|
Abundant respirable ergot alkaloids from the common airborne
fungus aspergillus fumigatus
(Appl Environ Microbiol. 2005 June; 71(6): 3106–3111)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ergot alkaloids are mycotoxins that interact with several
monoamine receptors, negatively affecting cardiovascular,
nervous, reproductive, and immune systems of exposed humans
and animals. Aspergillus fumigatus, a common airborne
fungus and opportunistic human pathogen, can produce ergot
alkaloids in broth culture. The objectives of this study
were to determine if A. fumigatus accumulates ergot
alkaloids in a respirable form in or on its conidia, to
quantify ergot alkaloids associated with conidia produced on
several different substrates, and to measure relevant
physical properties of the conidia. We found at least four
ergot alkaloids, fumigaclavine C, festuclavine,
fumigaclavine A, and fumigaclavine B (in order of
abundance), associated with conidia of A. fumigatus.
Under environmentally relevant conditions, the total mass of
ergot alkaloids often constituted >1% of the mass of the
conidium. Ergot alkaloids were extracted from conidia
produced on all media tested, and the greatest quantities
were observed when the fungus was cultured on latex paint or
cultured maize seedlings. The values for physical properties
of conidia likely to affect their respirability (i.e.,
diameter, mass, and specific gravity) were significantly
lower for A. fumigatus than for Aspergillus
nidulans, Aspergillus niger, and Stachybotrys
chartarum.
The demonstration of relatively high concentrations of ergot alkaloids associated with conidia of A. fumigatus presents opportunities for investigations of potential contributions of the toxins to adverse health effects associated with the fungus and to aspects of the biology of the fungus that contribute to its success. |