Ultrastructure of Diplodia maydis grown on selected synthetic media

Abnormal form of Aspergillus terreus isolated from mycotic abscesses

A remarkable outer cell-wall thickening (up to 1.5 muM) was observed on septate hyphae obtained from pus collected from multiple abscesses of a 25-year-old female patient. Ultrastructural examination of the hyphae showed a thick electron dense layer of microfibrillar material surrounding the electron transparent cell wall. The organism was able to grow only on hypertonic media upon initial isolation but on later subculture it grew on normal isotonic media. The thick microfibrillar material diminished progressively upon subculture but could be demonstrated in 7 day secondary cultures in isotonic liquid medium. There, microfibrillar bridges appeared to bind hyphae together. The observations suggested that this microfibrillar material was a true extracellular component. The immunological status of the patient was not examined, but her 10 year history of multiple mycotic abscesses and dermatophytoses suggested some abnormalities.