Tracheal Organ Cultures for the Bioassay of Nanogram Quantities of Mycotoxins

Abstract Tracheal organ cultures from day-old chicks can be used in a bioassay to detect nanogram quantities of several mycotoxins implicated in animal diseases. Mycotoxins assayed with the minimum amount detectable (ng) are as follows: anatoxins B1 (22), B2 (1367), and G1 (89); patulin (750); sporidesmin (139); sporidesmin B (163); sterigmatocystin (12); gliotoxin (85); and ochratoxin A (175). By using miniature tissue culture chambers the volume of toxin containing media bathing the explants is reduced to 0.1 ml. The test depends on a cytotoxic effect of the toxins and the 50% lethal concentration (LC50) is considered to be the minimum detectable concentration. Cytotoxic potencies of several mycotoxins vary in a manner similar to their toxicities to the intact animalas indicated by a comparison of the cytotoxic LC50 determined by bioassay to an LD50 for ducklings.</jats:p

Use of Tracheal Organ Cultures for Bioassay of Aflatoxins

Abstract Tracheal organ cultures from day-old chicks were used for the assay of aflatoxins. Ciliary epithelium in the organ culture was found to be highly sensitive to aflatoxins B1 and G1. Anatoxin B1, incorporated into the medium in which the organ cultures were established, readily caused distinguishable eytomorphological changes in 48 hr at a concentration of 0.2 μg/ml and complete cessation of ciliary movement at a concentration of 0.5 μg/ml. Anatoxin G1 produced the same effects, but at higher concentrations (0.5 μg/ml and 2.0–2.5μg/ml). The degree of cytomorphological changes of the ciliary epithelium in the organ cultures was proportional to the concentration of aflatoxins and the period of time exposed. A dose-response curve was developed for the period of observation. The technique is simple, reproducible, and inexpensive. The feasibility of developing this test system as a biological assay for the presence of aflatoxins and other mycotoxins in feeds and foodstuffs is being explored.</jats:p