Explore the vast range of titles available.

A human gut-on-a-chip microdevice was used to coculture multiple commensal microbes in contact with living human intestinal epithelial cells for more than a week in vitro and to analyze how gut microbiome, inflammatory cells, and peristalsis-associated mechanical deformations independently contribute to intestinal bacterial overgrowth and inflammation. This in vitro model replicated results from past animal and human studies, including demonstration that probiotic and antibiotic therapies can suppress villus injury induced by pathogenic bacteria. By ceasing peristalsis-like motions while maintaining luminal flow, lack of epithelial deformation was shown to trigger bacterial overgrowth similar to that observed in patients with ileus and inflammatory bowel disease. Analysis of intestinal inflammation on-chip revealed that immune cells and lipopolysaccharide endotoxin together stimulate epithelial cells to produce four proinflammatory cytokines (IL-8, IL-6, IL-1β, and TNF-α) that are necessary and sufficient to induce villus injury and compromise intestinal barrier function. Thus, this human gut-on-a-chip can be used to analyze contributions of microbiome to intestinal pathophysiology and dissect disease mechanisms in a controlled manner that is not possible using existing in vitro systems or animal models.

ObjectivePostoperative ileus (POI), the most frequent complication after intestinal surgery, depends on dendritic cells (DCs) and macrophages. Here, we have investigated the mechanism that activates these cells and the contribution of the intestinal microbiota for POI induction.DesignPOI was induced by manipulating the intestine of mice, which selectively lack DCs, monocytes or macrophages. The disease severity in the small and large intestine was analysed by determining the distribution of orally applied fluorescein isothiocyanate-dextran and by measuring the excretion time of a retrogradely inserted glass ball. The impact of the microbiota on intestinal peristalsis was evaluated after oral antibiotic treatment.ResultsWe found that Cd11c-Cre+ Irf4flox/flox mice lack CD103+CD11b+ DCs, a DC subset unique to the intestine whose function is poorly understood. Their absence in the intestinal muscularis reduced pathogenic inducible nitric oxide synthase (iNOS) production by monocytes and macrophages and ameliorated POI. Pathogenic iNOS was produced in the jejunum by resident Ly6C– macrophages and infiltrating chemokine receptor 2-dependent Ly6C+ monocytes, but in the colon only by the latter demonstrating differential tolerance mechanisms along the intestinal tract. Consistently, depletion of both cell subsets reduced small intestinal POI, whereas the depletion of Ly6C+ monocytes alone was sufficient to prevent large intestinal POI. The differential role of monocytes and macrophages in small and large intestinal POI suggested a potential role of the intestinal microbiota. Indeed, antibiotic treatment reduced iNOS levels and ameliorated POI.ConclusionsOur findings reveal that CD103+CD11b+ DCs and the intestinal microbiome are a prerequisite for the activation of intestinal monocytes and macrophages and for dysregulating intestinal motility in POI.

Pneumonic tularemia is caused by inhalation of the gram negative bacterium, Francisella tularensis. Because of concerns that tularemia could be used as a bioterrorism agent, vaccines and therapeutics are urgently needed. Animal models of pneumonic tularemia with a pathophysiology similar to the human disease are needed to evaluate the efficacy of these potential medical countermeasures. Rabbits exposed to aerosols containing Francisella tularensis strain SCHU S4 developed a rapidly progressive fatal pneumonic disease. Clinical signs became evident on the third day after exposure with development of a fever (>40.5°C) and a sharp decline in both food and water intake. Blood samples collected on day 4 found lymphopenia and a decrease in platelet counts coupled with elevations in erythrocyte sedimentation rate, alanine aminotransferase, cholesterol, granulocytes and monocytes. Radiographs demonstrated the development of pneumonia and abnormalities of intestinal gas consistent with ileus. On average, rabbits were moribund 5.1 days after exposure; no rabbits survived exposure at any dose (190-54,000 cfu). Gross evaluation of tissues taken at necropsy showed evidence of pathology in the lungs, spleen, liver, kidney and intestines. Bacterial counts confirmed bacterial dissemination from the lungs to the liver and spleen. The pathophysiology of pneumonic tularemia in rabbits resembles what has been reported for humans. Rabbits therefore are a relevant model of the human disease caused by type A strains of F. tularensis.

Loop ileostomy closure after colorectal surgery is often associated with Postoperative ileus, with an incidence between 13–20%. The aim of this study is to evaluate the efficacy and safety of preoperative stimulation of the efferent loop with probiotics prior to ileostomy closure in patients operated on for colorectal carcinoma. For this, a prospective, randomized, double-blind, controlled study is designed. All patients who underwent surgery for colorectal carcinoma with loop ileostomy were included. Randomized and divided into two groups, 34 cases and 35 controls were included in the study. Postoperative ileus, the need for nasogastric tube insertion, the time required to begin tolerating a diet, restoration of bowel function, and duration of hospital stay were evaluated. The incidence of Postoperative ileus was similar in both groups, 9/34 patients stimulated with probiotics and 10/35 in the control group (CG) with a p = 0.192. The comparative analysis showed a direct relationship between Postoperative ileus after oncological surgery and Postoperative ileus after reconstruction surgery, independently of stimulation. Postoperative ileus after closure ileostomy is independent of stimulation of the ileostomy with probiotics through the efferent loop. There seem to be a relationship between Postoperative ileus after reconstruction and the previous existence of Postoperative ileus after colorectal cancer surgery.

The composition of the distal ileum microbiota and the impact of fecal exposure during intracorporeal urinary diversion (ICUD) on gastrointestinal (GI) complications remain unclear. This study included 146 patients with bladder cancer who underwent ICUD without bowel preparation and received only a single day of antibiotic prophylaxis. Fecal samples were collected directly from the distal ileum during surgery, and ascitic fluid was obtained postoperatively from abdominal drains. Among the patients, 129 (88.3%) had minimal microbial growth in ileal feces, while 17 (11.7%) showed significant colonization. The most commonly identified organisms were Streptococcus , Enterococcus , Enterobacter , Klebsiella , and Candida . The incidence of GI complications was significantly higher in patients with positive ileal fecal cultures compared to those with no detectable growth (39.4% vs. 7.7%, P  < 0.001), and even more pronounced in patients with positive ascitic cultures (72.5% vs. 11.3%, P  < 0.001). Multivariate analysis identified positive ascitic cultures as an independent predictor of GI complications. Additionally, frailty was significantly associated with the presence of microbial growth in ascitic fluid. These findings suggest that, although the distal ileal microbiota is largely suppressed under short-term antibiotic prophylaxis, the presence of intra-abdominal bacteria or fungi is strongly linked to postoperative GI complications, including ileus. Frailty may contribute to microbial dysbiosis and the persistence of intra-abdominal pathogens, particularly Enterococcus and Enterobacter species.

Staphylococcus aureus is an uncommon cause of bacterial meningitis, and S. aureus meningitis complicated with adynamic ileus has not been previously documented. This report presents a rare case of a man in his late 30s who developed purulent meningitis and intestinal pseudo-obstruction secondary to a skin-derived S. aureus infection. The patient initially presented with persistent fever, headache, and altered mental status. Subsequently, he developed abdominal distention, vomiting, dysuria, and meningeal signs. Laboratory tests revealed hyponatremia and elevated cerebrospinal fluid pressure; however, conventional cerebrospinal fluid culture failed to detect any pathogen. Diagnosis was ultimately confirmed through metagenomic next-generation sequencing, which identified S. aureus as the causative agent. Targeted antimicrobial therapy with vancomycin and meropenem resulted in rapid clinical improvement. This case highlights the importance of considering central nervous system infections in patients presenting with unexplained gastrointestinal and autonomic symptoms. Moreover, it emphasizes the clinical utility of metagenomic next-generation sequencing in identifying pathogens in culture-negative, atypical infections. Early recognition and intervention are essential to improving outcomes in such complex presentations.

For 139 patients tested for Clostridium difficile infection by polymerase chain reaction, the sensitivity, specificity, positive predictive value, and negative predictive value of testing perirectal swabs vs stool specimens were 95.7%, 100%, 100%, and 99.1%, respectively. For selected patients, perirectal swabs provide an accurate toxigenic C. difficile detection strategy.

Background A clinical heterogeneity was reported in patients with Cystic Fibrosis (CF) with the same CFTR genotype and between siblings with CF. Methods We investigated all clinical aspects in a cohort of 101 pairs of siblings with CF (including 6 triplets) followed since diagnosis. Results Severe lung disease had a 22.2% concordance in sib-pairs, occurred early and the FEV 1 % at 12 years was predictive of the severity of lung disease in the adulthood. Similarly, CF liver disease occurred early (median: 15 years) and showed a concordance of 27.8% in sib-pairs suggesting a scarce contribution of genetic factors; in fact, only 2/15 patients with liver disease in discordant sib-pairs had a deficiency of alpha-1-antitrypsin (a known modifier gene of CF liver phenotype). CF related diabetes was found in 22 pairs (in 6 in both the siblings). It occurred later (median: 32.5 years) and is strongly associated with liver disease. Colonization by P. aeruginosa and nasal polyposis that required surgery had a concordance > 50% in sib-pairs and were poorly correlated to other clinical parameters. The pancreatic status was highly concordant in pairs of siblings (i.e., 95.1%) but a different pancreatic status was observed in patients with the same CFTR mutations. This suggests a close relationship of the pancreatic status with the “whole” CFTR genotype, including mutations in regulatory regions that may modulate the levels of CFTR expression. Finally, a severe course of CF was evident in a number of patients with pancreatic sufficiency. Conclusions Physicians involved in care of patients with CF and in genetic counseling must be aware of the clinical heterogeneity of CF even in sib-pairs that, at the state of the art, is difficult to explain.

Diarrhea, as the well-known clinical feature of Clostridioides difficile infection (CDI), may be absent at the initial presentation, leading to delays in diagnosis. The delay is due to both underrecognition of such presentations and the dependence of CDI diagnosis on stool samples. This review was conducted to evaluate the literature for CDI cases presenting without diarrhea, raise awareness about the possibility of CDI in the differential diagnosis regardless of diarrhea, and assemble relevant data to harmonize clinical approaches. The PubMED Medline database was used to conduct this literature review, focusing on reported CDI cases presenting without diarrhea. After exclusions, 22 articles were included for analysis, providing data for 48 cases. This paper will present the selected clinical data of these 48 patients and follow a real-life case with a clinical course of CDI including presentation, diagnosis, management, and outcomes. The excessive mortality and bowel resection rates of CDI patients presenting without diarrhea were the notable findings. Poor prognosis was possibly inflated by delayed diagnoses in an unfamiliar setting, emphasizing the importance of a high index of suspicion to allow early recognition of CDIs in the appropriate clinical context despite the absence of diarrhea.

Background Dysmotility and postoperative ileus (POI) are frequent major clinical problems post-abdominal surgery. Erythropoietin (EPO) is a multifunctional tissue-protective cytokine that promotes recovery of the intestine in various injury models. While EPO receptors (EPOR) are present in vagal Schwann cells, the role of EPOR in POI recovery is unknown because of the lack of EPOR antagonists or Schwann-cell specific EPOR knockout animals. This study was designed to explore the effect of EPO via EPOR in vagal nerve Schwann cells in a mouse model of POI. Results The structural features of EPOR and its activation by EPO-mediated dimerization were understood using structural analysis. Later, using the Cre-loxP system, we developed a myelin protein zero (Mpz) promoter-driven knockout mouse model of Schwann cell EPOR (MpzCre-EPOR flox/flox / Mpz-EPOR-KO) confirmed using PCR and qRT-PCR techniques. We then measured the intestinal transit time (ITT) at baseline and after induction of POI with and without EPO treatment. Although we have previously shown that EPO accelerates functional recovery in POI in wild type mice, EPO treatment did not improve functional recovery of ITT in POI of Mpz-EPOR-KO mice. Conclusions To the best of our knowledge, this is the first pre-clinical study to demonstrate a novel mouse model of EPOR specific knock out on Schwan cells with an effect in the gut. We also showed novel beneficial effects of EPO through vagus nerve Schwann cell-EPOR in intestinal dysmotility. Our findings suggest that EPO-EPOR signaling in the vagus nerve after POI is important for the functional recovery of ITT.