Using roquefortine C as a biomarker for penitrem A intoxication

Penitrem A is a well-recognized tremorgenic mycotoxin produced by several Penicillium spp. However, most natural cases of penitrem A intoxication have been associated with Penicillium crustosum. Another Penicillium sp., Penicillium roqueforti, is used for the production of blue cheese and is found in silage and feeds. Penicillium roqueforti produces a mycotoxin, roquefortine C, which is also produced by P. crustosum. In contrast to a tremorgenic syndrome produced by penitrem A, roquefortine C toxicosis is characterized by a paralytic syndrome. Two cases of penitrem A intoxication in dogs are presented to investigate the use of roquefortine C as a biomarker for penitrem A exposure. The vomitus, serum, and urine were analyzed for roquefortine C and penitrem A. Results suggest that roquefortine C can be a sensitive biomarker for penitrem A intoxication. However, the detection of roquefortine C in the absence of penitrem A could merely suggest ingestion of blue cheese or spoilt silage or feed. A review of the literature did not identify any case positive for penitrem A but negative for roquefortine C. In cases in which both mycotoxins were detected, roquefortine C concentration was always higher than penitrem A concentration. In contrast, several cases have been described where the clinical history suggested penitrem A intoxication, but only roquefortine C was detected. In conclusion, roquefortine C can serve as a sensitive biomarker for penitrem A intoxication, but the clinical presentation needs to be considered for proper interpretation of its detection in the absence of penitrem A.