Xanthoepocin, a photolabile antibiotic of Penicillium ochrochloron CBS 123823 with high activity against multiresistant gram-positive bacteria.

BACKGROUND: With the steady increase of antibiotic resistance, several strategies have been proposed in the scientific community to overcome the crisis. One of many successful strategies is the re-evaluation of known compounds, which have been early discarded out of the pipeline, with state-of-the-art know-how. Xanthoepocin, a polyketide widespread among the genus Penicillium with an interesting bioactivity spectrum against gram-positive bacteria, is such a discarded antibiotic. The purpose of this work was to (i) isolate larger quantities of this metabolite and chemically re-evaluate it with modern technology, (ii) to explore which factors lead to xanthoepocin biosynthesis in P. ochrochloron, and (iii) to test if it is beside its known activity against methicillin-resistant Staphylococcus aureus (MRSA), also active against linezolid and vancomycin-resistant Enterococcus faecium (LVRE)-a very problematic resistant bacterium which is currently on the rise. RESULTS: In this work, we developed several new protocols to isolate, extract, and quantify xanthoepocin out of bioreactor batch and petri dish-grown mycelium of P. ochrochloron. The (photo)chemical re-evaluation with state-of-the-art techniques revealed that xanthoepocin is a photolabile molecule, which produces singlet oxygen under blue light irradiation. The intracellular xanthoepocin content, which was highest under ammonium-limited conditions, varied considerably with the applied irradiation conditions in petri dish and bioreactor batch cultures. Using light-protecting measures, we achieved MIC values against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), which were up to 5 times lower than previously published. In addition, xanthoepocin was highly active against a clinical isolate of linezolid and vancomycin-resistant Enterococcus faecium (LVRE). CONCLUSIONS: This interdisciplinary work underlines that the re-evaluation of known compounds with state-of-the-art techniques is an important strategy in the combat against multiresistant bacteria and that light is a crucial factor on many levels that needs to receive more attention. With appropriate light protecting measures in the susceptibility tests, xanthoepocin proved to be a powerful antibiotic against MRSA and LVRE. Exploring the light response of other polyketides may be pivotal for re-introducing previously discarded metabolites into the antibiotic pipeline and to identify photosensitizers which might be used for (antimicrobial) photodynamic therapies.

The Effectiveness of Patient Training in Inflammatory Bowel Disease Knowledge via Instagram: Randomized Controlled Trial.

BACKGROUND: Patients' knowledge was found to be a key contributor to the success of therapy. Many efforts have been made to educate patients in their disease. However, research found that many patients still lack knowledge regarding their disease. Integrating patient education into social media platforms can bring materials closer to recipients. OBJECTIVE: The aim of this study is to test the effectiveness of patient education via Instagram. METHODS: A randomized controlled trial was conducted to test the effectiveness of patient education via Instagram among patients with inflammatory bowel disease. Participants were recruited online from the open Instagram page of a patient organization. The intervention group was educated via Instagram for 5 weeks by the research team; the control group did not receive any educational intervention. The knowledge about their disease was measured pre- and postintervention using the Inflammatory Bowel Disease Knowledge questionnaire. Data were analyzed by comparing mean knowledge scores and by regression analysis. The trial was purely web based. RESULTS: In total, 49 participants filled out both questionnaires. The intervention group included 25 participants, and the control group included 24 participants. The preintervention knowledge level of the intervention group was reflected as a score of 18.67 out of 24 points; this improved by 3 points to 21.67 postintervention. The postintervention difference between the control and intervention groups was 3.59 points and was statistically significant (t32.88=-4.56, 95% CI 1.98-5.19; P<.001). Results of the regression analysis, accounting for preintervention knowledge and group heterogeneity, indicated an increase of 3.33 points that was explained by the intervention (P<.001). CONCLUSIONS: Patient education via Instagram is an effective way to increase disease-related knowledge. Future studies are needed to assess the effects in other conditions and to compare different means of patient education. TRIAL REGISTRATION: German Clinical Trials Register DRKS00022935; https://tinyurl.com/bed4bzvh.