Loop ileostomy is an effective procedure to protect downstream intestinal anastomoses. Ileostomy reversal surgery is often performed within 12 months of formation but is associated with substantial morbidity due to severe post-surgical complications. Distal ileum is deprived of enteral nutrition and rendered inactive, often becoming atrophied and fibrotic. This study aimed to investigate the microbial and morphological changes that occur in the defunctioned ileum following loop ileostomy-mediated fecal stream diversion. Functional and defunctioned ileal resection tissue was obtained at the time of loop-ileostomy closure. Intrapatient comparisons, including histological assessment of morphology and epithelial cell proliferation, were performed on paired samples using the functional limb as control. Mucosal-associated microflora was quantified via determination of 16S rRNA gene copy number using qPCR analysis. DGGE with Sanger sequencing and qPCR methods profiled microflora to genus and phylum level, respectively. Reduced villous height and proliferation confirmed atrophy of the defunctioned ileum. DGGE analysis revealed that the microflora within defunctioned ileum is less diverse and convergence between defunctioned microbiota profiles was observed. Candidate Genera, notably Clostridia and Streptococcus, reduced in relative terms in defunctioned ileum. We conclude that Ileostomy-associated nutrient deprivation results in dysbiosis and impaired intestinal renewal in the defunctioned ileum. Altered host-microbial interactions at the mucosal surface likely contribute to the deterioration in homeostasis and thus may underpin numerous postoperative complications. Strategies to sustain the microflora before reanastomosis should be investigated.

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Typhoid vaccines based on protein-conjugated capsular Vi polysaccharide (TCVs) prevent typhoid in infants and young children. Analysis of the serum anti-Vi IgG response following immunisation against typhoid confirms the immunogenicity of TCVs and forms an important part of the pathway to licensing. Comparative studies could expedite the licencing process, and the availability of a standardised ELISA method alongside the 1st International Standard (IS) 16/138 for anti-typhoid capsular Vi polysaccharide IgG (human) will facilitate this process. To this end, a non-commercial ELISA based on a coat of Vi and poly- l -lysine (Vi-PLL ELISA) was evaluated by 10 laboratories. Eight serum samples, including IS 16/138, were tested in the standardised Vi-PLL ELISA ( n = 10), a commercial Vi ELISA ( n = 3) and a biotinylated Vi ELISA ( n = 1). Valid estimates of potencies relative to IS 16/138 were obtained for all samples in the Vi-PLL ELISA and the commercial ELISA, with good repeatability and reproducibility evident from the study results and concordant estimates obtained by the two ELISA methods. The study demonstrates that the Vi-PLL ELISA can be used in clinical trial studies to determine the immunogenicity of TCVs.

Dupuytren's disease is a common fibroproliferative disease of the palmar fascia of the hand with severe cases treated surgically. The rate of disease recurrence following treatment is high and a continual production of matrisomal proteins could lead to disease recurrence. There is no animal model for Dupuytren's disease, but analysis of the surgically excised tissue provides an accessible means to study the mechanisms of human tissue fibrosis. Here we sought to determine how new synthesis and the composition of matrisomal proteins in Dupuytren's differs from normal palmar fascia samples, using metabolic labelling approaches and proteomics. Model non-fibrotic, but fibrous connective tissues, equine flexor tendon and canine cranial cruciate ligament, were used to analyse active collagen-1 protein synthesis in development, ageing and degenerative disease, where it was restricted to early development and ruptured tissue. Dupuytren's tissue was shown to actively synthesise type I collagen, a proportion of which comprised abnormal collagen (I) homotrimer (mean 14.3% ± 14.4), as well as fibronectin, matrix metalloproteinases (MMP2, MMP3) and their inhibitors; Tissue Inhibitor of Metalloproteinases 2 (TIMP2). Insulin-Like Growth Factor Binding Protein 7 (IGFBP7) was actively synthesised by Dupuytren's as well as control tissue. Label-free analysis implicated the TGFβ pathway in the matrisomal profile of Dupuytren's tissue whilst myocilin, a Wnt-pathway regulator, was noticeably more abundant in control samples. No collagen (I) neopeptides representing the major collagenase cleavage site were identified, however periostin neopeptides were abundant in Dupuytren's tissue and gelatin neopeptides in both tissue types. Synthesis of MMP-resistant collagen-1 homotrimer, together with altered β and Wnt signalling environments, could contribute to the persistence of the fibrotic tissue and disease recurrence following treatment.

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