.

CONCLUSION: Our results do not confirm the associ-ation of Helicobacter species DNA in the liver of CHC patients with advanced liver disease. The lack of correlation between positive H pylori serology and the presence of H pylori-like DNA in the liver may indicate the presence of a variant of this species.

Influence of Helicobacter pylori infection on iron accumulation in hepatitis C

GOAL

Iron may play a role in the pathogenesis of chronic hepatitis C. Helicobacter pylori (Hp) infection was recently associated with iron-deficiency anemia. We examined the influence of Hp infection on hepatic iron accumulation in hepatitis C.

METHODS

Ninety-five hepatitis C virus (HCV)-RNA-positive patients, including 60 chronic hepatitis, 17 cirrhosis and 18 hepatocellular carcinoma as well as 95 age- and sex-matched normal subjects without HCV infection as control, were studied. Liver biopsies were also obtained from 44 HCV-infected patients. Serum Hp antibodies were measured by an enzyme-linked immunosorbent assay and clinical data, including iron parameters and histological findings, were compared between Hp-positive and -negative HCV-infected patients.

RESULTS

The percentage of serum Hp antibodies was lower in HCV-infected patients than in controls (52/95 (54.7%) vs. 68/95 (71.6%); P<0.05). HCV-infected patients had higher serum ferritin levels than controls (120 [2.8-1700] vs. 58 [2.2-420] ng/ml; P<0.0001). In HCV-infected patients, the serum ferritin levels (medians and [ranges]) in Hp-positive patients were significantly lower than those of Hp-negative patients (99 [8.5-770] vs. 150 [2.8-1700] ng/ml; P<0.05). The grades of hepatic iron deposit in Hp-positive patients were significantly lower than those in Hp-negative patients (P<0.01).

CONCLUSIONS

Hp infection may at least partly affect hepatic iron accumulation in HCV-related liver diseases.

Helicobacter infection in hepatocellular carcinoma tissue

AIM: To investigate whether Helicobacter species (Helicobacter spp.) could be detected in hepatocellular carcinoma (HCC) tissue.

METHODS: Liver samples from 28 patients with hepatocellular carcinoma (HCC) diagnosed by histopa-thology were studied. Twenty-two patients with other liver diseases (5 with liver trauma, 7 with cavernous liver hemangioma, 6 with liver cyst and 4 with hepatolithiasis), 25 patients with gastric cancer, 15 with colonic cancer and 15 with myoma of uterus served as controls. Two pieces of biopsy were obtained from each patient. One was cultured for Helicobacter spp. and extraction of DNA, the other was prepared for scanning electron microscopy (SEM) and in situ hybridization. The samples were cultured on Columbia agar plates with microaerobic techniques. Helicobacter spp. in biopsy from the studied subjects was detected by polymerase chain reaction (PCR) with Helicobacter spp. 16S rRNA primers. Amplified products were identified by Southern hybridization and sequenced further. Besides, other genes (vacA, cagA) specific for Helicobacter pylori (H pylori) were also detected by PCR. Helicobacter spp. in biopsies was observed by SEM. Transmission electron microscopy (TEM) was performed to identify the cultured positive Helicobacter spp. The presence of Helicobacter spp. was detected by in situ hybridization to confirm the type of Helicobacter.

RESULTS: The positive rate of Helicobacter cultured in HCC and gastric cancer tissue was 10.7% (3/28) and 24%(6/25), respectively. Helicobacter microorganisms were identified further by typical appearance on Gram staining, positive urease test and characteristic colony morphology on TEM. The bacterium was observed in adjacent hepatocytes of the two HCC samples by SEM. The number of cocci was greater than that of bacilli. The bacterium was also found in four gastric cancer samples. PCR showed that the positive rate of HCC and gastric cancer samples was 60.7% and 72% respectively, while the controls were negative (P < 0.01). The PCR-amplified products were identified by Southern hybridization and sequenced. The homology to 16S rRNA of H pylori was 97.80%. The samples were verified by in situ hybridization for Helicobacter spp. 16S rRNA-mRNA and proved to be H pylori positive. There was no statistical significance between HCC and gastric cancer (P > 0.05), but the positive rate of HCC and controls had statistical significance (P < 0.01). Only 3 HCC samples and 2 gastric cancer samples of the cagA genes were detected. None of the samples reacted with primers for vacA in the two groups. As for the genotype of H pylori, type II had preference over type I.

CONCLUSION: Helicobacter infection exists in liver tissues of HCC patients. Helicobacter spp. infection is related with HCC, which needs further research.

Helicobacter pylori and other Helicobacter species DNA in human bile samples from patients with various hepato-biliary diseases

AIM: To investigate the presence of Helicobacter species by nested PCR of 16S rRNA genes followed by the presence of Helicobacter pylori（H pylori）16S rRNA, ureA, cagA genes in bile obtained at endoscopic retrograde cholangio-pancreatography (ERCP) from 60 Indian subjects.

METHODS: Sixty bile samples were obtained from patients diagnosed with various hepato-biliary diseases and control subjects at ERCP. PCR analysis was carried out using primers for Helicobacter genus 16S rRNA gene and H pylori (16S rRNA, ureA and cagA) genes. Gastric H pylori status was also assessed from biopsies obtained at endoscopy from patients with various hepato-biliary diseases and controls. The control group mainly consisted of subjects with gastric disorders. Sequencing analysis was performed to confirm that PCR products with 16S rRNA and cagA primers were derived from H pylori.

RESULTS No Helicobacters were grown in culture from the bile samples. Helicobacter DNA was detected in bile of 96.7% and 6.6% of groups I and II respectively. Ten from group I were positive for 16S rRNA and ureA and 9 were positive for cagA gene. In contrast of the 2 from the control, 1 amplified with 16S rRNA, ureA and cagA primers used. The sequences of the 16S rRNA genes and cagA were 99% similar to Helicobacter pylori.

CONCLUSION: Helicobacters are associated with the pathogenesis of various hepato-biliary disorders.

Association between Helicobacter pylori infection and cirrhosis in patients with chronic hepatitis C virus

We evaluated, employing a logistic regression model, the association between Helicobacter pylori infection and cirrhosis in a cohort of 106 patients (57 males; mean age, 52.9 years; range, 20-78 years) with chronic hepatitis C virus (HCV) from Rosario, Argentina. HCV was confirmed by ELISA and PCR. H. pylori status was determined by ELISA. Of the 106 patients evaluated, 47 (44.3%) had cirrhosis. A total of 70.2% (33/47) of cirrhotic patients and 47.5% (28/59) of noncirrhotic patients were H. pylori-positive. In univariate analyses, cirrhosis was associated with age (P = 0.016) and H. pylori-positive status (P = 0.019) but not with gender (P = 0.28) or length of infection (P = 0.35). In multivariate analysis, H. pylori infection (P = 0.037; OR = 2.42; 95% CI = 1.06-5.53) and age (P = 0.033; OR = 1.04; 95% CI = 1.00-1.07) of patients remained significant and independently associated with cirrhosis. In conclusion, our results demonstrate an association between H. pylori infection and cirrhosis in patients with hepatitis C virus.

Helicobacter pylori and hepatocellular carcinoma: correlated or uncorrelated?

Helicobacter pylori can be detected in liver tissue resected from patients with hepatocellular carcinoma. Conflicting reports regarding the relationship between H. pylori and hepatocellular carcinoma mean it is uncertain whether H. pylori acts as a troublemaker, co-risk factor or innocent bystander to the development of hepatocellular carcinoma. Clinical studies in patients without known causes of hepatocellular carcinoma are important to discover whether H. pylori is involved in the carcinogenesis of hepatocellular carcinoma. High quality prospective studies in patients with hepatocellular carcinoma, hepatitis C virus infection and no cirrhosis are needed to determine whether H. pylori is a co-risk factor for hepatocellular carcinoma.

Comparative proteome analysis of untreated and Helicobacter pylori-treated HepG2

AIM: To investigate the pathological effect of Helicobacter pylori (H pylori) on human hepatic cells, proteomic methods were used to find and to identify proteins that were overexpressed in HepG2 cells treated by H pylori.

METHODS: H pylori was co-cultured with HepG2 for 6 h. Two-dimensional gel electrophoresis was used to gain the protein expression pattern of untreated and H pylori-treated HepG2. After staining and image analysis, spots of interest were isolated and subjected to mass spectrometry.

RESULTS: Seven proteins, which were up-regulated in H pylori-treated HepG2 cells, were identified. These proteins included integrin beta-1, protein kinase C alpha, LIM/homeobox protein Lhx1, eIF-2-beta, MAP kinase kinase 3, PINCH protein and Ras-related protein Rab-37, which involved in transcription regulation, signal transduction, metabolism and so on.

CONCLUSION: H pylori may exert the pathological effect on HepG2 cells by up-regulating the expression of some proteins.

Progression of chronic hepatitis and preneoplasia in Helicobacter hepaticus-infected A/JCr mice

Helicobacter hepaticus infection induces sustained inflammation and carcinoma of the liver in A/JCr mice, and serves as a model of human cancers associated with viral hepatitis and H. pylorichronic gastritis. Here we describe the pathogenesis of premalignant disease in A/JCr mice infected with H. hepaticus. We inoculated dams intragestationally and/or pups postnatally, and evaluated offspring at 3, 6, or 12 months. Mice infected at or before 3 weeks of age, but not at 12 weeks, developed disease. Male mice were most affected, but expressed a bimodal pattern of susceptibility. Males exhibited lobular necrogranulomatous and interface (chronic active) hepatitis, while females usually developed intraportal (chronic persistent) hepatitis. Portal inflammation was slowly progressive, with tertiary lymphoid nodule development by 12 months. Hepatic bacterial load and preneoplastic lesions, including clear and tigroid cell foci of cellular alteration, were correlated with lobular hepatitis severity. No extrahepatic surrogate disease marker reliably predicted individual hepatitis grade. In conclusion, gender and bacterial exposure timing are key determinants of H. hepaticus disease outcomes. Intrahepatic inflammation is driven by local signals characterized by a vigorous but nonsterilizing immune response. Continued study of chronic hepatitis progression may reveal therapeutic targets to reduce the risk of hepatocellular carcinoma.

Detection of Helicobacter ganmani-like 16S rDNA in pediatric liver tissue

BACKGROUND

To determine the presence of Helicobacter species in the liver biopsy specimens from children with various chronic liver diseases as data in adult literature suggests a possible role of these bacteria in their pathogenesis.

MATERIALS AND METHODS

Paraffin sections of 61 liver biopsies of pediatric patients with miscellaneous diseases and autopsy liver tissue from 10 control subjects with no evidence of preexisting liver disease were examined for the presence of Helicobacter species by a genus-specific seminested polymerase chain reaction (PCR) assay. PCR-products of positive samples were further characterized by denaturing gradient gel electrophoresis (DGGE) and DNA-sequence analysis. Based on those results, a seminested PCR assay for H. ganmani was developed and applied to the samples.

RESULTS

On analysis, 40/61 patient samples were positive in the genus-specific Helicobacter PCR and 4/10 from the control group. The nucleotide sequences of 16S rDNA fragments were 99-100% similar to mainly Helicobacter sp. 'liver' and H. ganmani. PCR-products similar to H. canis and H. bilis were also found. The 16S rDNAs of control specimens showed similarity to Helicobacter sp. 'liver'. In the H. ganmani-specific PCR analysis 19 patients, but none of the controls, were positive.

CONCLUSIONS

Amplified Helicobacter 16S rDNAs were related to Helicobacter sp. 'liver' or H. ganmani in liver biopsy specimens of pediatric patients. The possible significance of Helicobacter species in pediatric liver diseases needs to be evaluated further in prospective studies.

Effect of Helicobacter pylori on HepG2 proteome

AIM: To further explore the pathological effect mechanism of H. pylori on human hepatoma cells, and to analyze the differences on the protein expression in HepG2 induced by H. pylori preliminarily.

METHODS: H. pylori was co-cultured with HepG2 for 6 h. Two-dimensional polyacrylamide gel electrophoresis (2-DE) was used to screen protein patterns of control and H. pylori-treated HepG2 for quantitative and qualitative analyses in protein expression.

RESULTS: 988 94 spots were detected in control HepG2 cells and 996 68 spots were detected in H. pylori-treated HepG2 cells. A match rate 86.4% was achieved. The results also showed that 18 proteins spots displayed quantitative changes in expression after H. pylori treatment (P < 0.05),of which, 10 (M_r/pI: 91 326/6.21, 90 640/6.68, 87 833/5.65, 81 139 /6.55, 63 805/6.24, 60 445/7.38, 47 592/5.28, 46 293/7.21, 43 415/7.64, 21 704/5.66) were enhanced in abundance and 8 (M_r/pI: 70 839/7.02, 56 403/6.58, 44 076/6.86, 43 744/7.21, 42 497/6.64, 37 567/7.17, 22 342/7.49, 21 112/5.63) showed lower expression.

CONCLUSION: There is a significant difference at protein level between control and H. pylori-treated HepG2. These proteins may be involved in the pathological process of H. pylori on HepG2. It suggests that the differential expression analysis of proteomes may be useful to further study of the relation of H. pylori and human liver diseases.