Origin of bacteria in bileduct bile

A systematic review on omics data (metagenomics, metatranscriptomics, and metabolomics) in the role of microbiome in gallbladder disease

Microbiotas are the range of microorganisms (mainly bacteria and fungi) colonizing multicellular, macroscopic organisms. They are crucial for several metabolic functions affecting the health of the host. However, difficulties hamper the investigation of microbiota composition in cultivating microorganisms in standard growth media. For this reason, our knowledge of microbiota can benefit from the analysis of microbial macromolecules (DNA, transcripts, proteins, or by-products) present in various samples collected from the host. Various omics technologies are used to obtain different data. Metagenomics provides a taxonomical profile of the sample. It can also be used to obtain potential functional information. At the same time, metatranscriptomics can characterize members of a microbiome responsible for specific functions and elucidate genes that drive the microbiotas relationship with its host. Thus, while microbiota refers to microorganisms living in a determined environment (taxonomy of microorganisms identified), microbiome refers to the microorganisms and their genes living in a determined environment and, of course, metagenomics focuses on the genes and collective functions of identified microorganisms. Metabolomics completes this framework by determining the metabolite fluxes and the products released into the environment. The gallbladder is a sac localized under the liver in the human body and is difficult to access for bile and tissue sampling. It concentrates the bile produced in the hepatocytes, which drains into bile canaliculi. Bile promotes fat digestion and is released from the gallbladder into the upper small intestine in response to food. Considered sterile originally, recent data indicate that bile microbiota is associated with the biliary tract’s inflammation and carcinogenesis. The sample size is relevant for omic studies of rare diseases, such as gallbladder carcinoma. Although in its infancy, the study of the biliary microbiota has begun taking advantage of several omics strategies, mainly based on metagenomics, metabolomics, and mouse models. Here, we show that omics analyses from the literature may provide a more comprehensive image of the biliary microbiota. We review studies performed in this environmental niche and focus on network-based approaches for integrative studies.

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.

Infections of the biliary tract

Infection of the biliary tract, or cholangitis, is a potentially life-threatening condition. Bile duct stones are the most common cause of biliary obstruction predisposing to cholangitis. The key components in the pathogenesis of cholangitis are biliary obstruction and biliary infection. Several underlying mechanisms of bactibilia have been proposed. Characteristic clinical features of cholangitis include abdominal pain, fever, and jaundice. A combination of clinical features with laboratory tests and imaging studies are frequently used to diagnose cholangitis. Endoscopic retrograde cholangiopancreatography is the best diagnostic test. Less invasive imaging tests may be performed initially in clinically stable patients with uncertain diagnoses.

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.

Non-viral infections of the liver

The function and anatomy of the liver renders this organ peculiarly susceptible to bacterial and parasitic infections; fungal infections are increasingly recognised in the immunocompromised. As biochemical abnormalities of liver function can be non-specific, a high index of suspicion of liver or biliary infection is required. A need for prompt investigation is emphasised by the potentially rapid progression and poor prognosis of some bacterial and fungal infections, and the public health implications of parasitic diseases. This review encompasses the major infections of the liver and biliary tree other than viral hepatitis and includes aspects of pathogenicity, epidemiology, clinical presentation, diagnosis and management.

MR imaging findings of infectious cholangitis

The purpose of this study was to evaluate the appearance of infectious cholangitis on MRI. The MR images of 13 patients (9 women, 4 men; age range, 14-79 years) with clinically confirmed infectious cholangitis, who represent our complete 9.5 year experience with this entity, were retrospectively evaluated. All MR studies were performed at 1.5 T and included: in-phase and out-of-phase T(1)-weighted spoiled gradient echo (SGE), T(2)-weighted fat-suppressed echo train spin echo, single shot T(2)-weighted sequences, and serial postgadolinium T(1)-weighted SGE sequences without and with fat-suppression. The biliary ductal system was evaluated regarding presence of dilatation, stenosis, wall irregularities, wall thickening, and gadolinium enhancement of duct walls. The liver parenchyma was evaluated regarding focal signal abnormalities on precontrast and serial postgadolinium images. Biliary ductal dilatation was observed in 100% of patients. Mild to moderate thickening of bile duct walls combined with increased enhancement on postgadolinium images was observed in 92% of patients. The liver parenchyma showed periportal or wedge-shaped areas of hyperintense signal on T(2)-weighted images in 69% of patients. On T(1)-weighted images, 54% of patients showed areas of hypointense signal and 15% of patients showed wedge-shaped hyperintense areas. Areas with increased enhancement on immediate postgadolinium SGE were observed in 58% of patients, and in 42% of patients increased enhancement persisted on 2 min postgadolinium fat-suppressed images. Distinctive MRI findings on pre- and postgadolinium images are appreciated for infectious cholangitis.

Acute (ascending) cholangitis

Cholangitis is an infection of an obstructed biliary system, most commonly due to common bile duct stones. Bacteria reach the biliary system either by ascent from the intestine or by the portal venous system. Once the biliary system is colonized, biliary stasis allows bacterial multiplication, and increased biliary pressures enable the bacteria to penetrate cellular barriers and enter the bloodstream. Patients with cholangitis are febrile, often have abdominal pain, and are jaundiced. A minority of patients present in shock with hypotension and altered mentation. There is usually a leukocytosis, and the alkaline phosphatase and bilirubin levels are generally elevated. Noninvasive diagnostic techniques include sonography, which is the recommended initial imaging modality. Standard CT, helical CT cholangiography, and magnetic resonance cholangiography often add important information regarding the type and level of obstruction. Endoscopic sonography is a more invasive means of obtaining high-quality imaging, and endoscopic or percutaneous cholangiography offers the opportunity to perform a therapeutic procedure at the time of diagnostic imaging. Endoscopic modalities currently are favored over percutaneous procedures because of a lower risk of complication. Treatment includes fluid resuscitation and antimicrobial agents that cover enteric flora. Biliary decompression is required when patients do not rapidly respond to conservative therapy. Definitive therapy can be performed by a surgical, percutaneous, or endoscopic route; the last is favored because it is the least invasive and has the lowest complication rate. Overall prognosis depends on the severity of the illness at the time of presentation and the cause of the biliary obstruction.

Bacterial DNA in mixed cholesterol gallstones

OBJECTIVE

Numerous investigators have proposed a role for bacteria in biliary lithogenesis. We hypothesized that bacterial DNA is present in gallstones, and that categorical differences exist between gallstone type and the frequency of bacterial sequences.

METHODS

Polymerase chain reaction (PCR) was used to amplify bacterial 16S rRNA and uidA (encoding Escherichia coli [E. coli] beta-glucuronidase) genes in different types of gallstones. PCR products were sequenced.

RESULTS

Bacterial 16S rRNA and uidA DNA sequences in E. coli were detected in all brown pigment, common bile duct, and mixed cholesterol gallstones (n = 14). In contrast, only one (14%) of seven pure cholesterol gallstones yielded a PCR product. Most (88%) mixed cholesterol gallstones yielded PCR amplification products from their central, as well as their outer, portions. Sequenced products possessed 88-98% identity to 16S rRNA genes of E. coli and Pseudomonas species.

CONCLUSIONS

Bacterial DNA sequences are usually present in mixed cholesterol (to 95% cholesterol content), brown pigment, and common bile duct, but rarely in pure cholesterol gallstones. The presence of bacterial beta-glucuronidase is also suggested. The role of bacteria and their products in the formation of mixed cholesterol gallstones, which comprise the majority of cholesterol gallstones, warrants further study.

Review article: antibiotic prophylaxis for endoscopic retrograde cholangiopancreatography (ERCP)

This review examines the evidence for antibiotic prophylaxis in endoscopic retrograde cholangiopan-creatography (ERCP), and provides detailed advice about suitable antibiotic regimens in appropriate high-risk patients. Ascending cholangitis and infective endocarditis are potential complications of endoscopic ERCP. The pathophysiology of these two complications is quite separate and different sub-groups of patients require prophylaxis with appropriate antibiotic regimens. Ascending cholangitis results from bacterial infection of an obstructed biliary system, usually from enteric Gram-negative microorganisms, resulting in bacteraemia. There is incomplete drainage of the biliary system after ERCP in up to 10% of patients who require stenting. Antibiotics started in these patients will probably reduce the frequency of cholangitis by 80%. If antibiotics are restricted to this group, approximately 90% of all patients having an ERCP will avoid antibiotics, but 80% of cholangitic episodes will be prevented. Infective endocarditis may result from the bacteraemia caused at the time of the ERCP in patients with an abnormal heart valve. Antibiotic prophylaxis, in particular covering alpha-haemolytic streptococci, should be started before the procedure in this defined high-risk group.

Endoscopic dilatation of the biliary sphincter for removal of bile duct stones: an overview of current indications and limitations

Endoscopic balloon dilatation (EBD) of the biliary sphincter may be an alternative to endoscopic sphincterotomy (EST) for removal of bile duct stones. After EBD of the biliary sphincter to a diameter of 8 mm, stones are removed according to standard guidelines. In the event that stone removal fails after EBD, an additional EST is performed. The overall success rate of stone removal after EBD (90%) is comparable to that of EST. After EBD, an additional EST and mechanical lithotripsy are required in 10% and 30% of patients, respectively. In patients with bile duct stones < 10 mm and a stone number < or = 3, EBD is nearly always successful without the need for additional EST or mechanical lithotripsy. Pancreatitis post-EBD occurs at a rate of 5-7%, which is not significantly different from that after EST. Significant bleeding post-EBD has not been observed in over 400 patients undergoing EBD. EBD is a valuable alternative to EST, especially in patients with smaller bile duct stones and in patients with haemostatic disorders.

Long-term follow-up after endoscopic sphincterotomy for bile duct stones in patients younger than 60 years of age

BACKGROUND

Little is known about the long-term effects of endoscopic biliary sphincterotomy.

METHODS

We retrospectively evaluated the rate of late complications after endoscopic sphincterotomy (EST) for bile duct stones. Patients had to meet the following inclusion criteria: (1) treated between 1976 and 1980, (2) complete stone removal after EST, (3) prior cholecystectomy or elective cholecystectomy within 2 months after EST, and (4) 60 years old or younger at the time of ERCP. A total of 100 patients were identified. Information was obtained from general practitioners and patients by telephone. Patients completed a postal questionnaire and a blood sample was obtained for liver function tests.

RESULTS

Information was obtained for 94 patients (in the majority of cases [87%] from multiple sources). There were 26 men and 68 women with a mean age of 51 years at the time of ERCP (range, 23 to 60 years). Early complications (< 30 days) occurred in 14 patients (15%). One patient died of a retroperitoneal perforation secondary to EST. During a median period of 15 years (range, 3 to 18 years), 22 patients (24%) developed a total of 36 late complications. There were 21 patients with symptoms of recurrent bile duct stones and one patient with biliary pancreatitis. Other late complications, such as recurrent ascending cholangitis or malignant degeneration, were not observed. An ERCP was performed in 20 of the 22 patients with late complications and demonstrated bile duct stones in 13, combined with stenosis of the EST opening in 9 patients. Late complications were initially managed endoscopically and/or conservatively. One patient underwent surgery after failed endoscopic treatment and one patient died of cholangitis before she could undergo an ERCP. Twelve other patients died of unrelated causes during follow-up.

CONCLUSIONS

After EST for bile duct stones, late complications occur in a significant proportion of patients. Stone recurrence remains the most important problem, but can in general be managed endoscopically.

A major histocompatibility complex class I-related Fc receptor for IgG on rat hepatocytes

Intestinal epithelial cells of the neonatal rat and mouse have been shown to express a major histocompatibility complex (MHC) class I-like Fc receptor, or FcRn, which transports IgG in an apical to basolateral direction. Previous studies have suggested the possible expression of this receptor beyond the neonatal period within the liver. Since bile contains high levels of IgG, we sought to determine whether the FcRn was functionally expressed by adult rat hepatocytes. Using primers specific for FcRn, which did not cross hybridize with MHC class I transcripts, FcRn DNA was amplified by reverse transcriptase polymerase chain reaction from RNA of adult rat hepatocytes. This RNA contained functional FcRn transcripts as it encoded a beta 2-microglobulin-associated cell surface protein as determined by immunoprecipitation of biotinylated cell surface proteins with a polyclonal anti-FcRn specific antiserum. Western blotting of hepatocyte canalicular (apical) and sinusoidal (basolateral) plasma membranes with an FcRn-specific monoclonal antibody further confirmed the protein expression and suggested that FcRn was enriched on the canalicular surface membranes. FcRn, on the surface of hepatocytes, was biologically functional as it bound Fc fragments of IgG at pH 6.0 but not 8.0, which is the same pH dependence observed for FcRn in rat neonatal enterocytes. Thus, FcRn is functionally expressed outside of the neonatal period on the canalicular cell surface of adult hepatocytes. This suggests that hepatocyte FcRn may bind luminal IgG, providing a potential functional communication between parenchymal immune cells and bile.

Acute cholangitis

Cholangitis is an infection of the biliary ductal system that results from the combination of bactibilia and biliary obstruction. Choledocholithiasis has been the leading cause of cholangitis. However, in recent years, especially at tertiary referral centers, nonoperative biliary manipulations, often in patients with unresectable malignancies, have become the most common cause of cholangitis. As a result, the complete triad of fever and chills, jaundice, and abdominal pain, as originally described by Charcot, is now seen less frequently. Most patients still have leukocytosis and abnormal liver function tests, but many patients with indwelling tubes may develop cholangitis without significant jaundice. E. coli, Klebsiella species, and the enterococci remain the most frequently isolated organisms, and anaerobes including Bacteroides fragilis are recovered in 15% to 30% of patients. However, Enterobacter and Pseudomonas species, as well as yeasts, are now being isolated more frequently from patients with indwelling tubes, who often have been treated previously with antibiotics. Computed cholangiography usually is necessary to determine the cause and site of biliary obstruction. In the majority of patients with cholangitis, cholangiography can be delayed until the patient has been afebrile for a minimum of 24 to 48 hours. Initial therapy includes bowel rest, intravenous fluids, and antibiotics. Many antibiotic regimens are now available to cover the gram-negative aerobes, the enterococcus, and the anaerobes that are likely to be causing the biliary infection. The combination of a penicillin and an aminoglycoside has been the gold standard. However, recent studies suggest that the newer broad-spectrum penicillins provide adequate therapy for these patients. Only a small percentage (5%-10%) of patients with toxic cholangitis require emergency biliary decompression. The choice of percutaneous or endoscopic drainage should be made on the basis of the presumed site and cause of obstruction as well as local expertise. The nature of the biliary obstruction may be the most important determinant of outcome. At present, patients with end-stage malignant obstruction account for most of the deaths, whereas approximately 95% of patients survive an episode of cholangitis.

The occurrence and sources of natural antibody in human bile and serum against the O antigens of two Escherichia coli serotypes

Paired serum and bile samples from normal subjects as well as patients with biliary disease were tested for natural antibody to two individual Escherichia coli O antigens by ELISA. Serum antibody was most commonly of IgM and IgG class. Antibody was less frequently detected in bile and was more commonly IgM than IgA, with IgG activity detected infrequently. Little relation was apparent between antibody in paired samples; activity could be present in both serum and bile or in either fluid alone. Titres in paired samples also did not correspond when 'normalized' with respect to the concentrations of relevant isotypes; bile was frequently enriched for natural antibody as a proportion of total immunoglobulin compared with serum. Secretory component-bound antibody was detectable in some biles that contained IgA and/or IgM activity and in the serum of 33% of subjects with biliary disorders but not in normal sera. A series of paired samples taken from three individuals was also examined for antibody against each subject's own intestinal commensal E. coli. Serum IgM and IgG activity was present in all samples, but antibody in bile was less frequent and was of IgM or IgA class. These results suggest that natural antibody in human bile occurs independently of antibody in serum and that it is substantially derived from local sources.

Cefoperazone compared with ampicillin plus tobramycin for severe biliary tract infections

In a prospective, randomized, multicenter study, the efficacy and safety of cefoperazone and the combination ampicillin-tobramycin as initial therapy for patients with severe acute biliary tract infections were compared. Of 77 patients initially entered in the study, definite severe biliary tract infection was confirmed in 67. Sixty-four patients completed treatment. At the end of treatment, 35 of 36 (97%) patients given cefoperazone and 23 of 28 (82%) given ampicillin-tobramycin were cured of their infection (P = 0.07). Pathogens were recovered from the bile in 32 patients; microbiological cures were observed in 18 of 19 (94%) patients receiving cefoperazone and 8 of 13 (62%) receiving ampicillin-tobramycin (P = 0.03). Thirteen patients had septicemia. None (0%) of the eight septicemic patients from the cefoperazone group, but two of five (40%) from the ampicillin-tobramycin group, were clinical failures. Of the isolated pathogens, 51% were resistant to ampicillin, while the resistance rate was 4% for tobramycin and 1% for cefoperazone (P less than 0.001). Biliary concentrations of cefoperazone were maintained at high levels--236 +/- 87 micrograms/ml up to 12 h after administration. Even in the presence of severe obstruction, cefoperazone levels in the bile and gallbladder wall were above MICs for most pathogens. Cefoperazone may be considered as an excellent alternative in the therapy of severe biliary tract infections.

Percutaneous biliary drainage in acute suppurative cholangitis

One hundred and sixteen percutaneous drainage procedures of the biliary system were performed in a 2-year period. Eight of 9 acutely ill patients with the diagnosis of acute suppurative cholangitis were successfully treated nonoperatively. They represented 26% of all patients with benign or postsurgical obstruction referred for biliary decompression. Conversely, acute suppurative cholangitis only occurred in 2.3% of patients with underlying malignant disease. These observations are considered most relevant in predicting the purulent nature of the disease, with further implications for patient management. Early recognition and prompt decompression of the biliary system are mandatory, along with the appropriate antibiotic coverage. Our experience compares favorably with surgical results and the procedure is proposed as the method of choice for the initial treatment of acute suppurative cholangitis.

Impaired liver clearance of bacteria in rats with chronic biliary obstruction

125I-labeled E. coli was injected into the biliary tree of normal rats and rats with 3 weeks' obstruction of the common bile duct to investigate the liver clearance capacity for bacteria. Bile was collected during 15 min, immediately, 1 h, 4 h, or 24 h after the injection. Tissue specimens from the liver, lungs, spleen and kidneys, and blood and urine specimens were collected simultaneously. In normal rats, 40% of the bacteria was recovered in the bile immediately after the injection, whereas 30% was already trapped in the liver. Incubation of the bacteria in the bile duct for 1h, 4h, and 24h resulted in liver retentions of 43%, 15%, and 4%, respectively. The recovery in the bile was 13% after 1-h incubation, and further prolongation of the incubation did not result in a significant decrease. In contrast to these findings, 70% of the injected bacteria was retained in the biliary tree in rats with chronic biliary obstruction (P less than 0.05) as compared to normal rats) and only 1% was trapped in the liver (P less than 0.005) 15 min after injection. One-hour incubation of bacteria in the bile duct decreased the retention in the bile to 30%, but the retention in the liver increased only slightly in these animals. Four and 24 h after injection less than 30% of the bacteria was retained in the hepato-biliary system. Most of these animals showed almost no radioactivity exceeding the background count in the blood, urine, spleen, lungs, and kidneys 15 min after injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of sphincteroplasty and endoscopic sphincterotomy on the bacteriologic characteristics of the common bile duct

Forty-five patients with sphincter of Oddi stenosis had specimens of common bile duct cultured during ERCP before either sphincteroplasty or endoscopic sphincterotomy. All had sterile bile before sphincter ablation. Bile was recultured 6 to 36 months later during endoscopy at which time 70 percent of the sphincterotomy and 76 percent of the sphincteroplasty patients had bile colonized principally by enteric organisms. Growth was heavy to moderate in most of the patients and contained few nasopharyngeal organisms. Despite bactobilia, no patient had symptomatic cholangitis, presumably due to excellent drainage of bile. The most likely source of the bactobilia is from direct extension of duodenal organisms into the common bile duct.

Biliary obstruction and susceptibility to biliary sepsis in rats

The effect of retrograde intrabiliary (RI) injection of E. coli was studied in Sprague-Dawley rats with biliary obstruction of different duration (3 days; 2, 4, and 6 weeks). By the injection of 10(5) colony-forming units (CFU) immediately after occlusion of the common bile duct (CBD), 15 of 18 normal rats survived without clinical signs of infection. In contrast, six of 11 animals in 3-day obstruction (P = 0.04), seven of 12 in 2-week obstruction (P = 0.02), ten of 12 in both 4-week and 6-week obstruction (P = 0.0004) died of E. coli sepsis after injection of the same amount of bacteria. Animals with longstanding jaundice (4 and 6 weeks) were more susceptible than those with a shorter duration of jaundice (3 days and 2 weeks, P = 0.04). The results warrant the early decompression of the biliary tract in biliary obstruction.

Bacterial infection of the common bile duct in chronic fascioliasis in the rat

Bile taken from rats infected with the liver fluke, Fasciola hepatica contained spiral bacteria whereas bile from uninfected rats was free from spiral bacteria. The bacterium and its relationship to the bile duct epithelium and the liver fluke was studied with a combination of light microscopy, scanning and transmission electron microscopy. Its morphological characteristics suggest that the bacterium belongs to the genus Spirillum. In contrast to many other co-infections of bacteria and helminths, the present one seems to be a fairly passive relationship so that neither the helminth nor the rat suffers from the presence of bacteria. The presence of the bacteria is thought to be due to changes in the biliary environment, produced as a result of the fluke infection; these changes subsequently allow a multiplication of bacteria normally present in the uninfected animal.

Bacteriological study of transhepatically aspirated bile. Relation to cholangiographic findings in 295 patients

The purpose of this study was to elucidate the frequency of bacterial infection of intrahepatic bile in relation to biliary tract pathology. Bile was aspirated during percutaneous transhepatic cholangiography, with or without combined biliary tract drainage, and subjected to bacteriological investigations in 295 patients with various hepatobiliary diseases. Bile was infected in 89% of the 92 patients who had high fever and were on antibiotics at the time of study. Positive cultures were obtained in 39% of the patients who were not so ill as to require antibiotics. The overall incidence of biliary infection was 90% in bile duct stones, particularly high in patients with primary intrahepatic stones, regardless of the presence of stones in the common bile duct, and in patients who had dilation of the common bile duct, presumably due to obstructive involvement of the ampulla of Vater. E. coli and Klebsiella were the most frequent among the aerobic species isolated, and mixed infection involving these organisms was common. Anaerobes were much less frequent, always mixed with aerobes, but positive cultures would increase with more rigorous anaerobic conditions for culture. Duodenal fluid collected simultaneously did not always grow the same microorganisms, but showed a 86-87% coincidence with intrahepatic bile in terms of positive or negative cultures. It is recommended that bile be cultured at the time of percutaneous transhepatic cholangiography.

Wound sepsis after elective cholecystectomy. Restriction of prophylactic antibiotics to risk groups

This prospective study of elective cholecystectomy investigated the frequency and type of bacteria in gallbladder bile at operation, the factors predicting the presence of bacteria in bile, and the relationship between bacteria in bile and subsequent wound sepsis. In 148 consecutive cases 23% of bile cultures were positive. The overall wound infection rate was 15%, but 91% of all wound infections occurred in patients with positive bile cultures. Eighty-five per cent of all positive bile cultures and 86% of all wound infections occurred in 37% of the patients, characterized by age over 60 years and/or a history of previous attacks of acute cholecystitis. We suggest that in elective cholecystectomy prophylactic antibiotics should be restricted to this group of patients to limit the use of antibiotics.

Bile bacteria in patients with benign bile duct stricture

In a prospective study of 73 patients undergoing hepatodochojejunostomy for benign bile duct stricture who were covered by antibacterial prophylaxis with gentamicin and cephalolothin, bacteria were cultured from bile sampled at operation in 80 per cent of cases. Aerobic organisms were found in 50 cases (82 per cent) and anaerobic organisms in 11 cases (18 per cent). Seventy-three per cent of the patients with postoperative septic complications had bile cultures positive for anaerobes at operation, and the same organisms were cultured from pus. All patients with anaerobes in the bile at some time in the perioperative period developed postoperative sepsis. Antibacterial prophylaxis with gentamicin and cephalothin, together with specific therapy with drugs effective against anaerobes when indicated, are recommended in the management of these cases.

The bacterial flora of the biliary tract and liver in man

A bacteriological study was made of 106 patients undergoing elective surgery for gallbladder disease and as a control group, of patients with a normal biliary tract but requiring laparotomy for gastrointestinal disease. The isolation rate of all species of bacteria from the gallbladder and common bile duct in those patients with calculi in the duct system and in those with nonfunctioning gallbladders was considerably higher than in patients with a normal biliary system. Surprisingly, the number of isolates from patients with a history of cholsecystitis or cholelithiasis was no greater than in the control group of patients.

Using modern techniques of anaerobic retrieval and culture, only a small number of anaerobes were isolated, and despite the prevalence of Bacteroides species as a normal gut inhabitant and as an opportunistic pathogen, this organism was not recovered from any of the sites investigated. Anaerobic species were Isolated from 8 out of the 106 liver biopsy specimens taken at a very early stage after laparotomy, but in such patients only non-specific liver changes were found by histological examinmation. In 8 patients from whom Escherichia colt or other aerobes were isolated from bile samples, at concentrates ranging from 105 to 107/cm3, the same species of organism were consistently isolated from T tube drainage samples for up to 8 or 9 days despite tetracycline therapy.

Bacteriological studies of common duct bile in patients with gallstone disease and juxta-papillary duodenal diverticula

Bile samples from the common duct were collected at cholecystectomy and cultivated aerobically and anaerobically. Two groups of patients were studied, patients with juxta-papillary duodenal diverticula and patients without diverticula. All patients had chronic cholecystitis and concrements in the gallbladder, but no biliary obstruction. A significantly higher incidence of positive cultures was found in patients with diverticula than in the control group. The positive samples contained bacterial species belonging to the intestinal flora. We propose an ascending route of infection and assume that bacteria may play a role in the formation of gallstones so often seen in patients with juxta-papillary duodenal diverticula.

Biliary bacteria and hepatic histopathologic changes in gallstone disease

This study attempts to assess the frequency and severity of liver damage in patients with gallstone disease and the role of bacteria in the development of these changes. Needle biopsy of the liver demonstrated acute inflammation of portal triads in 19 of 126 patients with gallstones, a finding not present in control patients. Acute inflammation occurred more often in patients with acute cholecystitis and choledocholithiasis than in chronic cholecystitis. Cultures of the biliary tract or liver were positive in 23 of 64 patients. The frequency of positive bile cultures increased with the severity of the biliary tract disease. Five out of 6 positive liver cultures were from patients with acute cholecystitis or choledocholithiasis. The data suggest that impairment of bile flow is responsible for the acute hepatic inflammatory changes.

Spectrum of cholangitis

Of 402 patients admitted with biliary disease over the last three years, cholangitis has been diagnosed in 36. This represents an 8.8 per cent overal incidence and a 33.8 per cent incidence among patients who have undergone operation or manipulation involving the common duct. Based on this experience, a program of prophylaxis and treatment of cholangitis has been devised with special emphasis on the management of elderly patients in the initial postoperative period.

A controlled trial of parenteral prophylactic gentamicin therapy in biliary surgery

This trial has investigated the value of gentamicin therapy in patients requiring biliary surgery. One hundred consecutive patients were randomly allocated to receive either gentamicin or no antibiotic. Post-operative infection was assessed by an independent observer. Cultures and gentamicin assays were performed on bile and blood sampled during and after operation. The minimum inhibitory concentrations of gentamicin were measured with isolated bacterial. In 80 per cent of patients biliary organisms were inhibited by 2 mug/ml of gentamicin. Twice this concentration was found in the serum at operation in 88 per cent, but in the bile in only 18 per cent. Nevertheless, gentamicin lowered the incidence of bacteria in the bile from 42 to 25 per cent. There was a reduction in wound sepsis from 21 to 6 per cent (P less than 0-05). Bacteriaemia was demonstrated in only 1 patient receiving gentamicin compared with 5 controls and 1 death occurred from endotoxaemia in the control group. These data suggest that gentamicin will reduce the morbidity of biliary surgery, particularly in patients in whom the bile is infected at operation.

Empyema of the gallbladder due to Haemophilus parahaemolyticus, with a brief review of its role as a pathogen

A case of empyema of the gallbladder caused by Haemophilus parahaemolyticus is reported. This is believed to the the first report of such an infection. The literature relating to pathogenicity of this organism is reviewed.

Fatal endotoxic shock of biliary tract origin complicating transhepatic cholangiography

Images

Bacterial flora in the duodenum of patients after biliary fenestration

Fasting duodenal aspirates were studied in 15 patients with a biliary fenestration, 5 patients with a single duodenal diverticulum, 1 patient with a biliary fenestration and duodenal diverticulum, and 11 control subjects. A colonic type of bacterial flora, consisting of coliforms, Clostridium welchii, and Streptococcus faecalis, was found in 10 patients with biliary fenestration, 4 patients with a duodenal diverticulum, the patient with a fenestration and duodenal diverticulum, and in 1 of the control subjects. A high incidence of deconjugation of biles salts (10 out of 15 patients) and of steatorrhoea (8 out of 15 patients) was noted in the patients with biliary fenestration, as well as in those with a duodenal diverticulum (5 and 3 patients out of 5 respectively). Above-normal serum-folate levels were observed in 3 subjects with coliform colonization.

It is possible that vague abdominal symptoms which may be experienced by patients after biliary fenestration, may be due to the presence of an abnormal bacterial flora in the duodenum.

Effectiveness of choledochoduodenostomy and transduodenal sphincterotomy in the treatment of benign obstruction of the common duct

Images

Partial biliary obstruction with cholangitis producing a blind loop syndrome

Images