The prevalence of gut translocation in humans

Bacterial translocation and in vivo assessment of intestinal barrier permeability in rainbow trout (Oncorhynchus mykiss) with and without soyabean meal-induced inflammation

The primary aim of this experiment was to evaluate the intestinal barrier permeability in vivo in rainbow trout (Oncorhynchus mykiss) fed increasing levels of soyabean meal (SBM). The relationship between SBM-induced enteritis (SBMIE) and the permeability markers was also investigated. Our results showed that the mean score of morphological parameters was significantly higher as a result of 37·5 % SBM inclusion in the diet, while the scores of fish fed 25 % SBM or lower were not different from those of the fish meal-fed controls (P < 0·05). SBMIE was found in the distal intestine (DI) in 18 % of the fish (eleven of sixty): ten in the 37·5 % SBM-fed group and one in the 25 % SBM-fed group. Sugar markers in plasma showed large variation among individuals probably due to variation in feed intake. We found, however, a significant linear increase in the level of plasma d-lactate with increasing SBM inclusion level (P < 0·0001). Plasma concentration of endotoxin was not significantly different in groups with or without SBMIE. Some individual fish showed high values of endotoxin in blood, but the same individuals did not show any bacterial translocation. Plasma bacterial DNA was detected in 28 % of the fish with SBMIE, and 8 % of non-SBMIE fish (P = 0·07). Plasma concentration of d-lactate was significantly higher in fish with SBMIE (P < 0·0001). To conclude, SBMIE in the DI of rainbow trout was associated with an increase in bacterial translocation and plasma d-lactate concentration, suggesting that these permeability markers can be used to evaluate intestinal permeability in vivo.

Gut Microbiota-Induced Immunoglobulin G Controls Systemic Infection by Symbiotic Bacteria and Pathogens

The gut microbiota is compartmentalized in the intestinal lumen and induces local immune responses, but it remains unknown whether the gut microbiota can induce systemic response and contribute to systemic immunity. We report that selective gut symbiotic gram-negative bacteria were able to disseminate systemically to induce immunoglobulin G (IgG) response, which primarily targeted gram-negative bacterial antigens and conferred protection against systemic infections by E. coli and Salmonella by directly coating bacteria to promote killing by phagocytes. T cells and Toll-like receptor 4 on B cells were important in the generation of microbiota-specific IgG. We identified murein lipoprotein (MLP), a highly conserved gram-negative outer membrane protein, as a major antigen that induced systemic IgG homeostatically in both mice and humans. Administration of anti-MLP IgG conferred crucial protection against systemic Salmonella infection. Thus, our findings reveal an important function for the gut microbiota in combating systemic infection through the induction of protective IgG.

The microbiome and critical illness

The central role of the microbiome in critical illness is supported by a half century of experimental and clinical study. The physiological effects of critical illness and the clinical interventions of intensive care substantially alter the microbiome. In turn, the microbiome predicts patients' susceptibility to disease, and manipulation of the microbiome has prevented or modulated critical illness in animal models and clinical trials. This Review surveys the microbial ecology of critically ill patients, presents the facts and unanswered questions surrounding gut-derived sepsis, and explores the radically altered ecosystem of the injured alveolus. The revolution in culture-independent microbiology has provided the tools needed to target the microbiome rationally for the prevention and treatment of critical illness, holding great promise to improve the acute and chronic outcomes of the critically ill.

Gut commensal microbes do not represent a dominant antigenic source for continuous CD4+ T-cell activation during HIV-1 infection

Chronic immune activation is a hallmark of HIV-1 infection; specifically, the activation of T cells has predictive value for progression to AIDS. The majority of hyperactivated T cells are not HIV-specific and their antigenic specificities remain poorly understood. Translocation of gut luminal microbial products to systemic sites contributes to chronic immune activation during HIV-1 infection, but how it affects (TCR-dependent) immune activation remains elusive. We hypothesized that gut luminal antigens foster activation of CD4(+) T cells with specificities for commensal bacterial antigens, thereby contributing to the pool of activated CD4(+) T cells in the circulation of HIV-1 infected individuals. To test this hypothesis, we quantified the frequencies of gut microbe-specific CD4(+) T cells by cytokine production upon restimulation with selected gut commensal microbial antigens. Contrary to our hypothesis, we did not observe increased but rather decreased frequencies of gut microbe-specific CD4(+) T cells in HIV-1 infected individuals compared to healthy controls. We conclude that the increased activation status of circulating CD4(+) T cells in HIV-1 infected individuals is not driven by CD4(+) T cells with specificities for commensal bacterial antigens.

Periarrest intestinal bacterial translocation and resuscitation outcome

During the periarrest period, intestinal ischemia may result in barrier dysfunction and bacterial translocation, which has clear mechanistic links to inflammation and cascade stimulation, especially in patients who are treated with therapeutic hypothermia. Despite optimal management, periarrest bacterial translocation may worsen the outcome of cardiac arrest victims.

Translocation of gut flora and its role in sepsis

Bacterial translocation is the invasion of indigenous intestinal bacteria through the gut mucosa to normally sterile tissues and the internal organs. Sometimes instead of bacteria, inflammatory compounds are responsible for clinical symptoms as in systemic inflammatory response syndrome (SIRS). The difference between sepsis and SIRS is that pathogenic bacteria are isolated from patients with sepsis but not with those of SIRS. Bacterial translocation occurs more frequently in patients with intestinal obstruction and in immunocompromised patients and is the cause of subsequent sepsis. Factors that can trigger bacterial translocation from the gut are host immune deficiencies and immunosuppression, disturbances in normal ecological balance of gut, mucosal barrier permeability, obstructive jaundice, stress, etc. Bacterial translocation occurs through the transcellular and the paracellular pathways and can be measured both directly by culture of mesenteric lymph nodes and indirectly by using labeled bacteria, peripheral blood culture, detection of microbial DNA or endotoxin and urinary excretion of non-metabolisable sugars. Bacterial translocation may be a normal phenomenon occurring on frequent basis in healthy individuals without any deleterious consequences. But when the immune system is challenged extensively, it breaks down and results in septic complications at different sites away from the main focus. The factors released from the gut and carried in the mesenteric lymphatics but not in the portal blood are enough to cause multi-organ failure. Thus, bacterial translocation may be a promoter of sepsis but not the initiator. This paper reviews literature on the translocation of gut flora and its role in causing sepsis.

Interactions of uroseptic Escherichia coli with renal (A-498) and gastrointestinal (HT-29) cell lines

We investigated the ability of Escherichia coli isolated from septic patients with urinary tract infection (UTI) to translocate through the gastrointestinal (GI) tract of the same patients using cell-culture models. Forty-seven hospitalized patients with urosepsis were included in this study. E. coli was isolated from their urine and blood (total 94 isolates) and investigated for genetic relatedness and interaction with the cell lines A-498 and HT-29. An initial comparison of the strains isolated from urine and blood showed that 44 out of 47 patients (94 %) had identical strains in their blood and urine. The blood isolates adhered to both cell lines, although their rate of adherence to A-498 cells was significantly higher than that to HT-29 cells (5.8±3.8 per cell vs 2.8±1.9; P<0.0001). The rate of translocation in A-498 cells was also significantly higher after 120 min (8.7×10(5) vs 2.9×10(5); P = 0.0006). Three non-identical blood isolates were unable to translocate in HT-29 cells, indicating that host immune factors might be more important than bacterial ability to translocate the GI epithelium in these patients. Our data showed that blood isolates from uroseptic patients are able to adhere to and translocate through both cell lines. This suggests that E. coli in patients with UTI may translocate from either the GI tract or the urinary tract, hence questioning the assumption that the urinary tract is the only source of septicaemia in these patients.

Impaired intestinal mucosal barrier upon ischemia-reperfusion: "patching holes in the shield with a simple surgical method"

Mesenteric ischemia-reperfusion (IR) is associated with impairment of the gut barrier function and the initiation of a proinflammatory cascade with life-threatening results. Therefore methods directed to ameliorate IR injury are of great importance. We aimed at describing the effects of postconditioning (PC) on the alterations of the intestinal mucosal function and the inflammatory response upon mesenteric IR. Methods. Male Wistar rats were gavaged with green fluorescent protein-expressing E. coli suspensions. Animals were randomized into three groups (n = 15), sham-operated, IR-, and PC-groups, and underwent 60 minutes of superior mesenteric artery occlusion, followed by 6 hours of reperfusion. Postconditioning was performed at the onset of reperfusion. Blood and tissue samples were taken at the end of reperfusion, for histological, bacteriological, and plasma examinations. Results. The PC-group presented a more favorable claudin-2, claudin-3, claudin-4, and zonula occludens-1 membrane expression profile, and significantly lower rates of bacterial translocation to distant organs and plasma D-lactate levels compared to the IR-group. Histopathological lesions, plasma I-FABP, IL-6, and TNF-α levels were significantly lower in the PC-group compared to the IR-group. Conclusion. The use of postconditioning improved the integrity of the intestinal mucosal barrier upon mesenteric IR, and thus reduced the incidence of bacterial translocation and development of a systemic inflammatory response.

Bacterial translocation - impact on the adipocyte compartment

Over the last decade it became broadly recognized that adipokines and thus the fat tissue compartment exert a regulatory function on the immune system. Our own group described the pro-inflammatory function of the adipokine leptin within intestinal inflammation in a variety of animal models. Following-up on this initial work, the aim was to reveal stimuli and mechanisms involved in the activation of the fat tissue compartment and the subsequent release of adipokines and other mediators paralleled by the infiltration of immune cells. This review will summarize the current literature on the possible role of the mesenteric fat tissue in intestinal inflammation with a focus on Crohn’s disease (CD). CD is of particular interest in this context since the transmural intestinal inflammation has been associated with a characteristic hypertrophy of the mesenteric fat, a phenomenon called “creeping fat.” The review will address three consecutive questions: (i) What is inducing adipocyte activation, (ii) which factors are released after activation and what are the consequences for the local fat tissue compartment and infiltrating cells; (iii) do the answers generated before allow for an explanation of the role of the mesenteric fat tissue within intestinal inflammation? With this review we will provide a working model indicating a close interaction in between bacterial translocation, activation of the adipocytes, and subsequent direction of the infiltrating immune cells. In summary, the models system mesenteric fat indicates a unique way how adipocytes can directly interact with the immune system.

An occurrence of sepsis during inpatient fecal disimpaction

Functional constipation is a common pediatric problem that is often treated through well-established algorithms. Fecal disimpaction is the initial therapeutic step, and severe cases require hospitalization for intensive therapies. We describe a significant unexpected complication of this common clinical situation. An 8-year-old boy with suspected chronic functional constipation was hospitalized for disimpaction by continuous nasogastric administration of polyethylene glycol electrolyte (PEG-E) solution. On the sixth day of disimpaction, the patient abruptly developed fever, tachycardia, and tachypnea. Evaluation included blood culture, which grew Escherichia coli, and treatment with a course of appropriate antibiotics was provided. The safety of PEG-E solutions has been shown in studies of children with constipation, which made this patient's illness surprising. Several potential etiologies of his infection were considered, including bacterial translocation (BT). BT is defined as the passage of live microbes and microbial products from the gastrointestinal tract to extraintestinal sites, such as the bloodstream. It has been shown to occur in a variety of clinical conditions but is of unclear clinical significance. In this case, physical damage to the intestinal mucosa was thought to contribute to the potential occurrence of BT, and prolonged disimpaction was considered as a risk factor. E coli sepsis in a child undergoing inpatient nasogastric fecal disimpaction with PEG-E represents a clinical problem never before reported in the literature and should increase clinicians' indices of suspicion for uncommon complications of common procedures.

Bacteremia in patients with acute pancreatitis as revealed by 16S ribosomal RNA gene-based techniques*

OBJECTIVES

To define the characteristic of bacteremia in patients with acute pancreatitis and determine its possible association with the disease severity.

DESIGN

A prospective controlled study.

SETTING

ICU of Jinling Hospital, China.

PATIENTS

A total of 48 patients with mild or severe acute pancreatitis were enrolled in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Samples of peripheral blood were collected from the patients at 4 or 5 and 9 or 10 days after acute pancreatitis was definitely diagnosed. Resulting DNA from the blood was analyzed using denaturing gradient gel electrophoresis, and separated fragments were sequenced for identification of bacterial species. Bacterial DNA was detected in peripheral blood from 68.8% of patients with acute pancreatitis, and more than half (60.4%) of the patients encountered polymicrobial flora. Translocated bacteria in patients with acute pancreatitis were primarily constituted of opportunistic pathogens derived from the gut, including Escherichia coli, Shigella flexneri, Enterobacteriaceae bacterium, Acinetobacter lwoffii, Bacillus coagulans, and Enterococcus faecium. The species of circulating bacteria shifted remarkably among the patients with different severity. The presence of the bacteremia correlated positively with the Acute Physiology and Chronic Health Evaluation-II scores of patients with acute pancreatitis (r = 0.7918, p < 0.0001).

CONCLUSIONS

This study provides a detailed description on the prevalence of bacteremia and characteristic of bacterial species in patients with acute pancreatitis. We demonstrate an association between the bacteremia and the disease severity, which enables us to better understand a potential role of bacterial translocation in the pathogenesis of septic complication in acute pancreatitis.

Microbial characterization of probiotics--advisory report of the Working Group "8651 Probiotics" of the Belgian Superior Health Council (SHC)

When ingested in sufficient numbers, probiotics are expected to confer one or more proven health benefits on the consumer. Theoretically, the effectiveness of a probiotic food product is the sum of its microbial quality and its functional potential. Whereas the latter may vary much with the body (target) site, delivery mode, human target population, and health benefit envisaged microbial assessment of the probiotic product quality is more straightforward. The range of stakeholders that need to be informed on probiotic quality assessments is extremely broad, including academics, food and biotherapeutic industries, healthcare professionals, competent authorities, consumers, and professional press. In view of the rapidly expanding knowledge on this subject, the Belgian Superior Health Council installed Working Group "8651 Probiotics" to review the state of knowledge regarding the methodologies that make it possible to characterize strains and products with purported probiotic activity. This advisory report covers three main steps in the microbial quality assessment process, i.e. (i) correct species identification and strain-specific typing of bacterial and yeast strains used in probiotic applications, (ii) safety assessment of probiotic strains used for human consumption, and (iii) quality of the final probiotic product in terms of its microbial composition, concentration, stability, authenticity, and labeling.

Enterobacteriaceae surgical site infection after cardiac surgery: the hypothetical role of vancomycin

BACKGROUND

In the middle of October 2011, the Hygiene Department of Caen University Hospital suspected an outbreak of surgical site infections (SSI) after open-heart operations with an unusually high proportion of microorganisms belonging to the Enterobacteriaceae family. The attack rate was 3.8%, significantly different (p = 0.035) from the attack rate of 1.2% in 2010 over the equivalent period. A case-control study was conducted to search specifically for risk factors for Enterobacteriaceae infections after median sternotomy in cardiac patients.

METHODS

Case patients were defined retrospectively as patients with superficial or deep surgical site infection with Enterobacteriaceae within 30 days of median sternotomy. Four control patients were selected per case patient from patients matched for date of operation (± 15 days) and European System for Cardiac Operative Risk Evaluation (<5, [5-10], >10).

RESULTS

Univariate analysis identified the following risk factors: inappropriate skin preparation on the morning of the intervention (p = 0.046), use of vancomycin (p = 0.030), and number of sternotomy dressings (p = 0.033). A multivariate logistic regression analysis found that vancomycin use was independently associated with an increased risk of postoperative SSI with Enterobacteriaceae (p = 0.019; odds ratio = 7.4).

CONCLUSIONS

Although vancomycin is known to be effective for preventing infection with methicillin-sensitive organisms, our results suggest that it was associated with a risk for the development of SSI with gram-negative organisms after median sternotomy. This study led to a multidisciplinary meeting that defined new guidelines for prophylactic antibiotic therapy before open-heart operations.

Bacteria and tumours: causative agents or opportunistic inhabitants?

Associations between different bacteria and various tumours have been reported in patients for decades. Studies involving characterisation of bacteria within tumour tissues have traditionally been in the context of tumourigenesis as a result of bacterial presence within healthy tissues, and in general, dogma holds that such bacteria are causative agents of malignancy (directly or indirectly). While evidence suggests that this may be the case for certain tumour types and bacterial species, it is plausible that in many cases, clinical observations of bacteria within tumours arise from spontaneous infection of established tumours. Indeed, growth of bacteria specifically within tumours following deliberate systemic administration has been demonstrated for numerous bacterial species at preclinical and clinical levels. We present the available data on links between bacteria and tumours, and propose that besides the few instances in which pathogens are playing a pathogenic role in cancer, in many instances, the prevalent relationship between solid tumours and bacteria is opportunistic rather than causative, and discuss opportunities for exploiting tumour-specific bacterial growth for cancer treatment.

The effects of perioperative probiotic treatment on serum zonulin concentration and subsequent postoperative infectious complications after colorectal cancer surgery: a double-center and double-blind randomized clinical trial

BACKGROUND

Zonulin is a newly discovered protein that has an important role in the regulation of intestinal permeability. Our previous study showed that probiotics can decrease the rate of infectious complications in patients undergoing colectomy for colorectal cancer.

OBJECTIVE

The objective was to determine the effects of the perioperative administration of probiotics on serum zonulin concentrations and the subsequent effect on postoperative infectious complications in patients undergoing colorectal surgery.

DESIGN

A total of 150 patients with colorectal carcinoma were randomly assigned to the control group (n = 75), which received placebo, or the probiotics group (n = 75). Both the probiotics and placebo were given orally for 6 d preoperatively and 10 d postoperatively. Outcomes were measured by assessing bacterial translocation, postoperative intestinal permeability, serum zonulin concentrations, duration of postoperative pyrexia, and cumulative duration of antibiotic therapy. The postoperative infection rate, the positive rate of blood microbial DNA, and the incidence of postoperative infectious complications-including septicemia, central line infection, pneumonia, urinary tract infection, and diarrhea-were also assessed.

RESULTS

The infection rate was lower in the probiotics group than in the control group (P < 0.05). Probiotics decreased the serum zonulin concentration (P < 0.001), duration of postoperative pyrexia, duration of antibiotic therapy, and rate of postoperative infectious complications (all P < 0.05). The p38 mitogen-activated protein kinase signaling pathway was inhibited by probiotics.

CONCLUSIONS

Perioperative probiotic treatment can reduce the rate of postoperative septicemia and is associated with reduced serum zonulin concentrations in patients undergoing colectomy. We propose a clinical regulatory model that might explain this association. This trial was registered at http://www.chictr.org/en/ as ChiCTR-TRC-00000423.

Prevention and Treatment of Gastrointestinal Complications in Patients on Mechanical Ventilation

There exists a complex, dynamic interaction between mechanical ventilation and the splanchnic vasculature that contributes to a myriad of gastrointestinal tract complications that arise during critical illness. Positive pressure-induced splanchnic hypoperfusion appears to play a pivotal role in the pathogenesis of these complications, the most prevalent of which are stress-related mucosal damage, gastrointestinal hypomotility and diarrhea. Furthermore, characteristics of the splanchnic vasculature make the gastrointestinal tract vulnerable to adverse effects related to positive pressure ventilation. While most of these complications seen in mechanically ventilated patients are reflections of altered gastrointestinal physiology, some may be attributed to medical interventions instituted to treat critical illness. Since maintenance of normal hemodynamics cannot always be achieved, pharmacologic prophylactic therapy has become a mainstay in the prevention of gastrointestinal complications in the intensive care unit. Improved understanding of the systemic effects of mechanical ventilation and greater application of lung-protective ventilatory strategies may potentially minimize positive pressure-induced reductions in splanchnic perfusion, systemic cytokine release and, consequently, reduce the incidence of gastrointestinal complications associated with mechanical ventilation. Herein, we discuss the pathophysiology of gastrointestinal complications associated with mechanical ventilation, summarize the most prevalent complications and focus on preventive strategies and available treatment options for these complications. The most common causes of gastrointestinal hemorrhage in mechanically ventilated patients are bleeding from stress-related mucosal damage and erosive esophagitis. In general, histamine H(2) receptor antagonists and proton pump inhibitors prevent stress-related mucosal disease by raising the gastric fluid pH. Proton pump inhibitors tend to provide more consistent pH control than histamine H(2) receptor antagonists. There is no consensus on the drug of choice for stress ulcer prophylaxis with several meta-analyses providing conflicting results on the superiority of any medication. Prevention of erosive esophagitis include careful use of nasogastric tubes and institution of strategies that improve gastric emptying. Many mechanically ventilated patients have gastrointestinal hypomotility and diarrhea. Treatment options for gastrointestinal motility are limited, thus, preventive measures such as correction of electrolyte abnormalities and avoidance of medications that impair gastrointestinal motility are crucial. Treatment of diarrhea depends on the underlying cause. When associated with Clostridium difficile infection antibacterial therapy should be discontinued, if possible, and treatment with oral metronidazole should be initiated.More studies are warranted to better understand the systemic effects of mechanical ventilation on the gastrointestinal tract and to investigate the impact of lung protective ventilatory strategies on gastrointestinal complications.

Gut microbial translocation in critically ill children and effects of supplementation with pre- and pro biotics

Bacterial translocation as a direct cause of sepsis is an attractive hypothesis that presupposes that in specific situations bacteria cross the intestinal barrier, enter the systemic circulation, and cause a systemic inflammatory response syndrome. Critically ill children are at increased risk for bacterial translocation, particularly in the early postnatal age. Predisposing factors include intestinal obstruction, obstructive jaundice, intra-abdominal hypertension, intestinal ischemia/reperfusion injury and secondary ileus, and immaturity of the intestinal barrier per se. Despite good evidence from experimental studies to support the theory of bacterial translocation as a cause of sepsis, there is little evidence in human studies to confirm that translocation is directly correlated to bloodstream infections in critically ill children. This paper provides an overview of the gut microflora and its significance, a focus on the mechanisms employed by bacteria to gain access to the systemic circulation, and how critical illness creates a hostile environment in the gut and alters the microflora favoring the growth of pathogens that promote bacterial translocation. It also covers treatment with pre- and pro biotics during critical illness to restore the balance of microbial communities in a beneficial way with positive effects on intestinal permeability and bacterial translocation.

Gut-origin sepsis: evolution of a concept

The concept of bacterial translocation and gut-origin sepsis as a cause of systemic infectious complications and the multiple organ dysfunction syndrome (MODS) in surgical and ICU patients has emerged over the last several decades, although the exact clinical relevance of these phenomena continues to be debated. Thus, the goal of this review is to trace the evolution of gut-origin sepsis and gut-induced MODS and put these disorders and observations into clinical perspective. Additionally, the mechanisms leading to gut-derived complications are explored as well as therapeutic options to limit or prevent these complications. From this work, several major conclusions emerge. First, that bacterial translocation occurs clinically and is responsible for increased infectious complications in patients undergoing major abdominal surgery. However, the phenomenon of bacterial translocation is not sufficient to explain the development of MODS in ICU patients. Instead, the development of MODS in these high-risk patients is likely due to gut injury and the systemic spread of non-microbial, tissue-injurious factors that reach the systemic circulation via the intestinal lymphatics. These observations have resulted in the gut-lymph hypothesis of MODS.

Urinary tract infections in hospitalized inflammatory bowel disease patients: a 10-year experience

BACKGROUND

Cystitis is the most common genitourinary complication in Crohn's disease (CD). We assessed the prevalence of and risk factors for urinary tract infections (UTI) in inflammatory bowel diseases (IBD).

METHODS

Among the 1173 IBD patients of the "Nancy IBD cohort" seen between January 1, 2000 and December 31, 2009, 56 hospitalized patients had 76 documented UTI. Prevalence of UTI in IBD was calculated using rates of UTI among non-IBD patients hospitalized during the same period. The cases were compared to 175 matched IBD patients without UTI hospitalized during the same period to identify risk factors for UTI.

RESULTS

Prevalence of UTI was 4% in IBD patients versus 3.3% in non-IBD patients (P = 0.1). Prevalence of UTI was 4.5% and 2.1% in ulcerative colitis (UC) and CD patients, respectively (P = 0.6). Risk factors for UTI in CD patients were perianal disease (odds ratio [OR] = 2.28, 95% confidence interval [CI], 1.06-4.89; P = 0.04) and colonic disease (OR = 2.42, 95% CI, 1.05-5.58; P = 0.04). Male gender (OR = 0.38, 95% CI, 0.17-0.85, P = 0.02) and noncomplicated behavior (OR = 0.26, 95% CI, 0.11-0.60, P = 0.002) were protective factors against UTI in CD. In UC patients, age over 40 years (OR = 9.59, 95% CI, 1.93-47.74; P = 0.006) and disease duration over 11 months (OR = 10.77, 95% CI, 1.68-68.89, P = 0.01) were risk factors for UTI. Male gender was negatively associated with UTI (OR = 0.04, 95% CI, 0.01-0.36, P = 0.00006).

CONCLUSIONS

Hospitalized IBD patients are not at increased risk of UTI. Risk factors for UTI include perianal disease and colonic disease in CD and age and longer disease duration in UC.

Bacterial translocation in abdominal trauma and postoperative infections

BACKGROUND

Bacterial translocation (BT) describes the passage of bacteria residing into the gastrointestinal tract, through the intestinal mucosa barrier to sterile tissues such as mesenteric lymph nodes (MLN) and other organs. This phenomenon has not been thoroughly studied in patients with trauma to date, and an association between BT and postoperative infection has not been well established so far.

METHODS

MLNs from 36 patients with abdominal trauma were removed during laparotomy and cultured to detect BT. Postoperative infectious complications in these patients were registered, and both phenotypical and molecular typings (through multilocus sequencing) were carried out for microorganisms isolated from MLN and postoperative infection sites. Associations between clinical variables, BT presence, and postoperative infection development were established.

RESULTS

BT was detected in 33% of the patients (n = 12). Postoperative infections were present in 22.2% of the patients (n = 8). A significant statistical difference was found between postoperative infections in patients with BT evidence (41.6%), when compared with patients without BT (12.5%; p = 0.047). Bacteria isolated from infection sites were the same as those cultured in MLN in 40% of the cases (n = 2 of 5), allowing us to establish causality between BT and postoperative infection.

CONCLUSIONS

There is higher risk of BT in trauma patients, and it is associated with a significant increase of postoperative infections. An abdominal trauma index ≥10 was found to be associated with the development of BT. This is the first study describing BT among patients with abdominal trauma, where causality is confirmed at molecular level.

The relationships of nutrients, routes of delivery, and immunocompetence

Malnutrition has marked consequences on surgical outcomes. Adequate nutrition is important for the proper functioning of all organ systems, particularly the immune system. Determination of the type and amount of nutrient supplementation and the appropriate route of nutrient delivery is essential to bolster the immune system and enhance the host's response to stress. Correct administration of immunonutrients could lead to reductions in patient morbidity following major surgery, trauma, and critical illness.

Nod-like receptor pyrin domain-containing protein 6 (NLRP6) controls epithelial self-renewal and colorectal carcinogenesis upon injury

The colonic epithelium self-renews every 3 to 5 d, but our understanding of the underlying processes preserving wound healing from carcinogenesis remains incomplete. Here, we demonstrate that Nod-like receptor pyrin domain-containing protein 6 (NLRP6) suppresses inflammation and carcinogenesis by regulating tissue repair. NLRP6 was primarily produced by myofibroblasts within the stem-cell niche in the colon. Although NLRP6 expression was lowered in diseased colon, NLRP6-deficient mice were highly susceptible to experimental colitis. Upon injury, NLRP6 deficiency deregulated regeneration of the colonic mucosa and processes of epithelial proliferation and migration. Consistently, absence of NLRP6 accelerated colitis-associated tumor growth in mice. A gene-ontology analysis on a whole-genome expression profiling revealed a link between NLRP6 and self-renewal of the epithelium. Collectively, the integrity of the epithelial barrier is preserved by NLRP6 that may be manipulated to develop drugs capable of preventing adenoma formation in inflammatory bowel diseases.

Procession to pediatric bacteremia and sepsis: covert operations and failures in diplomacy

Despite advances in diagnosis and treatment, bacterial sepsis remains a major cause of pediatric morbidity and mortality, particularly among neonates, the critically ill, and the growing immunocompromised patient population. Sepsis is the end point of a complex and dynamic series of events in which both host and microbial factors drive high morbidity and potentially lethal physiologic alterations. In this article we provide a succinct overview of the events that lead to pediatric bloodstream infections (BSIs) and sepsis, with a focus on the molecular mechanisms used by bacteria to subvert host barriers and local immunity to gain access to and persist within the systemic circulation. In the events preceding and during BSI and sepsis, Gram-positive and Gram-negative pathogens use a battery of factors for translocation, inhibition of immunity, molecular mimicry, intracellular survival, and nutrient scavenging. Gaps in understanding the molecular pathogenesis of bacterial BSIs and sepsis are highlighted as opportunities to identify and develop new therapeutics.

Assessment of enteral bacteria

The disruption of intestinal barrier leads to the penetration of noxious luminal compounds into the gut wall, causing further damage. This unit describes the assessment of enteric bacteria translocation into the intestinal wall of rats, an established method for the evaluation of bowel damage to the mucosal epithelial barrier. The Basic Protocol provided in the present unit describes collection and preparation of small intestine sample, performing of sample serial dilutions for bacterial culture, performing of the culture of aerobic and anaerobic bacteria on petri dishes, incubation of the cultured plates, and counting of bacterial colonies. The Support Protocols describes the procedures for the preparation of petri dishes for the culture, using different employable media for aerobes or anaerobes. The Alternate Protocol describes the use of the "inclusion method," suitable for the culture of anaerobic bacteria.

Orally administered bifidobacteria as vehicles for delivery of agents to systemic tumors

Certain bacteria have emerged as biological gene vectors with natural tumor specificity, capable of specifically delivering genes or gene products to the tumor environment when intravenously (i.v.) administered to rodent models. We show for the first time that oral administration of bacteria to mice resulted in their translocation from the gastrointestinal tract (GIT) with subsequent homing to and replication specifically in tumors. The commensal, nonpathogenic Bifidobacterium breve UCC2003 harboring a plasmid expressing lux fed to mice bearing subcutaneous (s.c.) tumors were readily detected specifically in tumors, by live whole-body imaging, at levels similar to i.v. administration. Reporter gene expression was visible for >2 weeks in tumors. Mice remained healthy throughout experiments. Cytokine analyses indicated a significant upregulation of interferon-gamma (IFN-gamma) in the GIT of bifidobacteria-fed mice, which is associated with increases in epithelial permeability. However, B. breve feeding did not increase systemic levels of other commensal bacteria. The presence of tumor was not necessary for translocation to systemic organs to occur. These findings indicate potential for safe and efficient gene-based treatment and/or detection of tumors via ingestion of nonpathogenic bacteria expressing therapeutic or reporter genes.

Combining enteral with parenteral nutrition to improve postoperative glucose control

The provision of parenteral nutrition (PN) to ‘stressed’ patients often results in hyperglycaemia, which may be detrimental. In animal models limited amounts of enteral nutrition (EN) improve intestinal integrity and stimulate intestinal incretin production, which may lead to improved glucose control. We set out to assess if combining EN with PN results in improved glucose homeostasis rather than PN given alone. We conducted a randomised trial in a university teaching hospital of patients undergoing a ‘curative’ oesophagectomy for adenocarcinoma. Differences between the two intervention groups were assessed for continuous glucose measurement, insulin sensitivity using insulin tolerance tests (ITT) and homeostasis model analysis (HOMA), the incretin glucose-dependent insulinotropic polypeptide (GIP) and intestinal permeability. The combination of PN with EN resulted in lower interstitial glucose concentrations (P = 0·002), reduced insulin resistance, improved insulin sensitivity (HOMA-insulin resistance (IR)P = 0·045; HOMA βP = 0·037; ITTP = 0·006), improved intestinal permeability (P < 0·001) and increased GIP (P = 0·01) when compared with PN alone. The combination of EN with PN, when compared with PN alone, results in reduced glucose concentrations, reduced insulin resistance, increased incretins and improvements in intestinal permeability.

Inflammatory alterations in excluded colon in rats: a comparison with chemically induced colitis

Diversion colitis occurs commonly in the large bowel remnant after diversion of the fecal stream. Several experimental models of colitis have been described, but none examine the inflammatory alterations that can occur in experimentally defunctioned colons. This characterization could be useful in understanding pathophysiological aspects of diversion colitis, and in developing future therapeutic strategies. Thus, we evaluated the temporal inflammatory alterations in the defunctioned colon of rats by analyzing the histological results, infiltrating neutrophils, pro-inflammatory markers such as cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), and DNA damage in isolated colonocytes. We compared the obtained data with those from hapten-induced colitis. The experimental diversion of the colon fecal stream induces diversion colitis characterized by an early inflammatory process with increased neutrophil infiltrate, and COX-2 and iNOS expression that resembles, in some aspects, the inflammatory characteristics of chemically induced colitis. After acute inflammation resolution, there was an increase in COX-2 and iNOS expression and the presence of lymphoid follicular hyperplasia and ulcerations, suggesting that diversion colitis can be experimentally established and useful for studying different pathophysiological aspects of this condition.

Pneumonia as a long-term consequence of chronic psychological stress in BALB/c mice

Recently, we have shown that female BALB/c mice are highly sensitive to chronic psychological stress. They develop systemic neuroendocrine disturbances, a hypermetabolic syndrome, behavioral alterations and severe immunosuppression with a reduced antibacterial response during experimental infection. Here, we show that chronically stressed mice spontaneously suffered from increased bacterial load in the liver and lung that sustained for up to 10 days after the termination of stress exposure. Immediately after the last chronic stress cycle, splenocytes had a reduced ability to produce IFNgamma after ex vivo stimulation with LPS while showing enhanced inducibility of IL-10. When healthy animals were treated with anti-IFNgamma antiserum the antibacterial response against the small numbers of endogenous bacteria that physiologically penetrate the intestinal barrier was reduced causing increased bacterial burden in the liver. Thus, a deficient antibacterial response to translocated commensals in chronically stressed animals can contribute to long-lasting pneumonia.

Elevated systemic antibodies towards commensal gut microbiota in autoinflammatory condition

Background

Familial Mediterranean fever (FMF) is an autoinflammatory condition, which is characterized by acute, self-limiting episodes of fever and serositis and chronic subclinical inflammation in remission. Here we investigated the consequence of this condition on the level of systemic antibodies directed towards common intestinal bacteria.

Methodology/Principal Findings

The level of systemic antibodies towards the antigens of Bacteroides, Parabacteroides, Escherichia, Enteroccocus and Lactobaccilus was measured by ELISA in FMF patients at various stages of the disease and in healthy controls. The difference between remission and attack was not significant. IgG antibodies against the antigens of Bacteroides, Parabacteroides, Escherichia and Enteroccocus were significantly increased in FMF compared to control while IgA levels were not significantly affected. Western blot analyses demonstrated the IgG reactivity against multiple antigens of commensal bacteria in FMF. Serological expression cloning was performed to identify these antigens. No single dominant antigen was identified; the response was generalized and directed against a variety of proteins from Bacteroides, Parabacteroides, Escherichia, and other gut commensals.

Conclusions/Significance

This autoinflammatory syndrome is characterized by the increased systemic reactivity against commensal gut microbiota. This is probably the consequence of hypersensitivity of the inflammasome in FMF that triggers the inflammation and contributes to the excessive translocation of bacteria and bacterial antigens through the gut barrier.

Plasmodium yoelii sporozoites modulate cytokine profile and induce apoptosis in murine Kupffer cells

Plasmodium sporozoites traverse Kupffer cells on their way into the liver. Sporozoite contact does not elicit a respiratory burst in these hepatic macrophages and blocks the formation of reactive oxygen species in response to secondary stimuli via elevation of the intracellular cAMP concentration. Here we show that increasing the cAMP level with dibutyryl cyclic adenosine monophosphate (db-cAMP) or isobutylmethylxanthine (IBMX) also modulates cytokine secretion in murine Kupffer cells towards an overall anti-inflammatory profile. Stimulation of Plasmodium yoelii sporozoite-exposed Kupffer cells with lipopolysaccharide or IFN-gamma reveals down-modulation of TNF-alpha, IL-6 and MCP-1, and up-regulation of IL-10. Prerequisite for this shift of the cytokine profile are parasite viability and contact with Kupffer cells, but not invasion. Whilst sporozoite-exposed Kupffer cells become TUNEL-positive and exhibit other signs of apoptotic death such as membrane blebbing, nuclear condensation and fragmentation, sporozoites remain intact and appear to transform to early exo-erythrocytic forms in Kupffer cell cultures. Together, the in vitro data indicate that Plasmodium possesses mechanisms to render Kupffer cells insensitive to pro-inflammatory stimuli and eventually eliminates these macrophages by forcing them into programmed cell death.

The potential role for xanthine oxidase inhibition in major intra-abdominal surgery

BACKGROUND

Xanthine oxidase (XO) is a cytosolic metalloflavoprotein that has been implicated in the pathogenesis of a wide spectrum of diseases, and is thought to be the most important source of oxygen-free radicals and cell damage during re-oxygenation of hypoxic tissues. Clinical studies have already shown that XO inhibition is safe and effective for the treatment of gout, tumour-lysis syndrome, and to reduce complications such as post-operative arrhythmias, myocardial infarction and mortality in cardiovascular surgery. Here, we review the evidence from two decades of animal studies that have investigated the effects of XO inhibition during intra-abdominal surgery.

MATERIALS AND METHODS

A search of the Ovid MEDLINE database from 1950 through January 2007 was carried out using the following search terms: xanthine oxidase, allopurinol, ischemia, reperfusion, intestine, bowel, and general surgery.

RESULTS

The inhibition of XO has been shown to reduce oxidative stress, neutrophil priming, damage to intestinal mucosa due to ischemia reperfusion injuries, intestinal anastomotic dehiscence, bacterial translocation, adhesion formation, distant organ injury and mortality.

CONCLUSIONS

Despite this evidence which very strongly suggests a likely clinically beneficial role for XO inhibition in the elective and acute operative setting, it is surprising that such an approach has not been investigated in general surgery. There is now sufficient evidence to justify dedicated studies to determine the clinical benefits, dosing and duration of XO inhibition before and after gastrointestinal surgery.

Enteral versus parenteral nutrition after gastrointestinal surgery: a systematic review and meta-analysis of randomized controlled trials in the English literature

BACKGROUND

Although previous studies recommend the use of enteral nutrition (EN), the benefit of EN after elective gastrointestinal surgery has not been comprehensively demonstrated as through a meta-analysis. Our aim is to determine whether enteral nutrition is more beneficial than parenteral nutrition.

METHODS

A search was conducted on Medline, Web of Science, the Cochrane Library electronic databases, and bibliographic reviews. The trials were based on randomization, gastrointestinal surgery, and the reporting of at least one of the following end points: any complication, any infectious complication, mortality, wound infection and dehiscence, anastomotic leak, intraabdominal abscess, pneumonia, respiratory failure, urinary tract infection, renal failure, any adverse effect, and duration of hospital stay.

RESULTS

Twenty-nine trials, which included 2,552 patients, met the criteria. EN was beneficial in the reduction of any complication (relative risk (RR), 0.85; 95% confidence interval (CI), 0.74-0.99; P = 0.04), any infectious complication (RR, 0.69; 95% CI, 0.56-0.86; P = 0.001), anastomotic leak (RR, 0.67; 95% CI, 0.47-0.95; P = 0.03), intraabdominal abscess (RR, 0.63; 95% CI, 0.41-0.95; P = 0.03), and duration of hospital stay (weighted mean difference, -0.81; 95% CI, -1.25-0.38; P = 0.02). There were no clear benefits in any of the other complications.

CONCLUSION

The present findings would lead us to recommend the use of EN rather than PN when possible and indicated.

Rapid response systems

Intensive care medicine was for many years practiced within the four walls of an intensive care unit (ICU). Evidence then emerged that many serious adverse events in hospitals were preceded by many hours of slow deterioration, resulting in multi-organ failure and potentially preventable admissions to the ICU. Ironically, these admissions may have been prevented if the skills within the ICU had been available to the patient on the general ward at an earlier stage. The concept of a Medical Emergency Team (MET) was developed to enable staff from the ICU to rapidly identify and respond to serious illness at an earlier stage and, hopefully, prevent serious complications. Since then, other forms of rapid response and outreach systems have been developed. Increasingly, physicians working in ICUs can see the benefit of the early management of serious illness in order to improve patient outcome.

Relations among circulating monocytes, dendritic cells, and bacterial translocation in patients with intestinal obstruction

BACKGROUND

Little evidence is available regarding the relations among circulating monocytes, dendritic cells (DCs), and bacterial translocation (BT) in patients with intestinal obstruction.

METHODS

We investigated alterations in DCs in mesenteric lymph nodes (MLNs), circulating immune cells (white blood cell, lymphocyte, and monocyte counts), and BT to MLNs in 21 patients undergoing abdominal surgery because of intestinal obstruction. We also examined whether BT correlated with the development of perioperative systemic inflammatory response syndrome (SIRS) and postoperative septic complications.

RESULTS

BT subsequent to intestinal obstruction was observed in 7 (33%) patients. Preoperative circulating immune cell counts were significantly lower in BT-positive patients than those in BT-negative patients. The presence of preoperative SIRS was also significantly related to BT-positive status. A preoperative monocyte count <290/mm(3) was the best predictive factor for BT in MLNs during intestinal obstruction: sensitivity 85.7%; specificity 92.3%; positive and negative predictive values 85.7% and 92.9%, respectively. The area under the receiver operating characteristic curve was 0.944. The expression of S-100 protein-positive DCs in MLNs significantly increased in BT-positive patients.

CONCLUSIONS

A significant inverse correlation was observed between the circulating monocyte count and the ratio of DCs among all cells in MLNs (r(2)= 0.259). Postoperative septic complications were 3.3 times more common in BT-positive patients than in BT-negative patients. A significant increase in the expression of DCs in MLNs was observed in patients with BT subsequent to intestinal obstruction. Our findings suggested that a low monocyte count (<290 /mm(3)) and the presence of preoperative SIRS might be useful factors for predicting BT in patients with intestinal obstruction.

The significance of bowel permeability

PURPOSE OF REVIEW

In clinical research, increased permeability has been scrutinized as a potential indicator of the severity of gastrointestinal disease and as a potential cause of the perpetuation of severe inflammatory activity in infectious states. This review discusses old and recent epidemiological and clinical evidence to establish whether increased permeability in sepsis is a sequel or a cause of multiple organ failure. In addition, old and new evidence linking inflammation and permeability in abnormal gastrointestinal anatomy and function to liver abnormalities in susceptible patients will be reviewed.

RECENT FINDINGS

Intestinal permeability has been found to be increased in several gastrointestinal diseases but not to be a very good marker of the severity of disease. Evidence is put forward supporting the claim that increased intestinal permeability is part of generalized leakiness of tight junctions in multiple organ failure and to play a less strong role as a primary event in its pathogenesis. Endemic malnutrition has been shown to be caused by interplay between malnutrition and intestinal inflammation. Recently experimental evidence has been put forward suggesting that enteral fat has anti-inflammatory effects on the intestine via the autonomic nervous system. Old clinical and new epidemiological evidence links intestinal inflammation, disruption of the enterohepatic cycle of bile acids, and liver disease.

SUMMARY

The implications of the described findings are that inflammatory activity, locally induced by abnormal intestinal anatomy and disruption of the bile acid pool, or systemically by severe and uncontrolled inflammation/infection, should be the focus of treatment or research. In addition, the connection between intestinal inflammation and liver disease should be investigated.

Randomized clinical trial of effect of synbiotics, neomycin and mechanical bowel preparation on intestinal barrier function in patients undergoing colectomy

BACKGROUND

The aim of this study was to investigate whether it is possible to modulate gut microflora and preserve intestinal barrier function during elective colorectal surgery by using combinations of oral antibiotics, synbiotics and mechanical bowel preparation (MBP).

METHODS

Ninety-two patients were randomly assigned to one of four groups. Group 1 had MBP only, group 2 had neomycin + MBP, group 3 had synbiotics + neomycin + MBP, and group 4 had synbiotics + neomycin but no MBP. Changes in gut microflora were assessed by culturing nasogastric aspirates and polymerase chain reaction-denaturing gradient gel electrophoresis of faecal samples. Intestinal barrier function was determined by microbiological confirmation of bacterial translocation and measurement of intestinal permeability. The inflammatory response was monitored by measurement of serum C-reactive protein and interleukin 6, and septic morbidity was recorded prospectively.

RESULTS

Four patients were excluded owing to protocol violation, leaving 24 patients in group 1, 22 in group 2, 20 in group 3 and 22 in group 4 for analysis. There was a significant decrease in Enterobacteriaceae in group 3 compared with the other groups. Group 3 had a significantly lower incidence of translocation after bowel mobilization (P < 0.001). There was no significant difference between the groups in intestinal permeability, inflammatory response or septic morbidity.

CONCLUSION

The combination of MBP, neomycin and synbiotics reduces the prevalence of faecal Enterobacteriaceae and bacterial translocation; however, this was not associated with a reduction in inflammatory response or septic morbidity in this study. Larger trials are needed before a change in practice can be recommended.

Escherichia coli alpha-haemolysin induces focal leaks in colonic epithelium: a novel mechanism of bacterial translocation

Extraintestinal pathogenic Escherichia coli (ExPEC) are usually harmless colonizer of the intestinal microflora. However, they are capable to translocate and cause life-threatening disease. Translocation of ExPEC isolates was quantified in colonic monolayers. Transepithelial resistance (R(t)) was monitored and local changes in conductivity analysed with conductance scanning. Confocal microscopy visualized the translocation route. Corroboratory experiments were performed on native rat colon. One translocating strain E. coli O4 was identified. This translocation process was associated with an R(t) decrease (36 +/- 1% of initial resistance) beginning only 2 h after inoculation. The sites of translocation were small defects in epithelial integrity (focal leaks) exhibiting highly increased local ion permeability. Translocation was enhanced by preincubation of monolayers with tumour necrosis factor-alpha or interleukin-13. Mutant strains lacking alpha-haemolysin lost the ability to induce focal leaks, while this effect could be restored by re-introducing the haemolysin determinant. Filtrate of a laboratory strain carrying the alpha-haemolysin operon was sufficient for focal leak induction. In native rat colon, E. coli O4 decreased R(t) and immunohistology demonstrated focal leaks resembling those in cell monolayers. E. coli alpha-haemolysin is able to induce focal leaks in colonic cell cultures as well as in native colon. This process represents a novel route of bacterial translocation facilitated by pro-inflammatory cytokines.

Genetic variants in the NOD2/CARD15 gene are associated with early mortality in sepsis patients

OBJECTIVE

Genetic variants in the NOD2/CARD15 gene resulting in a diminished capacity to activate NF-kappaB in response to bacterial cell wall products have been associated with Crohn's disease (CD). Recently, we found an association between the variant Leu1007fsinsC of the NOD2/CARD15 gene (SNP13) and a significantly increased rate of transplant related mortality (TRM) due to intestinal and pulmonary complications in stem cell transplantation (SCT). To assess a possible contribution of variants in the NOD2/CARD15 gene to sepsis related mortality (SRM) we investigated 132 prospectively characterised, consecutive patients with sepsis.

DESIGN AND PATIENTS

The three most common NOD2/CARD15 variants (Arg702Trp, Gly908Arg, and Leu1007fsinsC) were determined in 132 prospectively characterised patients with sepsis attended to three intensive care units at the University of Regensburg by Taqman PCR. NOD2/CARD15 genotype and major patients' characteristics were correlated with SRM.

RESULTS

Patient groups with and without NOD2/CARD15 variants did not differ in their clinical characteristics such as median age, gender, reason for admission or APACHE score; however, SRM (day 30) was increased in patients with NOD2/CARD15 coding variants (42 vs. 31%) and was highest (57%) in 8 patients carrying the Leu1007fsinsC variant (p < 0.05). Multivariate analysis demonstrated the Leu1007fsinsC genetic variant as an independent risk factor for SRM.

CONCLUSION

Our findings indicate a major role of NOD2/CARD15 coding variants for SRM. This may be indicative for a role of impaired barrier function and bacterial translocation in the pathophysiology of early sepsis related death.

Does noncomplicated acute appendicitis cause bacterial translocation?

It is unknown whether noncomplicated acute appendicitis cause bacterial translocation. In this study, we aimed to test development of the bacterial translocation in the patients who were operated for acute appendicitis. In this prospective study, 10 control patients who underwent elective operations because of other reasons, and 18 patients with noncomplicated acute appendicitis were evaluated. No patients took prophylactic antibiotic. After laparotomy, samples were obtained from peritoneal leaf just close to wound edge, and peritoneal swab culture from right paracolic region. Before appendectomy, a mesenteric lymph node (MLN) adjacent to the terminal ileum was taken out. Tissue samples were placed in a sterile container for microbiological analysis, and 10% formalin for histopathological analysis. Control samples had no bacterial translocation. Only 3 of 18 (16.6%) patients with appendicitis included bacterial translocation to MLN. There was no significant difference between both groups. No bacterial colonization was detected in the peritoneal tissue and peritoneal swab culture. Peritoneal tissue injury score was 2 +/- 1.4 in controls and 2.8 +/- 1.7 in the patients with appendicitis (P>0.05). MLN injury score was 2.5 +/- 1.3 in controls and 3.2 +/- 1.5 in the patients with appendicitis (P>0.05). No patient developed wound and systemic infection. No significant bacterial translocation frequency and tissue injury score was identified in the children with noncomplicated acute appendicitis. This result suggests that antibiotic prophylaxis may be unnecessary in such patients.

Bacterial translocation in rats nonfunctioning diverted distal colon

PURPOSE: To investigate whether the alterations of the diverted colon segment mucosa, evidenced in fecal colitis, would be able to alter Bacterial Translocation (BT). METHODS: Sixty-two Wistar male rats ranging from 220 to 320 grams of weight, were divided in two groups: A (Colostomy) and B (Control), with 31 animals each one. In group A, all animals underwent end colostomy, one stoma, in ascending colon; and in the 70th POD was injected in five rats, by rectal route diverted segment - 2ml of a 0.9% saline solution in animals (A1 subgroup); in eight it was inoculated, by rectal route, 2ml of a solution containing Escherichia coli ATCC 25922 (American Type Culture Collection), in a concentration of 10(8) Colony Forming Unit for milliliters (CFU/ml) - A2 Subgroup; in ten animals the same solution of E. coli was inoculated, in a concentration of 10(11) CFU/ml (A3 Subgroup); and in eight it was collected part of the mucus found in the diverted distal colonic segment for neutral sugars and total proteins dosage (A4 subgroup). The animals from the group B underwent the same procedures of group A, but with differences in the colostomy confection. In rats from subgroups A1, A2, A3, B1, B2, and B3 2ml of blood were aspirated from the heart, and fragments from mesenteric lymphatic nodule, liver, spleen, lung and kidney taken for microbiological analysis, after their death. This analysis consisted of evidencing the presence of E. coli ATCC 25922 CFU. Mann-Whitney and ANOVA Tests were applied as analytic techniques for association of variables. RESULTS: The occurrence of BT was evidenced only in those animals in which inoculated concentration of E. coli ATCC 25922, reached levels of 10(11)CFU/ml, i.e. in Subgroups A3 and B3, although, being significantly greater (80%) in those animals without colostomy (subgroup B3) when compared to the ones with colostomy (20%) from the subgroup A3 (P <0.05). Lung, liver and mesenteric lymphatic nodules were the tissues with larger percentile of bacterial recovery, so much in subgroup A3, as in B3. Blood culture was considered positive in 60% of the animals from subgroup B3 and in 10% of those from subgroup A3 (p <0.05). There was greater concentration of neutral sugars, in subgroup A4 - mean 27.3mg/ml -, than in subgroup B4 - mean 8.4mg/ml - (P <0.05). CONCLUSION: The modifications in the architecture of intestinal mucosa in colitis following fecal diversion can cause alterations in the intestinal barrier, but it does not necessarily lead to an increased frequency of BT.

Enteral nutrition versus parenteral nutrition--the risks and benefits

The role of nutrition in patient care became a part of mainstream medicine at about the end of the 1960s, with the publication of several papers that showed a benefit of nutritional support in the prevention of complications. At that time, the emphasis was on nutrition given by the parenteral route. Since then, a series of studies that compared parenteral nutrition with enteral nutrition have suggested that the enteral route of feeding causes fewer complications than the parenteral route. A careful review of the data shows that nutritional support can increase the risk of complications when given to well-nourished, obese and hyperglycemic patients. The avoidance of overfeeding and hyperglycemia is, therefore, of paramount importance. In this context, enteral nutrition, for which gastrointestinal tolerance limits overfeeding, can protect the patient.