Severe and prolonged hypophosphatemia after intravenous iron administration in a malnourished patient.

Malnutrition may result in a phosphate-deficient state owing to a chronically insufficient phosphate intake. Concomitant iron deficiency is common and often supplemented by the intravenous route. It is not widely recognized that some parenteral iron formulations can induce hypophosphatemia. Herein we report a case of a severe and symptomatic hypophosphatemia (0.18 mM, normal range 0.8-1.4 mM) associated with an inappropriately reduced tubular reabsorption of phosphate (33%, norm >95%) in a malnourished patient with anorexia/bulimia who received 2 × 500 mg iron carboxymaltose (FCM) intravenously. Despite intravenous and oral phosphate supplements, it required 2 months to achieve a normal serum phosphate level. Our case demonstrates that in a chronically malnourished and phosphate-deficient state intravenous FCM could potentially be dangerous. If this form of iron application cannot be avoided, phosphate supplementation before and after iron infusion as well as close monitoring of phosphate levels are needed.

De Novo Production of Metabolites by Fungal Co-culture of Trichophyton rubrum and Bionectria ochroleuca.

The co-cultivation of fungi has recently been described as a promising strategy to induce the production of novel metabolites through possible gene activation. A large screening of fungal co-cultures in solid media has identified an unusual long-distance growth inhibition between Trichophyton rubrum and Bionectria ochroleuca. To study metabolite induction in this particular fungal interaction, differential LC-MS-based metabolomics was performed on pure strain cultures and on their co-cultures. The comparison of the resulting fingerprints highlighted five de novo induced compounds, which were purified using software-oriented semipreparative HPLC-MS. One metabolite was successfully identified as 4″-hydroxysulfoxy-2,2″-dimethylthielavin P (a substituted trimer of 3,5-dimethylorsellinic acid). The nonsulfated form, as well as three other related compounds, were found in the pure strain culture of B. ochroleuca.

Detection of metabolite induction in fungal co-cultures on solid media by high-throughput differential ultra-high pressure liquid chromatography-time-of-flight mass spectrometry fingerprinting.

Access to new biological sources is a key element of natural product research. A particularly large number of biologically active molecules have been found to originate from microorganisms. Very recently, the use of fungal co-culture to activate the silent genes involved in metabolite biosynthesis was found to be a successful method for the induction of new compounds. However, the detection and identification of the induced metabolites in the confrontation zone where fungi interact remain very challenging. To tackle this issue, a high-throughput UHPLC-TOF-MS-based metabolomic approach has been developed for the screening of fungal co-cultures in solid media at the petri dish level. The metabolites that were overexpressed because of fungal interactions were highlighted by comparing the LC-MS data obtained from the co-cultures and their corresponding mono-cultures. This comparison was achieved by subjecting automatically generated peak lists to statistical treatments. This strategy has been applied to more than 600 co-culture experiments that mainly involved fungal strains from the Fusarium genera, although experiments were also completed with a selection of several other filamentous fungi. This strategy was found to provide satisfactory repeatability and was used to detect the biomarkers of fungal induction in a large panel of filamentous fungi. This study demonstrates that co-culture results in consistent induction of potentially new metabolites.