Administration of branched chain amino acids prevents bacterial translocation after liver resection in the cirrhotic rat

After major liver resection, bacterial infectious complications, including sepsis and endotoxemia, can be at least in part, attributed to translocation of enteric bacteria and endotoxin. We evaluated the effectiveness of the enteral and parenteral administration of branched-chain amino acids (BCAA) in preventing bacterial translocation after 70% liver resection in rats with thioacetamide-induced-cirrhosis. Bacterial translocation after hepatectomy was induced by a disturbance of protein metabolism in intestinal epithelial cells. However, the administration of BCAA, particularly via the enteral route, improved amino acid metabolism in the gut and stimulated the synthesis of nonsecreted protein and the proliferation of crypt cells, thereby preventing bacterial translocation after liver resection. Improvement in this cascade of metabolic reactions is believed to have been responsible for the improved outcome after extensive resection of the cirrhotic liver.     

Bacterial translocation after cirrhotic liver resection: a clinical investigation of 181 patients

BACKGROUND: Cirrhotic patients are usually associated with a high susceptibility to infection. Although bacterial translocation from gut mucosa to mesenteric lymph node (MLN) and systemic circulation is a well-known phenomenon after hepatectomy, its role in cirrhotic patients remains unclear. MATERIALS AND METHODS: MLN was harvested for bacterial culture before and after liver resection in 181 cirrhotic patients. The characteristics and postoperative courses of patients with positive and negative bacterial culture for MLN after hepatectomy were compared. Postoperative systemic antibiotics were administered if infectious complications occurred. RESULTS: No bacteria were cultured in MLN before hepatectomy. Bacterial translocation (BT) to MLN after hepatectomy occurred in 36 patients (BT group). After multivariate analysis, intraoperative blood transfusion was the only independent factor that influenced bacterial translocation rates after cirrhotic liver resection. BT group patients also had higher infectious and overall complication rates, with a longer postoperative hospital stay. Among the cultured bacteriae from infected sites in BT group patients with infectious complications, only 2 patients (12.5%) had totally different bacterial species to those cultured from MLNs. CONCLUSIONS: Bacterial translocation more often occurred after liver resection in cirrhotic patients who received intraoperative blood transfusion. Such patients had higher postoperative infectious and overall complication rates. Thus, avoidance of intraoperative blood transfusion is mandatory for cirrhotic liver resection.     

Bacterial translocation after major hepatectomy in patients and rats.

Bacterial infections are frequent complications after liver resection. Of 138 patients who underwent major hepatectomy, 11 patients (8%) developed intra-abdominal sepsis in the postoperative period. Seven bacterial strains of gut origin were isolated from the abdominal cavity. Eight patients had multiple bacteria cultured. In the experimental studies on rat models, positive mesenteric lymph node cultures were seen 2 hours after removal of 70% and 90% of the total weight of the rat liver, and 12 hours after 50% hepatectomy, persisting for 3 and 4 days after 50% and 70% hepatectomy, respectively. The incidences of bacteremia 2 and 4 hours after 90% hepatectomy were 80% and 100%, respectively; 6 hours after 70% liver resection, the incidence of bacteremia was 33%. Blood cultures were positive in only 6% of the rats following 50% hepatectomy, and in none of the controls. Thus, bacterial translocation occurs in the early course after hepatectomy, the incidence being proportional to the amount of liver tissue removed.     

Nonabsorbable Antibiotics Reduce Bacterial and Endotoxin Translocation in Hepatectomised Rats

There is increasing evidence that septic complications, occurring after major hepatectomies, may be caused by gram negative bacteria, translocating from the gut. We investigated in rats, the effect of extended hepatectomy on the structure and morphology of the intestinal mucosa as well as on the translocation of intestinal bacteria and endotoxins. We also examined the effect of nonabsorbable antibiotics on reducing the intestinal flora and consequently the phenomenon of translocation by administering neomycin sulphate and cefazoline. Hepatectomy was found to increase translocation, while administration of nonabsorbable antibiotics decreased it significantly. In addition, hepatectomy increased the aerobic cecal bacterial population, which normalised in the group receiving antibiotics. Among the histological parameters evaluated, villus height demonstrated a significant reduction after hepatectomy, while the number of villi per cm and the number of mitoses per crypt, remained unchanged. Our results indicate that administration of nonabsorbable antibiotics presents a positive effect on bacterial and endotoxin translocation after extended hepatectomy, and this may be related to reduction of colonic bacterial load as an intraluminal effect of antibiotics.     

Probiotics partly reverse increased bacterial translocation after simultaneous liver resection and colonic anastomosis in rats

BACKGROUND: Bacterial translocation is one important cause of nosocomial infections following major abdominal surgery. Oral administration of probiotics has been proposed to diminish bacterial translocation. MATERIAL AND METHODS: In total 68 rats were divided into seven groups: five of the groups received standard rat chow and were subjected to either sham-operation, 70% liver resection, colonic anastomosis, or a combination of 30 or 70% liver resection with synchronous colonic anastomosis, respectively. In two additional groups with synchronous operation, a combination of four different lactic acid bacteria and four fibers was administered two times daily pre- and postoperatively. Bacterial concentrations in cecum, mesenteric lymph nodes, liver, and spleen were analyzed and blood cultures were taken 48 h after operation. Furthermore, the following parameters were assessed: histological changes in the intestine, intestinal paracellular permeability (Ussing chamber), bursting pressure of the colonic anastomosis, and mitosis rate of the remnant liver. RESULTS: Bacterial translocation was observed in all rats, except in the sham group. Following liver resection, the highest bacterial concentrations were seen in liver and spleen, following colon anastomosis in the mesenteric lymph nodes. Bacterial translocation was increased in the animals with combined operation, in parallel to the extent of liver resection. In rats with colon anastomosis, bacterial concentration in the cecum was also higher than in the sham group. Application of probiotics significantly decreased bacterial concentration in the lymph nodes. In addition, animals with a high cecal concentration of lactobacilli had less translocation than the others. No histological changes were observed in the intestine. Paracellular permeability for ions, but not for the larger molecule lactulose, was increased in the colon in all groups with colon anastomosis. The bursting pressure of the colon anastomosis was not significantly different between the groups. Seventy percent liver resection led to a high rate of hepatocyte mitosis, whereas combination with colon anastomosis impaired the regeneration process. CONCLUSION: Synchronous liver resection and colon anastomosis led to increased bacterial translocation compared to the single operations in the rat model. It is possible to diminish this process by oral administration of probiotics. Bacterial overgrowth in the cecum and impaired hepatic regeneration, but not histological changes or alterations of paracellular permeability, are potential pathogenic mechanisms for translocation in this setting.     

Intestinal permeability and bacterial translocation following small bowel transplantation in the rat

In addition to its role in absorbing nutrients, the intestinal mucosa provides an important barrier against toxins and bacteria in the bowel lumen. The present study evaluated gut barrier function following orthotopic (in continuity) intestinal grafting in rats. Graft histology, intestinal permeability, and bacterial translocation to the grafted mesenteric lymph nodes, the host's liver, and the host's spleen were assessed on the 3rd, 5th, and 7th postoperative days. The study group received no immunosuppression after allotransplantation. The two control groups included rats with isografts and rats with cyclosporine-treated allografts. On the 7th POD, the study animals had moderate transmural inflammation due to rejection, with normal histology in the isografts and CsA-treated allografts; increased intestinal permeability, measured by urinary excretion of oral 51Cr-EDTA (P less than 0.01); and increased number of bacteria in the MLN and spleen (P less than 0.05). The number of bacteria in the MLN and spleen of the study group positively correlated with the changes in intestinal permeability (P less than 0.05). Rejection of the orthotopic intestinal graft leads to increased intestinal permeability and bacterial translocation from the lumen of the graft to the host's reticuloendothelial system. Measures to improve gut barrier function and antibiotic therapy during rejection episodes may help reduce the incidence of septic complications after intestinal grafting.     

Promotion by burn stress of the translocation of bacteria from the gastrointestinal tracts of mice

A mouse burn model was established to test the effect of nonlethal thermal injury on the translocation of indigenous bacteria from the gastrointestinal (GI) tract to other organs. Specific pathogen-free (SPF) mice were given 15% or 30% total body surface area burns, and the mesenteric lymph nodes (MLNs), spleens, livers, blood, and peritoneal cavities were cultured for translocated bacteria at various time intervals. No viable aerobic, facultatively anaerobic, or strictly anaerobic bacteria of the indigenous flora grew in cultures from the MLNs of these mice. Consequently, SPF mice were antibiotic decontaminated and then colonized with Escherichia coli to develop a model in which E coli maintains abnormally high cecal population levels and translocates continuously to the MLN. These mice received 15% or 30% thermal burns four days after colonization with E coli. The incidence of bacterial translocation and the numbers of E coli translocating to the MLN, spleen, liver, blood, and peritoneal cavity increased with increasing burn area compared with controls. Mice receiving 15% burns could not clear intravenously challenged E coli from their bloodstream, MLN, or liver. Thus, burn stress promotes the translocation of bacteria from the GI tract to other organs to cause bacteremia.     

Effects of granulocyte colony-stimulating factor on bacterial translocation due to burn wound sepsis

The presence of certain defects in both cellular and humoral immunity after thermal injury has been established. Likewise, the translocation of enteric bacteria to the mesenteric lymph nodes and to distant organs has also been observed following serious thermal injury. The effects of granulocyte colony-stimulating factor (G-CSF) on bacterial translocation, the small bowel mucosa, and cecal bacterial content were investigated in a rat model of burn wound sepsis in which albino Wistar rats were scalded over 30% of their bodies, after which the lesions were infected by 1×10⁸ colony-forming units (cfu)Pseudomonas aeruginosa. The control group was treated with 5% dextrose solution subcutaneously starting 2 days preburn, while the treatment group received 100μg/kg human G-CSF subcutaneously. On the 4th day post burn all animals were killed to examine the bowel and culture of the mesenteric lymph nodes (MLN), livers, and spleens. No significant differences were observed between the groups regarding the cecal bacterial content and small bowel; however, a difference was seen in the ratio of translocation in the MLN liver and spleen and quantitative MLN cultures. Based on these findings, G-CSF was thus found to be significantly effective in reducing bacterial translocation due to burn wound sepsis.     

The effect of E coli virulence on bacterial translocation and systemic sepsis in the neonatal rabbit model

In the surgical neonate, three factors that promote bacterial translocation and systemic infection are: (1) intestinal bacterial colonization and overgrowth; (2) compromised host defenses; and (3) disruption of the mucosal epithelial barrier. The newborn rabbit provides an excellent model to study these factors. Like the human, there is early closure of the gut mucosa to macromolecules, and nutrition can be maintained by breast or formula feeding. This study examines translocation and systemic sepsis after colonization with virulent K1 and avirulent K100 strains of Escherichia coli. New Zealand white rabbit pups (2 to 5 days old) were studied. The gastrointestinal tracts of 12 were colonized with K1 E coli; 14 were colonized with K100 E coli; 12 control animals were not inoculated. Mesenteric lymph node (MLN), liver, spleen, and colon homogenate were cultured 72 hours postinoculation. No bacteria were isolated from the colons of all but one control animal. Translocation or systemic sepsis did not occur. Translocation to the MLN was significantly increased (P less than .03) in K1 (50%) and K100 (36%) groups compared with controls (0%). Translocation to liver and spleen (systemic sepsis) was significantly increased (P less than .03) in K1 animals (67%) compared with K100 (0%) or controls (0%). Colonization by both strains of E coli led to translocation to the MLN, but only K1 E coli caused systemic sepsis. This suggests that although colonization by E coli in the newborn leads to translocation to the MLN, progression to systemic sepsis is the result of characteristics of the bacteria and/or neonatal host responses.     

大鼠脊髓损伤致截瘫后肠道细菌移位的实验研究

目的：探讨大鼠脊髓损伤致截瘫后是否发生肠道细菌移位。方法：建立大鼠脊髓损伤性截瘫模型，以脊髓损伤性截瘫后12h、24h、48h大白鼠为实验组，未损伤脊髓的正常大白鼠为对照组。在无菌条件下，采集动物下腔静脉血进行内毒素定量测定和细菌培养，采集肝、脾、肠系膜淋巴结、肠腔内容物作细菌培养并进行菌种鉴定。取实验组和对照组各动物的肝、脾、肠系膜淋巴结、空肠、回肠进行病理切片HE染色检查，取空、回肠进行电镜检查。结果：大鼠脊髓损伤致截瘫后24h开始出现内毒素血症，截瘫后48h出现细菌移位。结论：大鼠脊髓损伤致截瘫后将发生肠道细菌移位，提示脊髓损伤截瘫的病人应尽早给予抗生素治疗。     

Role of bacterial adherence and the mucus barrier on bacterial translocation: effects of protein malnutrition and endotoxin in rats.

OBJECTIVE: The purpose of the study was to investigate the potential relations between mucosal bacterial adherence, intestinal mucus and mucin content, and bacterial translocation. SUMMARY BACKGROUND DATA: The attachment of bacteria to mucosal surfaces is the initial event in the pathogenesis of most bacterial infections that originate at mucosal surfaces, such as the gut. The intestinal mucus layer appears to function as a defensive barrier limiting micro-organisms present in the intestinal lumen from colonizing enterocytes. Consequently, studies focusing on the biology of bacterial adherence to the intestinal mucosa likely are to be important in clarifying the pathogenesis of gut origin sepsis. METHODS: To explore the relations between intestinal bacterial adherence, mucus bacterial binding, and bacterial translocation, two models were used. One (protein malnutrition) in which profound alterations in intestinal morphology occurs in the absence of significant translocation and one (endotoxin challenge) in which bacterial translocation occurs and intestinal morphology is relatively normal. RESULTS: Protein malnutrition was not associated with bacterial translocation and measurement of enteroadherent, mucosally associated bacterial population levels documented that the total number of gram-negative enteric bacilli adherent to the ileum and cecum was less in the protein-malnourished rats than in the normally nourished animals (p < 0.01). Furthermore, there was an inverse relation between the duration of protein malnutrition and bacterial adherence to the intestinal mucosa (r = 0.62, p < 0.002). In contrast, after endotoxin challenge, the level of enteroadherent bacteria was increased and bacterial translocation was observed. The binding of Escherichia coli to immobilized ileal mucus in vitro was decreased significantly in protein-malnourished rats, whereas E. coli binding to insoluble ileal mucus was increased in the rats receiving endotoxin. CONCLUSIONS: This study indicates that the adherence of bacteria to the intestinal mucosal surface is an important factor in bacterial translocation, that intestinal mucus modulates bacterial adherence, and that increased levels of mucosally associated bacteria are associated with a loss intestinal barrier function to bacteria.     

Effect of steroid on mitochondrial oxidative stress enzymes, intestinal microflora, and bacterial translocation in rats subjected to temporary liver inflow occlusion

Protective effects of steroids against ischemia-reperfusion (I/R) injury are well known, but there is little information about the influence of temporary inflow occlusion on intestinal barrier function or bacterial translocation. The aim of this experimental study was to investigate the effects on liver, kidney, spleen, ileal mitochondrial stress enzymes, and bacterial translocation of methylprednisolone (MP) in rats undergoing temporary liver inflow occlusion. Twenty-seven pathogen-free Wistar albino rats were randomized into three groups: group A: I/R (n = 10); group B: I/R + MP (n = 10); and group C: sham (n = 7). Rats in groups A and B were subjected to 20 minutes of portal vein and hepatic artery occlusion with 3 mg/kg MP injected into group B animals intraperitoneally during the occlusion. Twenty-two hours later, all rats were sacrificed to measure mitochondrial oxidative stress enzymes in liver, kidney, spleen, and ileum. We evaluated intestinal bacterial counts, intestinal mucosal histopathology, bacterial translocation to mesenteric lymph nodes (MLN), liver, spleen, and kidney. Decreased levels of malondialdehyde and increased levels of glutathione were observed in all examined tissues of group B compared to those of group A rats. Statistically significant increases in the intestinal counts of Klebsiella spp and Proteus spp and of bacterial translocation to liver, kidney, spleen, and MLN were measured in group B with respect to group A.     

N-acetylcysteine attenuates bacterial translocation after partial hepatectomy in rats

BACKGROUND: Translocating enteric bacteria have been suggested as playing a major role in the development of infections after partial hepatectomy. We investigated the effect of N-acetylcysteine (NAC) on bacterial translocation (BT) and intestinal mucosa as the first line of defense against BT. MATERIALS AND METHODS: We compared four groups of eight Sprague-Dawley male rats each: sham, control (partially hepatectomized), partial hepatectomy plus preoperative single-dose NAC, and a fourth that received partial hepatectomy with a preoperative single-dose NAC plus treatment with NAC for 2 days. Microorganism counts of tissues, lung injury score, lung tissue glutathione, and malondialdehyde levels and microscopy of intestinal mucosa were studied at the end of 48 h. RESULTS: Microorganism count in the lung and mesenteric lymph node cultures and lung injury score were significantly higher in the control group when compared with the sham, third, and fourth groups (lung: 9919.6 versus 0.0, 2912.9, 1550.0 cfu/g tissue; mesenteric lymph nodes: 8458.3 versus 0.0, 89.0, 88.9 cfu/g tissue; lung injury score: 3.25 versus 0.5, 1.13, 1.75). In the control group, the villous height of the distal ileal mucosa was significantly shorter than the sham group (65.25 versus 75.25 microm) and the difference from groups 3 and 4 was not statistically significant. Neutrophil infiltration in the distal ileal mucosa of the control group was significantly higher than the sham, third and fourth groups (3.13 versus 0.25, 0.38 and 1.0). CONCLUSIONS: The parenteral use of NAC attenuates bacterial translocation after partial hepatectomy in rats. Attenuation of the lung injury after partial hepatectomy in NAC-treated groups might be attributable to both anti-inflammatory effect and the effect on BT.     

Endotoxin promotes the translocation of bacteria from the gut

Experiments were performed in mice to determine whether endotoxin could cause bacteria normally colonizing the gut to spread systemically, a process termed bacterial translocation. Endotoxin given intraperitoneally promoted bacterial translocation in a dose-dependent fashion from the gut to the mesenteric lymph node (MLN). The incidence of bacterial translocation to the MLN was similar whether the endotoxin was administered intramuscularly or intraperitoneally, although the number of bacteria colonizing the MLN was greater with intraperitoneal endotoxin. The incidence and magnitude of endotoxin-induced bacterial translocation were similar between CD-1 and C3H/HeJ (endotoxin-resistant) mice, indicating that bacterial translocation is not prevented by genetic resistance to endotoxin. Thus, it appears that the gut may serve as a reservoir for bacteria causing systemic infections during endotoxemia.     

Antibiotic prophylaxis diminishes bacterial translocation but not mortality in experimental burn wound sepsis

Pseudomonas (PSA) burn wound sepsis results in prolonged bacterial translocation (BT) of enteric organisms such as E. coli to the mesenteric lymph nodes (MLN) and organs in rats. Intestinal decontamination with oral antibiotics may improve mortality after burn injury, perhaps due to decreased BT. To determine the effect of oral antibiotic prophylaxis effective against E. coli but not PSA on BT and subsequent mortality in a model of PSA burn wound sepsis, rats were given a 30% scald burn and wound inoculation with 10(8) PSA followed by randomization to either ampicillin (50 mg/kg/d) or saline gavage. Cultures of MLN, organs, blood, and cecal contents were obtained on days 1, 4, and 7 after injury, with additional animals observed for 14-day mortality. Although oral antibiotic prophylaxis resulted in increased cecal colony counts, the incidence of BT was unchanged. The number of organisms present in both the MLN and organs, however, was significantly reduced with prophylaxis, indicating cecal overgrowth by non-translocating bacteria. Reduction of the number of translocating organisms did not result in improved mean survival time after injury, suggesting that mortality from PSA burn wound sepsis occurs independently of bacterial translocation.     

C-reactive protein may be a marker of bacterial translocation in experimental intestinal obstruction

BACKGROUND: C-reactive protein (CRP) is used as a marker of intestinal ischaemia. This study evaluated whether CRP levels can be used to detect ischaemia-induced (strangulated) intestinal obstruction and subsequent bacterial translocation. METHODS: Forty-eight rats, divided into four groups underwent the following procedures: anaesthesia alone (native controls), laparotomy (sham-operated controls), or surgical induction of simple or strangulated intestinal obstruction (simple and strangulated obstruction groups, respectively). Blood samples were collected for culture and serum CRP analysis. In addition, liver and mesenteric lymph node (MLN) specimens were collected for culture, to determine the presence of bacterial translocation; and ileal segments, for histopathological investigation. RESULTS: CRP levels and rates of bacterial translocation, expressed as colony forming units (cfu) per gram wet tissue, were higher in both intestinal obstruction groups than in the native and sham-operated control groups (P < 0.001 for both). The increases in CRP levels paralleled increases in the number of cfu in the MLN and liver cultures (P < 0.01). Compared to controls, animals in the obstruction groups also had a higher incidence of positive blood cultures (P < 0.005) and greater histopathologic evidence of inflammatory infiltration of the lamina propria (P < 0.01). However, no significant difference between the simple and strangulated obstruction groups was observed. CONCLUSION: CRP levels increase with the severity of bacterial translocation in acute intestinal obstruction but do not permit discrimination between simple and strangulated intestinal obstruction.     

Bacterial translocation in trauma patients

Sepsis and multiple system organ failure (MSOF) are major causes of morbidity and mortality in trauma patients. Bacterial translocation induced by hypotension, endotoxemia, or burns is a reproducible phenomenon in the laboratory. The incidence of bacterial translocation to mesenteric lymph nodes (MLNs) in 29 critically ill patients was evaluated to determine its relationship to subsequent sepsis and MSOF. Bacterial translocation was documented in 3 of 4 patients who underwent laparotomy for gastrointestinal (GI) disease. No trauma patient (25 patients), even at second exploration 3-5 days after injury, had a positive MLN culture. Five patients died; 4 trauma patients, one with GI disease. Forty percent of the trauma patients had major complications, predominantly pulmonary infections with gram-negative bacteria. However, infectious complications and outcome were not related to MLN culture results. The classical progression of bacteria from the gut to the bloodstream via the MLNs may require time and gut mucosal injury. The data suggest that bacterial translocation to the MLNs is not a common occurrence in acutely injured trauma patients.     

N-acetylcysteine improves intestinal barrier in partially hepatectomized rats

BACKGROUND: Translocating enteric bacteria play an important role in the development of infections following partial hepatectomy. The intestine itself is the first line of defence against bacterial translocation (BT). We investigated the effect of N-acetylcysteine (NAC) on BT and the intestinal wall. METHODS: We compared four groups of Sprague-Dawley male rats (eight in each group): sham, sham plus preoperative single dose of NAC, partial hepatectomy and partial hepatectomy plus preoperative single dose of NAC. Microorganism count in the tissues and the glutathione and malondialdehyte contents of the intestinal wall were studied at the end of the 24th hour. RESULTS: Bacterial growth was observed in the spleen and mesenteric lymph nodes in the sham group. There was bacterial growth in all the samples of the partial hepatectomy group. Differences were significant except in atrial and portal blood counts. In the partial hepatectomy plus NAC treatment group, counts were significantly low in all, except atrial and portal blood samples. The malondialdehyte level in the intestinal wall was 35.38 +/- 10.27 in the sham group, increasing significantly in the partial hepatectomy group (69.50 +/- 21.48), and decreasing in the partial hepatectomy plus NAC treatment group (35.63 +/- 14.12). Glutathione levels decreased significantly in the partial hepatectomy group and increased with preoperative single-dose NAC. CONCLUSION: Partial hepatectomy resulted in oxidative disturbances in intestinal wall, which in turn gave rise to BT. Parenteral NAC protects the intestinal wall from oxidative injury and attenuates BT.     

半肝与全肝入肝血流阻断下肝切除术后肠道细菌易位影响对比研究

目的探讨半肝血流阻断与第一肝门阻断法（Pringle法）对肝叶切除术后肠道细菌易位的影响。方法对2003-2006年中国人民解放军总医院及第一附属医院55例肝叶切除术病人分别选用两种不同阻断血流方法,术前和术后2h、24h、48h采集外周血,应用聚合酶链反应（PCR）方法检测全血细菌DNA,同时行血D 乳酸、内毒素（LPS）浓度检测。结果术前PCR均为阴性,术后共有32例PCR阳性,两组PCR阳性率差异有统计学意义（P<001）。全肝阻断组外周血浆D 乳酸及LPS浓度较半肝阻断组明显升高（P<001）。结论肝叶切除术中采用半肝血流阻断较全入肝血流阻断肠黏膜屏障受损较轻,肠道细菌易位明显减少。     

Patterns of bacterial translocation in experimental biliary obstruction

INTRODUCTION: Biliary obstruction is associated with impaired intestinal barrier function and translocation of enteric bacteria to the systemic circulation. Traditional live culture techniques may overlook translocation of dead bacterial fragments that stimulate the inflammatory response. The aim of this study was to estimate the extent and pattern of bacterial translocation in experimental biliary obstruction. MATERIALS AND METHODS: Thirty 9-week-old male Wistar rats were randomized to undergo bile duct ligation (BDL, n = 20) or sham operation (n = 10). Seven days after operation, each animal received 1 ml of (111)indium-oxyquinolone-labeled Escherichia coli p.o. Samples of liver, spleen, mesenteric lymph nodes, and lung were harvested 4 h later and analyzed for live bacteria and (111)indium activity. RESULTS: There was significantly more live bacterial translocation detected in BDL animals than in sham-operated animals (P = 0.00008, chi(2)). Labeled bacterial fragments were detected in all locations sampled in all animals. Sham-operated animals had significantly more labeled bacterial fragments detected in the liver (P = 0.0001) and the spleen (P = 0.03) than the BDL animals. The mean total bacterial survival in the BDL group was 30 +/- 13% and 0% in the sham operated group. CONCLUSION: These results demonstrate that non-viable bacterial fragments are present in sterile extra-intestinal sites in normal animals and that translocation of live bacteria is markedly increased in experimental biliary obstruction. These results also suggest that failure of bacterial killing is an important factor facilitating bacterial translocation in the presence of established biliary obstruction.