Identification of poisonous mushrooms is an important piece of information in the management of patients with suspected mushroom poisoning. Morphological and microscopic examination of fungi can only be performed by expert mycologists with many years of training.
The use of DNA sequencing in fungal identification can be particularly useful when we are faced with cooked, mixed or even partially digested mushrooms in gastric aspirate - situations where morphological or microscopic identification can be difficult or impossible. We have established a method of fungal identification based on nuclear ribosomal internal transcribed spacer sequencing.
We validated the technique with both patient samples (43 samples from 25 patient cases) and local samples (50 samples) by comparing the identification result with biochemical analysis of fungal toxin and morphological identification by a local expert mycologist. The technique was able to provide additional information in 76% of clinical cases and 80% of survey specimens and was in complete agreement with biochemical analysis of locally-important fungal toxins viz. alpha, beta and gamma amatoxin, phallodin, phallacidin, psilocin, and muscarine.
The present study demonstrated that this molecular technique for fungal identification is inexpensive, accurate and clinically useful in the diagnosis and management of suspected fungal poisoning.
