Identification of Helicobacter pylori DNA in human cholesterol gallstones

Investigating the influence of the gut microbiome on cholelithiasis: unveiling insights through sequencing and predictive modeling

BACKGROUND

Cholelithiasis is one of the most common disorders of hepatobiliary system. Gut bacteria may be involved in the process of gallstone formation and are, therefore considered as potential targets for cholelithiasis prediction.

OBJECTIVE

To reveal the correlation between cholelithiasis and gut bacteria.

METHODS

Stool samples were collected from 100 cholelithiasis and 250 healthy individuals from Huzhou Central Hospital; The 16S rRNA of gut bacteria in the stool samples was sequenced using the third-generation Pacbio sequencing platform; Mothur v.1.21.1 was used to analyze the diversity of gut bacteria; Wilcoxon rank-sum test and linear discriminant analysis of effect sizes (LEfSe) were used to analyze differences in gut bacteria between patients suffering from cholelithiasis and healthy individuals; Chord diagram and Plot-related heat maps were used to analyze the correlation between cholelithiasis and gut bacteria; six machine algorithms were used to construct models to predict cholelithiasis.

RESULTS

There were differences in the abundance of gut bacteria between cholelithiasis and healthy individuals, but there were no differences in their community diversity. Increased abundance of Costridia, Escherichia flexneri, and Klebsiella pneumonae were found in cholelithiasis, while Bacteroidia, Phocaeicola, and Phocaeicola vulgatus were more abundant in healthy individuals. The top four bacteria that were most closely associated with cholelithiasis were Escherichia flexneri, Escherichia dysenteriae, Streptococcus salivarius, and Phocaeicola vulgatus. The cholelithiasis model based on CatBoost algorithm had the best prediction effect (sensitivity: 90.48%, specificity: 88.32%, and AUC: 0.962).

CONCLUSION

The identification of characteristic gut bacteria may provide new predictive targets for gallstone screening. As being screened by the predictive model, people at high risk of cholelithiasis can determine the need for further testing, thus enabling early warning of cholelithiasis.

Helicobacter pylori and Gastrointestinal Cancers: Recent Advances and Controversies

Helicobacter pylori (H pylori), a gastric bacterium, has been extensively studied for its association with gastritis, peptic ulcers, and gastric cancer. However, recent evidence suggests its potential implications beyond the stomach, linking it to other gastrointestinal malignancies, such as esophageal cancer, liver cancer, pancreatic cancer, gallbladder cancer, and colorectal cancer. In light of the expanding research landscape and the increasing interest in exploring H pylori broader role in gastrointestinal tumorigenesis, this comprehensive review aims to elucidate the relationship between H pylori and gastrointestinal tumors. This review encompasses recent epidemiological studies, research progress, and emerging perspectives, providing a comprehensive assessment of the relationship between H pylori and gastrointestinal tumors. The findings highlight the captivating world of H pylori and its intricate involvement in gastrointestinal malignancies.

The potential bidirectional association between Helicobacter pylori infection and gallstone disease in adults: A two-cohort study

BACKGROUND

Previous studies have suggested that Helicobacter pylori (H. pylori) may act as a precipitating factor in gallstone formation, and the potential association between H. pylori infection and gallstone disease (GD) is still unclear and controversial. This study aimed to clarify the potential bidirectional relationship between H. pylori infection and GD.

METHODS

This retrospective cohort study was performed in a population that underwent health checkups at the hospital between 2013 and 2018. H. pylori infection status was evaluated by urea breath test (UBT), and GD was diagnosed via ultrasound. Cox regression and propensity score matching (PSM) were used.

RESULTS

Among 1011 participants without H. pylori infection at baseline, 134 participants were infected with H. pylori. Among 1192 participants without gallstones or cholecystectomy at baseline, 60 participants developed gallstones or cholecystectomy. The hazard ratio (HR) (95% CI) for incident H. pylori infection comparing the GD versus the no GD group was 1.84 (1.19, 2.85). The age- and sex-adjusted HR (95% CI) for incident GD comparing H. pylori-positive subjects to H. pylori-negative subjects was 1.74 (1.01, 2.98). Consistent results were also found with PSM and multivariate analysis.

CONCLUSIONS

This cohort study demonstrated a potential bidirectional association between H. pylori infection and GD, which provides a basis for indicating the risk of GD and implementing the clinical strategies for GD. For the prevention and treatment of GD, H. pylori infection should be carefully considered and evaluated.

Association Between Anti-Helicobacter pylori Antibody Seropositive and De Novo Gallstone Formation After Laparoscopic Sleeve Gastrectomy for Japanese Patients with Severe Obesity

PURPOSE

Patients who have undergone bariatric surgery are at risk for gallstone formation. However, the incidence of gallstone formation after bariatric surgery has not been adequately studied in the Japanese population. We aimed to elucidate the incidence and risk factors for gallstone formation after laparoscopic sleeve gastrectomy (LSG) for Japanese patients with severe obesity.

METHODS

We conducted a retrospective cohort study among patients with severe obesity treated with LSG between April 2017 and June 2020 at two institutions. Patients who had received previous cholecystectomy, had preoperative gallstones, and had received postoperative prophylactic ursodeoxycholic acid were excluded. Body weight, body mass index, and blood data were collected at each follow-up visit before and after the surgery. Follow-up abdominal ultrasonography was performed 6-12 months after surgery, and the incidence of gallstones was calculated. The association between the data and gallstone formation was evaluated.

RESULTS

During the study period, we performed LSG for 98 patients. Of these, 61 cases remained by above conditions and were examined using abdominal ultrasonography over 6 months after surgery. The incidence of gallstones was 23.0% and that of symptomatic gallstones was 3.3%. Anti-Helicobacter pylori antibody seropositive and titer were the only factors that showed significant association with de novo gallstone formation after LSG.

CONCLUSIONS

Anti-Helicobacter pylori antibody seropositive may be associated with de novo gallstone formation after LSG for Japanese patients with severe obesity.

Factors Influencing Gallstone Formation: A Review of the Literature

Gallstone disease is a common pathology of the digestive system with nearly a 10–20% incidence rate among adults. The mainstay of treatment is cholecystectomy, which is commonly associated with physical pain and may also seriously affect a patient’s quality of life. Clinical research suggests that cholelithiasis is closely related to the age, gender, body mass index, and other basic physical characteristics of patients. Clinical research further suggests that the occurrence of cholelithiasis is related to obesity, diabetes, non-alcoholic fatty liver, and other diseases. For this reason, we reviewed the following: genetic factors; excessive liver cholesterol secretion (causing cholesterol supersaturation in gallbladder bile); accelerated growth of cholesterol crystals and solid cholesterol crystals; gallbladder motility impairment; and cardiovascular factors. Herein, we summarize and analyze the causes and mechanisms of cholelithiasis, discuss its correlation with the pathogenesis of related diseases, and discuss possible mechanisms.

Demographic, Chemical, and Helicobacter pylori Positivity Assessment in Different Types of Gallstones and the Bile in a Random Sample of Cholecystectomied Iranian Patients with Cholelithiasis

BACKGROUND

The occurrence of stones in the gallbladder or common bile duct and the symptoms and complications they cause is called gallstone disease. The symptoms of gallstone disease range from mild, nonspecific symptoms to a severe right quadrant abdominal pain. Characteristics of gallstone types in an Iranian population have not been well studied before and there are very limited studies on the demographic pattern of stone types in our country, so this study is one of the first studies on its kind on the epidemiology of gallstone types in Iran. As information on chemical components of the stone will help in the management and prevention of gallstones, in this study, we aimed to do chemical component analysis of gallstones including cholesterol, bilirubin, and calcium. Given the conflicting reports about the relationship between H. pylori infections and gallstone formation, this study aimed to investigate the relationship between H. pylori positivity in the bile specimen of Iranian patients with cholelithiasis and formation and type of stone.

METHODS

This prospective study reviewed a total of 196 patients who underwent cholecystectomy for symptomatic cholelithiasis at Shahid Beheshti Training and Research Hospital affiliated to the Yasuj University of Medical Sciences between September 2015 and May 2018. Chemical analysis of gallstone components performed using the colorimetry method. Microbiological analysis for H. pylori was done using the OnSite H. pylori Ag Rapid Test on the bile sample. For the validation test of bile, the H. pylori Rapid Stool Ag Test on stool was used, and Cohen's Kappa statistical analysis was done next.

RESULTS

There were significant associations between the stone types and age, chemical composition of the stones such as calcium, cholesterol, and bilirubin levels, and also H. pylori positivity and cholesterol and bilirubin levels; however, no significant association was found between the stone types and sex, H. pylori positivity and age, sex, stone types, and calcium level. The main bile and validity tests were matched to the substantial agreement according to Cohen's Kappa analysis. The most common drugs used were proton pump inhibitors, nonsteroidal anti-inflammatory drugs, antihypertensive drugs, and oral contraceptives.

CONCLUSIONS

This study suggested that the chemical composition of the stones could predict the presence of bacteria, there is no correlation between H. pylori and gallstone formation, and some of the drugs could be predisposing factors for gallstones. This work provides an objective basis for further research into gallbladder stone formation; meanwhile, it has great significance in the treatment and prevention of gallbladder stones. Trial registration. The project was found to be in accordance to the ethical principles and the national norms and standards for conducting research in Iran with the approval ID IR.YUMS.REC.1399.147 and date 2020.09.23, and this project is the result of a residency dissertation to obtain the specialty in general surgery, which has been registered with the research project number 960159 in the Vice Chancellor for Research and Technology Development of the Yasuj University of Medical Sciences, Yasuj, Iran, URL: https://ethics.research.ac.ir/EthicsProposalViewEn.php?id=160634.

Gallstone Frequency in Patients with Helicobacter pylori Gastritis

Background: Identification of the causes of gallstone would result in better planning for the prevention of this disease. One of the proposed risk factors for this problem is Helicobacter pylori (H. pylori) infection. Objectives: The purpose of this study was to determine the incidence rate of gallstone in patients with H. pylori gastritis. Methods: This was an observational study performed as a descriptive-comparative cross-sectional survey. We enrolled 169 consecutive patients with H. pylori gastritis admitted to Imam-Hossein Hospital, Tehran, Iran, in 2018, and gallstone frequency in them was determined and compared with other variables. Results: Overall, 14 (8.3%) patients had gallstone, and all the patients had H. pylori gastritis. There was no significant association between gallstone and H. pylori gastritis (P = 0.561). Conclusions: It may be concluded that gallstone frequency in patients with H. pylori gastritis is low, and there is no significant association between these two conditions.

The Relationship between Helicobacter pylori Infection of the Gallbladder and Chronic Cholecystitis and Cholelithiasis: A Systematic Review and Meta-Analysis

Helicobacter pylori (H. pylori) is proved to be the main pathogenic agent of various diseases, including chronic gastritis, gastric ulcer, duodenal ulcer, and gastric cancer. In addition, chronic cholecystitis and cholelithiasis are common worldwide, which are supposed to increase the total mortality of patients. Epidemiologic evidence on the relationship between H. pylori infection of the gallbladder and chronic cholecystitis/cholelithiasis still remains unclear. We conducted a systematic review and meta-analysis of overall studies to investigate the relationship between H. pylori infection of the gallbladder and chronic cholecystitis/cholelithiasis. Two researchers searched PubMed, Embase, and Cochrane Library databases to obtain all related and eligible studies published before July 2020. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated by the random-effects model. Subgroup analysis, heterogeneity, publication bias, and sensitivity analysis were also conducted. Twenty studies were included in the meta-analysis, involving 1735 participants and 1197 patients with chronic cholecystitis/cholelithiasis. Helicobacter species infection of the gallbladder was positively correlated with increased risk of chronic cholecystitis and cholelithiasis, especially H. pylori (OR = 3.05; 95% CI, 1.81-5.14; I 2 = 23.5%). Besides, country-based subgroup analysis also showed a positive correlation between the gallbladder H. pylori positivity and chronic cholecystitis/cholelithiasis risk. For Asian and non-Asian country studies, the ORs were 4.30 (95% CI, 1.76-10.50; I 2 = 37.4%) and 2.13 (95% CI, 1.23-3.70; I 2 = 0.0%), respectively. The association was more obvious using the bile sample and urease gene primer. In conclusion, this meta-analysis provided evidence that there is a positive correlation between H. pylori infection in the gallbladder and increased risk of chronic cholecystitis and cholelithiasis.

Helicobacter pylori is not a contributing factor in gallbladder polyps or gallstones: a case-control matching study of Chinese individuals

OBJECTIVE

To investigate the relationship between Helicobacter pylori (H. pylori) infection and gallstones or gallbladder polyps.

METHODS

This retrospective analysis included 27,881 individuals who underwent health examinations that included a H. pylori test and an abdominal ultrasound scan. Patients were divided into four groups: gallbladder polyp (P group), gallstone (S group), gallstone and gallbladder polyp (SP group), and no gallbladder disease (N group). Case-control matching was used to select the participants in the control group.

RESULTS

The mean ages of participants in the P, S, and SP groups were all significantly higher than the mean age of participants in the N group. The proportions of participants with each type of body mass index significantly differed between the N and P groups, and between the N and S groups. In total 45.7% of participants exhibited H. pylori infection. After case-control matching, the proportion of participants with H. pylori infection did not significantly differ according to the presence or absence of gallbladder polyps. Similar results were observed regarding gallstones, as well as gallstones and gallbladder polyps.

CONCLUSION

H. pylori infection might not be related to gallbladder polyps or gallstones.

Gallstone Disease and Microbiome

Gallstone disease (GSD) has, for many years, remained a high-cost, socially significant public health problem. Over the past decade, a number of studies have been carried out—both in humans and in animal models—confirming the role of the microbiota in various sections of the gastrointestinal tract as a new link in the etiopathogenesis of GSD. The microbiome of bile correlates with the bacterial composition of saliva, and the microbiome of the biliary tract has a high similarity with the microbiota of the duodenum. Pathogenic microflora of the oral cavity, through mechanisms of immunomodulation, can affect the motility of the gallbladder and the expression of mucin genes (MUC1,Muc3, MUC4), and represent one of the promoters of stone formation in the gallbladder. The presence of H. pylori infection contributes to the formation of gallstones and affects the occurrence of complications of GSD, including acute and chronic cholecystitis, cholangitis, pancreatitis. Intestinal bacteria (Clostridium, Bifidobacterium, Peptostreptococcus, Bacteroides, Eubacterium, and Escherichia coli) participating in the oxidation and epimerization of bile acids can disrupt enterohepatic circulation and lead to the formation of gallstones. At the same time, cholecystectomy due to GSD leads to the further transformation of the composition of the microbiota in various parts of the gastrointestinal tract, increasing the risk of developing stomach cancer and colorectal cancer. Further research is required to determine the possibility of using the evaluation of the composition of the microbiota of the gastrointestinal and biliary tracts as an early diagnostic marker of various gastroenterological diseases.

Role of the biliary microbiome in gallstone disease

Gallstone disease is caused by multiple pathogenic factors and is common worldwide. Most studies have focused on the significance of the biliary microbiome in gallstone pathogenesis. Areas covered: In this study, the epidemiology of gallstone diseases and the existence, composition, origin, and mechanisms of the biliary microbiota were reviewed. Mechanisms involved in promoting the formation of different types of gallstones were also emphasized. The antibiotic susceptibility of the biliary microbiota is briefly discussed because it may guide clinical strategies. Expert commentary: The biliary microbiome facilitates the formation of brown pigment stones. Although glycoprotein (mucin) may be pivotal for many promoting substances to coagulate and integrate relevant components, new mechanisms involving prostaglandins, oxysterols, oxygen free radicals, and lipopolysaccharides have been discovered. Furthermore, specific bacterial species such as Helicobacter and Salmonella are involved in the pathogenesis of cholesterol gallstones. Recently, metabolomics of the biliary microbiome has been used to determine the detailed mechanisms that promote gallstone formation. Previously, the bacterial effects involved in the pathogenesis of brown pigment stones have not been analyzed in detail. Whether the administration of antibiotics is related to prophylaxis for gallstone formation and gallstone-associated infections remains unclear.

Helicobacter Pylori infection of the gallbladder and the risk of chronic cholecystitis and cholelithiasis: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is coexisted with various diseases, including chronic gastritis, ulcer, and gastric cancer. Besides, chronic cholecystitis and cholelithiasis are extremely widespread over the world, which are considered as high health-care cost burdens of digestive diseases. Epidemiologic evidence on Helicobacter pylori infection in gallbladder increasing the risk of biliary diseases has been contradictory.

AIM

Conduct a meta-analysis of overall studies and investigate an association between Helicobacter pylori infection of the gallbladder with chronic cholecystitis/cholelithiasis.

METHODS

We used PubMed, EMBASE, and Cochrane library databases to identify all published studies before August 2017. Pooled odds ratios (OR) and corresponding 95% confidence intervals (CIs) were obtained using the random effects model. Heterogeneity, sensitivity, and stratified analyses were also performed.

RESULTS

Eighteen studies involving 1544 participants and 1061 biliary cases with chronic cholecystitis/cholelithiasis were included. Helicobacter pylori infection of the gallbladder was significantly associated with an increased risk of chronic cholecystitis and cholecystitis (OR = 3.022; 95% CI, 1.897-4.815; I²  = 20.1%). In addition, country-based subgroup analysis also showed a positive association between Helicobacter pylori positivity and chronic cholecystitis/cholelithiasis risk. The ORs (95% CIs) for Asian and non-Asian region studies were 3.75 (1.83-7.71) and 2.25 (1.29-3.89), respectively.

CONCLUSION

This meta-analysis suggests that infection of the gallbladder with Helicobacter pylori is closely related to an increased risk of chronic cholecystitis and cholelithiasis.

Is There a Correlation between Helicobacter Pylori and Enterohepatic Helicobacter Species and Gallstone Cholecystitis?

BACKGROUND

Cholecystitis is a common surgical condition. Recently, several authors have reported that DNA of bile tolerant Helicobacter spp. has been found in the human bile colonizing the biliary tract. The aim of this study was to evaluate the association between the presence of Helicobacter spp. and gallstone cholecystitis.

METHODS

In this case-control study, gallstones, bile, and gallbladder mucosa were collected from 25 patients without gallstone disease, 24 with acute cholecystitis, and 28 with chronic cholecystitis. The presence of Helicobacter pylori (H. pylori), Helicobacter bilis (H. bilis), Helicobacter hepaticus (H. hepaticus) , and Helicobacter pullorum (H. pullorum) were investigated by polymerase chain reaction (PCR) using species-specific primers.

RESULTS

In this study, 77 subjects with acute and chronic cholecystitis and control groups with a mean age of 46.85 ± 14.53 years, including 58 (67.25%) women and 19 (32.75%) men were included. DNA of 10 Helicobacter spp. was detected in the bile of the patients with cholecystitis including eight H. pylori and two H. bilis. However, we could not detect H. hepaticus and H. pullorum DNA in the samples. Moreover, there was an association between H. pylori and acute cholecystitis (p = 0.048), which was found to be stronger in 31-40-year-olds group (p = 0.003).

CONCLUSION

We found an association between the presence of H. pylori DNA and acute gallstone cholecystitis. There is not statistically significant correlation between three enterohepatic Helicobacter spp. ( H. bilis, H. hepaticus , and H. pullorum) and cholelithiasis. Given the low sample size of the patients, more studies are required to clear the clinical role of Helicobacter spp. in the gallstone disease and cholecystitis.

Diagnosis of Genus Helicobacter through a hemi-nested PCR assay of 16S rRNA

The present study aimed to establish a genus-specific PCR-based assay to detect helicobacters using 16S rRNA gene as the target template. We designed the hemi-nested primers based on sequences of 16S rRNA gene of 34 types of Helicobacter species. The inclusivity, sensitivity, and specificity of the PCR assay using these primers were examined in three different models, comprising feces simulated samples, BLAB/c mice infection model and clinic patients samples. The detection sensitivity of Helicobacter pylori, Helicobacter hepaticus and Helicobacter bilis strains from feces simulated samples was all 102 CFU/ml. We successfully detected H. hepaticus and H. bilis in the liver, cecum and feces of experimentally infected mice. H. pylori was successfully detected in the feces samples from 3 patients infected with H. pylori while not in the feces samples from 3 healthy human. However, the C97/C05–C97/C98 PCR assay detected H. pylori in the 2 positive samples. Due to the PCR assay’s excellent inclusivity, high sensitivity and specificity it may be used to detect the presence of Helicobacters.

Gut microbiota dysbiosis and bacterial community assembly associated with cholesterol gallstones in large-scale study

Background

Elucidating gut microbiota among gallstone patients as well as the complex bacterial colonization of cholesterol gallstones may help in both the prediction and subsequent lowered risk of cholelithiasis. To this end, we studied the composition of bacterial communities of gut, bile, and gallstones from 29 gallstone patients as well as the gut of 38 normal individuals, examining and analyzing some 299, 217 bacterial 16S rRNA gene sequences from 120 samples.

Results

First, as compared with normal individuals, in gallstone patients there were significant (P < 0.001) increases of gut bacterial phylum Proteobacteria and decreases of three gut bacterial genera, Faecalibacterium, Lachnospira, and Roseburia. Second, about 70% of gut bacterial operational taxonomic units (OTUs) from gallstone patients were detectable in the biliary tract and bacteria diversity of biliary tract was significantly (P < 0.001) higher than that of gut. Third, analysis of the biliary tract core microbiome (represented by 106 bacteria OTUs) among gallstone patients showed that 33.96% (36/106) of constituents can be matched to known bacterial species (15 of which have publicly available genomes). A genome-wide search of MDR, BSH, bG, and phL genes purpotedly associated with the formation of cholesterol gallstones showed that all 15 species with known genomes (e.g., Propionibacterium acnes, Bacteroides vulgates, and Pseudomonas putida) contained at least contained one of the four genes. This finding could potentially provide underlying information needed to explain the association between biliary tract microbiota and the formation of cholesterol gallstones.

Conclusions

To the best of our knowledge, this is the first study to discover gut microbiota dysbiosis among gallstone patients, the presence of which may be a key contributor to the complex bacteria community assembly linked with the presence of cholesterol gallstones. Likewise, this study also provides the first large-scale glimpse of biliary tract microbiota potentially associated with cholesterol gallstones. Such a characterization of the biliary tract core microbiome has potentially important biological and medical implications regarding the role of bacteria in the formation cholesterol gallstones.

Gallstones and Concomitant Gastric Helicobacter pylori Infection

Background. The association of gallstones with Helicobacter pylori has been investigated but not clearly demonstrated. In this study, the presence of H. pylori in the gallbladder mucosa of patients with symptomatic gallstones was investigated. Method. Ninety-four consecutive patients with symptomatic gallstone disease were enrolled for the study. Gastroscopy and gastric H. pylori urease test were done before cholecystectomy to all patients who accepted. After cholecystectomy, the gallbladder tissue was investigated in terms of H. pylori by urease test, Giemsa, and immunohistochemical stain. Results. Overall 35 patients (37%) gallbladder mucosa tested positive for H. pylori with any of the three tests. Correlation of the three tests Giemsa, IHC, and rapid urease test was significant (r_s: 0590, P > 0.001). Rapid urease test was positive in the gastric mucosa in 47 (58.7%) patients, and it was positive in the gallbladder mucosa in 21 patients (22%). In 15 patients both gastric and gallbladder tested positive with the urease test. There was significant correlation of rapid urease test in both of gallbladder and gastric mucosa (P = 0.0001). Conclusion. Study demonstrates the presence of H. pylori in the gallbladders of 37% of patients with symptomatic gallstones.

PCR in Helicobacter spp. diagnostic in extragastric malignancies of digestive system

Recognition of Helicobacter pylori as an important factor in genesis of gastric adenocarcinoma lead to a large number of studies concerning potential role of Helicobacter spp. in the development of extragastric digestive malignancies. The serological studies indicated possible localizations in the digestive system being from interest in enlightening Helicobacter spp. carcinogenic potential. The PCR obtruded itself as a gold standard in proving existence of actual correlation. In this review, the authors have examined studies conducted in the last 10 years examining Helicobacter spp. correlation with extragastric digestive carcinogenesis. Studies have been observed in four groups referring to hepatic carcinoma, bile duct cancer, pancreatic cancer, and colon cancer. The results of these researches have shown that there is a strong correlation between Helicobacter spp. colonization and primary liver tumors as well as bile duct tumors, whereas conclusions made by authors examining pancreatic cancer are contradictory and demands further investigation. No correlation between Helicobacter spp. and colon cancer have been proven. The PCR subtype most widely used in studies included in this review was nested PCR, whereas genes targeted most frequently for amplification are 16S rDNA of Helicobacter spp. and UreA gene or cagA gene of H. pylori. During the last 10 years PCR has proven itself as a sovereign method for Helicobacter spp. diagnostic in extragastric organs in the digestive system. Knowledge and experiences obtained in this domain could be encouraging for researchers in analogous fields of interest.

[Histopathological study of the presence of Helicobacter pylori-type bacteria in surgical specimens from patients with chronic cholecystitis]

INTRODUCTION

Helicobacter species have recently been found to be associated with some diseases of the biliary tree but this relationship remains unclear and further studies are required. The aim of this study was to determine the presence of H. pylori-type bacteria in patients with a diagnosis of chronic cholecystitis through histopathological study of surgical gallbladder specimens.

MATERIALS AND METHODS

Surgical gallbladder specimens from patients with a diagnosis of chronic cholecystitis were examined histopathologically. The macroscopic characteristics of the specimens were identified. Histopathological slices were stained with hematoxylin-eosin and Giemsa.

RESULTS

Of the 68 patients who underwent cholecystectomy, 56 (81%) were women and 12 (19%) were men. The mean age was 39.56+11.94 years. H. pylori-type bacteria were found in 6%.

CONCLUSIONS

The results of this study do not allow us to conclude that the presence of H. pylori-type bacteria is a major factor in the etiology and/or pathogenesis of chronic cholecystitis. In patients with chronic cholecystitis undergoing cholecystectomy included in the present study, the etiology of the disease may be more closely linked with the presence of gallstones.

Helicobacter species and common gut bacterial DNA in gallbladder with cholecystitis

AIM: To analyze the association between Helicobacter spp. and some common gut bacteria in patients with cholecystitis.

METHODS: A nested-polymerase chain reaction (PCR), specific to 16S rRNA of Helicobacter spp. was performed on paraffin-embedded gallbladder samples of 100 cholecystitis and 102 control cases. The samples were also analyzed for some common gut bacteria by PCR. Positive samples were sequenced for species identification.

RESULTS: Helicobacter DNA was found in seven out of 100 cases of acute and chronic cholecystitis. Sequence analysis displayed Helicobacter pullorum (H. pullorum) in six cases and Helicobacter pylori in one; H. pullorum was only found in cases with metaplasia. Control samples were negative for Helicobacter spp. and some common gut bacteria. There was a significant difference (P = 0.007) between cholecystitis and control samples for Helicobacter DNA.

CONCLUSION: A possible relationship was detected between Helicobacter DNA and cholecystitis. Further serological and immunohistochemical studies are needed to support these data.

Identification of Helicobacter pylori in Gallstone, Bile, and Other Hepatobiliary Tissues of Patients with Cholecystitis

BACKGROUND/AIMS

Bacterial infection is accepted as a precipitating factor in cholesterol gallstone formation, and recent studies have revealed the presence of Helicobacter species in the hepatobiliary system. We utilized the polymerase chain reaction (PCR) to establish the presence of bacterial DNA, including from Helicobacter species, in gallstones, bile juice, and gallbladder mucosa from patients with gallstones.

METHODS

At cholecystectomy, 58 gallstones, 48 bile samples, and 46 gallbladder mucosa specimens were obtained and subjected to nested PCR using specific 16S rRNA primers of H. pylori and other bacteria. Bacterial species were identified by DNA sequencing analysis. Bacterial 16S rRNA was detected in 25 out of 36 mixed-cholesterol gallstones, 1 out of 10 pure-cholesterol gallstones, and 9 out of 12 pigmented stones. Furthermore, 16S rDNA sequencing identified Escherichia coli, Pseudomonas, Citrobacter, Klebsiella, and Helicobacter species.

RESULTS

Helicobacter DNA was detected in 4 out of 58 gallstones, 6 out of 48 bile samples, and 5 out of 46 gallbladder specimens. Direct sequencing of Helicobacter amplicons confirmed strains of H. pylori in all four gallstones, five out of six bile samples, and three out of five gallbladder specimens. Almost all mixed-cholesterol gallstones appear to harbor bacterial DNA, predominantly E. coli.

CONCLUSIONS

H. pylori was also found in the biliary system, suggesting that these bacteria are of etiological importance in gallstone formation.

Identification of Helicobacter spp. in bile and gallbladder tissue of patients with symptomatic gallbladder disease

BACKGROUND

This experimental study was designed to determine if Helicobacter spp. contribute to benign gallbladder disease using polymerase chain reaction (PCR) methods.

METHODS

Patients with benign gallbladder disease scheduled for elective cholecystectomy at New York University Langone Medical Center were recruited from February to May 2008. Bile, gallbladder tissue and gallstones were collected. DNA was isolated from these specimens and amplified via PCR using C97F and C98R primers specific for Helicobacter spp. Appropriate positive and negative controls were used. Products were analysed with agarose gel electrophoresis, sequenced and results aligned using sequencher. Plasma was collected for detection of anti-Helicobacter pylori antibodies via enzyme-linked immunosorbent assay.

RESULTS

Of 36 patients, 12 patients' bile and/or tissue were positive for Helicobacter spp. by PCR. Species were most homologous with H. pylori, although other Helicobacter spp. were suggested. Six of 12 patients demonstrated anti-Helicobacter antibodies in plasma, suggesting that the remaining six might have demonstrated other species besides H. pylori. Four of six plasma samples with anti-Helicobacter antibodies were anti-CagA (cytotoxin associated gene) negative.

DISCUSSION

Helicobacter spp. can be detected in bile and gallbladder tissue of patients with benign gallbladder disease. The contribution of these bacteria to the pathophysiology of gallbladder disease and gallstone formation requires further study.

Roles of infection, inflammation, and the immune system in cholesterol gallstone formation

Cholesterol gallstone formation is a complex process mediated by genetic and environmental factors. Until recently, the role of the immune system in the pathogenesis of cholesterol gallstones was not considered a valid topic of research interest. This review collates and interprets an extensive body of basic literature, some of which is not customarily considered to be related to cholelithogenesis, describing the multiple facets of the immune system that appear to be involved in cholesterol cholelithogenesis. A thorough understanding of the immune interactions with biliary lipids and cholecystocytes should modify current views of the pathogenesis of cholesterol gallstones, promote further research on the pathways involved, and lead to novel diagnostic tools, treatments, and preventive measures.

Helicobacter species in cancers of the gallbladder and extrahepatic biliary tract

Helicobacter species have been found in human bile and biliary tract (BT) tissue and are suspected to cause BT diseases, including gallbladder and extrahepatic cancers, collectively referred to in this work as BT cancers. We conducted a literature review of the epidemiological evidence linking the presence of Helicobacter species in bile or BT biopsies to BT cancers and benign diseases. Reports showed great variability with respect to study methods. Nine studies of BT cancers were identified, all with 30 or fewer BT cancers; eight included cancer-free control subjects and used polymerase chain reaction (PCR) as a means of Helicobacter species detection. In four of these studies, Helicobacter species were detected in patients with BT cancer significantly more frequently than in controls, at least when controls without BT diseases were used. In two studies, no Helicobacter species were detected in either cases or controls. Helicobacter species were also often detected in benign BT diseases such as gallstone disease or chronic cholecystitis. As our current knowledge relies on a few small studies that showed substantial differences, larger studies and more standardised protocols for detecting DNA and antibodies against Helicobacter species are needed to investigate a potential association with BT cancer.

Concurrent genotyping of Helicobacter pylori virulence genes and human cytokine SNP sites using whole genome amplified DNA derived from minute amounts of gastric biopsy specimen DNA

Background

Bacterial and cellular genotyping is becoming increasingly important in the diagnosis of infectious diseases. However, difficulties in obtaining sufficient amount of bacterial and cellular DNA extracted from the same human biopsy specimens is often a limiting factor. In this study, total DNA (host and bacterial DNA) was isolated from minute amounts of gastric biopsy specimens and amplified by means of whole genome amplification using the multiple displacement amplification (MDA) technique. Subsequently, MDA-DNA was used for concurrent Helicobacter pylori and human host cellular DNA genotyping analysis using PCR-based methods.

Results

Total DNA was isolated from gastric biopsy specimens of 12 subjects with gastritis and 16 control subjects having a normal mucosa. The DNA was amplified using a multiple displacement amplification (MDA) kit. Next, concurrent genotyping was performed using H. pylori-specific virulence gene PCR amplification assays, pyrosequencing of bacterial 16S rDNA and PCR characterisation of various host genes. This includes Interleukin 1-beta (IL1B) and Interferon-gamma receptor (IFNGR1) SNP analysis, and Interleukin-1 receptor antagonist (IL1RN) variable tandem repeats (VNTR) in intron 2. Finally, regions of the vacA-gene were PCR amplified using M13-sequence tagged primers which allowed for direct DNA sequencing, omitting cloning of PCR amplicons. H. pylori specific multiplex PCR assays revealed the presence of H. pylori cagA and vacA genotypic variations in 11 of 12 gastritis biopsy specimens. Using pyrosequencing, 16S rDNA variable V3 region signatures of H. pylori were found in 11 of 12 individuals with gastritis, but in none of the control subjects. Similarly, IL1B and IFNGR1-SNP and IL1RN-VNTR patterns could be established in all individuals. Furthermore, sequencing of M13-sequence tagged vacA-PCR amplicons revealed the presence of highly diverse H. pylori vacA-s/i/m regions.

Conclusion

The PCR-based molecular typing methods applied, using MDA-amplified DNA derived from small amounts of gastric biopsy specimens, enabled a rapid and concurrent molecular analysis of bacterial and host genes in the same biopsy specimen. The principles and technologies used in this study could also be applied to any situation in which human host and microbial genes of interest in microbial-host interactions would need to be sequenced.

Primary biliary cirrhosis, similar to that in human beings, in a male C57BL/6 mouse infected with Helicobacter pylori

We report a case of primary biliary cirrhosis (PBC) that occurred in a 24-month-old male C57BL/6 mouse infected with Helicobacter pylori (H. pylori). Microscopically, the portal tract in the liver showed nonsuppurative destructive cholangitis with variable cytologic distortion of the epithelial cells and peribiliary lymphoplasmacytic infiltration. Immunohistochemistry using alpha-smooth muscle actin demonstrated fibrous bands associating with the wall of vasculature. The level of serum antivacuolating toxin IgG in this mouse showed the highest value (optical density=2.1470) of the H. pylori-infected group (n=13) (optical density=1.7168+/-0.1759, mean+/-SD). Spontaneously developed PBC-like lesions in C57BL/6 mice have been reported by several authors. However, this case strikingly resembles human PBC with its characterized histological features. Therefore, we propose that the increase in vacuolating toxin caused by H. pylori infection may be related to the development of PBC by molecular mimicry.

Helicobacter pylori in areas of gastric metaplasia in the gallbladder and isolation of H. pylori DNA from gallstones

AIMS

To assess if the areas of gastric metaplasia in the gallbladder are colonised by Helicobacter pylori and to conduct a molecular study of gallstones for presence of H. pylori DNA.

METHODS

Sections from 111 gallbladders with evidence of gastric metaplasia on H&E and Alcian blue-periodic acid-Schiff (pH 2.5) stain were stained with Loeffler's methylene blue and Warthin Starry stain for demonstration of H. pylori. Presence of H. pylori was confirmed by immunohistochemistry. Formalin fixed mucosal tissues and gallstones from 11 cases showing heavy colonisation were subjected to molecular analysis.

RESULTS

Helicobacter pylori was present in 50 of 111 (45%) sections with gastric metaplasia. Areas adjacent to gastric metaplasia in gallbladder showed acute inflammation (6%) and lymphoid follicle formation in 58% of cases with H. pylori that were significantly higher than those seen in sections without H. pylori. In molecular study, 8 of 11 gallstones showed 16S rDNA. Amplification of material from one stone showed positivity for atpA, efp, mutY, ppa, trpC, UreI and vacA genes. Phylogenetic affiliation study of the isolates indicated that H. pylori sequence from the gallstones clustered with Indian strains of H. pylori. No considerable difference was observed in phylogenetic affiliations of eight stones studied.

CONCLUSION

H. pylori colonises areas of gastric metaplasia in gallbladder producing histological changes similar to those seen in gastric mucosa. Isolation of H. pylori DNA from gallstones further support its presence in the gallbladder.

H pylori exist in the gallbladder mucosa of patients with chronic cholecystitis

AIM: To study whether H pylori locate in the gallbladder mucosa of patients with chronic cholecystitis.

METHODS: Using Warthy-Starry (W-S) silver stain and immunohistochemistry stain with anti-H pylori antibodies, we screened paraffin specimens in 524 cases of cholecystitis. H pylori urease gene A (HPUA) and H pylori urease gene B (HPUB) were analyzed by polymerase chain reaction (PCR) in the fresh tissue specimens from 81 cases of cholecystitis.

RESULTS: H pylori-like bacteria were found in 13.55% of the gallbladders of the cholecystitis patients using W-S stain. Meanwhile, bacteria positive for H pylori antibodies were also found in 7.1% of the gallbladders of patients with cholecystitis by immunohistochemistry. Of 81 gallbladders, 11 were positive for both HPUA and HPUB, 4 were positive for HPUA only and 7 were positive for HPUB only.

CONCLUSION: H pylori exist in the gallbladders of patients with chronic cholecystitis.

Low prevalence of Helicobacteraceae in gall-stone disease and gall-bladder carcinoma in the German population

Colonisation of the hepatobiliary system with bile-resistant Helicobacter spp. has been proposed as a novel risk-factor in the pathogenesis of gall-bladder carcinoma (GBC). There are reports that biliary Helicobacter colonisation is frequent in countries with a high incidence of gall-bladder carcinoma. However, the prevalence of Helicobacteraceae in the gall-bladders of patients with GBC in Germany, a region with a low incidence of GBC, is unknown. Therefore, gall-bladder tissue from 99 patients who had undergone cholecystectomy was tested, including 57 cases of gall-stone disease (GSD), 20 cases of GBC, and 22 control patients. The presence of Helicobacter spp. was investigated by culture, immunohistochemistry and a group-specific PCR targeting the 16S rRNA gene of all currently known Helicobacteraceae. Of the 99 cases investigated, only one patient with GSD was PCR-positive for Helicobacteraceae. For this individual, sequence analysis of the 16S rRNA gene showed that it had homology closest to the 16S rRNA sequence of Helicobacter ganmani. Helicobacteraceae were not detected by culture or immunohistochemistry. The low prevalence of Helicobacteraceae in the gall-bladders investigated suggests that Helicobacteraceae do not play a predominant role in the pathogenesis of GSD and GBC in the German population. The low prevalence could be a possible explanation for a relatively low incidence of GBC in the German population, despite the fact that GSD, the major risk-factor for GBC, is highly prevalent.

H pylori are associated with chronic cholecystitis

AIM: To study whether H pylori are associated with chronic cholecystitis.

METHODS: The subjects were divided into three groups: H pylori-infected cholecystitis group, H pylori-negative cholecystitis group and control group. Pathologic changes of the gallbladder were observed by optic and electronic microscopes and the levels of interleukin-1, 6 and 8 (IL-1, 6 and 8) were detected by radioimmunoassay.

RESULTS: Histological evidence of chronic cholecystitis including degeneration, necrosis, inflammatory cell infiltration, were found in the region where H pylori colonized. Levels of IL-1, 6 and 8 in gallbladder mucosa homogenates were significantly higher in H pylori-infected cholecystitis group than those in H pylori-negative cholecystitis group and control group.

CONCLUSION: H pylori infection may be related to cholecystitis.

Helicobacter pylori infection causes gastric cancer? A review of the epidemiological, meta-analytic, and experimental evidence

Since the discovery of Campylobacter-like organisms Helicobacter pylori (H pylori) more than two decades ago the possibility of a relationship with gastric cancer has been postulated, tested and supposedly proven. There have been numerous human studies of various designs from many countries around the world. Several meta-analyses have been published and more recently a small number of experimental animal studies were reported looking at the association between H pylori infection and gastric cancer. Over the years, the human epidemiological studies have produced conflicting results; the meta-analyses have as one would expect produced similar pooled estimates; while the early experimental animal studies require replication. The exact mechanisms by which H pylori might cause gastric cancer are still under investigation and remain to be elucidated.

Multiple displacement amplification of isolated DNA from human gallstones: molecular identification of Helicobacter DNA by means of 16S rDNA-based pyrosequencing analysis

BACKGROUND

Molecular typing of Helicobacter spp. in clinical biopsy specimens has become increasingly important. By means of nested polymerase chain reaction (PCR) amplification and Southern blot analysis of the PCR amplicons, we have shown that Helicobacter spp. DNA is present in human gallstones. In this study we have investigated the possibility of using multiple displacement amplification (MDA) of isolated gallstone DNA and pyrosequencing analysis for the molecular identification of Helicobacter spp.

MATERIALS AND METHODS

DNA isolated from the nucleus of 33 human gallstones and one control strain were used in a MDA assay. Subsequently, pyrosequencing analysis was performed either directly on MDA-DNA using primers flanking the Helicobacter spp. 16S rDNA variable V3 region or on PCR amplicons derived from broad-range primers flanking the 16S rDNA variable V3, V4, and V9 regions.

RESULTS

Pyrosequencing analysis of 16S rDNA derived from MDA-DNA revealed that Helicobacter spp.-like DNA was present in 25 of 33 (approximately 76%) gallstones. Using an H. pylori-specific Southern blot analysis, Helicobacter spp.-like DNA was present in 20 of 33 [approximately 61%] of the gallstones. Using MDA-DNA directly in pyrosequencing analysis, Helicobacter spp.-like DNA was present in 13 of 33 [approximately 39%] gallstones.

CONCLUSIONS

We conclude that multiple displacement amplification combined with pyrosequencing enables a rapid and accurate molecular typing of Helicobacter spp. from small and precious biopsy specimens.

Identification of cholelithogenic enterohepatic helicobacter species and their role in murine cholesterol gallstone formation

BACKGROUND & AIMS

Helicobacter spp are common inhabitants of the hepatobiliary and gastrointestinal tracts of humans and animals and cause a variety of well-described diseases. Recent epidemiologic results suggest a possible association between enterohepatic Helicobacter spp and cholesterol cholelithiasis, chronic cholecystitis, and gallbladder cancer. To test this, we prospectively investigated the effects of Helicobacter spp infection in cholesterol gallstone pathogenesis in the highly susceptible C57L/J mouse model.

METHODS

Helicobacter spp-free adult male C57L mice were infected with several different enterohepatic Helicobacter spp or left uninfected and fed either a lithogenic diet or standard mouse chow for 8 and 18 weeks. At the conclusion of the study, bile was examined microscopically and diagnostic culture and polymerase chain reaction were performed.

RESULTS

Mice infected with Helicobacter bilis or coinfected with Helicobacter hepaticus and Helicobacter rodentium and fed a lithogenic diet developed cholesterol gallstones at 80% prevalence by 8 weeks compared with approximately 10% in uninfected controls. Monoinfections with H hepaticus , Helicobacter cinaedi , and H rodentium gave a cholesterol gallstone prevalence of 40%, 30%, and 20%, respectively; the latter 2 groups did not differ significantly from uninfected animals. Neither infected nor uninfected mice fed a chow diet developed cholesterol gallstones.

CONCLUSIONS

These findings, along with prior epidemiologic studies, suggest that Helicobacter spp play a major role in the pathophysiology of cholesterol gallstone formation in mice and perhaps humans.

Helicobacter pylori and other Helicobacter species in gallbladder and liver of patients with chronic cholecystitis detected by immunological and molecular methods

OBJECTIVE

Despite several recent reports on the detection of Helicobacter DNA in human bile, there are still uncertainties concerning the correlation of these findings with biliary tract and liver diseases.

MATERIAL AND METHODS

Using molecular methods and immunohistochemistry (IHC), we investigated gallbladder and liver biopsy specimens from 22 adult Ukrainian patients with chronic cholecystitis for the presence of Helicobacter species. Patient sera were collected and tested for antibody reactivity to antigens of three Helicobacter spp. Detection of Helicobacter DNA was performed using a Helicobacter genus-specific 16S rDNA PCR. Amplified DNA was identified by PCR-denaturating gradient gel electrophoresis (DGGE) and DNA sequencing. Tissue sections of gallbladder and liver were examined by IHC with antibodies specific to H. pylori, the CagA and VacA cytotoxins of H. pylori, H. hepaticus and to Campylobacter jejuni. Patient sera were analysed by immunoblot for IgG antibodies to soluble surface proteins of H. pylori, H. hepaticus and H. bilis.

RESULTS

Helicobacter DNA was found in 16/22 (73%) of the gallbladder samples and in 11/22 (50%) of the liver samples. IHC showed the presence of the H. pylori specific cytotoxins CagA and VacA inside the gallbladder epithelial cells without co-localization of H. pylori at the epithelial lining. Immunoblot analysis of the patient sera did not show any correlation between the presence of Helicobacter DNA and IgG antibody responses.

CONCLUSIONS

The high prevalence of Helicobacter DNA and the positive findings by IHC in gallbladder and liver raise questions concerning an infectious role of Helicobacter in patients with chronic cholecystitis.

Extensive homology between the major immunodominant mitochondrial antigen in primary biliary cirrhosis and Helicobacter pylori does not lead to immunological cross-reactivity

BACKGROUND

Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic disease characterized by the presence of antibodies directed predominantly against the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2). What provokes tolerance breakdown in PBC remains to be established, though there is evidence to indicate that microbes may induce anti-mitochondrial antibodies (AMA) through a mechanism of molecular mimicry.

METHODS

Having found that urease beta (UREB)(22-36) antigen of Helicobacter pylori (HELPY) shares extensive (87%) similarity with PDC-E2(212-226), the major mitochondrial autoepitope, it was hypothesized that this would also lead to cross-reactivity. The UREB/PDC-E2 mimics were thus constructed and tested by ELISA in 112 PBC patients and 114 controls.

RESULTS

Reactivity to PDC-E2(212-226) was found in 104 patients but to UREB(22-36) in only 2. In these two patients, the double reactivity was not cross-reactive. The lack of surface antibody accessibility to UREB(22-36), as demonstrated through three-dimensional model prediction analysis, may explain this unexpected finding. There was some speculation on whether HELPY UREB(22-36) might act as a cross-reactive CD4 T-cell epitope. All seven PBC patients, tested in a standard proliferation assay against PDC-E2(212-226), gave a positive response. All seven were unresponsive to HELPY UREB(22-36). The pattern of reactivity to HELPY antigens by immunoblot was similar between anti-PDC-E2-positive and negative PBC cases, as well as between PBC patients and controls.

CONCLUSION

Contrary to common belief, extensive sequence homology (molecular mimicry) between self and microbe does not necessarily result in cross-reactivity. It is therefore likely that, when present, cross-reactivity between self and microbes is of biological importance.

Relationship between Helicobacter pylori and chronic cholecystitis

AIM: To study whether Helicobacter pylori (H. pylori) is associated with chronic cholecystitis.

METHODS: Chronic cholecystitis specimens confirmed by pathological analysis were divided into three groups: H. pylori infected group, H. pylori negative group and control group. The pathologic changes of cholecystitis were observed with light and electron microscopy, and the levels of interleukins (IL-1, IL-6 and IL-8) were also detected by radioimmunoassy.

RESULTS: Histological evidences of chronic choleystitis were found in the region where H. pylori colonized, including degeneration, necrosis, inflammatory cell infiltration, etc. Levels of interleukins (IL-1, 6, 8) in gallbladder homogenate were significantly higher in H. pylori-infected cholecystitis group than those in H. pylori -negative cholecystitis group and control group.

CONCLUSION: H. pylori virulence factor and interleukins may be involved in the pathogenesis of H. pylori -related cholecystitis.

Characteristics of Helicobacter pylori from gallbladder mucosal scrapings in patients with chronic cholecystitis

AIM: To study the characteristics of Helicobacter pylori (H. pylori) isolated from gallbladder mucosal scrapings in patients with chronic cholecystitis.

METHODS: H. pylori -like bacteria isolated from gallbladder mucosal scrapings and stomach in 81 patients with chronic cholecystitis were identified as H. pylori. The amplification bands were observed by PCR method using the H. pylori -specific primers, HPUA, and HPUB. Ultrastructural characteristics were also examined with transmission electron microscope.

RESULTS: The urease activity of H. pylori derived from cholecyst was lower than that from the patients' stomach. The other characteristics were the same in both cholecystic H. pylori and gastric H. pylori.

CONCLUSION: It is most likely that H. pylori excretes from the stomach into the duodenum and then is retrogradely transferred to the gallbladder by the ascending routes of infection.

Common presence of Helicobacter DNA in the gallbladder of patients with gallstone diseases and controls

BACKGROUND

Several species of Helicobacter colonise the biliary tract of animals and cause hepatobiliary diseases. Helicobacter species have also been identified in the gallbladder of a high proportion of Chilean patients with gallbladder cancer.

AIM

To determine the presence of Helicobacter species, particularly Helicobacter pylori and Helicobacter bilis, in the gallbladder of patients with non-malignant gallbladder diseases and control patients.

PATIENTS AND METHODS

DNA was extracted from gallbladder samples from 122 consecutive patients undergoing cholecystectomy. The presence of Helicobacter genus-specific or Helicobacter pylori and Helicobacter bilis species-specific DNA was determined by polymerase chain reaction and sequence analysis. The presence of Helicobacter pylori-specific immunoglobulin G in the serum (n=84) and bile (n=104) samples was determined by enzyme linked immunosorbent assay.

RESULTS

Helicobacter DNA was detected in 61 (50.0%) gallbladder samples: 29 of 60 (48.3%) patients with symptomatic gallstone, six of 10 (60.0%) patients with asymptomatic gallstones, 11 of 15 (73.3%) patients with other biliary diseases, and 15 of 37 (40.5%) control patients, respectively. Among them, 39 samples were positive for Helicobacter pylori but none were positive for Helicobacter bilis. Sequence analysis of Helicobacter genus-positive samples showed that 56 samples were Helicobacter pylori and five were Helicobacter species 'Liver 3' strain. Overall, there was no significant difference in the detection rate of Helicobacter DNA or the levels of serum and bile Helicobacter pylori-specific immunoglobulin G in the various biliary disease groups compared with control patients. Neither was there any significant difference in the blood biochemistry and liver function tests between patients with positive and negative Helicobacter DNA detection.

CONCLUSION

Helicobacter species' DNA are commonly present in the gallbladder of patients with gallstone diseases and in controls, implying that Helicobacter infection alone may not play a significant role in the formation of gallstones. However, our results do not exclude the possibility of Helicobacter infection as a cofactor in the development of gallstones.

Profiling and identification of eubacteria in the stomach of Mongolian gerbils with and without Helicobacter pylori infection

BACKGROUND

Mongolian gerbils are frequently used to study Helicobacter pylori-induced gastritis and its consequences. The presence of an indigenous bacterial flora with suppressive effect on H. pylori may cause difficulties with establishing this experimental model.

AIM

The aim of the present study was to determine bacterial profiles in the stomach of Mongolian gerbils with and without (controls) H. pylori infection.

METHODS

Gastric tissue from H. pylori ATCC 43504 and CCUG 17874 infected and control animals were subjected to microbial culturing and histology. In addition, gastric mucosal samples from H. pylori ATCC 43504 infected and control animals were analyzed for bacterial profiling by temporal temperature gradient gel electrophoresis (TTGE), cloning and pyrosequencing of 16S rDNA variable V3 region derived PCR amplicons.

RESULTS

Oral administration of H. pylori ATCC 43504, but not CCUG 17874, induced colonization and gastric inflammation in the stomach of Mongolian gerbils. Temporal temperature gradient gel electrophoresis (TTGE) and partial 16S rDNA pyrosequencing revealed the presence of DNA representing a mixed bacterial flora in the stomach of both H. pylori ATCC 43504 infected and control animals. In both cases, lactobacilli appeared to be dominant.

CONCLUSION

These findings suggest that indigenous bacteria, particularly lactobacilli, may have an impact on the colonization and growth of H. pylori strains in the stomach of Mongolian gerbils.

Helicobacter DNA in bile: correlation with hepato-biliary diseases

BACKGROUND

Helicobacter has been identified in isolated cases of hepato-biliary diseases, but its role in the pathogenesis of these conditions remains unclear.

AIM

To determine whether Helicobacter could be detected in bile obtained at endoscopic retrograde cholangiopancreatography, and to evaluate the prevalence of this infection in patients with hepato-biliary diseases.

METHODS

Bile was collected from 125 patients with various hepato-biliary diseases undergoing endoscopic retrograde cholangiopancreatography. Among them, 75 were diagnosed with biliary stones, 15 with pancreatico-biliary malignancies and four with primary sclerosing cholangitis. The detection of Helicobacter in DNA extracted from these bile samples was performed using Helicobacter genus-specific primers (capable of detecting 100-1000 organisms/mL).

RESULTS

Helicobacter was detected in all positive controls. Only three samples had polymerase chain reaction inhibitors. All remaining bile samples (122 patients with hepato-biliary diseases) were negative for Helicobacter DNA.

CONCLUSIONS

Helicobacter can be detected in bile samples using polymerase chain reaction. This infection, however, was not present in any of our patients diagnosed with gallstones or hepato-biliary malignancies, raising doubt as to the possible association between Helicobacter and these entities. Given the low sample size of patients with primary sclerosing cholangitis, more studies are required to determine whether an association exists with this condition.

Molecular typing of the bacterial flora in sputum of cystic fibrosis patients

Despite recent advances in therapy, lower airway infections remain the major cause of morbidity and mortality in cystic fibrosis (CF) patients. Bacterial colonisation of the lower airways in CF is limited to a few bacterial species, commonly Staphylococcus aureus, Pseudomonas aeruginosa and Haemophilus influenzae. Burkholderia cepacia colonisation is much rarer, but it has been thought to be associated with more advanced lung disease and increased mortality. A rapid characterisation of the bacterial flora in sputum of CF patients is of great importance for proper treatment. The aim of this study was to establish bacterial profiles and to identify pathogenic bacteria in respiratory specimens by means of molecular methods including temporal temperature gradient gel electrophoresis (TTGE) and DNA sequencing of PCR amplicons derived from 16S rDNA variable V3 and V6 regions. Sputa of 13 CF patients (7 males/6 females, age 19-59 years) collected at the Stockholm CF centre were analysed. TTGE revealed the presence of complex bacterial profiles in all samples. The V3 and V6 PCR amplicons were cloned and sequenced by real-time DNA Pyrosequencing. DNA from Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa, respectively, was identified together with sequences from normal oral cavity flora. The results were in reasonable agreement with those obtained by conventional bacterial culture, considering that only known CF pathogens are included in routine reports. However, the methodology seems too elaborate to be introduced into daily routine

Helicobacter pylori and the risk of benign and malignant biliary tract disease

BACKGROUND

The etiology of tumors arising in the biliary tract remains unclear. Several previous studies have detected Helicobacter pylori organisms in bile from patients with gallstones or cholecystitis. The objective of this study was to determine whether there is an association between H. pylori in bile and biliary tract carcinoma.

METHODS

The authors used polymerase chain reaction (PCR) assays to detect the presence of H. pylori in the stomach and bile from 89 patients: Sixty-three disease free patients had biliary calculi, 15 patients had carcinoma of the biliary tract, and 11 patients had neither gallstones nor carcinoma. Bile was considered to contain H. pylori only if the results of PCR determinations were positive in two or more samples assayed independently in two separate laboratories.

RESULTS

There was a strong association between the presence of H. pylori in the stomach and in the bile (P < or = 0.01). Biliary H. pylori was associated with age but not with gender, and it was associated strongly with the clinical diagnosis. Patients with gallstones were 3.5 times as likely to have H. pylori in the bile compared with patients in a control group (95% confidence interval [95%CI], 0.8-15.8; P = 0.100), and H. pylori was 9.9 times more frequent in patients with biliary tract carcinoma compared with patients in the control group (95%CI, 1.4-70.5; P = 0.022).

CONCLUSIONS

There is a strong association between biliary tract carcinoma and H. pylori in bile. If these results are confirmed by prospective studies, H. pylori may be responsible for a significant proportion of malignant biliary tract disease.

The role of microorganisms in biliary tract disease

The biliary tract is normally sterile, but bile-tolerant bacteria are frequently isolated from patients with cholecystitis. Since the identification of about 25 Helicobacter species, some of which may grow in bile, studies have addressed the role of these organisms in primary biliary cirrhosis, primary sclerosing cholangitis, and cholelithiasis. Most of these bacteria show the presence of Helicobacter DNA or antigens in the bile tract and in liver samples. Altogether, data from studies on biliary and hepatic diseases, as well as pancreatic disorders, suggest that bile-tolerant Helicobacter species may induce a chronic infection with possible malignant transformation.