Review article: bacterial translocation in the critically ill--evidence and methods of prevention

Bacterial Translocation As the Origin of Gram-Negative Rods Bloodstream Infection Among Older Patients in Rural Hospitals: A Cross-Sectional Study

Introduction Bloodstream infections caused by Gram-negative rods are a pressing concern for the aging global population, particularly in rural settings. This study investigates the prevalence and entry pathways of Gram-negative rod bloodstream infections in elderly patients at a rural Japanese hospital, aiming to clarify the frequency and associated factors of straightforward entry and bacterial translocation. Method In this cross-sectional study, we analyzed electronic medical records of patients over 18 years of age with symptomatic Gram-negative rod bloodstream infections at Unnan City Hospital, Japan, from September 2021 to August 2023. We used multivariate logistic regression to assess factors of age, sex, body mass index, care dependency, and comorbidities. Results Among the participants who met the inclusion criteria, significant differences were observed in age, sex, inpatient status, and prevalence of conditions like respiratory diseases and cancer between the straightforward entry and bacterial translocation groups. Escherichia coli was the most common pathogen identified. Conclusion The study emphasizes the need for tailored medical approaches for elderly patients with bloodstream infections, considering their unique health profiles and risks. It highlights the importance of age, inpatient status, and cancer in determining infection risks, pointing to areas for further research to enhance infection management and healthcare outcomes in older populations.

Liver microbial community and associated host transcriptome in calves with feed induced acidosis

Introduction

In the dairy industry, calves are typically fed diets rich in highly fermentable carbohydrates and low in fibrous feeds to maximize ruminal papillae and tissue development. Calves on such diets are vulnerable at developing ruminal acidosis. Prevalent in cattle, liver abscess (LA) is considered a sequela to ruminal acidosis. LAs can cause significant liver function condemnation and decreased growth and production. Currently, we know little about the liver microbiome in calves with feed-induced acidosis.

Methods

Using our established model of ruminal acidosis, where young calves were fed an acidosis-inducing (AC) or -blunting (control) diet starting at birth until 17-week of age, we investigated microbial community changes in the liver resultant from ruminal acidosis. Eight calves were randomly assigned to each diet, with four animals per treatment. Rumen epithelium and liver tissues were collected at 17 weeks of age right after euthanasia. Total RNAs were extracted and followed by whole transcriptome sequencing. Microbial RNA reads were enriched bioinformatically and used for microbial taxonomy classification using Kraken2.

Results

AC Calves showed significantly less weight gain over the course of the experiment, in addition to significantly lower ruminal pH, and rumen degradation comparison to the control group (p < 0.05). In the liver, a total of 29 genera showed a significant (p < 0.05) abundance change (> 2-fold) between the treatments at 17-week of age. Among these, Fibrobacter, Treponema, Lactobacillus, and Olsenella have been reported in abscessed liver in cattle. Concurrent abundance changes in 9 of the genera were observed in both the liver and rumen tissues collected at 17-week of age, indicating potential crosstalk between the liver and rumen epithelial microbial communities. Significant association was identified between host liver gene and its embedded microbial taxa. Aside from identifying previously reported microbial taxa in cattle abscessed liver, new repertoire of actively transcribed microbial taxa was identified in this study.

Discussion

By employing metatranscriptome sequencing, our study painted a picture of liver microbiome in young calves with or without feed induced acidosis. Our study suggested that liver microbiome may have a critical impact on host liver physiology. Novel findings of this study emphasize the need for further in-depth analysis to uncover the functional roles of liver resident microbiome in liver metabolic acidosis resultant from feed-related ruminal acidosis.

Abdominal perfusion in canine patients with pyometra and sepsis evaluated by Doppler and contrast-enhanced ultrasound

BACKGROUND

Sepsis is a condition characterized by organic dysfunction, leading to hemodynamic instability and high morbidity and mortality rates in humans and animals. Early identification of perfusion changes and appropriate management of sepsis are crucial for improving patient prognosis. Currently, the Systemic Inflammatory Response Syndrome (SIRS) and Sequential Organ Failure Assessment (SOFA) scores are widely studied for sepsis identification and evaluation of organ dysfunction. However, these scores do not assess gastrointestinal involvement, which is common in this condition. Contrast-enhanced ultrasound (CEUS) and Doppler have been considered promising diagnostic techniques for detecting changes in vascularization and microcirculation in a non-invasive and safe manner, particularly in the gastrointestinal system. This study aimed to evaluate duodenal perfusion using CEUS, as well as abdominal aortic and cranial mesenteric artery blood flow using Doppler ultrasound, and systolic arterial pressure (SAP) in 17 bitches with pyometra and in 10 healthy animals.

RESULTS

The variables were compared between the pyometra and control groups, as well between patients with and without sepsis determined by the SOFA or SIRS scores. Pyometra was found to cause a reduction in abdominal aortic blood flow volume, aortic peak systolic velocity, and resistivity index as evaluated by Doppler ultrasound. Patients with sepsis according to the SOFA criteria only presented lower SAP. In contrast, sepsis animals identified by the SIRS score exhibited lower SAP, aortic peak systolic velocity, aortic blood flow volume, and aortic resistivity index and additionally, higher peak intensity of contrast in the duodenal wall.

CONCLUSIONS

Pyometra causes a reduction in abdominal aortic blood flow, which is more pronounced in animals with sepsis identified by the SIRS criteria. These animals also exhibited a decrease in systolic blood pressure and an increase in duodenal perfusion, as evident by CEUS. However, these changes were not observed in patients with sepsis identified by the SOFA criteria. The alterations in intestinal perfusion observed in animals with sepsis indicate the presence of inflammation or dysfunction. In this regard, CEUS proves to be a valuable technique for detecting subtle changes in tissue hemodynamics that may not be apparent in conventional exams.

An Overview of the Microbiota of the Human Urinary Tract in Health and Disease: Current Issues and Perspectives

This article is intended to deepen our knowledge to date regarding the functions of the resident microbiota/microbiome in the urinary system for human health and disease. First, we sought to report the general characteristics (composition and stability) of the normal urinary system microbiota in the different anatomical sites in relation to some factors such as the effect of age, gender and diet, analyzing in detail the functions and the composition of the microbiota in the light of current knowledge. Several pieces of evidence suggest the importance of preserving the micro-ecosystem of the urinary system, and in some cases their relationship with diseases is important for maintaining human health is well understood. The female and male reproductive microbiota have mainly been studied over the past decade. In the past, the arrest was thought to have taken place in a sterile environment. Microorganisms of the microbiota form biofilms, three-dimensional structures, that differ in the reproductive organs and interact with both gametes and the embryo as well as with maternal tissues. These biofilms from the reproductive system also interact with others, such as that of the gastrointestinal tract. Reduction in its diversity intestinal microbiota can disrupt estrogen metabolism and affect the reproductive microbiota. It is therefore understood that its quantitative and qualitative identification is important for microbiota, but also the study of the structures formed by the microorganisms. A dysbiosis with local or systemic causes can lead to serious diseases. The role of probiotics in maintaining microbial population harmony (eubiosis) and preventing certain pathologies of the urinary and reproductive system was also investigated. A negative variation in the qualitative and quantitative composition of certain strains of microorganisms (dysbiosis) due to local or systemic causes can even lead to serious diseases. The role of probiotics in maintaining the healthy balance of microorganism populations (eubiosis), and thus in the prevention of certain pathologies of the urinary and reproductive system, has also been studied.

Recognition and management of hemorrhaging in combination with emerging enterogenic sepsis during a hepatectomy: a case report

BACKGROUND

Patients with hemorrhagic shock may develop emerging enterogenic sepsis due to damage to the intestinal mucosal barrier and translocation of intestinal bacteria and endotoxins caused by ischemic injury. Because of the dual effects of anesthesia state and hemorrhagic shock, perioperative emerging enterogenic sepsis is even more rare and insidious.

CASE PRESENTATION

We reported a case of 56-year-old man who underwent right hepatectomy for intrahepatic bile duct stones. Severe hemorrhage occurred during the procedure and the hemodynamics neither improved nor worsened after rehydration therapy and vasoactive drug administration. Based on the patient's history and clinical presentation, a possible enterogenic sepsis was considered. After anti-infective treatment and hormone supplementation, the patient's circulation improved significantly and he had an uneventful recovery.

CONCLUSION

The possibility of emerging enterogenic sepsis in hemorrhagic shock must always be taken into consideration. Familiarity with the risk factors and pathophysiological alterations of enterogenic sepsis is a prerequisite for early recognition and sound clinical decision making.

Effect of end-stage kidney disease on the return of spontaneous circulation in Taiwanese adults with out-of-hospital cardiac arrest

Rescuing patients with out-of-hospital cardiac arrest (OHCA), especially those with end-stage kidney disease (ESKD), is challenging. This study hypothesizes that OHCA patients with ESKD undergoing maintenance hemodialysis have (1) higher rates of return of spontaneous circulation (ROSC) during cardio-pulmonary resuscitation (CPR) and (2) lower rates of hyperkalemia and less severe acidosis than those without ESKD. OHCA patients who received CPR between 2011 and 2020 were dichotomized into ESKD and non-ESKD groups. The association of ESKD with "any" and "sustained" ROSC were examined using logistic regression analysis. Furthermore, the effect of ESKD on hospital outcomes for OHCA patients who survived to admission was evaluated using Kaplan-Meier analysis. ESKD patients without "any" ROSC displayed lower potassium and higher pH levels than non-ESKD patients. ESKD was positively associated with "any" ROSC (adjusted-OR: 4.82, 95% CI 2.70-5.16, P < 0.01) and "sustained" ROSC (adjusted-OR: 9.45, 95% CI 3.83-24.13, P < 0.01). Kaplan-Meier analysis demonstrated ESKD patients had a non-inferior hospital survival than non-ESKD patients. OHCA patients with ESKD had lower serum potassium level and less severe acidosis compared to the general population in Taiwan; therefore, should not be treated under the stereotypical assumption that hyperkalemia and acidosis always occur.

Preceding Clinical Events in High-risk, Postoperative, Pediatric Cardiac Patients- A Novel Association With Bacteremia

Objective: Blood stream infections (BSIs) are well described in pediatric cardiac intensive care units (PCICU). We noted that postoperative high-risk patients may develop BSI after a preceding clinical event (PCE). The study aim was to investigate whether high-risk patients who developed bacteremia experienced more PCEs than a similar group of high-risk patients. Design: Retrospective case-control study. Setting: Referral pediatric center. Patients: We enrolled patients who developed bacteremia from March 2010 to November 2019, after undergoing open-heart surgery at a pediatric center. The control group was comprised of case-matched patients with immediate consecutive same surgery. Interventions: None. Measurements: We recorded operative data, common risk factors, postoperative indicators of organ dysfunction, mortality, and PCEs 72 to 24 h before bacteremia emerged. Main results: A total of 200 patients were included (100 with bacteremia and 100 controls). Key demographic and operative parameters were matched. Bacteremia emerged on average on postoperative day 12.8. Skin-associated Gram-positive bacteria were cultured in 10% and Gram-negative bacteria in 84% of the patients. Average central-venous lines (CVL) duration was 9.5 ± 8.4 days. Postoperatively (72 h), indicators of organ dysfunction were significantly worse in patients with bacteremia, with a higher rate of postoperative complications during PCICU length-of-stay (LOS). In the bacteremia group, 72 to 24 h prior to the development of bacteremia, 92 (92%) PCEs were recorded, as compared to 21 (21%) in controls during their entire LOS (odds ratio [OR] 43.3, confidence interval [CI] 18.2-103.1, P < .0001). Conclusions: We propose a 3-hit model demonstrating that high-risk patients undergoing open-heart surgery have significantly higher risk for bacteremia after a PCE.

Central Venous Catheter-Related Infectious Complications in Pediatric Surgical Patients: A Single-Center Experience

The purpose of this study was to estimate the rate of central venous catheter (CVC) colonization and catheter-related bloodstream infections (CRBSIs) in pediatric surgical patients at our institute and to determine the various risk factors for their occurrence. The electronic medical records of 260 children undergoing surgery with simultaneous CVC insertion were retrospectively reviewed. Data on demographics, primary organ system involved, site of CVC, CVC dwell time, CVC colonization, CRBSI, and organisms isolated on culture were collated, categorized, and analyzed. The rate of CVC colonization and CRBSI was 32.8 per 1,000 catheter days (19.6%) and 17.4 per 1,000 catheter days (10.4%), respectively. Patients with CVC colonization and CRBSI had a significantly higher proportion of patients younger than 1 year of age (p = 0.014). The CVC dwell time was significantly higher in both CVC colonization (7 [5–8] days) and CRBSI (6 [5–9] days) patients (p = 0.005). The frequency of femoral catheterization was significantly higher in patients with CRBSI and CVC colonization (p < 0.001). Coagulase negative staphylococcus was the commonest isolate in CVC infections. Age (adjusted odds ratio [OR] = 0.87; p = 0.009), CVC dwell time (adjusted OR = 1.28; p = 0.003), and femoral CVC (adjusted OR = 9.61; p < 0.001) were independent risk factors for CRBSI. Conclusion: This study reveals important observations regarding the infectious complications of CVC in pediatric surgical patients. The rates of CVC colonization and CRBSI in this study were found to be higher as compared with previously reported rates in Western literature. However, these findings are significant in view of paucity of existing literature in pediatric surgical patients. In our study, higher risk of CRBSI was associated with younger age, increasing CVC dwell time, and femoral venous catheterization. We recommend strict compliance with CVC insertion and maintenance practices and adherence to CVC care bundles to minimize these serious complications.

Fecal calprotectin as a biomarker of intestinal inflammation in ICU patients with diarrhea - testing the pipette method against the collection pin and weighing methods

Fecal calprotectin is an established biomarker in inflammatory bowel disease, but its role in assessment of intestinal inflammation in ICU patients is yet to be explored. ICU patients tend to acquire diarrhea, which complicates the extraction of fecal calprotectin using a collection pin for stool sampling. Pipetting is an alternative sampling method. The aim of the study was to compare the collection pin method with the pipette method for measurement of fecal calprotectin in ICU patients with diarrhea. Stool samples were collected from fecal bags used in the patients and then analyzed for calprotectin using an extraction device and a piston pipette, respectively. In addition, a validation test for the pipette method of extraction was conducted on liquid stool samples. Eleven stool samples were collected from five randomly selected ICU patients. Calprotectin was detectable in all fecal samples. On average the collection pin measured 45% lower than the pipette method with a 95% confidence interval (30 - 59%). The coefficient of variation when using the pipette method was 13% in low calprotectin concentrations and 39% in high concentrations. In conclusion, the pipette method seems to be appropriate for measuring calprotectin in liquid feces, due to practicalities and a greater precision.

Preventing Bacterial Translocation in Patients with Leaky Gut Syndrome: Nutrition and Pharmacological Treatment Options

Leaky gut syndrome is a medical condition characterized by intestinal hyperpermeability. Since the intestinal barrier is one of the essential components maintaining homeostasis along the gastrointestinal tract, loss of its integrity due to changes in bacterial composition, decreased expression levels of tight junction proteins, and increased concentration of pro-inflammatory cytokines may lead to intestinal hyperpermeability followed by the development of gastrointestinal and non-gastrointestinal diseases. Translocation of microorganisms and their toxic metabolites beyond the gastrointestinal tract is one of the fallouts of the leaky gut syndrome. The presence of intestinal bacteria in sterile tissues and distant organs may cause damage due to chronic inflammation and progression of disorders, including inflammatory bowel diseases, liver cirrhosis, and acute pancreatitis. Currently, there are no medical guidelines for the treatment or prevention of bacterial translocation in patients with the leaky gut syndrome; however, several studies suggest that dietary intervention can improve barrier function and restrict bacteria invasion. This review contains current literature data concerning the influence of diet, dietary supplements, probiotics, and drugs on intestinal permeability and bacterial translocation.

Preoperative Elemental Diet before Laparoscopic Anterior Resection in Patients with Advanced Stenotic Rectal Cancer

Objectives:

To evaluate the feasibility of our new preoperative enteral nutrition protocol using Elental^Ⓡ without mechanical bowel preparation (MBP) before laparoscopic anterior resection (LAR) in patients with advanced stenotic rectal cancer.

Methods:

Among 74 patients with advanced rectal cancer (clinical stages T3 and T4) scheduled to undergo LAR, 42 patients with stenotic rectal cancer were administered Elental^Ⓡ (900 kcal/day) without MBP before LAR (group S). Thirty-two patients without stenosis (group NS) did not receive preoperative nutritional support but underwent MBP.

Results:

Group S patients were maintained in a fasting state and received an elemental diet approximately 10 days preoperatively without severe adverse effects. The incidence of postoperative complications (Clavien-Dindo classification ≥ grade 2) was significantly lower in group S than that in group NS (adjusted odds ratio [OR]: 6.046, P = 0.008). Logistic regression analysis revealed that group NS exhibited higher risks of developing postoperative complications than those exhibited by group S (OR: 4.32, 95% confidence interval [CI]: 1.28-17.28, P = 0.018). Among preoperative characteristics, the clinical tumor stage indicated a significant intergroup difference. Thus, the clinical stage was selected as a covariate and adjusted in the logistic regression model to calculate a covariate-adjusted OR. Group NS exhibited a higher incidence of postoperative complications than group S (adjusted OR: 6.05, 95% CI: 1.58-28.35, P = 0.008).

Conclusions:

Administration of an elemental diet using Elental^Ⓡ without MBP before LAR is a feasible strategy in patients with advanced stenotic rectal cancer. Application of this research may encourage use of Elental^Ⓡ in the clinical setting.

A retrospective study of 237 dogs hospitalized with suspected acute hemorrhagic diarrhea syndrome: Disease severity, treatment, and outcome

BACKGROUND

Few studies have investigated management and outcome in dogs with acute hemorrhagic diarrhea syndrome (AHDS), and there is a paucity of data on dogs with concurrent signs of sepsis.

OBJECTIVES

To report outcome in dogs with suspected AHDS according to disease severity and antimicrobial treatment, and to evaluate effect of fluid resuscitation on clinical criteria.

ANIMALS

Two hundred thirty-seven dogs hospitalized with suspected AHDS.

METHODS

Retrospective study based on medical records. Disease severity was evaluated using AHDS index, systemic inflammatory response syndrome (SIRS) criteria, and serum C-reactive protein (CRP) according to 3 treatment groups: No, 1, or 2 antimicrobials.

RESULTS

Sixty-two percent received no antimicrobials, 31% received 1 antimicrobial, predominantly aminopenicillins, and 7% received 2 antimicrobials. At admission, median AHDS index was 13 (interquartile range, 11-15), which decreased significantly after the first day's hospitalization (P < .001) for all groups. Compared with no antimicrobials (7%), more dogs had ≥2 SIRS criteria in the antimicrobial groups (15% and 36%, respectively). C-reactive protein (CRP) correlated positively with AHDS index at hospitalization (P < .001). Across treatment groups, rehydration markedly reduced number of clinical SIRS criteria. Survival to discharge was 96%, lower for dogs receiving 2 antimicrobials (77%, P < .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

The majority of dogs hospitalized with suspected AHDS improve rapidly with symptomatic treatment only, despite signs of systemic disease on initial presentation. The often-used SIRS criteria might be a poor proxy for identifying dogs with AHDS in need of antimicrobial treatment, in particular when hypovolemic. The role of CRP in clinical decision-making or prognostication warrants further investigation.

D-Lactate and intestinal fatty acid-binding protein are elevated in serum in patients with acute ischemic stroke

Experimental studies suggest that the intestinal barrier is affected in ischemic stroke. D-Lactate and intestinal fatty acid-binding protein (IFABP) are markers of intestinal mucosa integrity and barrier function. Our purpose was to evaluate the serum concentrations of these markers in patients with acute ischemic stroke (AIS). We included patients with AIS and used healthy subjects as controls. Clinical, demographic and outcome measures were recorded. Blood was drawn within 24 h of symptom onset. Serum concentrations of D-Lactate and IFABP were determined using commercially available colorimetric and ELISA kits, respectively. We included a total of 61 patients (median age of 64 years). The majority of patients were male (57.4%). The most common cause of stroke was atherosclerosis (34.4%), followed by small-vessel disease and cardioembolic (32.7% each). Mean admission NIHSS score was 8. Median IFABP and D-Lactate concentrations were significantly higher in patients than in controls. Concentrations were not associated with stroke severity or 3-month outcome. Patients with large-artery atherosclerosis and cardioembolic etiology had higher D-Lactate values than patients with small-vessel disease. D-Lactate and IFABP were significantly elevated in patients with AIS. This suggests that there is disruption of the intestinal barrier in patients with AIS.

Shifting focus toward healthcare-associated bloodstream infections: The need for neonatal intensive care unit-specific NHSN definitions

OBJECTIVE

Healthcare-associated bloodstream infections (HABSIs) are a significant cause of mortality and morbidity in the neonatal intensive care unit (NICU) population. Our objectives were to review the epidemiology of HABSIs in our NICU and to examine the applicability of National Healthcare Safety Network (NHSN) definitions to the NICU population.

METHODS

We performed a retrospective review of all neonates admitted to the 54-bed, level IV NICU at Yale-New Haven Children's Hospital with a HABSI between January 1, 2013, and December 31, 2018. Clinical definitions per NICU team and NHSN site-specific definitions used for source identification were compared using the McNemar χ2 test.

RESULTS

We identified 86 HABSIs with an incidence rate of 0.80 per 1,000 patient days. Only 13% of these were CLABSIs. Both CLABSIs and non-catheter-related bloodstream infections occurred primarily in preterm neonates, but the latter were associated with a significantly higher incidence of comorbidities and the need for respiratory support. The NHSN definitions were less likely to identify a source compared to the clinical definitions agreed upon by our NICU treating team (P < .001). Furthermore, 50% of patients without an identified source of infection by NHSN definitions were bacteremic with a mucosal barrier injury organism, likely from gut translocation.

CONCLUSIONS

HABSIs occur primarily in premature infants with comorbidities, and CLABSIs account for a small proportion of these infections. With the increasing focus on HABSI prevention, there is a need for better NHSN site-specific definitions for the NICU population to prevent misclassification and direct prevention efforts.

Current progress of research on intestinal bacterial translocation

Under normal conditions, the intestinal flora and the body are in dynamic equilibrium. When the barrier function of the intestinal tract is damaged due to various reasons, changes in the number and proportion of bacteria or spatial displacement result in bacterial translocation (BT), which ultimately leads to multiple organ dysfunction syndrome (MODS). Endogenous infections and endotoxemia caused by intestinal flora and endotoxin translocation are the origins of inflammatory responses, and the intestinal tract is the organ in which MODS both initiates and targets. Only by ensuring the integrity of the intestinal mucosal barrier can intestinal BT be effectively prevented. Elimination of the primary disease and maintaining blood and oxygen supply to the intestine is the most basic treatment. Early initiation of the intestinal tract, establishment of enteral nutrition, and selective digestive decontamination are also highly effective treatments. Early diagnosis, intervention, or prevention of BT may be a new avenue or important connection in the treatment of various diseases. The mechanism of BT, detection techniques, prevention and treatment, and its interaction with parenteral diseases were reviewed.

Case report: fatal pneumonia caused by new sequence type Legionella pneumophilia serogroup 1

INTRODUCTION

Legionnaires' disease is caused by Legionella bacteria, and commonly manifests as pneumonia and has a high fatality rate.

PATIENT CONCERNS

This case study reports on the fatal incident of a patient, initially diagnosed with pneumonia, and subsequently diagnosed with Legionnaires' disease caused by a new sequence type (ST) of Legionella.

DIAGNOSIS

It is speculated that the patient acquired Legionnaires' disease from a contaminated water source. Legionnaires' disease was diagnosed using the Legionella urinary antigen assay and bacterial cultures of respiratory secretions; Legionella pneumophilia Type 1 was also identified through serological testing. Sequence-based typing of the cultured bacterium revealed it to be a previously unidentified species, and it was named ST2345 new-type.

INTERVENTIONS

In addition to the treatment of Legionnaires' disease, blood samples taken on the second day of admission showed a co-infection of Candida tropicalis, which was treated with anti-fungal treatment. The patient improved after a week, however, on the seventh day of administration lower respiratory secretions showed the growth of Klebsiella pneumonia, indicative of ventilator-associated pneumonia.

OUTCOMES

Despite active treatment, the patient passed away due to multiple organ failure. As this was a fatal case, further research is needed to determine whether the critical condition of this case was related to the virulence of the novel Legionella strain.

CONCLUSION

A key finding of this study is that treatment for suspected Legionnaires' disease must be administered rapidly, as infection with Legionella may give rise to secondary pathogenic infections.

Lactobacillus salivarius LI01 encapsulated in alginate-pectin microgels ameliorates D-galactosamine-induced acute liver injury in rats

Acute liver failure is a clinical emergency associated with high mortality. Accumulating evidence indicates that gut microbiota participates in the progression of liver injury, and preventive therapies based on altering gut microbiota are of great interest. Previous studies demonstrated that Lactobacillus salivarius LI01 attenuates hepatic injury, though efficiency in curtailed in the harsh environment in the gastrointestinal tract. In this study, a system to encapsulate LI01 in alginate-pectin (AP) microgels was investigated. Encapsulation significantly enhances probiotic viability for long-term storage and heat treatment, and in simulated gastrointestinal fluids (SGF or SIF) and bile salt solutions. Acute liver injury was induced in Sprague-Dawley (SD) rats by D-galactosamine (D-GaIN) injection following pretreatment with probiotics. Liver and gut barrier function, cytokines, liver and gut histology, bacterial translocation, and gut microbiota were assessed. Administration of encapsulated LI01 more effectively upregulates hepatic anti-inflammatory cytokine IL-10 and TLR-3, restores expressions of gut barrier biomarkers Claudin-1 and MUC2 and attenuates destruction of mucosal ultrastructure compared with unencapsulated probiotics pretreatment. Pretreatment with AP-LI01 microgels altered the microbial community, decreasing the abundance of pathogenic taxa Ruminiclostridium, Dorea and Ruminococcaceae_UCG-004 and enriching beneficial taxa Ruminococcaceae_UCG-014, Eubacterium, and Prevotella_1 that produce short-chain fatty acids. These results suggest that AP encapsulation of LI01 boosts viability and attenuates liver injury by reducing inflammation and restoring intestinal barrier function. These beneficial effects are probably due to alternation of gut flora. These findings provide new insight into encapsulation technology and prevention of liver failure. KEY POINTS: • Alginate-pectin encapsulation enhances the viability of Lactobacillus salivarius LI01 under simulated commercial conditions and simulated gastrointestinal environment. • AP-LI01 microgel attenuates hepatic and intestinal inflammation and restores gut barrier function. • AP-LI01 microgel alters gut microbial community with increased SCFAs producers and decreased pathogenic microbes. • Beneficial improvements after administration of probiotics are highly associated with alternation of gut microbial community.

Influence of skin wounds on the intestinal inflammatory response and barrier function: Protective role of dietary Shewanella putrefaciens SpPdp11 administration to gilthead seabream (Sparus aurata L.)

The effects of skin wounds on the intestinal barrier function and the beneficial effects of the dietary administration of Shewanella putrefaciens (known as SpPdp11) in gilthead seabream (Sparus aurata L.) were studied. Two replicates of fish were fed a commercial diet (control, CON) or CON diet enriched with 10⁹ cfu g^-1 SpPdp11 (SP diet) for 30 days. After this time, half of the fish were sampled, while the others were injured below the lateral line (wounded fish, W) and fed the same diets for an extra week before sampling (CON + W and SP + W groups). The intestinal histology and gene expression of different genes relevant for the intestinal barrier function were studied. The results showed that injured fish had a disordered enterocyte nucleus disposition, a more intense infiltration of mixed leucocytes and a thicker lamina propria in the intestine compared to the control fish. However, the fish in the SP + W group did not present these pathological symptoms in the intestine. No significant variations in the number of goblet cells were detected among the different experimental groups. Pro-inflammatory cytokines (colony-stimulating factor receptor 1, CSF1R, myeloperoxidase, MPO and interleukin-1β, IL-1β), mucins (intestinal mucin, IMUC and mucin 2, MUC2), and immunoglobulin T heavy chain (IGHT) were up-regulated, while tight junction protein occludin was down-regulated in the intestine from fish of the CON + W group. Similarly, the dietary administration of SpPdp11 markedly depressed the gene expression of pro-inflammatory cytokines, MUC2 and IGHT, but increased the gene expression of anti-inflammatory cytokine transforming growth factor-β1 (TGF-β1) and the tight junction proteins tricellulin and occluding after wounding. In brief, the skin wounds provoked an intestinal inflammatory response that included changes in the mucus layer and tight junction disruptions. Besides this, preventive administration of SpPdp11 alleviated the intestinal dysfunctions caused by skin wounds in gilthead seabream.

Dual roles of commensal bacteria after intestinal ischemia and reperfusion

PURPOSE

The roles of commensal bacteria after intestinal ischemia and reperfusion (IIR) are unclear. In current study, we aim to investigate the effects and underlying mechanisms of commensal bacteria in injury and epithelial restitution after IIR.

METHODS

Commensal gut bacteria were deleted by broad-spectrum antibiotics in mice. IIR was induced by clamping superior mesenteric artery. Intestinal injury, permeability, epithelial proliferation, and proinflammatory activity of mesenteric lymph were investigated.

RESULTS

Commensals deletion improved mice survival in the early phase, but failed to improve the overall survival at 96 h after IIR. Commensals deletion reduced proliferation of intestinal epithelial cells (IEC) and augmented proinflammatory activity of mesenteric lymph after IIR. Lipopolysaccharides (LPS) supplement promoted IEC proliferation and improved survival in mice with commensals deletion after IIR. LPS induced production of prostaglandin E2 (PGE2) in mucosa via toll-like receptor 4-NFκB-cyclooxygenase 2 pathway. PGE2 enhanced IEC proliferation in vivo, which was preceded by activation of Akt and extracellular signal-regulated kinase (ERK) 1/2. Blocking of EGFR, PI3K/Akt activity abolished LPS-induced IEC proliferation.

CONCLUSIONS

Commensal bacteria are essential for epithelial restitution after IIR, which enhance IEC proliferation via induction of PGE2.

Effect of broad-spectrum antibiotics on bacterial translocation in burned or septic rats

Background:

Antibiotics are frequently used to treat critically ill patients, and its use is often accompanied by intestinal dysbiosis that might further lead to bacterial translocation (BT). Nevertheless, studies on the relationship between antibiotic therapy and BT are rare. In the present study, we investigated the effect of broad-spectrum antibiotics on BT in an experimental rat model of burn or sepsis injury.

Methods:

The septic rat model was simulated by a second insult with lipopolysaccharides after burn injury. Ninety-two male Sprague-Dawley rats were randomly divided into control, burn, and sepsis groups (n = 8 or 9, each group), and the latter two groups were then treated with imipenem or ceftriaxone for 3 or 9 days. The mesenteric lymph nodes, liver, lungs, and blood were collected at each time point under sterile conditions for quantitative bacterial culture and strain identification. The differences between the groups were compared by Fisher exact test or Mann-Whitney U test.

Results:

Only minimal Escherichia coli translocation to the mesenteric lymph nodes was observed in the normal control group, in which the BT rate was 12.5%. Burn injury did not affect the BT rate (Burn group vs. Control group, 12.5% vs. 12.5%, P = 1.000), whereas the BT rate showed an increased trend after the second insult with lipopolysaccharide (Sepsis group vs. Control group, 44.4% vs. 12.5%, P = 0.294), and many strains of Enterobacteria spp. were detected in distant organs (liver, lung, and blood) [Sepsis group vs. Control group, 0 (0,3) vs. 0 (0,0), U = 20, P = 0.045]. After the antibiotic treatment, BT to the distant organs was increased in burned rats [Burn IT3 group vs. Burn group, 0 (0,2) vs. 0 (0,0); Burn IT9 group vs. Burn group, 0 (0,1) vs. 0 (0,0); Burn CT9 group vs. Burn group, 0 (0,2) vs. 0 (0,0); all U = 20 and P = 0.076] but decreased in septic rats [Sepsis CT3 group vs. Sepsis group, 0 (0,0) vs. 0 (0,3), U = 20, P = 0.045]. The total amount of translocated bacteria, regardless of which antibiotic was used, was increased in burned rats [Burn IT9 group vs. Burn group, 2.389 (0,2.845) vs. 0 (0,2.301) Log₁₀ colony-forming units (CFU)/g, U = 14, P = 0.034; Burn CT3 group vs. Burn group, 2.602 (0,3.633) vs. 0 (0,2.301) Log₁₀ CFU/g, U = 10.5, P = 0.009], but there was a slightly decreased trend in septic rats [Sepsis IT9 group vs. Sepsis group, 2.301 (2,3.146) vs. 0 (0,4.185) Log₁₀ CFU/g, U = 36, P = 0.721; Sepsis CT9 group vs. Sepsis group, 2 (0,3.279) vs. 0 (0,4.185) Log₁₀ CFU/g, U = 32.5, P = 0.760]. Remarkably, the quantity of Enterococci spp. dramatically increased after broad-spectrum antibiotic treatment in both the burned and septic groups [Burn IT3 group vs. Burn group, 1 (0,5.164) vs. 0 (0,0) Log₁₀ CFU/g, U = 16; Burn IT9 group vs. Burn group, 1 (0,2.845) vs. 0 (0,0) Log₁₀ CFU/g, U = 16; Burn CT3 group vs. Burn group, 2.602 (0,3.633) vs. 0 (0,0) Log₁₀ CFU/g, U = 8; Burn CT9 group vs. Burn group, 1 (0,4.326) vs. 0 (0,0) Log₁₀ CFU/g, U = 16; Sepsis IT3 group vs. Sepsis group, 2.477 (0,2.903) vs. 0 (0,0) Log₁₀ CFU/g, U = 4.5; Sepsis IT9 group vs. Sepsis group, 2 (0,3.146) vs. 0 (0,0) Log₁₀ CFU/g, U = 9; Sepsis CT3 group vs. Sepsis group, 1.151 (0,2.477) vs. 0 (0,0) Log₁₀ CFU/g, U = 18; Sepsis CT9 group vs. Sepsis group, 2 (0,3) vs. 0 (0,0) Log₁₀ CFU/g, U = 13.5; all P < 0.05].

Conclusions:

Broad-spectrum antibiotics promote BT in burned rats but prevent BT in septic rats, especially preventing BT to distant organs, such as the liver and lung. Moreover, Enterococci spp. with high drug resistance and high pathogenicity translocated most after antibiotic treatment.

Gastrointestinal Failure in Critically Ill Patients With Cirrhosis

Gastrointestinal failure (GIF) is frequent in patients managed in the intensive care units and manifests as gut paralysis or ileus. GIF is often associated with sepsis or multiorgan failure. In critically ill patients, the precipitating causes of GIF include inflammation, sepsis, electrolyte abnormalities, and acidosis. It is possible that GIF is associated with an increase in bacterial translocation, especially in those with cirrhosis and portal hypertension, and this may play a significant pathogenic or prognostic role in acute-on-chronic liver failure (ACLF). The critical care literature suggests that GIF is associated with a higher mortality risk. In this review, we summarize the evidence for a potential association between GIF and ACLF and propose treatment options for the management of GIF. Moreover, we suggest GIF to be considered as another organ failure when the severity of ACLF is assessed.

Upregulation of proBDNF in the Mesenteric Lymph Nodes in Septic Mice

The immune status in the lymphatic system, especially mesenteric lymph nodes (MLNs), is critical to regulate the septic shock. Brain-derived neurotrophic factor (BDNF) in the enteric system has been reported to regulate enteric immunity. However, the role of its precursor, proBDNF, in the immune status of MLNs under sepsis condition is still unclear. This study aimed to characterize the expression pattern of proBDNF in MLNs after lipopolysaccharide (LPS) stimulation, and to investigate the association of pathogenesis of sepsis. LPS (20 mg/kg) was intraperitoneally injected to induce sepsis in mice. Survival curve analysis, routine blood tests, and liver and kidney function tests were performed to evaluate the severity of sepsis. QPCR and histological staining were performed to assess the mRNA levels of proinflammatory cytokines and degree of immune-inflammatory response in the MLNs. Furthermore, Western blotting, flow cytometry, and immunofluorescence were performed to examine the key molecules expression of proBDNF signaling. Intraperitoneal LPS injection significantly decreased the number of lymphocytes in blood but increased the number of T lymphocytes in MLNs. Serum alanine transaminase, aspartate transaminase, and blood urea nitrogen levels were increased in LPS-challenged mice compared to control mice. LPS administration upregulated proinflammatory cytokine gene expression and induced histological changes in the MLNs. LPS injection increased BDNF, proBDNF, and its receptor pan neutrophin receptor 75 (p75^NTR) expression in MLNs. The increased proBDNF was mainly localized on CD3⁺ and CD4⁺ T cells in the medulla of MLNs. LPS-induced sepsis upregulated proBDNF expression in medulla T cells of MLNs. ProBDNF upregulation may be involved in the pathogenesis of septic shock.

Dietary leonurine hydrochloride supplementation attenuates lipopolysaccharide challenge-induced intestinal inflammation and barrier dysfunction by inhibiting the NF-κB/MAPK signaling pathway in broilers

This study was performed to evaluate the beneficial effects of dietary leonurine hydrochloride (LH) supplementation on intestinal morphology and barrier integrity and further illuminate its underlying antioxidant and immunomodulatory mechanisms in lipopolysaccharide (LPS)-treated broilers. A total of 120 1-d-old male broilers (Ross 308) were assigned to 4 treatment groups with 6 replicates of 5 birds per cage. The experiment was designed in a 2 × 2 factorial arrangement with LH (0 or 120 mg/kg) and LPS (injection of saline or 1.5 mg/kg body weight) as treatments. On days 14, 16, 18, and 20 of the trial, broilers were intraperitoneally injected with LPS or physiological saline. Compared with the control group, LPS-challenged broilers showed impaired growth performance (P < 0.05) from day 15 to day 21 of the trial, increased serum diamine oxidase (DAO) and D-lactic acid (D-LA) levels coupled with reduced glutathione (GSH) content and total superoxide dismutase (T-SOD) activity (duodenal and jejunal mucosa), reduced malondialdehyde (MDA) content (duodenal, jejunal, and ileal mucosa), and compromised morphological structure of the duodenum and jejunum. Additionally, LPS challenge increased (P < 0.05) the mRNA expression of proinflammatory cytokine genes and reduced tight junction (TJ) protein expression in the jejunum. However, dietary LH prevented LPS-induced reductions in average daily gain (ADG) and average daily feed intake (ADFI) in broilers. It also alleviated LPS challenge-induced increases in serum DAO levels, MDA content (duodenal and jejunal mucosa), and jejunal crypt depth (P < 0.05) but reduced villus height, GSH content (jejunal mucosa), and T-SOD activity (duodenal and jejunal mucosa) (P < 0.05). Additionally, LH supplementation significantly downregulated the mRNA expression of nuclear factor (NF)-κB, cyclooxygenase-2 (COX-2), and proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and upregulated the mRNA expression of zonula occludens-1 (ZO-1) and Occludin in the jejunal mucosa induced by LPS (P < 0.05). On the other hand, LH administration prevented LPS-induced activation of the p38, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs) and attenuated IkB alpha (IκBα) phosphorylation and nuclear translocation of NF-κB (p65) in the jejunal mucosa. In conclusion, dietary LH supplementation attenuates intestinal mucosal disruption mainly by accelerating the expression of TJ proteins and inhibiting activation of the NF-κB/MAPK signaling pathway.

Exposure to Stress-Dose Steroids and Lethal Septic Shock After In-Hospital Cardiac Arrest: Individual Patient Data Reanalysis of Two Prior Randomized Clinical Trials that Evaluated the Vasopressin-Steroids-Epinephrine Combination Versus Epinephrine Alone

PURPOSE

Low-dose steroids may reduce the mortality of severely ill patients with septic shock. We sought to determine whether exposure to stress-dose steroids during and/or after cardiopulmonary resuscitation is associated with reduced risk of death due to postresuscitation septic shock.

METHODS

We analyzed pooled, individual patient data from two prior, randomized clinical trials (RCTs). RCTs evaluated vasopressin, steroids, and epinephrine (VSE) during resuscitation and stress-dose steroids after resuscitation in vasopressor-requiring, in-hospital cardiac arrest. In the second RCT, 15 control group patients received open-label, stress-dose steroids. Patients with postresuscitation shock were assigned to a Steroids (n = 118) or No Steroids (n = 73) group according to an "as-treated" principle. We used cumulative incidence competing risks Cox regression to determine cause-specific hazard ratios (CSHRs) for pre-specified predictors of lethal septic shock (primary outcome). In sensitivity analyses, data were analyzed according to the intention-to-treat (ITT) principle (VSE group, n = 103; control group, n = 88).

RESULTS

Lethal septic shock was less likely in Steroids versus No Steroids group, CSHR, 0.40, 95% confidence interval (CI), 0.20-0.82; p = 0.012. ITT analysis yielded similar results: VSE versus Control, CSHR, 0.44, 95% CI, 0.23-0.87; p = 0.019. Adjustment for significant, between-group baseline differences in composite cardiac arrest causes such as "hypotension and/or myocardial ischemia" did not appreciably affect the aforementioned CSHRs.

CONCLUSIONS

In this reanalysis, exposure to stress-dose steroids (primarily in the context of a combined VSE intervention) was associated with lower risk of postresuscitation lethal septic shock.

Influence of indigenous microbiota on experimental toxoplasmosis in conventional and germ-free mice

Toxoplasmosis represents one of the most common zoonoses worldwide. Its agent, Toxoplasma gondii, causes a severe innate pro-inflammatory response. The indigenous intestinal microbiota promotes host animal homoeostasis and may protect the host against pathogens. Germ-free (GF) animals provide an important tool for the study of interactions between host and microbiota. In this study, we assessed the role of indigenous microorganisms in disease development utilizing a murine toxoplasmosis model, which includes conventional (CV) and GF NIH Swiss mice. CV and GF mice orally inoculated with T. gondii had similar survival curves. However, disease developed differently in the two animal groups. In CV mice, intestinal permeability increased and levels of intestinal pro-inflammatory cytokines were altered. In GF animals, there were discrete epithelial degenerative changes and mucosal oedema, but the liver and lungs displayed significant lesions. We conclude that, despite similar survival curves, CV animals succumb to an exaggerated inflammatory response, whereas GF mice fail to produce an adequate systemic response.

Asparagine preserves intestinal barrier function from LPS-induced injury and regulates CRF/CRFR signaling pathway

Stress causes intestinal inflammation and barrier dysfunction. Corticotrophin-releasing factor (CRF)/CRF receptor (CRFR) signaling pathway has been shown to be important for stress-induced intestinal mucosal alteration. L-Asparagine (ASN) is a powerful stimulator of ornithine decarboxylase and cell proliferation in a variety of cell types, including colonic cells. In the present study, we investigated whether dietary ASN supplementation could alleviate the damage of intestinal barrier function caused by LPS through modulation of CRF/CRFR signaling pathway. Twenty-four weaned pigs were randomly divided into one of four treatments: (1) non-challenged control; (2) Escherichia coli LPS challenged control; (3) LPS + 0.5% ASN; (4) LPS + 1.0% ASN. LPS stress induced villous atrophy, intestinal morphology disruption and decreased claudin-1 expression. ASN supplementation increased intestinal claudin-1 protein expression and alleviated villous atrophy and intestinal morphology impairment caused by LPS stress. In addition, ASN supplementation increased the number of intestinal intraepithelial lymphocytes and reversed the elevations of intestinal mast cell number and neutrophil number induced by LPS stress. Moreover, ASN decreased the mRNA expression of intestinal CRF, glucocorticoid receptors and tryptase. These results indicate that ASN attenuates intestinal barrier dysfunction induced by LPS stress, and regulates CRF/CRFR1 signaling pathway and mast cell activation.

Systemic blockade of P2X7 receptor protects against sepsis-induced intestinal barrier disruption

Sepsis, during which the intestinal epithelial barrier is frequently disrupted, remains a challenging and life-threatening problem in clinical practice. The P2X7 receptor (P2X7R) is a non-selective adenosine triphosphate-gated cation channel present in macrophages that is involved in inflammatory responses. However, little is known about the role of P2X7R in macrophages during sepsis-induced intestinal barrier disruption. In this study, mice were treated with the P2X7R antagonist A740003 or the agonist BzATP by intra-peritoneal injection after the induction of gut-origin sepsis. The survival rates, inflammatory responses, intestinal barrier integrity, macrophage marker expression, and ERK and NF-κB activities were evaluated. Intestinal macrophages were also isolated and studied after exposure to Brilliant Blue G or BzATP. We found that a systemic P2X7R blockade downregulated sepsis-induced inflammatory responses and attenuated intestinal barrier dysfunction based on the evidence that mice in the A740003-treated group exhibited alleviated pro-inflammatory cytokine synthesis, intestinal hyperpermeability, epithelial apoptosis rates and tight junction damage compared with the septic mice. These changes were partly mediated by the inhibition of M1 macrophages activation via ERK/NF-κB pathways. Our data presented herein show that a P2X7R blockade could be a potential therapeutic target for the treatment of sepsis-induced intestinal barrier dysfunction.

Intravenous citrulline generation test to assess intestinal function in intensive care unit patients

Background

Assessment of a quantifiable small intestinal function test is cumbersome. Fasting citrulline concentrations have been proposed as a measure of enterocyte function and elaborated into a citrulline generation test (CGT), which is applicable only when glutamine is administered orally. CGT is an oral test, limiting its use, for example, in critically ill patients.

Objective

Assessment of normative values and feasibility of an intravenously performed CGT in intensive care unit (ICU) patients with presumed gastrointestinal motility disturbances, especially when performed intravenously.

Design

CGT reference values were determined in 16 stable ICU patients using two different CGT methods, namely following either enteral or intravenous glutamine administration and both with simultaneous arterial and venous plasma citrulline sampling at six time-points. Plasma amino acid analysis was performed using reverse-phase high-performance liquid chromatography.

Results

The median total generation of citrulline in 90 min (CGT iAUCT90) was markedly higher with arterial citrulline sampling compared with venous citrulline sampling, being 724±585 and 556±418 µmol/L/min for enteral glutamine, respectively (p=0.02) and 977±283 and 769±231 µmol/L/min for intravenous glutamine, respectively (p=0.0004). The median slope (time-dependent increase) for plasma arterial and venous citrulline during the CGT was 0.20±0.16 and 0.18±0.12 µmol/L/min for enteral glutamine, respectively (p=0.004) and 0.22±0.16 and 0.19±0.05 µmol/L/min for intravenous glutamine, respectively (p=0.02).

Conclusion

Intravenous glutamine administration combined with arterial plasma citrulline sampling yielded the least variation in CGT characteristics in stable ICU patients. A 2-point measurement test had comparable test characteristics as a 6-point measurement CGT and seems promising.

Bacterial translocation in critical illness

Bacterial translocation involves the passage of intestinal bacteria to extraintestinal sites and has been shown to increase morbidity and mortality in critical illness. This review outlines the pathophysiology of bacterial translocation, host defence mechanisms, and reviews the evidence for the clinical management of critically ill patients in order to minimise the negative outcomes associated with bacterial translocation.

Gut dysbiosis impairs recovery after spinal cord injury

Kigerl et al. show that spinal cord injury causes profound changes in gut microbiota and that these changes in gut ecology are associated with activation of GALT immune cells. They show that feeding mice probiotics after SCI confers neuroprotection and improves functional recovery.

The trillions of microbes that exist in the gastrointestinal tract have emerged as pivotal regulators of mammalian development and physiology. Disruption of this gut microbiome, a process known as dysbiosis, causes or exacerbates various diseases, but whether gut dysbiosis affects recovery of neurological function or lesion pathology after traumatic spinal cord injury (SCI) is unknown. Data in this study show that SCI increases intestinal permeability and bacterial translocation from the gut. These changes are associated with immune cell activation in gut-associated lymphoid tissues (GALTs) and significant changes in the composition of both major and minor gut bacterial taxa. Postinjury changes in gut microbiota persist for at least one month and predict the magnitude of locomotor impairment. Experimental induction of gut dysbiosis in naive mice before SCI (e.g., via oral delivery of broad-spectrum antibiotics) exacerbates neurological impairment and spinal cord pathology after SCI. Conversely, feeding SCI mice commercial probiotics (VSL#3) enriched with lactic acid–producing bacteria triggers a protective immune response in GALTs and confers neuroprotection with improved locomotor recovery. Our data reveal a previously unknown role for the gut microbiota in influencing recovery of neurological function and neuropathology after SCI.

CLABSI Risk Factors in the NICU: Potential for Prevention: A PICNIC Study

OBJECTIVE Central-line-associated bloodstream infections (CLABSI) are an important cause of morbidity and mortality in neonates. We aimed to determine whether intra-abdominal pathologies are an independent risk factor for CLABSI. METHODS We performed a retrospective matched case-control study of infants admitted to the neonatal intensive care units (NICUs) of the Montreal Children's Hospital (Montreal) and the Royal Alexandra Hospital, Edmonton, Canada. CLABSI cases that occurred between April 2009 and March 2014 were identified through local infection control databases. For each case, up to 3 controls were matched (National Healthcare Safety Network [NHSN] birth weight category, chronological age, and central venous catheter (CVC) dwell time at the time of CLABSI onset). Data were analyzed using conditional logistic regression. RESULTS We identified 120 cases and 293 controls. According to a matched univariate analysis, the following variables were significant risk factors for CLABSI: active intra-abdominal pathology (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.8-6.4), abdominal surgery in the prior 7 days (OR, 3.5; 95% CI, 1.0-10.9); male sex (OR, 1.7; 95% CI, 1.1-2.6) and ≥3 heel punctures (OR, 4.0; 95% CI, 1.9-8.3). According to a multivariate matched analysis, intra-abdominal pathology (OR, 5.9; 95% CI, 2.5-14.1), and ≥3 heel punctures (OR, 5.4; 95% CI, 2.4-12.2) remained independent risk factors for CLABSI. CONCLUSION The presence of an active intra-abdominal pathology increased the risk of CLABSI by almost 6-fold. Similar to CLABSI in oncology patients, a subgroup of CLABSI with mucosal barrier injury should be considered for infants in the NICU with active intra-abdominal pathology. Infect Control Hosp Epidemiol 2016;1446-1452.

Ginsenoside Rb1 protects the intestinal mucosal barrier following peritoneal air exposure

Ginsenoside Rb1 (GRb1), which is one of the main ingredients derived from Panax ginseng, has been widely used to treat various gastrointestinal disorders. The present study aimed to determine whether GRb1 was able to prevent intestinal mucosal barrier damage in rats following peritoneal air exposure for 3 h. GRb1 (5, 10, and 20 mg/kg) was orally administrated via gavage four times prior to and following surgery. Blood and terminal ileum were sampled 24 h following surgery. Levels of serum D-lactate (D-LA) were detected using an enzyme-linked immunosorbent assay kit. Intestinal permeability was assessed by determining the intestinal clearance of fluorescein isothiocyanate-dextran (FD4). Activity of intestinal myeloperoxidase was measured to assess intestinal inflammation, and intestinal histopathology was assessed by light microscopy. The results showed that GRb1 reduced the level of serum D-LA, intestinal clearance of FD4, and the activity of intestinal myeloperoxidase. Intestinal edema and inflammation were also ameliorated by GRb1, and the Chiu's scores employed for assessing intestinal mucosal damage were also reduced in the GRb1-treated peritoneal air exposure group. In addition, GRb1 induced a significant difference at 10 and 20 mg/kg, indicating a dose-dependent effect. The results of the present study suggest that GRb1 may be able to protect the intestinal mucosal barrier against damage induced by peritoneal air exposure, which may be associated with its anti-inflammatory action.

Chronic Kidney Disease Induced Intestinal Mucosal Barrier Damage Associated with Intestinal Oxidative Stress Injury

Background. To investigate whether intestinal mucosal barrier was damaged or not in chronic kidney disease progression and the status of oxidative stress. Methods. Rats were randomized into two groups: a control group and a uremia group. The uremia rat model was induced by 5/6 kidney resection. In postoperative weeks (POW) 4, 6, 8, and 10, eight rats were randomly selected from each group to prepare samples for assessing systemic inflammation, intestinal mucosal barrier changes, and the status of intestinal oxidative stress. Results. The uremia group presented an increase trend over time in the serum tumor necrosis factor-alpha, interleukin-6 (IL-6) and IL-10, serum D-lactate and diamine oxidase, and intestinal permeability, and these biomarkers were significantly higher than those in control group in POW 8 and/or 10. Chiu's scores in uremia group were also increased over time, especially in POW 8 and 10. Furthermore, the intestinal malondialdehyde, superoxide dismutase, and glutathione peroxidase levels were significantly higher in uremia group when compared with those in control group in POW 8 and/or 10. Conclusions. The advanced chronic kidney disease could induce intestinal mucosal barrier damage and further lead to systemic inflammation. The underlying mechanism may be associated with the intestinal oxidative stress injury.

Indications, techniques, and clinical outcomes of thoracic duct interventions in patients: a forgotten literature?

BACKGROUND

The evolution of the "gut-lymph concept" has promoted thoracic duct (TD) lymph drainage as a possible treatment to reduce systemic inflammation and end-organ dysfunction in acute illness. The aim was to review the published experience of thoracic duct interventions (TDIs) aimed at improving clinical outcomes.

METHODS

A search of three databases (MEDLINE, EMBASE, and EMBASE CLASSIC) over the last 60 y. The indications for intervention, the technique, and clinical outcomes were reviewed.

RESULTS

There were a wide range of indications for TDI. These included reducing rejection after transplantation, treating inflammatory diseases, and reducing chronic failure of the liver, kidney, and heart. The techniques included TD cannulation and lymphovenuous fistula. The outcomes were variable and often equivocal, and this appears to reflect poor design quality. There is clinical equipoise regarding a therapeutic role of (TD lymph drainage in acute pancreatitis, and probably other acute diseases.

CONCLUSIONS

Until well-designed clinical trials are undertaken, the clinical benefits of TDIs will remain promising, but uncertain.

Fish oil enhances intestinal barrier function and inhibits corticotropin-releasing hormone/corticotropin-releasing hormone receptor 1 signalling pathway in weaned pigs after lipopolysaccharide challenge

Stress induces injury in intestinal barrier function in piglets. Long-chain n-3 PUFA have been shown to exhibit potential immunomodulatory and barrier protective effects in animal models and clinical trials. In addition, corticotropin-releasing hormone (CRH)/CRH receptor (CRHR) signalling pathways play an important role in stress-induced alterations of intestinal barrier function. We hypothesised that fish oil could affect intestinal barrier function and CRH/CRHR signalling pathways. In total, thirty-two weaned pigs were allocated to one of four treatments. The experiment consisted of a 2×2 factorial design, and the main factors included immunological challenge (saline or lipopolysaccharide (LPS)) and diet (5 % maize oil or 5 % fish oil). On d 19 of the trial, piglets were treated with saline or LPS. At 4 h after injection, all pigs were killed, and the mesenteric lymph nodes (MLN), liver, spleen and intestinal samples were collected. Fish oil decreased bacterial translocation incidence and the number of translocated micro-organisms in the MLN. Fish oil increased intestinal claudin-1 protein relative concentration and villus height, as well as improved the intestinal morphology. In addition, fish oil supplementation increased intestinal intraepithelial lymphocyte number and prevented elevations in intestinal mast cell and neutrophil numbers induced by LPS challenge. Moreover, fish oil tended to decrease the mRNA expression of intestinal CRHR1, CRH and glucocorticoid receptors. These results suggest that fish oil supplementation improves intestinal barrier function and inhibits CRH/CRHR1 signalling pathway and mast cell tissue density.

Association of proton pump inhibitors with the occurrence of gut-derived bacteraemia in patients with haematological malignancy after chemotherapy

BACKGROUND

Gut-derived bacteraemia is a major complication in patients with haematological malignancy after chemotherapy.

OBJECTIVE

Our study aimed to investigate the role of proton pump inhibitors (PPIs) in the occurrence of gut-derived bacteraemia.

METHODS

We compared data from 92 hospitalized haematological malignancy patients after chemotherapy with gut-derived bacteraemia, collected from January 2009 to July 2015, with those of 92 contemporaneous, hospitalized haematological malignancy patients without bacteraemia. We evaluated PPIs use and analysed the effects of covariates.

RESULTS

Patients with gut-derived bacteraemia had a significantly higher incidence of PPIs use (69.6%) than that of controls (47.8%). Of the patients with gut-derived bacteraemia, only 44.6% had a documented indication for PPIs therapy. The antibacterial prophylaxis rate was 38.0% in the bacteraemia group and 58.7% in the non-antibacterial group. Based on multivariable logistic regression analysis, only PPIs use (P = 0.00, odds ratio (OR) = 0.546) was found to be associated with the risk of bacteraemia whereas antibacterial prophylaxis (P = 0.00, OR = 0.652) was protective. There were no significant differences in demographics, malignancy status, length of neutropenia, complications, or steroid use between the gut-derived bacteraemia and control group.

CONCLUSIONS

This study suggests a potential association between PPIs use and development of gut-derived bacteraemia in haematological malignancy patients after chemotherapy.

Bacterial Translocation and Sample Contamination in Postmortem Microbiological Analyses

The diagnostic value of postmortem bacteriology has been discussed controversially for decades. In the study herein, contamination during sampling procedures and postmortem translocation were investigated to interpret postmortem microbiology results. One hundred medicolegal autopsy cases in total were included. Radiology, histology, bacteriology, and biochemistry were performed in all cases. Based on all investigation findings, 4 groups of cases were identified: death unrelated to infection, true infections, false positive (contamination during sampling procedures, postmortem translocation and mixed situations), and undetermined. The results of this study indicate that postmortem bacteriology provides useful data supporting infection-related deaths, especially when potentially significant observations are accompanied by consistent autopsy, histology, and biochemistry. Result interpretation requires careful evaluation of number and type of isolated microorganisms.

High-fat enteral nutrition reduces intestinal mucosal barrier damage after peritoneal air exposure

BACKGROUND

Peritoneal air exposure is needed in open abdominal surgery, but long-time exposure could induce intestinal mucosal barrier dysfunction followed by many postoperative complications. High-fat enteral nutrition can ameliorate intestinal injury and improve intestinal function in many gastrointestinal diseases. In the present study, we investigated the effect of high-fat enteral nutrition on intestinal mucosal barrier after peritoneal air exposure and the underlying mechanism.

METHODS

Male adult rats were administrated saline, low-fat or high-fat enteral nutrition via gavage before and after peritoneal air exposure for 3 h. Rats undergoing anesthesia without laparotomy received saline as control. Twenty four hours after surgery, samples were collected to assess intestinal mucosal barrier changes in serum D-lactate levels, intestinal permeability, intestinal tight junction protein ZO-1 and occludin levels, and intestinal histopathology. The levels of malondialdehyde and the activity of superoxide dismutase in the ileum tissue were also measured to assess the status of intestinal oxidative stress.

RESULTS

High-fat enteral nutrition significantly decreased the serum D-lactate level and increased the intestinal tight junction protein ZO-1 level when compared to the group treated with low-fat enteral nutrition (P < 0.05). Meanwhile, histopathologic findings showed that the intestinal mucosal injury assessed by the Chiu's score and the intestinal epithelial tight junction were also improved much more in the high-fat enteral nutrition-treated group (P < 0.05). In addition, the intestinal malondialdehyde level was lower, and the intestinal superoxide dismutase activity was higher in the high-fat enteral nutrition-treated group than that in the low-fat enteral nutrition-treated group (P < 0.05).

CONCLUSIONS

These results suggest that high-fat enteral nutrition could reduce intestinal mucosal barrier damage after peritoneal air exposure, and the underlying mechanism may be associated with its antioxidative action. Perioperative administration of high-fat enteral nutrition may be a promising intervention to preserve intestinal mucosal barrier function in open abdominal surgery.

Outbreak of KPC-3 Producing Carbapenem-Resistant Klebsiella pneumoniae in a US Pediatric Hospital

BACKGROUND

The increase in carbapenem-resistant Enterobacteriaceae (CRE) infections is a critical public health issue. We recently experienced the largest single-center pediatric outbreak of carbapenem-resistant Klebsiella pneumoniae (CRKP) at our hospital. The objective of this study was to describe the molecular epidemiology of this outbreak before and after infection-prevention interventions.

METHODS

All positive cultures and associated clinical conditions were reviewed to determine whether health care-associated infections (HAIs) exist. HAIs were defined using Centers for Disease Control and Prevention guidelines. CRKP isolates were collected and screened for the presence of β-lactamase genes. Strain relatedness of CRKP isolates was determined by field-inversion gel electrophoresis (FIGE) and multilocus sequence typing (MLST). Polymerase chain reaction (PCR) amplification and sequencing of blaTEM, blaSHV, and blaKPC genes were performed on representative isolates.

RESULTS

During March-July 2010, 18 CRKP isolates were recovered from 15 unique patients. Six isolates were considered HAIs; all were central-line-associated bloodstream infections. All isolates testing positive by PCR for blaKPC were found to carry KPC-3 in transposon Tn4401 isotype "b." FIGE revealed 2 prevalent patterns (accounting for 10 and 3 CRKP isolates, respectively) that MLST demonstrated to consist entirely of strains from ST730; the remaining FIGE types corresponded to ST14, ST15, and ST1559 (a single-locus variant of ST730), with these alternate backgrounds appearing later in the outbreak. New CRKP cases decreased after the implementation of infection-control interventions. All isolates were ciprofloxacin sensitive.

CONCLUSIONS

Molecular analyses document the introduction of a KPC-3-producing CRKP clone into our hospital setting, though some isolates appear to have other mechanisms of carbapenem resistance. The transition to a polyclonal epidemiology suggests that the initial outbreak was due to nosocomial spread of a single ST730 clone, while latter isolates may have been secondary to the introduction of a blaKPC-3/Tn4401 isotype "b"-containing plasmid into other K pneumoniae strain backgrounds versus new carbapenemase-producing bacteria.

Nod2-Rip2 Signaling Contributes to Intestinal Injury Induced by Muramyl Dipeptide Via Oligopeptide Transporter in Rats

BACKGROUND AND AIMS

PepT1 can transport bacterial oligopeptide products and induce intestinal inflammation. Our aim was to investigate the mechanism of the small intestine injury induced by bacterial oligopeptide product muramyl dipeptide (MDP) which is transported by PepT1.

METHODS

We perfused the jejunum with a solution with or without MDP, or with a solution of MDP + Gly-Gly and explored the degree of inflammation to determine the role of PepT1-Nod2 signaling pathway in small intestine mucosa.

RESULTS

MDP perfusion induced inflammatory cell accumulation and intestinal damage, accompanied by an increase in mucosal Nod2 and Rip2 transcript expression. NFκB activity and inflammatory cytokine expression, including serum levels of TNF-α, IL-1β, and IL-6, increased in the MDP group compared to the controls; these effects were reversed by perfusion of the nutritional dipeptide Gly-Gly.

CONCLUSION

MDP can be transported through PepT1, causing inflammatory damage in the rat small intestine. Nod2-Rip2-NFκB signaling involved in the small intestinal inflammatory injury caused by MDP which is transported through PepT1.

The Effect of Curcumin on an Animal Intestinal Ischemia/Reperfusion Model for Bacterial Translocation and Inflammatory Response

Ischemia/reperfusion (IR) injury of the intestine is a major problem in abdominal pathological condition and is associated with a high morbidity and mortality. The purpose of the study is to investigate the effects of curcumin on the bacterial translocation incidence and inflammatory response in rats submitted to bowel ischemia reperfusion injury. Thirty-two Wistar albino rats with a weight of 200 to 250 g were used in the study. They were randomly divided into 3 groups (n = 10 for each group): sham only operated group(group I); IR group (group II); and IR + curcumin treatment group (group III). Curcumin (curcumin from Curcuma longa) 20 mg/kg/day was given orally to the curcumin group. All animals were given 109 E. Coli by orogastric intubation 12 hours before sampling. Seventy-two hours after the first operation, mesenteric lymph node and blood samples were obtained and cultured. Blood samples of 2 mL were obtained for a polymerase chain reaction study. A piece of terminal ileum was also sampled for histopathologic examination. Mesenteric lymph node and blood cultures of all control animals were positive for microbiological growth, and polymerase chain reaction results were positive in seven of the eight rats. Histopathologically, edema, vasodilatation and inflammatory cell infiltration were found to be less in the other groups in comparison to the control group. Curcumin reduced bacterial translocation in blood, hepatocellular damage, and plasma cytokine levels. Curcumin reduced the incidence of bacterial translocation in intestinal I/R. rats. These results suggest that Curcumin would be clinically useful in the treatment of intestinal I/R injury.

Innate immune perturbations, accumulating DAMPs and inflammasome dysregulation: A ticking time bomb in ageing

Ageing has pronounced effects on the immune system, including on innate immune cells. Whilst most studies suggest that total numbers of different innate immune cell populations do not change dramatically during ageing, many of their functions such as phagocytosis, antigen presentation and inflammatory molecule secretion decline. In contrast, many endogenous damage-associated molecular patterns (DAMPs) accumulate during ageing. These include reactive oxygen species (ROS) released from damaged mitochondria, extracellular nucleotides like ATP, high mobility group box (HMGB) 1 protein, oxidized low density lipoprotein, amyloid-beta (Aβ), islet amyloid polypeptide and particulates like monosodium urate (MSU) crystals and cholesterol crystals. Some of these DAMPs trigger the activation of inflammasomes, cytosolic danger sensing signalling platforms that drive both the maturation of specific pro-inflammatory mediators such as IL-1β, as well as the initiation of pro-inflammatory pyroptotic cell death. Herein, we review the evidence that dysregulated inflammasome activation, via altered innate immune cell functions and elevated levels of DAMPs, contributes to the establishment of chronic, low-grade inflammation (characterized by elevated levels of IL-6 and C-reactive protein) and the development of age-related pathological processes.

Surveillance of Food- and Smear-Transmitted Pathogens in European Soldiers with Diarrhea on Deployment in the Tropics: Experience from the European Union Training Mission (EUTM) Mali

Introduction. Since 2013, European soldiers have been deployed on the European Union Training Mission (EUTM) in Mali. From the beginning, diarrhea has been among the most “urgent” concerns. Diarrhea surveillance based on deployable real-time PCR equipment was conducted between December 2013 and August 2014. Material and Methods. In total, 53 stool samples were obtained from 51 soldiers with acute diarrhea. Multiplex PCR panels comprised enteroinvasive bacteria, diarrhea-associated Escherichia coli (EPEC, ETEC, EAEC, and EIEC), enteropathogenic viruses, and protozoa. Noroviruses were characterized by sequencing. Cultural screening for Enterobacteriaceae with extended-spectrum beta-lactamases (ESBL) with subsequent repetitive sequence-based PCR (rep-PCR) typing was performed. Clinical information was assessed. Results. Positive PCR results for diarrhea-associated pathogens were detected in 43/53 samples, comprising EPEC (n = 21), ETEC (n = 19), EAEC (n = 15), Norovirus (n = 10), Shigella spp./EIEC (n = 6), Cryptosporidium parvum (n = 3), Giardia duodenalis (n = 2), Salmonella spp. (n = 1), Astrovirus (n = 1), Rotavirus (n = 1), and Sapovirus (n = 1). ESBL-positive Enterobacteriaceae were grown from 13 out of 48 samples. Simultaneous infections with several enteropathogenic agents were observed in 23 instances. Symptoms were mild to moderate. There were hints of autochthonous transmission. Conclusions. Multiplex real-time PCR proved to be suitable for diarrhea surveillance on deployment. Etiological attribution is challenging in cases of detection of multiple pathogens.