Acquired Low Factor XIII Activity Is Associated with an Increased Need for Blood Transfusions in Patients with Gastrointestinal Bleedings.

BACKGROUND: Factor XIII plays a key role within the coagulation cascade. OBJECTIVE: We aimed to investigate the relevance of factor XIII activity on the outcome of patients with gastrointestinal bleedings. METHODS: In this retrospective, single-center study patients with gastrointestinal bleeding and measurement of factor XIII activity were included. The primary endpoint was the number of red blood cell transfusions in patients with reduced factor XIII activity (< 70%) compared to patients with normal activity. Additionally, the influence of factor XIII substitution was assessed. RESULTS: Ninety-seven patients (median age: 64 [IQR 55, 77] years, 31 (32%) females) were included in the analysis. Fifty-six (58%) patients suffered from an upper gastrointestinal bleeding. 66 (68%) patients had a factor XIII activity < 70% and 24 (36%) of those received factor XIII substitution. Patients with reduced FXIII activity needed significantly more red blood cell transfusions than patients with normal activity (9 [5, 12] vs. 4 [1, 8], p < 0.001). Patients receiving factor XIII substitution showed a trend toward a decreased need for transfusions after substitution (0 [0, 5] vs. 3 [1, 6], p = 0.066). Factor XIII activity correlated negatively with the INR (rs = -0.24, p = 0.018) and positively with hemoglobin levels (rs = 0.28, p = 0.006) and with thrombocyte counts (rs = 0.30, p = 0.003). CONCLUSION: The present study shows an association of factor XIII activity with the requirement of blood transfusions in patients with gastrointestinal bleedings and indicates a potential benefit of factor XIII substitution. Factor XIII activity seems to be dependent from the amount of blood loss and the global coagulation parameters.

Gut Microbiota Dysbiosis in Suspected Food Protein Induced Proctocolitis-A Prospective Comparative Cohort Trial.

OBJECTIVES: In infants with suspected food protein induced proctocolitis (sFPIP) only a minority of patients are finally diagnosed with the disease following diagnostic dietary intervention (DDI). There is a need for a pathophysiological explanation for the cause of hematochezia in the majority of sFPIP infants. METHODS: We prospectively recruited infants with sFPIP and healthy controls. Fecal samples were collected at inclusion, week 4 (end of DDI in sFPIP), and week 8. For 16S rRNA sequencing (515F/806R) we used Illumina MiSeq sequencing system. Amplicon sequence variants were generated using Qiime2 and DADA2. Qiime diversity alpha and beta group comparisons and linear discriminant analysis effect size analysis was performed. For shotgun metagenomic analysis on species level we used KneadData and MetaPhlAn2. RESULTS: Fourteen sFPIP infants were compared to 55 healthy infants. At inclusion overall microbial composition of sFPIP infants differed significantly from controls (weighted UniFrac; Pairwise PERMANOVA, P = 0.002, pseudo- F = 5.008). On genus level healthy infant microbiota was significantly enriched with Bifidobacterium ( B ) compared to sFPIP patients (linear discriminant analysis [LDA] = 5.5, P < 0.001, 31.3% vs 12.1%). sFPIP stool was significantly enriched by Clostridium sensu stricto 1 over controls (LDA = 5.3, P = 0.003, 3.5% vs 18.3%). DDI caused a significant and sustained increase of Bifidobacterium (LDA = 5.4, P = 0.048, 27.9%) in sFPIP infants. Species level analysis revealed significant reduction of abundance of B longum in sFPIP patients, which after DDI was reversed by B. species other than B longum . CONCLUSIONS: We revealed a gut microbiota dysbiosis phenomenon in sFPIP infants. DDI induces a microbiota composition comparable to that of healthy infants. In most sFPIP infants hematochezia might be triggered by a gut microbiota dysbiosis phenomenon.

Treatment persistence of ustekinumab and vedolizumab in IBD patients is independent of prior immunogenicity to anti-TNFs: a retrospective study.

BACKGROUND AND AIMS: Immunological treatment failure of anti-TNF therapy negatively influences treatment persistence of a second anti-TNF in IBD patients. So far it is unknown if this effect is also observed for other monoclonal antibodies. We assessed the influence of immunogenicity to anti-TNFs on treatment persistence of subsequent ustekinumab and vedolizumab therapy. METHODS: IBD patients with and without immunogenicity to anti-TNFs (undetectable trough levels and antibody titers ≥20 ng/mL) and subsequent ustekinumab (UST) and/or vedolizumab (VDZ) therapy were included in this retrospective, single-center study. The Kaplan-Meier method with the log-rank test and Cox proportional hazards were used as statistical methods. RESULTS: One hundred patients (Crohn's disease: 62, Ulcerative colitis: 31, IBD unclassified: 7) with 127 treatment lines (62 with UST, 65 with VDZ) were included in the analysis. Immunogenicity to previous anti-TNFs did not influence treatment persistence of subsequent ustekinumab and vedolizumab therapy (UST: Log rank: p = .95, Immunogenicity: HR for treatment discontinuation: 0.97 [95% CI 0.31-3.04]; VDZ: p = .65, HR: 0.85 [0.41-1.75]; total cohort [UST and VDZ]: p = .62, HR: 0.86 [0.47-1.57]). Azathioprine co-treatment did not lengthen treatment persistence (UST: Log rank: p = .77, azathioprine: HR: 1.20 [0.34-4.27]; VDZ: p = .92, HR: 0.58 [0.17-1.99]; total cohort: p = .79, HR: 1.10 [0.55-2.20]). In this anti-TNF experienced cohort, patients with ustekinumab remained longer on treatment than patients receiving vedolizumab (Log rank: p = .005, UST: HR: 0.43 [0.23-0.79]). CONCLUSIONS: Immunogenicity to anti-TNFs does not influence treatment persistence of subsequent ustekinumab and vedolizumab therapy.

Toxin-Producing Klebsiella oxytoca in Healthy Infants: Commensal or Pathobiont?

OBJECTIVES: Klebsiella oxytoca is a gastrointestinal pathobiont with the potential to produce the toxins tilivalline and tilimycin, which cause antibiotic-associated hemorrhagic colitis. Overgrowth of toxigenic K oxytoca has recently been implicated in necrotizing enterocolitis. K oxytoca colonizes 2-9% of healthy adults, however, there is no systematic data on colonization in healthy children. We investigated K oxytoca colonization and its toxigenic properties in healthy infants. METHODS: We sampled stool of healthy infants and determined K oxytoca colonization using stool culture and PCR (pehX). Toxin in stool was measured with HPLC/high-resolution mass spectrometry. K oxytoca isolates were typed using multi-locus sequence typing (MLST) and K oxytoca toxin PCR (npsA/B). Cytotoxin production of isolates was analyzed by MTT assay. RESULTS: K oxytoca was detected in 30 of 61 infants (49%) using stool culture and in 45 of 61 (73%) using PCR (pehX). Toxin marker PCR (npsA/B) was positive in 66% of stool samples positive for K oxytoca PCR. Stool toxin levels were too low for quantitation but traces of tilivalline were detected. Contrarily, 49% of K oxytoca isolates demonstrated toxicity in the MTT assay. MLST revealed 36 distinct sequence types affiliated with all known K oxytoca sequence type clusters (A, B1 and B2). CONCLUSIONS: More than 70% of healthy infants were colonized with K oxytoca. Toxin quantities in stool of colonized healthy infants were below detection level, yet half of the isolates produced toxin in vitro demonstrating their pathobiont potential. The high occurrence of toxigenic K oxytoca in healthy infants has to be considered for future disease association studies.

Klebsiella oxytoca enterotoxins tilimycin and tilivalline have distinct host DNA-damaging and microtubule-stabilizing activities.

Establishing causal links between bacterial metabolites and human intestinal disease is a significant challenge. This study reveals the molecular basis of antibiotic-associated hemorrhagic colitis (AAHC) caused by intestinal resident Klebsiella oxytoca Colitogenic strains produce the nonribosomal peptides tilivalline and tilimycin. Here, we verify that these enterotoxins are present in the human intestine during active colitis and determine their concentrations in a murine disease model. Although both toxins share a pyrrolobenzodiazepine structure, they have distinct molecular targets. Tilimycin acts as a genotoxin. Its interaction with DNA activates damage repair mechanisms in cultured cells and causes DNA strand breakage and an increased lesion burden in cecal enterocytes of colonized mice. In contrast, tilivalline binds tubulin and stabilizes microtubules leading to mitotic arrest. To our knowledge, this activity is unique for microbiota-derived metabolites of the human intestine. The capacity of both toxins to induce apoptosis in intestinal epithelial cells-a hallmark feature of AAHC-by independent modes of action, strengthens our proposal that these metabolites act collectively in the pathogenicity of colitis.

Effects of an oral synbiotic on the gastrointestinal immune system and microbiota in patients with diarrhea-predominant irritable bowel syndrome.

PURPOSE: Diarrhea-predominant irritable bowel syndrome (IBS-D) is a common functional gastrointestinal disorder. Probiotics and synbiotics have been shown to improve symptoms of IBS, although mechanisms of action are currently not understood. METHODS: We investigated the effects of a 4-week oral synbiotic treatment (OMNi-BiOTiC® Stress Repair) in ten IBS-D patients on gastrointestinal mucosal and fecal microbiota, mucosa-associated immune cells, and fecal short-chain fatty acids. The upper and lower gastrointestinal tracts were compared before and after a 4-week synbiotic treatment using endoscopic evaluation to collect mucosal specimens for FACS analysis and mucosal 16S rRNA gene analysis. In stool samples, analysis for fecal SCFAs using GC-MS, fecal zonulin using ELISA, and fecal 16S rRNA gene analysis was performed. RESULTS: Synbiotics led to an increased microbial diversity in gastric (p = 0.008) and duodenal (p = 0.025) mucosal specimens. FACS analysis of mucosal immune cells showed a treatment-induced reduction of CD4+ T cells (60 vs. 55%, p = 0.042) in the ascending colon. Short-chain fatty acids (acetate 101 vs. 202 µmol/g; p = 0.007) and butyrate (27 vs. 40 µmol/g; p = 0.037) were elevated in fecal samples after treatment. Furthermore, treatment was accompanied by a reduction of fecal zonulin concentration (67 vs. 36 ng/ml; p = 0.035) and disease severity measured by IBS-SSS (237 vs. 54; p = 0.002). CONCLUSIONS: Our findings indicate that a short-course oral synbiotic trial may influence the human gastrointestinal tract in IBS-D patients on different levels which are region specific.

Involvement of EP2 and EP4 Receptors in Eosinophilic Esophagitis: A Pilot Study.

BACKGROUND: The prostaglandin D2 receptor DP2 has been implicated in eosinophil infiltration and the development of eosinophilic esophagitis (EoE). AIMS AND METHODS: In this study, we investigated an involvement of PGE2 (EP1-EP4) and PGD2 (DP1) receptors in EoE by measuring their expression in peripheral blood eosinophils and esophageal mucosal biopsies of EoE patients and by performing migration and adhesion assays with eosinophils from healthy donors. RESULTS: Expression of EP2 and EP4, but not EP1 and EP3, was decreased in blood eosinophils of patients with EoE vs. control subjects. Adhesion of eosinophils to esophageal epithelial cells was decreased by EP2 receptor agonist butaprost and EP4 agonist ONO-AE1-329, whereas DP1 agonist BW245C increased adhesion. In chemotaxis assays with supernatant from human esophageal epithelial cells, only ONO-AE1-329 but not butaprost or BW245C inhibited the migration of eosinophils. Expression of EP and DP receptors in epithelial cells and eosinophils was detected in sections of esophageal biopsies from EoE patients by immunohistochemistry. qPCR of biopsies from EoE patients revealed that gene expression of EP4 and DP1 was the highest among PGE2 and PGD2 receptors. Esophageal epithelial cells in culture showed high gene expression for EP2 and EP4. Activation of EP2 and EP4 receptors decreased barrier integrity of esophageal epithelial cells in impedance assays. CONCLUSIONS: Activation of EP2 and EP4 receptors may inhibit eosinophil recruitment to the esophageal mucosa. However, their activation could negatively affect esophageal barrier integrity suggesting that eosinophilic rather than epithelial EP2 and EP4 have a protective role in EoE.

Tilivalline- and Tilimycin-Independent Effects of Klebsiella oxytoca on Tight Junction-Mediated Intestinal Barrier Impairment.

Klebsiella oxytoca causes antibiotic-associated hemorrhagic colitis and diarrhea. This was attributed largely to its secreted cytotoxins tilivalline and tilimycin, inductors of epithelial apoptosis. To study whether Klebsiella oxytoca exerts further barrier effects, T84 monolayers were challenged with bacterial supernatants derived from tilivalline/tilimycin-producing AHC6 or its isogeneic tilivalline/tilimycin-deficient strain Mut-89. Both preparations decreased transepithelial resistance, enhanced fluorescein and FITC-dextran-4kDa permeabilities, and reduced expression of barrier-forming tight junction proteins claudin-5 and -8. Laser scanning microscopy indicated redistribution of both claudins off the tight junction region in T84 monolayers as well as in colon crypts of mice infected with AHC6 or Mut-89, indicating that these effects are tilivalline/tilimycin-independent. Furthermore, claudin-1 was affected, but only in a tilivalline/tilimycin-dependent manner. In conclusion, Klebsiella oxytoca induced intestinal barrier impairment by two mechanisms: the tilivalline/tilimycin-dependent one, acting by increasing cellular apoptosis and a tilivalline/tilimycin-independent one, acting by weakening the paracellular pathway through the tight junction proteins claudin-5 and -8.

Pharmacokinetics and safety of fidaxomicin in patients with inflammatory bowel disease and Clostridium difficile infection: an open-label Phase IIIb/IV study (PROFILE).

Objectives: Inflammatory bowel disease (IBD) poses an increased risk for Clostridium difficile infection (CDI). Fidaxomicin has demonstrated non-inferiority to vancomycin for initial clinical cure of CDI in patients without IBD; however, lack of data has caused concerns regarding potential systemic absorption of fidaxomicin in patients with IBD. Methods: The plasma pharmacokinetics (PK) of fidaxomicin and its primary metabolite OP-1118 were evaluated in a multicentre, open-label, single-arm, Phase IIIb/IV study enrolling patients with active IBD and CDI. Patients received fidaxomicin, 200 mg twice daily for 10 days. The primary and secondary endpoints were, respectively, plasma and stool PK of fidaxomicin and OP-1118 on Days 1, 5 and 10 of treatment. Other secondary endpoints included safety of fidaxomicin treatment (assessed until Day 180). ClinicalTrials.gov identifier: NCT02437591. Results: Median Tmax of fidaxomicin and OP-1118 for the PK analysis set (PKAS; 24 patients) was 1-2 h across Days 1, 5 and 10. Cmax ranges were 1.2-154 ng/mL for fidaxomicin and 4.7-555 ng/mL for OP-1118 across Days 1, 5 and 10 (PKAS). The ranges of concentrations in stool were 17.8-2170 µg/g for fidaxomicin and 0-1940 µg/g for OP-1118. Sixty percent (15/25) of patients experienced treatment-emergent adverse events (TEAEs), none of which led to treatment discontinuation or death. Conclusions: Maximum fidaxomicin and OP-1118 plasma concentrations observed in this study population suggest no increase in absorption, compared with patients without IBD. Incidence of TEAEs was similar to previous Phase III trials, suggesting that fidaxomicin is comparatively well tolerated in patients with IBD.

Secondary tumors of the GI tract: origin, histology, and endoscopic findings.

BACKGROUND AND AIMS: The GI tract is rarely affected by secondary tumors. Patients often present at an advanced stage of the disease, and prognosis is dismal. This study aimed to analyze the clinical, endoscopic, and pathologic features of secondary tumors that had been diagnosed endoscopically. METHODS: We conducted a retrospective database analysis of 217 patients with secondary tumors of the GI tract. Endoscopic findings and histologic diagnoses were systematically re-evaluated. RESULTS: Malignant melanoma (n = 33, 15%), breast cancer (n = 32, 15%), and pancreatic cancer (n = 27, 12%) were the most common corresponding primaries. About one-third of secondary tumors were detected in the stomach (n = 76, 35%), followed by small intestine (n = 54, 25%) and rectum (n = 53, 24%). The median time between the diagnoses of primary and secondary tumors was 19 months (mean, 31; range, 0-251), and this time was particularly long for renal cell carcinoma and breast cancer (median, 38 and 45 months, respectively). Direct invasion from extra-GI malignancies was more common (56%) than vascular cancer spread (44%) and depended on both sites of tumor involvement and corresponding primary. The lesions presented with various endoscopic patterns. In patients for whom a definitive diagnosis of cancer was known before the examination (n = 168), a secondary tumor was included in the differential diagnosis in only 48% of lesions. It is of note that the remaining cases were diagnosed endoscopically as primary tumors and rarely also as nonneoplastic change. CONCLUSIONS: Secondary tumors may affect all parts of the GI tract. Malignant melanoma and breast and pancreatic cancer represent the most common primaries. Diagnosis based on examination of biopsy specimens is crucial to avoid misclassification.

[Ustekinumab - Current position]. / Ustekinumab ­ eine Standortbestimmung.

The present review by the IBD-Dach group provides a comprehensive summary of the mode of action, clinical development, approval, efficacy and safety aspects of the novel anti-p40 antibody Ustekinumab. The review provides current data, including the large clinical trials as well as smaller case series and work outside the field of inflammatory bowel diseases for shedding more light into special situations. Together, the data indicate that Ustekinumab shows clinical efficacy as well as a good safety profile for the treatment of Crohn's disease.

[Second Austrian consensus on the safe use of anti-TNFα-antibodies in patients with inflammatory bowel diseases]. / Zweiter österreichischer Konsensus zur sicheren Anwendung von anti-TNF-α-Antikörpern bei chronisch-entzündlichen Darmerkrankungen.

Anti-TNFα-antibodies have revolutionized the therapy of inflammatory bowel diseases and other immune-mediated inflammatory diseases. Due to the increasing application of these substances, the Working Group of Inflammatory Bowel Diseases of the Austrian Association of Gastroenterology and Hepatology intended to update their consensus report on the safe use of Infliximab (published in 2010) and to enlarge its scope to cover all anti-TNFα-antibodies. The present consensus report summarizes the current evidence on the safe use of anti-TNFα-antibodies and covers the following topics: general risk of infection, bacterial infections (i. e., Clostridium difficile, Tuberculosis, food hygiene), Pneumocystis jiroveci, viral infections (i. e., Hepatitis B, Hepatitis C, HIV, CMV, VZV), vaccination in general and recommendation for vaccines, gastrointestinal aspects (i. e., perianal fistula, abdominal fistula, intestinal strictures, stenosis and bowel obstruction), dermatologic aspects (skin malignancies, eczema-like drug-related skin eruption), infusion reactions and immunogenicity, demyelinating diseases, hepatotoxicity, haematotoxicity, congestive heart failure, risk and history of malignancies, and pregnancy and breast feeding. For practical reasons, the relevant aspects are summarized in a checklist which is divided into two parts: issues to be addressed before therapy and issues to be addressed during therapy.

European consensus conference on faecal microbiota transplantation in clinical practice.

Faecal microbiota transplantation (FMT) is an important therapeutic option for Clostridium difficile infection. Promising findings suggest that FMT may play a role also in the management of other disorders associated with the alteration of gut microbiota. Although the health community is assessing FMT with renewed interest and patients are becoming more aware, there are technical and logistical issues in establishing such a non-standardised treatment into the clinical practice with safety and proper governance. In view of this, an evidence-based recommendation is needed to drive the practical implementation of FMT. In this European Consensus Conference, 28 experts from 10 countries collaborated, in separate working groups and through an evidence-based process, to provide statements on the following key issues: FMT indications; donor selection; preparation of faecal material; clinical management and faecal delivery and basic requirements for implementing an FMT centre. Statements developed by each working group were evaluated and voted by all members, first through an electronic Delphi process, and then in a plenary consensus conference. The recommendations were released according to best available evidence, in order to act as guidance for physicians who plan to implement FMT, aiming at supporting the broad availability of the procedure, discussing other issues relevant to FMT and promoting future clinical research in the area of gut microbiota manipulation. This consensus report strongly recommends the implementation of FMT centres for the treatment of C. difficile infection as well as traces the guidelines of technicality, regulatory, administrative and laboratory requirements.

Antibiotic-Associated Apoptotic Enterocolitis in the Absence of a Defined Pathogen: The Role of Intestinal Microbiota Depletion.

OBJECTIVE: Antibiotic therapy is a major risk factor for the development of diarrhea and colitis with varying severity. Often the origin of antibiotic-associated gastrointestinal deterioration remains elusive and no specific infectious agents could be discerned. PATIENTS: We represent three cases of intractable high-volume diarrhea associated with combined antibiotic and steroid therapy in critically ill patients not fitting into established disease entities. Cases presented with severe apoptotic enterocolitis resembling acute intestinal graft-versus-host-disease. Microbiologic workup precluded known enteropathogens, but microbiota analysis revealed a severely depleted gut microbiota with concomitant opportunistic pathogen overgrowth. INTERVENTIONS: Fecal microbiota transplantation, performed in one patient, was associated with correction of dysbiosis, rapid clinical improvement, and healing of enterocolitis. CONCLUSIONS: Our series represents a severe form of antibiotic-associated colitis in critically ill patients signified by microbiota depletion, and reestablishment of a physiologic gastrointestinal microbiota might be beneficial for this condition.

Propionibacterium acnes overabundance and natural killer group 2 member D system activation in corpus-dominant lymphocytic gastritis.

Corpus-dominant lymphocytic gastritis (LyG) is characterized by CD8+ T-cell infiltration of the stomach epithelium by a so far uncharacterized mechanism. Although Helicobacter pylori is typically undetectable in LyG, patients respond to H. pylori antibiotic eradication therapy, suggesting a non-H. pylori microbial trigger for the disease. Comparative microbiota analysis of specimens from LyG, H. pylori gastritis and healthy controls precluded involvement of H. pylori in LyG but identified Propionibacterium acnes as a possible disease trigger. In addition, the natural killer group 2 member D (NKG2D) system and the proinflammatory cytokine interleukin (IL)-15 are significantly upregulated in the gastric mucosa of LyG patients, and gastric epithelial cells respond to microbe-derived stimuli, including live P. acnes and the microbial products short-chain fatty acids, with induction of NKG2D ligands. In contrast, H. pylori infection does not activate or even repress NKG2D ligands. Together, our findings identify P. acnes as a possible causative agent for LyG, which is dependent on the NKG2D system and IL-15 activation. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Enterotoxicity of a nonribosomal peptide causes antibiotic-associated colitis.

Antibiotic therapy disrupts the human intestinal microbiota. In some patients rapid overgrowth of the enteric bacterium Klebsiella oxytoca results in antibiotic-associated hemorrhagic colitis (AAHC). We isolated and identified a toxin produced by K. oxytoca as the pyrrolobenzodiazepine tilivalline and demonstrated its causative action in the pathogenesis of colitis in an animal model. Tilivalline induced apoptosis in cultured human cells in vitro and disrupted epithelial barrier function, consistent with the mucosal damage associated with colitis observed in human AAHC and the corresponding animal model. Our findings reveal the presence of pyrrolobenzodiazepines in the intestinal microbiota and provide a mechanism for colitis caused by a resident pathobiont. The data link pyrrolobenzodiazepines to human disease and identify tilivalline as a target for diagnosis and neutralizing strategies in prevention and treatment of colitis.

D-lactic acidosis - case report and review of the literature.

D-lactic acidosis is a rare complication that occurs mainly in patients with malabsorption due to a surgically altered gastrointestinal tract anatomy, namely in short bowel syndrome or after bariatric surgery. It is characterized by rapid development of neurological symptoms and severe metabolic acidosis, often with a high serum anion gap. Malabsorbed carbohydrates can be fermented by colonic microbiota capable of producing D-lactic acid. Routine clinical assessment of serum lactate covers only L-lactic acid; when clinical suspicion for D-lactic acidosis is high, special assays for D-lactic acid are called for. A serum level of more than 3 mmol/L of D-lactate confirms the diagnosis. Management includes correction of metabolic acidosis by intravenous bicarbonate, restriction of carbohydrates or fasting, and antibiotics to eliminate intestinal bacteria that produce D-lactic acid. We report a case of D-lactic acidosis in a patient with short bowel syndrome and review the pathophysiology of D-lactic acidosis with its biochemical and clinical features. D-lactic acidosis should be considered when patients with short bowel syndrome or other malabsorption syndromes due to an altered gastrointestinal tract anatomy present with metabolic acidosis and neurological symptoms that cannot be attributed to other causes. With the growing popularity of bariatric surgery, this metabolic derangement may be seen more frequently in the future.

Biosynthesis of the Enterotoxic Pyrrolobenzodiazepine Natural Product Tilivalline.

The nonribosomal enterotoxin tilivalline was the first naturally occurring pyrrolobenzodiazepine to be linked to disease in the human intestine. Since the producing organism Klebsiella oxytoca is part of the intestinal microbiota and the pyrrolobenzodiazepine causes the pathogenesis of colitis it is important to understand the biosynthesis and regulation of tilivalline activity. Here we report the biosynthesis of tilivalline and show that this nonribosomal peptide assembly pathway initially generates tilimycin, a simple pyrrolobenzodiazepine with cytotoxic properties. Tilivalline results from the non-enzymatic spontaneous reaction of tilimycin with biogenetically generated indole. Through a chemical total synthesis of tilimycin we could corroborate the predictions made about the biosynthesis. Production of two cytotoxic pyrrolobenzodiazepines with distinct functionalities by human gut resident Klebsiella oxytoca has important implications for intestinal disease.

Primary resistance of Helicobacter pylori is still low in Southern Austria.

OBJECTIVES: We determined primary and secondary resistance rates of H. pylori in different regions of Austria and potential bacterial and host factors associated with resistance. METHODS: In a prospective multicentre study H. pylori was cultivated from biopsies and susceptibility testing was performed according to EUCAST. Resistance to clarithromycin and levofloxacin was determined by sequencing of the resistance-determining regions of 23S rRNA and gyrA genes. cagA, vacA and babA2 genotypes were determined. RESULTS: A total of 1266 patients were included. 178 isolates were cultured: 128 from patients without prior eradication therapy, 50 from patients after failed eradication. Primary resistance to clarithromycin, levofloxacin and metronidazole were 17.2%, 9.4% and 10.2%, respectively. Secondary resistance to clarithromycin, levofloxacin and metronidazole were 64%, 18% and 44%, respectively. Prior eradication was associated with a higher risk of clarithromycin as well as metronidazole resistance (OR=8.1; 95% CI 3.8-17.1 and OR 5.7; 95% CI 2.5-13, respectively). CONCLUSION: Primary resistance to both clarithromycin and levofloxacin was markedly lower in Southern Austria than recently reported.

Any Future for Fecal Microbiota Transplantation as Treatment Strategy for Inflammatory Bowel Diseases?

Fecal microbiota transplantation (FMT) is a novel therapeutic procedure aiming at restoring a normal intestinal microbiota by application of fecal microorganisms from a healthy subject into the gastrointestinal tract of a patient. FMT is the most effective treatment for recurrent Clostridium difficile infections (CDI). These infections also occur in patients with inflammatory bowel diseases (IBDs), where case series demonstrated a successful treatment of CDI by FMT in 83-92% of patients. The effect of FMT on the activity of IBD has mainly been investigated in ulcerative colitis (UC) patients, including 3 randomized controlled trials. So far, 2 randomized controlled trials showed a superiority of FMT compared to placebo in inducing remission in UC, while 1 study found no significant difference to placebo. The variation in response to FMT between these studies as well as in the uncontrolled trials might be explained by many differences in the way of FMT application, patient pretreatment and patient and donor selection. The data for the use of FMT in Crohn's disease and pouchitis are sparse; currently, no conclusion can be drawn regarding the effectiveness of FMT in these indications. It needs to be noted that cases of IBD activation after FMT have been reported. So far, FMT can only be recommended to be used for the treatment of concomitant CDI in IBD in clinical practice. For treating IBD irrespective of CDI, FMT should be only used in clinical trials. Current forms of FMT, especially protocols using repeated application, are very time and personnel consuming. Future trends are the use of defined stable microbiota preparations, in particular oral preparations, which will enable better and larger controlled trails for investigating FMT in IBD.