Adherent-invasive Escherichia coli (AIEC) has been reported as associated with the pathogenesis of inflammatory bowel disease (IBD). We aimed to investigate the characteristics of mucosa-associated E. coli and the clinical significance of AIEC in Korean IBD patients. E. coli strains were isolated from the mucosal tissues of 18 Crohn’s disease (CD) patients, 24 ulcerative colitis (UC) patients, and 9 healthy controls (HC). Adhesion, invasion, and survival assays were performed to evaluate phenotypic features of E. coli isolates and to identify AIEC. The presence of virulence genes and cytokine expression were examined using PCR. In addition, data on IBD-related hospitalization were collected. A total of 59 E. coli strains were isolated (25 from CD, 27 from UC, and 7 from HC). The average levels of adhesion, invasion, and survival were higher in E. coli strains from IBD patients than those from HC (adhesion: 1.65 vs. 0.71, p = 0.046; invasion: 1.68 vs. 0.52, p = 0.039; survival: 519.55 vs. 47.55, p = 0.363). Prevalence of AIEC in HC, CD and UC patients was 22.2%, 38.9% and 37.5%, respectively. E. coli isolates from IBD patients had various virulence genes and were associated with increased expression of TNF-α and IL-17. IBD-related hospitalization within 3 years was 18.8% in patients with AIEC and 11.5% in patients without AIEC. E. coli strains from IBD patients showed high levels of adhesion, invasion, and survival. AIEC strains were identified in both CD and UC patients at a similar rate. AIEC may be associated with sustaining inflammation in the pre-existing inflammatory mucosa.

Jeong JY, et al. J Korean Med Sci. 2018 Oct;33(50):e299. https://doi.org/10.3346/jkms.2018.33.e299

Background/Aims: Infliximab (IFX) has proven effective as rescue therapy in steroid-refractory acute severe ulcerative colitis (ASUC), however, the long-term real-world data are scarce. Our study aimed to assess the long-term treatment outcomes of IFX in a real-life cohort.Methods: We established a multicenter retrospective cohort of hospitalized patients with ASUC, who met Truelove and Witt’s criteria and received intravenous corticosteroid (IVCS) or IFX during index hospitalization between 2006 and 2016 in 5 university hospitals in Korea. The cohort was systematically followed up until colectomy, death or last follow-up visit.Results: A total of 296 patients were followed up for a mean of 68.9 ± 44.0 months. During index hospitalization, 49 patients were treated with IFX; as rescue therapy for IVCS failure in 37 and as first-line medical therapy for ASUC in 12. All patients treated with IFX avoided colectomy during index hospitalization. The cumulative rates of rehospitalization and colectomy were 20.4% and 6.1% at 3 months and 39.6% and 18.8% at the end of follow-up, respectively. Patients treated with IFX presented with significantly shorter colectomy-free survival than IVCS responders (P= 0.04, log-rank test). Both cytomegalovirus colitis and Clostridioides difficile infection (CDI) were the significant predictors of colectomy in the overall study cohort (hazard ratios of 6.57 and 4.61, respectively). There were no fatalities.Conclusions: Our real-world cohort study demonstrated that IFX is an effective therapeutic option in Korean patients with ASUC, irrespective of IFX indication. Aggressive vigilance for cytomegalovirus colitis and CDI is warranted for hospitalized patients with ASUC.

It has been suggested that manipulation of gut microbiota using antibiotics can inhibit colitis-associated colorectal cancer (CAC) in a mouse model. We investigated whether timing of gut microbial manipulation using antibiotics affects colon tumorigenesis in the azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CAC model. CAC was induced in C57BL/6 mice by injection of 12.5 mg/kg AOM followed by three rounds of 1.7% DSS exposure. There were six groups based on timing of antibiotic administration. Colonic inflammation, proliferation, and tumorigenesis were evaluated after animal sacrifice. High-throughput sequencing of the mice feces was performed to characterize changes in gut microbiota. Full-time antibiotic treatment significantly decreased the number and size of tumors, histological scores, and expression of pro-inflammatory cytokines compared to the AOM/DSS group without antibiotic treatment. The early and late antibiotic groups, antibiotic administration from the first and second rounds of DSS to the end of the study, showed significantly lower histological scores and tumor burden. In contrast, the pretreatment antibiotic group, antibiotic administration from 3 weeks prior to AOM to the first round of DSS, did not exhibit decreased tumorigenesis. Principal coordinate analysis showed similar gut microbial community structures among the full-time, early, and late antibiotic groups, whereas other groups showed distinct gut microbial profiles. There was a positive correlation between number of tumors and number of operational taxonomic units. Colonic tumorigenesis was attenuated by antibiotic administration, except for that only prior to DSS administration, suggesting that gut microbial changes should be maintained throughout the entire period of inflammation to suppress tumorigenesis.

It is unclear whether continuous infusion or intermittent bolus injection of propofol is better for achieving adequate sedation in endoscopic retrograde cholangiopancreatography (ERCP). We aimed to compare the efficacy and safety of continuous infusion and intermittent bolus injection of propofol during therapeutic ERCP. In this prospective study, we randomly assigned 232 patients undergoing therapeutic ERCP to either continuous infusion (CI group, n = 113) or intermittent bolus injection (BI group, n = 119) of propofol. The primary outcome was the quality of sedation as assessed by the endoscopist. Other sedation-related parameters included sedation induction time, total dose of propofol, recovery time, involuntary patient movement, and adverse events. Overall satisfaction with sedation by the endoscopist and monitoring nurse were significantly higher in the CI group than the BI group (mean satisfaction score, 9.66 vs. 8.0 and 9.47 vs. 7.96, respectively, p < 0.01 for both). However, patients in the CI group had a significantly longer sedation induction time (5.28 minutes vs. 4.34 minutes, p < 0.01) and received a higher dose of propofol than patients in the BI group (4.22 mg/kg vs. 2.08 mg/kg, p < 0.01). There was no significant difference in adverse events between the two groups. Continuous infusion of propofol during therapeutic ERCP had the advantage over intermittent bolus injection of maintaining a constant level of sedation without increasing adverse events. However, it was associated with an increased total dose of propofol and prolonged sedation induction time.

Double-balloon enteroscopy (DBE) has become one of the standard methods in the diagnosis and treatment of small bowel (SB) disease. However, previous studies for DBE have limitations due to heterogeneity of indications and operators. The aim was to investigate the indication, location of the lesion, diagnostic yield, and therapeutic yield of DBE based on long-term data from a single operator. A retrospective study was performed by reviewing medical records of subjects who had received DBE at our unit in the past 17 years. Overall diagnostic yield was 78.7% (210/267). The diagnostic yield for obscure gastrointestinal bleeding (OGIB) was 68.3% (84/123). The diagnostic yield for OGIB was significantly lower (p < 0.001) than that for other indications. Therapeutic yield was 24.7% (66/267). Complications occurred in 7 (2.6%). Crohn’s disease, intestinal tuberculosis, nonsteroidal anti-inflammatory drug enteropathy, and diverticular lesions were mainly found in the ileum. Vascular lesions, non-specific inflammation, and neoplastic lesions were found more frequently in the jejunum. DBE is an excellent and safe endoscopic method for the diagnosis and treatment of SB lesions. DBE has a lower diagnostic rate for OGIB than for other indications. The location where a lesion is commonly found depends on the type of the lesion.