Gallbladder microbial species and host bile acids biosynthesis linked to cholesterol gallstone comparing to pigment individuals

Gallstones are crystalline deposits in the gallbladder that are traditionally classified as cholesterol, pigment, or mixed stones based on their composition. Microbiota and host metabolism variances among the different types of gallstones remain largely unclear. Here, the bile and gallstone microbial species spectra of 29 subjects with gallstone disease (GSD, 24 cholesterol and 5 pigment) were revealed by type IIB restriction site-associated DNA microbiome sequencing (2bRAD-M). Among them (21 subjects: 18 cholesterol and 3 pigment), plasma samples were subjected to liquid chromatography-mass spectrometry (LC-MS) untargeted metabolomics. The microbiome yielded 896 species comprising 882 bacteria, 13 fungi, and 1 archaeon. Microbial profiling revealed significant enrichment of Cutibacterium acnes and Microbacterium sp005774735 in gallstone and Agrobacterium pusense and Enterovirga sp013044135 in the bile of cholesterol GSD subjects. The metabolome revealed 2296 metabolites, in which malvidin 3-(6''-malonylglucoside), 2-Methylpropyl glucosinolate, and ergothioneine were markedly enriched in cholesterol GSD subjects. Metabolite set enrichment analysis (MSEA) demonstrated enriched bile acids biosynthesis in individuals with cholesterol GSD. Overall, the multi-omics analysis revealed that microbiota and host metabolism interaction perturbations differ depending on the disease type. Perturbed gallstone type-related microbiota may contribute to unbalanced bile acids metabolism in the gallbladder and host, representing a potential early diagnostic marker and therapeutic target for GSD.

The role of bacteria in gallstone formation

Gallstones are a prevalent biliary system disorder that is particularly common in women. They can lead to various complications, such as biliary colic, infection, cholecystitis, and even gallbladder cancer. However, the etiology of gallstones remains incompletely understood. The significant role of bacteria in gallstone formation has been demonstrated in recent studies. Certain bacteria not only influence bile composition and the gallbladder environment but also actively participate in stone formation by producing enzymes such as β-glucuronidase and mucus. Therefore, this review aimed to analyze the mechanisms involving the types and quantities of bacteria involved in gallstone formation, providing valuable references for understanding the etiology and clinical treatment of gallstones.

Patients with Primary and Secondary Bile Duct Stones Harbor Distinct Biliary Microbial Composition and Metabolic Potential

Introduction

Cholelithiasis has a high incidence worldwide and limited treatment options due to its poorly understood pathogenesis. Furthermore, the role of biliary microbiota in cholelithiasis remains understudied. To address these questions, we performed microbial sequencing from biliary samples from primary bile duct stone (PBDS) and secondary bile duct stone (SBDS) patients.

Results

We analyzed in total 45 biliary samples, including those from cholelithiasis patients with PBDS or SBDS and people with other digestive diseases. 16S rRNA sequencing showed the bacteria family Alcaligenaceae increased in relative abundance in the lithiasis group compared with the non-lithiasis group. In addition, the PBDS group showed significantly lower bacterial diversity than SBDS, with Propionibacteriaceae, Sphingomonadaceae, and Lactobacillaceae as the most significant bacteria families decreased in relative abundance. We further performed whole metagenomic shotgun sequencing (wMGS) and found increased ability of biofilm synthesis and the ability to sense external stimuli in PBDS based on functional annotation of mapped reads. From genome-resolved analysis of the samples, we identified 36 high-quality draft bacterial genome sequences with completion ≥70% and contamination ≤10%. Most of these genomes were classified into Proteobacteria, Firmicutes, or Actinobacteria.

Conclusions

Our findings indicated that there is a subtle impact on biliary microbiome from cholelithiasis while the difference is more pronounced between the PBDS and SBDS. It was revealed that the diversity of biliary microbiota in PBDS is lower, while some metabolic pathways are up-regulated, including those linked to higher incidence of different types of cancer, providing new insights for the understanding of cholelithiasis with different origin.

Biliary microbiota and mucin 4 impact the calcification of cholesterol gallstones

BACKGROUND

Cholesterol gallstones account for over 80% of gallstones, and the pathogenesis of gallstone formation involves genetic and environmental factors. However, data on the evolution of cholesterol gallstones with various densities are limited. This study aimed to determine the roles of microbiota and mucins on the formation of calcified cholesterol gallstones in patients with cholelithiasis.

METHODS

Paired gallbladder tissues and bile specimens were obtained from cholelithiasis patients who were categorized into the isodense group and calcified group according to the density of gallstones. The relative abundance of microbiota in gallbladder tissues was detected. Immunohistochemistry and enzyme-linked immunosorbent assay were performed to detect the expression levels of MUC1, MUC2, MUC3a, MUC3b, MUC4, MUC5ac and MUC5b in gallbladder tissues and bile. The correlation of microbiota abundance with MUC4 expression was evaluated by linear regression.

RESULTS

A total of 23 patients with gallbladder stones were included. The density of gallstones in the isodense group was significantly lower than that of the calcified group (34.20 ± 1.50 vs. 109.40 ± 3.84 HU, P < 0.0001). Compared to the isodense group, the calcified group showed a higher abundance of gram-positive bacteria at the fundus, in the body and neck of gallbladder tissues. The concentrations of MUC1, MUC2, MUC3a, MUC3b, MUC5ac and MUC5b in the epithelial cells of gallbladder tissues showed no difference between the two groups, while the concentrations of MUC4 were significantly higher in the calcified group than that in the isodense group at the fundus (15.49 ± 0.69 vs. 10.23 ± 0.54 ng/mL, P < 0.05), in the body (14.54 ± 0.94 vs. 11.87 ± 0.85 ng/mL, P < 0.05) as well as in the neck (14.77 ± 1.04 vs. 10.85 ± 0.72 ng/mL, P < 0.05) of gallbladder tissues. Moreover, the abundance of bacteria was positively correlated with the expression of MUC4 (r = 0.569, P < 0.05) in the calcified group.

CONCLUSIONS

This study showed the potential clinical relevance among biliary microbiota, mucins and calcified gallstones in patients with gallstones. Gram-positive microbiota and MUC4 may be positively associated with the calcification of cholesterol gallstones.

Circadian Rhythm Disruption Influenced Hepatic Lipid Metabolism, Gut Microbiota and Promoted Cholesterol Gallstone Formation in Mice

BACKGROUND

Hepatic lipid metabolism regulates biliary composition and influences the formation of cholesterol gallstones. The genes Hmgcr and Cyp7a1, which encode key liver enzymes, are regulated by circadian rhythm-related transcription factors. We aimed to investigate the effect of circadian rhythm disruption on hepatic cholesterol and bile acid metabolism and the incidence of cholesterol stone formation.

METHODS

Adult male C57BL/6J mice were fed either a lithogenic diet (LD) only during the sleep phase (time-restricted lithogenic diet feeding, TRF) or an LD ad libitum (non-time-restricted lithogenic diet feeding, nTRF) for 4 weeks. Food consumption, body mass gain, and the incidence of gallstones were assessed. Circulating metabolic parameters, lipid accumulation in the liver, the circadian expression of hepatic clock and metabolic genes, and the gut microbiota were analyzed.

RESULTS

TRF caused a dysregulation of the circadian rhythm in the mice, characterized by significant differences in the circadian expression patterns of clock-related genes. In TRF mice, the circadian rhythms in the expression of genes involved in bile acid and cholesterol metabolism were disrupted, as was the circadian rhythm of the gut microbiota. These changes were associated with high biliary cholesterol content, which promoted gallstone formation in the TRF mice.

CONCLUSION

Disordered circadian rhythm is associated with abnormal hepatic bile acid and cholesterol metabolism in mice, which promotes gallstone formation.

Biofilm Formation Protects Salmonella from the Antibiotic Ciprofloxacin In Vitro and In Vivo in the Mouse Model of chronic Carriage

Typhoid fever is caused by the human-restricted pathogen Salmonella enterica sv. Typhi. Approximately 5% of people that resolve the disease become chronic carriers, with the gallbladder as the main reservoir of the bacteria. Of these, about 90% present with gallstones, on which Salmonella form biofilms. Because S. Typhi is a human-restricted pathogen, these carriers are the main source of dissemination of the disease; unfortunately, antibiotic treatment has shown to be an ineffective therapy. This is believed to be caused by the inherent antibiotic resistance conferred by Salmonella biofilms growing on gallstones. The gallstone mouse model with S. Typhimurium has proven to be an excellent surrogate for S. Typhi chronic infection. In this study, we test the hypothesis that the biofilm state confers Salmonella with the increased resistance to antibiotics observed in cases of chronic carriage. We found that, in the biofilm state, Salmonella is significantly more resistant to ciprofloxacin, a common antibiotic used for the treatment of Salmonella, both in vitro (p < 0.001 for both S. Typhi and S. Typhimurium with respect to planktonic cells) and in vivo (p = 0.0035 with respect to control mice).

In vitro Salmonella typhi biofilm formation on gallstones and its disruption by Manuka honey

Biofilm is a complex community of single or different types of microorganisms (bacteria, viruses, fungi, protozoa) attached to a surface and stick to each other through production of extracellular matrix. Salmonella typhi forms biofilm on cholesterol gallstones resulting in carrier state. Once formed, biofilm is difficult to treat. To date cholecystectomy is the only cure for this condition. Manuka honey is known to have tremendous antibiofilm activity against various organisms. S. typhi biofilm was grown in vitro on clinical samples of human cholesterol gallstones by Gallstone tube assay method for 12 days. Biofilm mass was quantified on day 1, 5, 7, 9 and 12 by crystal violet assay and was also examined by scanning electron microscope. Three concentrations w/v of Manuka honey (40%, 60% and 80%) were used, each one at 24, 48 and 72 hours. The most effective concentration (80% w/v) was repeated on two sets of gallstones. Biofilm mass was re quantified by crystal violet assay and was examined by scanning electron microscope. S. typhi formed uniform biofilm on cholesterol gallstone surface. The optical density measurements exhibited a rising pattern with time thereby indicating an increase in biofilm mass. It was 0.2 on day 1 and 0.9 on day 12. With 80% w/v Manuka honey, biofilm mass decreased most effectively with 0.5 OD after 72 hours. Biofilm formation by S, typhi on gallstones is surface specific and bile dependant. Either increasing the duration (beyond 72 hours) of the effective concentration (80% w/v) of honey or increasing the concentration (above 80%) of honey for a specific duration (72 hour) may cause complete disruption of the S. typhi biofilm on gallstone. S. typhi forms biofilm on cholesterol gallstones surface in vitro and it can be visualized by scanning electron microscopy. Biofilm mass can be quantified using crystal violet assay. Among various concentrations 80% Manuka honey for 72 hours is most effective in disrupting S. typhi biofilm on gallstones in vitro as evident from crystal violet assay.

Biliary Microbiota, Gallstone Disease and Infection with Opisthorchis felineus

Background

There is increasing interest in the microbiome of the hepatobiliary system. This study investigated the influence of infection with the fish-borne liver fluke, Opisthorchis felineus on the biliary microbiome of residents of the Tomsk region of western Siberia.

Methodology/Principal Findings

Samples of bile were provided by 56 study participants, half of who were infected with O. felineus, and all of who were diagnosed with gallstone disease. The microbiota of the bile was investigated using high throughput, Illumina-based sequencing targeting the prokaryotic 16S rRNA gene. About 2,797, discrete phylotypes of prokaryotes were detected. At the level of phylum, bile from participants with opisthorchiasis showed greater numbers of Synergistetes, Spirochaetes, Planctomycetes, TM7 and Verrucomicrobia. Numbers of > 20 phylotypes differed in bile of the O. felineus-infected compared to non-infected participants, including presence of species of the genera Mycoplana, Cellulosimicrobium, Microlunatus and Phycicoccus, and the Archaeans genus, Halogeometricum, and increased numbers of Selenomonas, Bacteroides, Rothia, Leptotrichia, Lactobacillus, Treponema and Klebsiella.

Conclusions/Significance

Overall, infection with the liver fluke O. felineus modified the biliary microbiome, increasing abundance of bacterial and archaeal phylotypes.

The microbiota of the alimentary tract and other sites of the body influences human health. Contrary to popular belief, the bile within the liver is not sterile, and may host a microbiome consisting of diverse species of microbes. The spectrum of microbial species and their numbers within the biliary system may be influenced by disease including infection with pathogens such as parasitic worms and with gallstone disease, liver cancer and other ailments. Here we examined the microbes in the bile of patients from western Siberia, Russia who were concurrently infected with a food-borne parasitic worm, the liver fluke Opisthorchis felineus. Infection with this liver fluke is common in western Siberia, as a consequence of dietary preference for undercooked or smoked fresh-water fishes that often carry the larva of the liver fluke. Using high throughput sequencing targeting a conserved bacterial gene and statistical analyses, numerous bacterial species were identified in the bile of the patients. Infection with the liver fluke modified the biliary microbiome, resulting in abundant and diverse species of bacteria and Archaea.

The correlation of Helicobacter Pylori with the development of cholelithiasis and cholecystitis: the results of a prospective clinical study in Saudi Arabia

OBJECTIVE

Gallstone disease is a common surgical ailment. Helicobacter pylori has a role in upper gastrointestinal disorders, including gallstones. This study aimed to determine the association of H. pylori with gallstones, so developing a preventative strategy for gallstone formations.

PATIENTS AND METHODS

A prospective study was conducted on 95 patients referred to the surgical clinic of Al-Meeqat General Hospital, Al-Madinah Al-Munawarah, with gallstone disease. Detection of H. pylori antibodies (IgG) in serum was done in all the patients who underwent cholecystectomy. H. pylori stool antigen (HPSA) using stool samples was done for IgG sero-positive patients prior to the cholecystectomy. The bile collected from the gall bladder during operation was examined for the presence of H. pylori by Gram stain, culture and HPSA assay. Gallbladder mucosa was examined for urease A gene by polymerase chain reaction (PCR) in patients proven to be positive for stool or bile serology.

RESULTS

Of the 95 patients, 75 (79%) were positive for H. pylori antibodies. Twenty-six (34.7%) patients were positive with H. pylori antigens in bile and 21 (28%) with H. pylori antigens in the stool samples. Among these 47 patients, PCR was positive in 29 (62%) subjects. H. pylori couldn't be detected among the studied patients by using either Gram stain or culture.

CONCLUSIONS

The presence of H. pylori in bile may indicate a significant risk for cholelithiasis. PCR is a rapid reliable method for the detection of H. pylori DNA in bile. This rapid molecular approach together with culture and immunological methods could help clinicians to effectively manage patients at high risk of developing gallstones at an earlier stage.

Helicobacter pylori infection is associated with gallstones: Epidemiological survey in China

AIM: To elucidate the prevalence and risk factors for gallstones, primarily focusing on Helicobacter pylori (H. pylori) infection.

METHODS: A total of 10016 Chinese subjects, who had undergone physical examination, fasting ¹³C urea breath test and abdominal ultrasonography, had sufficient blood test data, and had finished a questionnaire, were included in this cross-sectional study. Participants (n = 1122) who had previous eradication of H. pylori were studied separately.

RESULTS: Gallstones were discovered in 9.10% of men and 8.58% of women, with no significant sex difference. Multivariate analyses displayed that age, aspartate aminotransferase, total cholesterol, H. pylori infection, hepatitis C virus (HCV) infection, and fatty liver had a significant association with gallstones (P < 0.05). Successive multiple logistic regression analysis including index of odds ratio (OR) and standardized coefficient (β) indicated that older age (OR/β = 1.056/0.055), H. pylori infection (OR/β = 1.454/0.109), HCV infection (OR/β = 1.871/0.123), and fatty liver (OR/β = 1.947/0.189) had a significant positive association with gallstones. After age stratification, H. pylori infection and fatty liver still had a significant positive association with gallstones in any age-specific groups, whereas HCV infection had a significant positive association in patients aged > 40 years. The prevalence of gallstones among H. pylori-positive, H. pylori-eradicated, and H. pylori-negative subjects was 9.47%, 9.02%, and 8.46%, respectively. The matched analysis showed that gallstones among H. pylori eradicated subjects was significantly lower compared with H. pylori-positive subjects (P < 0.05).

CONCLUSION: H. pylori infection and fatty liver have a significant positive association with gallstones. H. pylori eradication may lead to prevention of gallstones.

Visualization of extracellular matrix components within sectioned Salmonella biofilms on the surface of human gallstones

Chronic carriage of Salmonella Typhi is mediated primarily through the formation of bacterial biofilms on the surface of cholesterol gallstones. Biofilms, by definition, involve the formation of a bacterial community encased within a protective macromolecular matrix. Previous work has demonstrated the composition of the biofilm matrix to be complex and highly variable in response to altered environmental conditions. Although known to play an important role in bacterial persistence in a variety of contexts, the Salmonella biofilm matrix remains largely uncharacterized under physiological conditions. Initial attempts to study matrix components and architecture of the biofilm matrix on gallstone surfaces were hindered by the auto-fluorescence of cholesterol. In this work we describe a method for sectioning and direct visualization of extracellular matrix components of the Salmonella biofilm on the surface of human cholesterol gallstones and provide a description of the major matrix components observed therein. Confocal micrographs revealed robust biofilm formation, characterized by abundant but highly heterogeneous expression of polysaccharides such as LPS, Vi and O-antigen capsule. CsgA was not observed in the biofilm matrix and flagellar expression was tightly restricted to the biofilm-cholesterol interface. Images also revealed the presence of preexisting Enterobacteriaceae encased within the structure of the gallstone. These results demonstrate the use and feasibility of this method while highlighting the importance of studying the native architecture of the gallstone biofilm. A better understanding of the contribution of individual matrix components to the overall biofilm structure will facilitate the development of more effective and specific methods to disrupt these bacterial communities.

A selective antibiotic prophylaxis policy for laparoscopic cholecystectomy is effective in minimising infective complications

INTRODUCTION

It has been demonstrated previously that the identification of bactibilia during cholecystectomy is associated with the presence of one or more risk factors: acute cholecystitis, common duct stones, emergency surgery, intraoperative findings and age >70 years. Current evidence-based guidance on antibiotic prophylaxis during laparoscopic cholecystectomy (LC) is based on elective procedures and does not take into account these factors. The aim of this study was to assess the effectiveness of a selective antibiotic prophylaxis policy limited to high risk patients undergoing LC with the development of port site infections as the primary endpoint.

METHODS

One hundred consecutive patients undergoing LC under the care of a single consultant surgeon during a one-year period were studied prospectively. Data collected included patient demographics (age, sex) as well as details of the history of gallstone disease to determine those with complex disease and risk factors for bactibilia. A single dose of antibiotics (second generation cephalosporin and metronidazole) was administered on induction to patients with a risk factor present. Information relating to all radiologically or microbiologically confirmed infections was documented.

RESULTS

Eighty-four of the patients were female and the mean age was 47.7 ±16.0 years. Nineteen LCs were performed as emergencies and the remainder were elective procedures. A risk factor for bactibilia was present in 35 patients. A wound infection was identified in four cases, two of which were Staphylococcus aureus (one methicillin resistant), one was a coagulase negative Staphylococcus and one wound cultured a mixed anaerobic growth. Three of the infections occurred in patients receiving prophylaxis (2 staphylococcal and 1 anaerobic) at intervals of 7, 14 and 19 days respectively. One patient with a body mass index of 32kg/m² in the 'no prophylaxis' group developed a coagulase negative staphylococcal infection at 10 days. No intra or extra-abdominal abdominal infections were identified.

CONCLUSIONS

This study has demonstrated that restricting antibiotic prophylaxis to high risk patients has no detrimental effects in terms of increasing the rate of infections in those with no risk factors. Furthermore, the act of not prescribing to low risk patients will limit costs and the risk of adverse events. It will also reduce the risk of resistance and clostridial infections in this cohort.

Symbiotic bacteria induced necrotizing pancreatitis

CONTEXT

Intestinal flora and anaerobes are frequently implicated in causing infectious necrotizing pancreatitis however Bifidobacterium and Veillonella have rarely been isolated as the causative agents. Bifidobacterium and Veillonella are commensal anaerobes which reside in gastrointestinal tract and help deconjugate bile acids. Bifidobacterium is also frequently used in probiotics.

CASE REPORT

We present a 68-year-old man who initially presented with gallstone pancreatitis but eventually developed Bifidobacterium and Veillonella species induced necrotizing pancreatitis and pseudocyst formation.

CONCLUSION

Under rare circumstances commensal gut flora can turn pathogenic which can lead to life-threatening morbidity and may even result in mortality.

The short term effects of infected gallstones lost intraperitoneally

In this experimental study, an animal model was set up to evaluate what sort of complications may cause intraperitoneal retained bile stones. Forty rats were divided into 4 groups. The first group was assigned as the control group and the subjects had only laparatomy. In the 2nd group, during laparotomy, sterile bile and bile stones were placed within the peritoneal cavity. In the 3rd group, contaminated bile and bile stones were placed within the peritoneal cavity. In the 4th group, again contaminated bile and bile stones were placed and prophylactic antibiotic (Ceftriaxon) was used for 7 days. After a 4 week interval, survivors were subjected to laparatomy and necropsy. As a conclusion, the peritoneal adhesion difference between the infected bile and stone inooculation group without antibiotic and the other group with antibiotic usage may show that antibiotics might prevent further complications in case of abdominal contamination. Available clinical and experimental data is not enough to recommend laparatomy to collect stones. We conclude that more detailed studies with larger series are necessary to clarify the issue (Tab. 1, Fig. 1, Ref. 26).

Does Helicobacter pylori identification in the mucosa of the gallbladder correlate with cholesterol gallstone formation?

OBJECTIVE

Helicobacter pylori (H pylori) represents a potential initiator of cholesterol crystallization and it has been proposed that it is related to gallstone formation. In this study, any possible association between the H pylori identification in the mucosa of gallbladder and cholesterol gallstone formation was evaluated

METHODS

Gallbladders containing pure or mixed cholesterol gallstones (cholelithiasis group, n = 89) and gallbladders without gallstones (control group, n = 42) were submitted to standard histopathological examination for H pylori detection, as well as to nested polymerase chain reaction amplification for H pylori DNA detection.

RESULTS

Helicobacter pylori was identified in the gallbladder's epithelium in four patients with cholelithiasis and in two patients in the control group by histology. In all the cases which were found to be H pylori positive by histological examination, H pylori DNA were also detected. No correlation between gallstone formation and H pylori detection in the biliary epithelium was found. A higher incidence of acute inflammation in the cholelithiasis (22.5% vs 9.5%, p = not significant [ns]) and in the H pylori positive groups (33% vs 17.6%, p = ns) were histologically detected. A higher incidence (10% vs 0%), p = ns) of H pylori in gallbladders with gallstones and acute inflammation, compared to gallbladders with acute inflammation but without gallstones, was noticed

CONCLUSION

Helicobacter pylori is detectable in low frequency in the mucosa of the gallbladder and it does not seem to act as a lithogenic component for cholesterol gallstone formation. Its higher incidence in gallbladders with gallstones and acute inflammation, suggests a possible accessory role in a subset of patients with cholelithiasis.

[Role of salmonella in biliary lithogenesis]

By the methods of light microscopy and immunocytochemistry studies of interaction between S. typhimurium and corpuscular biliary components was investigated in experimental model "bile-bacteria" It was shown that the results of this interaction was bacterial-biliary sludge formation. Bacterial extracellular mucopolysaccharides matrix and flagella's play crucial role in mechanism of sludge formation.

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.

Bacteria entombed in the center of cholesterol gallstones induce fewer infectious manifestations than bacteria in the matrix of pigment stones

PURPOSE

The clinical significance of bacteria in the pigment centers of cholesterol stones is unknown. We compared the infectious manifestations and characteristics of bacteria from pigment stones and predominantly cholesterol stones.

METHODS

Three hundred forty patients were studied. Bile was cultured. Gallstones were cultured and examined with scanning electron microscopy. Level of bacterial immunoglobulin G (bile, serum), complement killing, and tumor necrosis factor-alpha production were determined.

RESULTS

Twenty-three percent of cholesterol stones and 68% of pigment stones contained bacteria (P < 0.0001). Stone culture correlated with scanning electron microscopy results. Pigment stone bacteria were more often present in bile and blood. Cholesterol stone bacteria caused more severe infections (19%) than sterile stones (0%), but less than pigment stone bacteria (57%) (P < 0.0001). Serum and bile from patients with cholesterol stone bacteria had less bacterial-specific immunoglobulin G. Cholesterol stone bacteria produced more slime. Pigment stone bacteria were more often killed by a patient's serum. Tumor necrosis factor-alpha production of the groups was similar.

CONCLUSIONS

Bacteria are readily cultured from cholesterol stones with pigment centers, allowing for analysis of their virulence factors. Bacteria sequestered in cholesterol stones cause infectious manifestations, but less than bacteria in pigment stones. Possibly because of their isolation, cholesterol stone bacteria were less often present in bile and blood, induced less immunoglobulin G, were less often killed by a patient's serum, and demonstrated fewer infectious manifestations than pigment stone bacteria. This is the first study to analyze the clinical relevance of bacteria within cholesterol gallstones.

Gallstones containing bacteria are biofilms: bacterial slime production and ability to form pigment solids determines infection severity and bacteremia

OBJECTIVE

Gallstone bacteria provide a reservoir for biliary infections. Slime production facilitates adherence, whereas beta-glucuronidase and phospholipase generate colonization surface. These factors facilitate gallstone formation, but their influence on infection severity is unknown.

METHODS

Two hundred ninety-two patients were studied. Gallstones, bile, and blood (as applicable) were cultured. Bacteria were tested for beta-glucuronidase/phospholipase production and quantitative slime production. Infection severity was correlated with bacterial factors.

RESULTS

Bacteria were present in 43% of cases, 13% with bacteremia. Severe infections correlated directly with beta-glucuronidase/phospholipase (55% with vs 13% without, P < 0.0001), but inversely with slime production (55 vs 8%, slime <75 or >75, P = 0.008). Low slime production and beta-glucuronidase/phospholipase production were additive: Severe infections were present in 76% with both, but 10% with either or none (P < 0.0001). beta-Glucuronidase/phospholipase production facilitated bactibilia (86% with vs 62% without, P = 0.03). Slime production was 19 (+/-8) vs 50 (+/-10) for bacteria that did or did not cause bacteremia (P = 0.004). No bacteria with slime >75 demonstrated bacteremia.

CONCLUSIONS

Bacteria-laden gallstones are biofilms whose characteristics influence illness severity. Factors creating colonization surface (beta-glucuronidase/phospholipase) facilitated bacteremia and severe infections; but abundant slime production, while facilitating colonization, inhibited detachment and cholangiovenous reflux. This shows how properties of the gallstone biofilm determine the severity of the associated illness.

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.

Biliary bacterial factors determine the path of gallstone formation

BACKGROUND

Bacteria cause pigment gallstones and can act as a nidus for cholesterol gallstone formation. Bacterial factors that facilitate gallstone formation include beta-glucuronidase (bG), phospholipase (PhL), and slime. The current study sought to determine whether bacterial factors influence the path of gallstone formation.

METHODS

A total of 382 gallstones were cultured and/or examined using scanning electron microscopy (SEM). Bacteria were tested for bG and slime production. Gallstone composition was determined using infrared spectrography. Ca-palmitate presence documented bacterial PhL production. Groups were identified based upon bacterial factors present: slime and bGPhL (slime/bGPhL), bGPhL only, and slime only. Influence of bacterial stone-forming factors on gallstone composition and morphology was analyzed.

RESULTS

Bacteria were present in 75% of pigment, 76% of mixed, and 20% of cholesterol stones. Gallstones with bGPhL producing bacteria contained more pigment (71% vs. 26%, P < .0001). The slime/bGPhL group was associated (79%) with pigment stones, bGPhL was associated (56%) with mixed stones, while slime (or none) only was associated (67%) with cholesterol stones (P < .031, all comparisons).

CONCLUSIONS

Bacterial properties determined the path of gallstone formation. Bacteria that produced all stone-forming factors promoted pigment stone formation, while those that produced only bGPhL promoted mixed stone formation. Bacteria that only produced slime lacked the ability to generate pigment solids, and consequently were more common in the centers of cholesterol stones. This shows how bacterial characteristics may govern the process of gallstone formation.

An animal model of black pigment gallstones caused by nanobacteria

Black pigment gallstones are often founded in gallbladder, but their pathogenesis is unclear. The present study was undertaken to study the role of nanobacteria in pigment gallstone formation in Japanese white rabbits. Nanobacteria were successfully cultured from 3 of 7 cholecystolithiasis patients gallbladder (without acute cholecystitis) bile samples and affirmed by Hoechst 33258 staining and specific immunostaining using monoclonal antibody. Nanobacteria were injected into rabbits' gallbladder. After 2 weeks follow-up, the incidence of black pigment gallstones in rabbits was significantly greater in nanobacteria-injected group (8/10) than that in DMEM-injected group (2/10) and that in hydroxyapatite-injected group (2/10). This study indicates that nanobacteria exists in gallbladder bile of cholelithiasis patients and causes the formation of black pigment gallstones in rabbits. For the first time, we successfully established an animal model of black pigment gallstones caused by nanobacteria. This will be helpful in further delineating the pathogenesis of black pigment gallstones.

Bacteriological and electron microscopic examination of primary intrahepatic stones

BACKGROUND

Primary intrahepatic cholelithiasis is usually combined with biliary tract infection. This research was undertaken to investigate the relationship between intrahepatic stones and biliary tract infection.

METHODS

Thirty-five bile samples and 30 stones specimens were cultured for bacteria and 12 stones specimens were examined with a scan electron microscope (SEM) or a transmission electron microscope (TEM).

RESULT

94.2% bile samples and 96.7% stones specimens were positive in bacteria culture. Bacteria were found in stones under SEM and TEM.

CONCLUSION

Bacteria in stones are associated with the infection of the biliary tract.

Antibiotic activity of antimicrobial peptide against Pseudomonads isolated from a patient with gallstones

We investigated the in vitro antibiotic activity of the 19-amino acid antimicrobial peptide HP (2-20), derived from the N-terminus of Helicobacter pylori Ribosomal Protein L1 (RPL1), against antibiotic susceptible and resistant pathogens from a patient with gallstones. HP (2-20) was active against antibiotic-susceptible and antibiotic-resistant clinical isolates of pathogens from a patient with gallstones, but this peptide showed no hemolytic activity against normal human erythrocytes. HP (2-20) acted synergistically with ciprofloxacin against pathogenic bacteria. Fluorescence activated flow cytometry revealed that the effect of HP (2-20) was dependent on energy and salt concentration. In addition, scanning electron microscopy showed that HP (2-20) caused significant morphological alterations to the cell surface of pathogens. Using 16S rDNA sequences, we found that isolates from bile were 100% homologous to Pseudomonas aeruginosa. These findings suggest that HP (2-20) may be useful clinically as an antibiotic against acquired pathogens from patients with gallstones and against pathogens resistant to other antibiotics.

Helicobacter pylori and cholesterol gallstone formation in C57L/J mice: a prospective study

Recently, we demonstrated that cholesterol gallstone-prone C57L/J mice rarely develop gallstones unless they are infected with certain cholelithogenic enterohepatic Helicobacter species. Because the common gastric pathogen H. pylori has been identified in the hepatobiliary tree of cholesterol gallstone patients, we wanted to ascertain if H. pylori is cholelithogenic, by prospectively studying C57L infected mice fed a lithogenic diet. Weanling, Helicobacter spp.-free male C57L mice were either infected with H. pylori SS1 or sham dosed. Mice were then fed a lithogenic diet (1.0% cholesterol, 0.5% cholic acid, and 15% dairy triglycerides) for 8 wk. At 16 wk of age, mice were euthanatized, the biliary phenotype was analyzed microscopically, and tissues were analyzed histopathologically. H. pylori infection did not promote cholesterol monohydrate crystal formation (20% vs. 10%), sandy stone formation (0% for both), or true gallstone formation (20%) compared with uninfected mice fed the lithogenic diet (10%). Additionally, H. pylori failed to stimulate mucin gel accumulation in the gallbladder or alter gallbladder size compared with uninfected animals. H. pylori-infected C57L mice developed moderate to severe gastritis by 12 wk, and the lithogenic diet itself produced lesions in the forestomach, which were exacerbated by the infection. We conclude that H. pylori infection does not play any role in murine cholesterol gallstone formation. Nonetheless, the C57L mouse develops severe lesions of both the glandular and nonglandular stomach in response to H. pylori infection and the lithogenic diet, respectively.

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.

DNA sequences and proteic antigens of H. pylori in cholecystic bile and tissue of patients with gallstones

BACKGROUND

Although Helicobacter pylori DNA sequences have been detected in cholecystic bile and tissue of patients with gallstones, controversial results are reported from different geographic areas.

AIM

To detect H. pylori in cholecystic bile and tissue of patients with gallstones from a previously uninvestigated geographic area, southern Italy. Detection included both the bacterial DNA and the specific antigen (H. pylori stool antigen) identified in the stools of infected patients for diagnostic purposes.

PATIENTS AND METHODS

The study enclosed 33 consecutive patients undergoing laparoscopic cholecystectomy for gallstones. DNA sequences of H. pylori were detected by polymerase chain reaction in both cholecystic bile and tissue homogenate. Moreover, we assayed H.pylori stool antigen on gall-bladder cytosolic and biliary proteins after their extraction. Bacterial presence in the stomach was assessed by urea breath test in all patients and Deltadelta13CPDB value assumed as marker of intragastric load. Fisher's exact probability and Student's t-tests were used for statistical analysis.

RESULTS

DNA sequences of H. pylori in bile were found in 51.5% and significantly correlated with its presence in cholecystic tissue homogenate (P<0.005), H. pylori stool antigen in gall-bladder (P=0.0013) and bile (P=0.04) proteins, gastric infection (P<0.01) and intragastric bacterial load (P<0.001). No correlation was found, however, with sex and age of the patients.

CONCLUSIONS

Our prevalence value of bacterial DNA in bile and gall-bladder of patients with gallstones agreed with that of the only other Italian study. The simultaneous presence of both bacterial DNA and proteic antigen suggests that the same prototype of bacterium could be located at both intestinal and cholecystic level and, therefore, the intestine represents the source of biliary contagion.

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.

Predicting Infected Bile Among Patients Undergoing Percutaneous Cholecystostomy

PURPOSE

Patients may not achieve a clinical benefit after percutaneous cholecystostomy due to the inherent difficulty in identifying patients who truly have infected gallbladders. We attempted to identify imaging and biochemical parameters which would help to predict which patients have infected gallbladders.

METHODS

A retrospective review was performed of 52 patients undergoing percutaneous cholecystostomy for clinical suspicion of acute cholecystitis in whom bile culture results were available. Multiple imaging and biochemical variables were examined alone and in combination as predictors of infected bile, using logistic regression.

RESULTS

Of the 52 patients, 25 (48%) had infected bile. Organisms cultured included Enterococcus, Enterobacter, Klebsiella, Pseudomonas, E. coli, Citrobacter and Candida. No biochemical parameters were significantly predictive of infected bile; white blood cell count >15,000 was weakly associated with greater odds of infected bile (odds ratio 2.0, p = NS). The presence of gallstones, sludge, gallbladder wall thickening and pericholecystic fluid by ultrasound or CT were not predictive of infected bile, alone or in combination, although a trend was observed among patients with CT findings of acute cholecystitis toward a higher 30-day mortality. Radionuclide scans were performed in 31% of patients; all were positive and 66% of these patients had infected bile. Since no patient who underwent a radionuclide scan had a negative study, this variable could not be entered into the regression model due to collinearity.

CONCLUSION

No single CT or ultrasound imaging variable was predictive of infected bile, and only a weak association of white blood cell count with infected bile was seen. No other biochemical parameters had any association with infected bile. The ability of radionuclide scanning to predict infected bile was higher than that of ultrasound or CT. This study illustrates the continued challenge to identify bacterial cholecystitis among patients referred for percutaneous cholecystostomy.

Helicobacter pylori in the etiology of cholesterol gallstones

GOALS

We aimed to investigate the presence of bacterial structures in cholesterol gallstones and particularly presence of Helicobacter spp/H. pylori in gallstones by microbiologic cultivation, histopathologic staining, and polymerase chain reaction (PCR).

BACKGROUND

Many studies suggest that different mechanisms are responsible for the formation of pigmented gallstones and cholesterol gallstones. Recently, studies showed that infection could have an important role in the formation of cholesterol gallbladder stones.

STUDY

We examined 77 mixed cholesterol gallstones. After cholecystectomy, gallbladder cultures were done for H. pylori and other bacterium. Gallbladder has also been examined by three histopathologic staining methods (Warthin-Starry, hematoxylin eosin, and gram staining) for Helicobacter spp. In addition, 16S rRNA-PCR amplification was performed for Helicobacter spp in gallstones. Twenty postmortem gallbladders without gallstones were investigated by the same histopathologic and PCR methods for Helicobacter spp. as a control group.

RESULTS

Different bacterium were isolated from 22 gallbladder samples (12 Escherichia coli, 8 Pseudomonas, and 2 clostridium) and H. pylori was isolated in 6 gallbladder samples. Helicobacter spp was found in 7 gallstones by PCR amplification. Helicobacter-like organisms were demonstrated in 18 samples by three different histopathologic methods. Helicobacter-like organisms were also found in five samples by the same histopathologic methods (Warthin-Starry, hematoxylin-eosin, and gram staining). Only four samples were found positive for Helicobacter spp/H. pylori by all methods.

CONCLUSIONS

Bacterial population including H. pylori could have a possible role in the formation of cholesterol gallstones.

Identification of Helicobacter pylori DNA in Iranian patients with gallstones

In order to identify Helicobacter in gallstones of Iranian patients with biliary disease, gallstone and bile samples from 33 patients were subjected to rapid urease test, culture and Multiplex PCR using primers based on 16s rRNA and isocitrate dehydrogenase genes for the identification of Helicobacter genus and H. pylori respectively. This PCR was also done on bile samples from 40 autopsied gallbladders with normal pathology (control group). In 18.1% of stone and 12.1% of bile samples, H. pylori DNA was detected using PCR. Rapid urease and culture tests were negative for all samples. The PCR was negative in the control group. In conclusion, H. pylori DNA was detected in stone samples of Iranian patients with gallstones but we are not sure of their viability. To clarify the clinical role of Helicobacter in gallbladder diseases, studies using accurate tests on larger patient and control groups are needed to ascertain whether this microorganism is an innocent bystander or active participant in gallstone formation.

Antibiotic activity and synergistic effect of antimicrobial peptide against pathogens from a patient with gallstones

HP (2-20) is a peptide derived from the N-terminus of Helicobacter pylori ribosomal protein L1 that has been shown to have antimicrobial activity against various species of bacteria. When we tested the effects of HP (2-20), we found that this peptide displayed strong activity against pathogens from a patient with gallstones, but it did not have hemolytic activity against human erythrocytes. We also found that HP (2-20) had potent activity against cefazolin sodium-resistant bacterial cell lines, and that HP (2-20) and cefazolin sodium had synergistic effects against cell lines resistant to the latter. To investigate the mechanism of action of HP (2-20), we performed fluorescence activated flow cytometry using pathogens from the patient with gallstones. As determined by propidium iodide (PI) staining, pathogenic bacteria treated with HP (2-20) showed higher fluorescence intensity than untreated cells, similar to melittin-treated cells, and that HP (2-20) acted in an energy- and salt-dependent manner. Scanning electron microscopy showed that HP (2-20) caused significant morphological alterations in the cell surface of pathogens from the patient with gallstones. By determining their 16S rDNA sequences, we found that both the pathogens from the patient with gallstones and the cefazolin sodium-resistant cell lines showed 100% homology with sequences from Pseudomonas aeruginosa. Taken together, these results suggest that HP (2-20) has antibiotic activity and that it may be used as a lead drug for the treatment of acquired pathogens from patients with gallstones and antibiotic-resistant cell lines.

US-guided Percutaneous Cholecystostomy: Features Predicting Culture-Positive Bile and Clinical Outcome

PURPOSE

To assess sonographic and clinical features that might be used to predict infected bile and/or patient outcome from ultrasonography (US)-guided percutaneous cholecystostomy.

MATERIALS AND METHODS

Between February 1997 and August 2002 at one institution, 112 patients underwent US-guided percutaneous cholecystostomy (59 men, 53 women; average age, 69.3 years). All US images were scored on a defined semiquantitative scale according to preset parameters: (a) gallbladder distention, (b) sludge and/or stones, (c) wall appearance, (d) pericholecystic fluid, and (e) common bile duct size and/or choledocholithiasis. Separate and total scores were generated. Retrospective evaluation of (a) the bacteriologic growth of aspirated bile and its color and (b) clinical indices (fever, white blood cell count, bilirubin level, liver function test results) was conducted by reviewing medical records. For each patient, the clinical manifestation was classified into four groups: (a) localized right upper quadrant symptoms, (b) generalized abdominal symptoms, (c) unexplained sepsis, or (d) sepsis with other known infection. Logistic regression models, exact Wilcoxon-Mann-Whitney test, and the Kruskal-Wallis test were used.

RESULTS

Forty-seven (44%) of 107 patients had infected bile. A logistic regression model showed that wall appearance, distention, bile color, and pericholecystic fluid were not individually significant predictors for culture-positive bile, leaving sludge and/or stones (P =.003, odds ratio = 1.647), common bile duct status (P =.02, odds ratio = 2.214), and total score (P =.007, odds ratio = 1.267). No US covariates or clinical indices predicted clinical outcome. Clinical manifestation was predictive of clinical outcome (P =.001) and aspirating culture-positive bile (P =.008); specifically, 30 (86%) of 35 patients with right upper quadrant symptoms had their condition improve, compared with one (7%) of 15 asymptomatic patients with other known causes of infection.

CONCLUSION

US variables can be used to predict culture-positive bile but not patient outcome. Clinical manifestation is important because patients with right upper quadrant symptoms have the best clinical outcome.

Retroperitoneal actinomycosis due to dropped gallstones

Dropped bile and gallstones after accidental perforation of the biliary gallbladder is a frequent event during laparoscopic cholecystectomy and is generally of no clinical importance. However, calculi left in the abdominal cavity can produce a series of severe late complications. We present a patient with retroperitoneal actinomycosis produced by dropped gallstones after a laparoscopic cholecystectomy.

Comparative analysis of Salmonella enterica serovar Typhimurium biofilm formation on gallstones and on glass

In this study, the roles of global regulators, motility, lipopolysaccharide, and exopolysaccharides were further characterized with respect to biofilm formation on both gallstones and glass surfaces. These studies show the complex nature of biofilms and demonstrate that characteristics observed for each biofilm are unique to the particular culture condition.

Bile anaerobic bacteria detection and antibiotic susceptibility in patients with gallstone

OBJECTIVE

To detect bile anaerobic bacteria and antibiotic susceptibility in 59 patients with gallstones who had had cholecystectomy.

METHODS

BACT/ALERT 120 microbe detection system and SCEPTOR microbe detection system were used to detect bile anaerobic bacteria, antibiotic susceptibility.

RESULTS

The ratio of anaerobic bacteria to the patients examined was 52.5% (31/59). Obligate anaerobe bile culture showed positive results in 4 patients. B. fragilis (37.8%) was the major type of anaerobic bacteria in bile. Most (81.8%) of anaerobic bacteria were sensitive to metronidazole, and imipenem was suitable for beta-lactamase bacteria.

CONCLUSIONS

Culture of anaerobic bacteria in logarithmic phase can improve the positive rate of the culture. There are some relations between anaerobic infection and gallstone formation.

Microbiology of choledochal bile in patients with choledocholithiasis admitted to a tertiary hospital

AIM

The present study was designed to investigate the microbiology of choledochal bile of patients with cholangitis and choledocholithiasis.

METHODS

We identified and determined the antimicrobial susceptibility of bacteria isolated in the bile of patients with cholangitis and choledocholithiasis diagnosed by endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

Nineteen (82.6%) of 23 patients with choledocholithiasis had positive bile cultures. A single agent was detected in 11 patients (57.9%), while a mixed growth, with pathogens ranging from two to three species, were seen in eight patients (42.1%). Patients with clinical manifestations of cholangitis had significantly higher counts of colonies per mL of bile (> 105 cfu/mL). The predominant Gram-negative aerobic bacteria isolated were Escherichia coli (9, 31.0%), Klebsiella pneumoniae (5, 17.2%), Enterobacter cloacae (2, 6.9%), Pantoea agglomerans (1, 3.4%), and Pseudomonas aeruginosa (1, 3.4%). The predominant Gram-positive bacteria were Enterococcus faecalis (5, 17.2%) and Streptococcus sp. (5, 17.2%). Bacteroides fragilis was isolated in one patient with mixed growth. All Gram-positive bacteria isolated in bile were sensitive to ampicillin, and all Gram-negative bacteria isolated were sensitive to gentamicin with a minimum inhibitory concentration (CIM90) ranging from 0.5 to 1.0- micro g/mL. Gram-negative bacteria were also sensitive to imipenem, fluorquinolones, second and third generation cephalosporins. Although all five isolates of E. faecalis were sensitive to ampicillin, two of five (40%) E. faecalis isolates demonstrated high levels of resistance to gentamicin.

CONCLUSION

E. coli, K. pneumoniae, E. faecalis and Streptoccocus sp. were the most common bacteria isolated in the bile of patients with cholangitis and choledocholithiasis, which were sensitive to a simple therapeutic regimen, such as the combination of ampicilin and gentamicin.

Pathogenesis of pigment gallstones in Western societies: the central role of bacteria

Bacteria are traditionally accorded a greater role in pigment gallstone formation in Eastern populations. Stone color is thought to predict the presence of bacteria; that is, black stones (Western predominant) are supposedly sterile and brown stones (Eastern predominant) contain bacteria. We previously reported that, regardless of appearance, most pigment gallstones contain bacteria. This study examined, in a large Western population (370 patients), the incidence, appearance, and chemical composition of pigment stones, and the characteristics of gallstone bacteria. One hundred eighty-six pigment stones were obtained aseptically. Bacteria were detected by means of scanning electron microscopy and gallstone culture. Chemical composition was determined by infrared spectroscopy. Bacteria were tested for slime and beta-glucuronidase production. Seventy-three percent of pigment stones contained bacteria. Choledocholithiasis was associated with gallstone bacteria. Ca-bilirubinate was present in all pigment stones. Ca-palmitate was characteristic of infected stones, and more than 75% Ca-carbonate was characteristic of sterile stones. Neither chemical composition nor stone appearance predicted the presence of bacteria. Ninety-five percent and 67% of infected pigment stones contained bacteria that produced slime and beta-glucuronidase, respectively. Most pigment stones contained bacteria that produced beta-glucuronidase, slime, and phospholipase, factors that facilitate stone formation. Thus bacteria have a major role in Western pigment gallstone formation. Furthermore, gallstone color did not predict composition or bacterial presence.

Bacteriology and antimicrobial susceptibility in biliary tract disease: an audit of 10-year's experience

Cholelithiasis, choledocholithiasis and hepatolithiasis are common biliary tract diseases. These diseases may cause severe infection and/or sepsis. In addition to surgical treatments, prompt administration of appropriate antibiotic is important to control the biliary tract infection. The purpose of this study is to illustrate the bacteriology in biliary tract disease and provide information for antibiotic choices. From Jan 1991 to Aug 2000, 1394 patients including gallbladder (GB) stones, common bile duct (CBD) stones, intrahepatic duct (IHD) stones, GB polyps and biliary malignancy were subjects for this retrospective study. The overall positive rate of bile culture is 36% in this study while it was 25%, 66%, 67% and 9% for GB stones, CBD stones, IHD stones and biliary malignancy, respectively. A significantly higher (p = 0.001) positive culture rate was found for GB stones with acute cholecystits (47%) compared with that without inflammation (17%). Similarly, the culture rate for hepatolithiasis with acute cholangitis was higher than that without cholangitis (75% vs 51%, p = 0.011). Long-term external biliary drainage in biliary malignancy increased the risk of bacterial culture rate. For gallstone diseases, the most common organisms cultured were Gram negative bacteria (74%), in which Escherichia coli (36%) and Klebsiella (15%) were most commonly found, followed by Gram positive (15%) bacteria such as Enterococcus (6%), Staphylcoccus (3%), Streptococcus (2%). Bacteroides (5%) and Clostridium (3%) were occasionally found anaerobes (9%). Polymicrobial infection was encountered in 19%, 31% and 29% for patients with GB stones, CBD stones and IHD stones, respectively; frequency of mixed aerobic and anaerobic infection was 7%, 12% and 9%. In the current study, ampicillin in combination with sulbactam and aminoglycoside is still a suggestive empirical therapy. Antibiotic treatment should be adjusted based on later bacteriological cultures and clinical condition.

Pigment gallstone pathogenesis: slime production by biliary bacteria is more important than beta-glucuronidase production

Pigment stones are thought to form as a result of deconjugation of bilirubin by bacterial beta-glucuronidase, which results in precipitation of calcium bilirubinate. Calcium bilirubinate is then aggregated into stones by an anionic glycoprotein. Slime (glycocalyx), an anionic glycoprotein produced by bacteria causing foreign body infections, has been implicated in the formation of the precipitate that blocks biliary stents. We previously showed that bacteria are present within the pigment portions of gallstones and postulated a bacterial role in pigment stone formation through beta-glucuronidase or slime production. Ninety-one biliary bacterial isolates from 61 patients and 12 control stool organisms were tested for their production of beta-glucuronidase and slime. The average slime production was 42 for biliary bacteria and 2.5 for stool bacteria (P <0.001). Overall, 73% of biliary bacteria and 8% of stool bacteria produced slime (optical density >3). In contrast, only 38% of biliary bacteria produced beta-glucuronidase. Eighty-two percent of all patients, 90% of patients with common bile duct (CBD) stones, 100% of patients with primary CBD stones, and 93% of patients with biliary tubes had one or more bacterial species in their stones that produced slime. By comparison, only 47% of all patients, 60% of patients with CBD stones, 62% of patients with primary CBD stones, and 50% of patients with biliary tubes had one or more bacteria that produced beta-glucuronidase. Most biliary bacteria produced slime, and slime production correlated better than beta-glucuronidase production did with stone formation and the presence of biliary tubes or stents. Patients with primary CBD stones and biliary tubes had the highest incidence of slime production. These findings suggest that bacterial slime is important in gallstone formation and the blockage of biliary tubes.

Infected bile-induced acute pancreatitis in rabbits. The role of bacteria

CONCLUSIONS

Bacteria species commonly found in bile of patients with choledocholithiasis render human bile toxic to the pancreas. The severity of infected bile-induced acute pancreatitis depends on the bacterial species. Infected bile-induced acute pancreatitis turns into a sterile inflammation within 10 d.

BACKGROUND

Flow of bile into the pancreatic duct was proposed to cause some forms of gallstone pancreatitis. The development of bile-induced acute pancreatitis at physiologic ductal pressure is known to depend on the bacterial infection of bile. In this study, we investigated the effect of a variety of bacteria species commonly found in bile of patients with choledocholithiasis upon the pancreatic toxicity of human bile. The time-course of pancreatic infection in infected bile-induced acute pancreatitis was also analyzed.

METHODS

In rabbits, the pancreatic duct was kept obstructed throughout the experiment. After 24 h, 50 microL of pancreatic juice was obtained from the congested pancreatic duct and replaced with the same quantity of infected human bile. Bile contained bacteria (10(7) microorganisms/microL) of species frequently found in choledochal secretions of patients with gallstone disease. Effects on pancreatic morphology were studied after 48 h. In another experiment, the number of Escherichia coli/mg of pancreatic tissue was determined in a time sequence study following exposure of the rabbit pancreatic duct to 50 microL E. coli-infected bile (10(7) microorganisms/mL) and temporary (12 h) or permanent duct obstruction.

RESULTS

Sterile bile was not harmful to the pancreas. Infected bile caused an interstitial-edematous pancreatitis with occasional acinar necrosis. The severity of acute pancreatitis depended on the bacterial species. Following pancreatic duct exposure to E. coli-infected bile, there was complete clearance of the bacteria from the gland with a concomitant interstitial leukocyte infiltration within a period of 2-10 d.

Lipopolysaccharides and beta-glucuronidase activity in choledochal bile in relation to choledocholithiasis

Common duct gallstones are mainly of the brown pigment type, which are usually attributed to bacterial factors. Bacterial beta-glucuronidase most probably plays a role in the pathogenesis in many but not all patients. The role of other bacterial factors is more undecided. The aims of this study were to investigate a possible association between lipopolysaccharides (LPS) and choledocholithiasis, and to examine the interrelationship to beta-glucuronidase. Common duct bile obtained at endoscopic retrograde cholangiography in 86 patients was assayed for LPS by a limulus amebocyte lysate test, and beta-glucuronidase activity at pH 7.0 was measured. We found that both elevated concentration of LPS and the presence of juxtapapillary duodenal diverticula were associated with common duct stones (p < 0.01, both). Patients who had their common duct stones removed recently had a lower LPS concentration and a lower activity of beta-glucuronidase than those who had a stone in situ (p < 0.01, both), but still higher LPS concentration than those without choledocholithiasis at all (p < 0.01). In multiple logistic regression analysis, elevated LPS was the significant predictor of common duct stones (p < 0.01), and not confounding with neither beta-glucuronidase nor juxtapapillary diverticula. We conclude that gram-negative bacteria convey bacterial factors associated with choledocholithiasis, by mechanisms independent of, and additional to beta-glucuronidase.

Counts of bacteria and pyocites of choledochal bile in controls and in patients with gallstones or common bile duct stones with or without acute cholangitis

BACKGROUND/AIMS

The number of colonies of bacteria and the number of pyocites present per ml of choledochal bile was studied.

PATIENTS AND METHODS

There were 42 controls, 100 patients with symptomatic gallstones, 42 patients with common duct stones without cholangitis and 24 patients with common duct stones and acute cholangitis.

RESULTS

Control subjects had no bacteria present at gallbladder bile. Only 3% of patients with gallstones had more than 10(5) colonies per ml which increased to 36% in patients with common duct stones without cholangitis and to 84% among patients with acute cholangitis (p < 0.001). There were more polybacterial flora among patients with acute cholangitis and anaerobic bacteria were not seen in patients with gallstones. Patients with acute cholangitis had significantly more pyocites present at choledochal bile.

CONCLUSION

There is a direct correlation between the number of colonies present per ml of choledochal bile and the severity of biliary tract disease. Patients with acute cholangitis had significantly more pyocites present at choledochal bile compared to gallstones or patients with CBD stones without cholangitis.

Simultaneous bacteriologic assessment of bile from gallbladder and common bile duct in control subjects and patients with gallstones and common duct stones

OBJECTIVES

To determine the simultaneous prevalence of bacteria in bile from the gallbladder and common bile duct and to determine the influence of the number of stones present on bacteriologic findings.

METHODS

A prospective study was performed in 467 subjects divided into seven groups: 42 control subjects with normal biliary tracts, 221 patients with symptomatic gallstone disease, 12 patients with hydropic gallbladder, 52 patients with acute cholecystitis, 67 patients with common bile duct stones without cholangitis, 49 patients with common bile duct stones and acute cholangitis, and 24 patients with previous cholecystectomy and common bile duct stones. In all except controls, bile samples from the gallbladder and common bile duct were taken simultaneously for aerobic and anaerobic cultures.

RESULTS

Control subjects had no bacteria in gallbladder bile. Patients with gallstones, acute cholecystitis, and hydropic gallbladder had similar rates of positive cultures in the gallbladder and common bile duct, ranging from 22% to 46%, but the rate was significantly higher in patients with common bile duct stones without cholangitis (58.2%). Patients with cholangitis or previous cholecystectomy had a high rate of positive cultures of common duct bile (93% to 100%). Age greater than 60 years had a significant influence on the rate of positive bile cultures. There was no relationship between the number of stones in the gallbladder or common bile duct and the percentage of positive cultures. In 98% of the patients, the same bacteria were isolated from gallbladder and common duct bile.

CONCLUSIONS

In normal subjects, no bacteria were present in the biliary tract. Among patients with common bile duct stones, there was an increasing percentage of positive cultures according to the severity of the disease. Age had an important influence, but sex and the number of common bile duct stones had no influence on positive cultures.

Bacteriological studies of liver parenchyma in controls and in patients with gallstones or common bile duct stones with or without acute cholangitis

BACKGROUND/AIMS

The presence of aerobic and/or anaerobic bacteria in the liver parenchyma, gallbladder bile, and common bile duct was investigated.

MATERIALS AND METHODS

There were 15 control subjects, 32 cases with symptomatic gallstones, 16 patients with common bile duct stones without acute cholangitis and 8 cases with common bile duct stones with an acute suppurative cholangitis.

RESULTS

No bacteria were isolated in controls. The percentage of positive cultures in liver parenchyma increased in proportion to the severity of the biliary tract disease. There was no clear correlation between normal and altered hepatic histology and the presence or absence of bacteria except in patients with acute cholangitis.

CONCLUSIONS

When biliary tract obstruction is present, the biliary tract is more vulnerable to invasion of bacteria and therefore increases the chance of spread into the liver parenchyma.