This study encourages further investigation of natural products for treatment of CDI.

The physicochemical parameters and antibacterial activity of 10 Western Australian (WA) and two comparator honeys were determined. Honeys showed a pH range of 4.0-4.7, colour range of 41.3-470.7 mAU, methylglyoxal levels ranging from 82.2 to 325.9 mg kg and hydrogen peroxide levels after 2 h of 22.7-295.5 µM. Antibacterial activity was assessed by the disc diffusion assay, phenol equivalence assay, determination of minimum inhibitory and bactericidal concentrations and a time-kill assay. Activity was shown for all honeys by one or more method, however, activity varied according to which assay was used. Minimum inhibitory concentrations for WA honeys against 10 organisms ranged from 4.0 to >32.0% (w/v). Removal of hydrogen peroxide activity by catalase resulted in decreased activity for several honeys. Overall, the data showed that honeys in addition to those derived from Leptospermum spp. have antimicrobial activity and should not be overlooked as potential sources of clinically useful honey.

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Clostridium difficile infection is a toxin-mediated disease of the colon. C. difficile virulence is primarily attributed to the production of toxin A and toxin B; thus this study was aimed to investigate the effect of a range of natural products on the production and activity of C. difficile toxins in vitro. Twenty-two natural products were investigated against four C. difficile strains. The activity of products against toxins was determined using Vero and HT-29 cells cytotoxicity and neutral red uptake assays. The indirect effect of products on toxin-mediated cytotoxicity was determined using the same cell lines. The effect of seven products on toxin production by C. difficile was determined using ELISA. Zingerone (0.3 mg/ml) protected both cell lines from C. difficile cytopathic effects, confirmed by the neutral red uptake assay (P < 0.05). Three Leptospermum honeys (4% w/v), fresh onion bulb extract (12.5% v/v) and trans-cinnamaldehyde (0.005% v/v) all reduced toxin production and activity significantly (P ≤ 0.023). Garlic clove powder (4.7 mg/ml) only reduced toxin activity (P ≤ 0.047). Overall, several natural products had activity against C. difficile toxins in vitro encouraging further investigation against C. difficile toxins in vivo.

Introduction: Clostridium difficile (C. difficile) infection (CDI) is commonly recognised as a nosocomial infection but is increasingly identified in patients in the community. Antimicrobial exposure which compromises gut microbiota is the main risk factor for CDI, although antibiotics remain the main treatment for this infection. Faecal microbiota transplantation (FMT) is also an effective treatment for CDI. FMT involves the transfer of microbiota from a healthy donor to an unwell patient. Currently FMT is mostly used after repeated antibiotic treatments fail to cure CDI. This study investigated the effect of FMT as first-line treatment for CDI to avoid repeated antibiotic damage of the microbiome. Methods: This retrospective, single-centre study included 59 patients between 2012 and 2017 whose first episode of CDI was treated with FMT. The patients' symptoms and presence of C. difficile in stool samples both at the baseline and post treatment were documented. Results: Fifty-four patients completed a final stool test 4-8 weeks post treatment in which 98% of patients were negative for C. difficile. There were no adverse effects. There was a significant reduction in abdominal pain, diarrhoea, bloating and blood in the stool at 4-8 weeks post treatment. Data from 24 patients who completed an extended 6 months followup showed significant reduction in abdominal pain, diarrhoea and blood in the stool. Conclusion: This study demonstrates the safety and efficacy of FMT as first-line treatment for patients' initial episode of CDI. Future randomised studies are required to confirm FMT as the initial treatment for CDI.