Outcomes of Fecal Microbiota Transplantation for Clostridium difficile Infection in Patients with Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Fecal microbiota transplantation (FMT) has recently been shown to be a promising therapy for recurrent and refractory Clostridium difficile infections (CDI) despite lack of protocol standardization. Patients with inflammatory bowel disease (IBD) present a particular challenge to CDI therapy as they are reported to have worse clinical outcomes, including higher colectomy rates and increased mortality. We aimed to assess the outcomes of FMT for recurrent CDI in patients with IBD at our healthcare system. METHODS: We constructed a retrospective cohort of all patients who underwent FMT at our healthcare system between December 2012 and May 2014. Patients with concurrent IBD were identified. We evaluated the differences in demographic and clinical characteristics, along with the outcomes to FMT between patients with IBD as compared to the general population. RESULTS: Over the study period, 201 patients underwent FMT of which 20 patients had concurrent IBD. Patients with IBD were younger but did not differ from the general population in terms of CDI risk factors or disease severity. The response to FMT and rate of CDI relapse in the IBD group were not statistically different compared to the rest of the cohort. The overall response rate in the IBD population was 75% at 12 weeks. Of the patients who failed FMT 4 of 5 patients had active or untreated IBD. CONCLUSION: Fecal microbiota transplantation provides a good alternative treatment option with high success rates for recurrent or refractory Clostridium difficile infection in patients with well-controlled IBD who fail standard antimicrobial therapy.

Unexpected coregulator range for the global regulator Lrp of Escherichia coli and Proteus mirabilis.

The Lrp/AsnC family of transcription factors links gene regulation to metabolism in bacteria and archaea. Members of this family, collectively, respond to a wide range of amino acids as coregulators. In Escherichia coli, Lrp regulates over 200 genes directly and is well known to respond to leucine and, to a somewhat lesser extent, alanine. We focused on Lrp from Proteus mirabilis and E. coli, orthologs with 98% identity overall and identical helix-turn-helix motifs, for which a previous study nevertheless found functional differences. Sequence differences between these orthologs, within and adjacent to the amino acid-responsive RAM domain, led us to test for differential sensitivity to coregulatory amino acids. In the course of this investigation, we found, via in vivo reporter fusion assays and in vitro electrophoretic mobility shift experiments, that E. coli Lrp itself responded to a broader range of amino acids than was previously appreciated. In particular, for both the E. coli and P. mirabilis orthologs, Lrp responsiveness to methionine was similar in magnitude to that to leucine. Both Lrp orthologs are also fairly sensitive to Ile, His, and Thr. These observations suggest that Lrp ties gene expression in the Enterobacteriaceae rather extensively to physiological status, as reflected in amino acid pools. These findings also have substantial implications for attempts to model regulatory architecture from transcriptome measurements or to infer such architecture from genome sequences, and they suggest that even well-studied regulators deserve ongoing exploration.

Recognition of DNA by the helix-turn-helix global regulatory protein Lrp is modulated by the amino terminus.

The AsnC/Lrp family of regulatory proteins links bacterial and archaeal transcription patterns to metabolism. In Escherichia coli, Lrp regulates approximately 400 genes, over 200 of them directly. In earlier studies, lrp genes from Vibrio cholerae, Proteus mirabilis, and E. coli were introduced into the same E. coli background and yielded overlapping but significantly different regulons. These differences were seen despite amino acid sequence identities of 92% (Vibrio) and 98% (Proteus) to E. coli Lrp, including complete conservation of the helix-turn-helix motifs. The N-terminal region contains many of the sequence differences among these Lrp orthologs, which led us to investigate its role in Lrp function. Through the generation of hybrid proteins, we found that the N-terminal diversity is responsible for some of the differences between orthologs in terms of DNA binding (as revealed by mobility shift assays) and multimerization (as revealed by gel filtration, dynamic light scattering, and analytical ultracentrifugation). These observations indicate that the N-terminal tail plays a significant role in modulating Lrp function, similar to what is seen for a number of other regulatory proteins.

Predictors of fecal transplant failure.

BACKGROUND: Clostridium difficile infection (CDI) is a significant healthcare burden, with increased morbidity and mortality. Traditional treatment regimens using antibiotics for recurrent CDI are significantly less successful compared with 80-90% with fecal microbiota transplantation (FMT). There is a paucity of data on failure rates and mortality after FMT in CDI. This study aims to identify the rates of failure, relapse, and mortality associated with FMT as well as the risk factors for FMT failure. METHODS: A large retrospective cohort study was carried out including all patients who underwent FMT from December 2012 through May 2014. Patient factors (demographics, comorbidities, immune-suppression, transplant history, antibiotics used, hospitalization, and surgeries), disease factors (number of episodes of CDI, treatments, and severity), and transplant factors (route and number of FMT) were examined. Failure of treatment was defined as no resolution of diarrhea in patients who had been treated with one or more fecal microbiota transplantation within 90 days of FMT. RESULTS: A total of 201 patients (age 66.6±18.3 years, 62.2% women) were included. The overall failure rate was 12.4%. Patients with failed fecal transplant had increased number of FMTs compared with those who responded (mean 1.92±0.997 vs. 1.29±0.615; P=0.004). No colectomies or death related to CDI were found in our patient population. Significant predictors of failure were female sex (P=0.016), previous hospitalization (P=0.006), and surgery before FMT (P=0.005). The overall mortality rate was 9.0% and failure of FMT was associated with an increased risk of death (odds ratio=5.833, confidence interval 2.01-16.925; P<0.05). CONCLUSION: FMT is a suitable alterative to antibiotic use for recurrent CDIs, with a high success rate. The results indicate that hospital-acquired CDI may be a predictor of failure of FMT.