Nicotine in the button mushroom Agaricus bisporus, endogenous biosynthesis?

In early 2009 nicotine was unexpectedly detected in dried mushroom samples. As its origin has not yet been elucidated, this study addressed possible endogenous synthesis of nicotine. Therefore, Agaricus bisporus fruiting bodies were grown in a representative and controlled (nicotine-free) setup. Fruiting bodies (fresh versus stored, intact versus processed (sliced/cooked)) from different harvest days and flushes were analysed with a validated, sensitive dilute-and-shoot UHPLC-MS/MS methodology for nicotine and its precursors putrescine and nicotinic acid. Neither storage nor processing initiated any endogenous nicotine biosynthesis (detection limit 1.6 ng g-1 fresh weight). In contrast, putrescine and nicotinic acid were detected in all samples, with increasing amounts in the different treatments. In silico analysis of the fully sequenced genome of A. bisporus confirmed its inability to produce nicotine. The data obtained do not provide evidence for natural, endogenous presence of nicotine in mushrooms, indicating an exogenous contamination source (e.g. contamination during hand-picking, sample preparation/analysis).

Consensus on the guidelines for the dietary management of classical galactosemia.

BACKGROUND AND AIM: Worldwide there is scientific discussion about the dietary management of galactosemia. The dietary management is very different in several countries among Europe, the US and Canada. The main points of discussion are related to the fact that i) despite a strict diet some patients still have poor outcomes; ii) there is lack of scientific knowledge about the role of endogenous production of galactose on disease evolution, with or without diet. The aim of the current work was the creation of a Belgian consensus on dietary guidelines for the management of galactosemia. METHODS: A step-wise approach was used to achieve a consensus, including: a workshop, a Delphi round, discussion groups and a round table of different Belgian experts. RESULTS: The consensus is an agreement between strict guidelines (strict limitation of fruits, vegetables and soybean products/French guidelines) and the more liberal guidelines (comparable with a diet free of lactose/guidelines of UK and the Netherlands). The consensus document consists of different modules, including the medical context, the theoretical background of dietary guidelines and the age-specific practical dietary guidelines. CONCLUSION: A Belgian consensus on the guidelines for the dietary management of classical galactosemia was developed despite the uncertainties of the efficacy and practical application of these guidelines. The final consensus is based on scientific knowledge and practical agreement among experts. In the future, regular revision of the guidelines is recommended and a uniform European guideline is desirable.

The taxonomic status of Trichophyton quinckeanum and T. interdigitale revisited: a multigene phylogenetic approach.

Trichophyton quinckeanum, known as the causative agent of mouse favus, has been a subject of controversy since its discovery, 125 years ago. The purpose of this study was to examine the phylogenetic relationships between this fungus and related taxa. To achieve this objective, the ITS rDNA region, as well as actin and ß-tubulin gene regions of various isolates were sequenced. Bayesian inference and maximum likelihood analyses were conducted with T. rubrum as outgroup. Our study showed that strains identified as T. quinckeanum and others identified as T. schoenleinii are part of the complex T. mentagrophytes, and that their genotype cannot be confused with any other dermatophytes. Furthermore, this study demonstrates that the choice of the neotype of T. mentagrophytes was inappropriate. The beta-tubulin topology also revealed that isolates of T. interdigitale form a genetically distinct population from the type strains of Arthroderma vanbreuseghemii. Therefore, contrary to what is generally accepted, the anthropophilic species T. interdigitale cannot be considered as the anamorph associated with the latter.

Phylogeny of the Linnaea clade: are Abelia and Zabelia closely related?

Phylogenetic investigations based on molecular and morphological data have improved our understanding of Dipsacales phylogeny dramatically over the past 20 years. The Linnaea clade, however, has mostly been neglected and Zabelia has rarely been included in previous studies. We present the results of a molecular investigation including nine Abelia and five Zabelia species based on nuclear (ITS) and plastid (trnK, matK, atpB-rbcL, trnL-F) sequence data using maximum parsimony, Bayesian inference, and maximum likelihood. Our results indicate that Abelia is paraphyletic and possibly polyphyletic. The genus falls apart into a Mexican clade, corresponding to Abelia section Vesalea, and an Asian clade (excluding A. spathulata), corresponding to Abelia section Abelia. A close relationship between Zabelia and other members of the traditional Linnaea clade is not recovered by our analyses. Instead, Zabelia is associated with either the Morina or the Valeriana clade. Support for a monophyletic Linnaea clade without Zabelia is strong.