Mycotoxin Research

, Volume 35, Issue 1, pp 9–16 | Cite as

Putative neuromycotoxicoses in an adult male following ingestion of moldy walnuts

  • C. J. BothaEmail author
  • C. M. Visagie
  • M. Sulyok
Original Article


A tremorgenic syndrome occurs in dogs following ingestion of moldy walnuts, and Penicillium crustosum has been implicated as the offending fungus. This is the first report of suspected moldy walnut toxicosis in man. An adult male ingested approximately eight fungal-infected walnut kernels and after 12 h experienced tremors, generalized pain, incoordination, confusion, anxiety, and diaphoresis. Following symptomatic and supportive treatment at a local hospital, the man made an uneventful recovery. A batch of walnuts (approximately 20) was submitted for mycological culturing and identification as well as for mycotoxin analysis. Penicillium crustosum Thom was the most abundant fungus present on walnut samples, often occurring as monocultures on isolation plates. Identifications were confirmed with DNA sequences. The kernels and shells of the moldy walnuts as well as P. crustosum isolates plated on yeast extract sucrose (YES) and Czapek yeast autolysate (CYA) agars and incubated in the dark at 25 °C for 7 days were screened for tremorgenic mycotoxins and known P. crustosum metabolites using a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method. A relatively low penitrem A concentration of only 1.9 ng/g was detected on the walnut kernels when compared to roquefortine C concentrations of 21.7 μg/g. A similar result was obtained from P. crustosum isolates cultured on YES and CYA, with penitrem A concentrations much lower (0.6–6.4 μg per g mycelium/agar) compared to roquefortine C concentrations (172–1225 μg/g). The authors surmised that besides penitrem A, roquefortine C might also play an additive or synergistic role in intoxication of man.


Moldy walnuts Penicillium crustosum Penitrem Roquefortine Tremorgenic mycotoxins 



This work is based on research supported in part by the National Research Foundation of South Africa (grant number 103747). The authors would like to thank Dr. Leopold Podlashuc for bringing this case to our attention, and we would also like to express our gratitude to Danielle Henn who assisted with the drawing of the chemical structures.

Compliance with ethical standards

Conflict of interest



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Copyright information

© Society for Mycotoxin Research and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Paraclinical Sciences, Faculty of Veterinary ScienceUniversity of PretoriaOnderstepoortSouth Africa
  2. 2.Biosystematics DivisionAgricultural Research Council – Plant Health and ProtectionPretoriaSouth Africa
  3. 3.Centre for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln)University of Natural Resources and Life SciencesTullnAustria

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