AEM article: trichothecenes on small particles 05

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AEM article: trichothecenes on small particles

http://aem.asm.org/cgi/content/abstract/71/1/114?etoc

Applied and Environmental Microbiology, January 2005, p. 114-122,

Vol. 71, No. 1

" Detection of Airborne Stachybotrys chartarum Macrocyclic

Trichothecene Mycotoxins on Particulates Smaller than Conidia "

T. L. Brasel, D. R. , S. C. , and D. C. Straus

Department of Microbiology and Immunology, Texas Tech University

Health Sciences Center, Lubbock, Texas

Received 22 March 2004/ Accepted 16 August 2004

Abstract: [broken into paragraphs to improve readability -wab]

Highly respirable particles (diameter, <1 µm) constitute the

majority of particulate matter found in indoor air. It is

hypothesized that these particles serve as carriers for toxic

compounds, specifically the compounds produced by molds in water-

damaged buildings.

The presence of airborne Stachybotrys chartarum trichothecene

mycotoxins on particles smaller than conidia (e.g., fungal

fragments) was therefore investigated. Cellulose ceiling tiles with

confluent Stachybotrys growth were placed in gas-drying containers

through which filtered air was passed. Exiting particulates were

collected by using a series of polycarbonate membrane filters with

decreasing pore sizes. Scanning electron microscopy was employed to

determine the presence of conidia on the filters.

A competitive enzyme-linked immunosorbent assay (ELISA) specific for

macrocyclic trichothecenes was used to analyze filter extracts.

Cross-reactivity to various mycotoxins was examined to confirm the

specificity. Statistically significant (P < 0.05) ELISA binding was

observed primarily for macrocyclic trichothecenes at concentrations

of 50 and 5 ng/ml and 500 pg/ml (58.4 to 83.5% inhibition).

Of the remaining toxins tested, only verrucarol and

diacetylverrucarol (nonmacrocyclic trichothecenes) demonstrated

significant binding (18.2 and 51.7% inhibition, respectively) and

then only at high concentrations.

The results showed that extracts from conidium-free filters

demonstrated statistically significant (P < 0.05) antibody binding

that increased with sampling time (38.4 to 71.9% inhibition,

representing a range of 0.5 to 4.0 ng/ml). High-performance liquid

chromatography analysis suggested the presence of satratoxin H in

conidium-free filter extracts.

These data show that S. chartarum trichothecene mycotoxins can

become airborne in association with intact conidia or smaller

particles. These findings may have important implications for indoor

air quality assessment.