Postmortem isolation of Pseudotaeniolina globosa from a patient with aortic aneurysm

A New Extremotolerant Ecotype of the Fungus Pseudotaeniolina globosa Isolated from Djoser Pyramid, Memphis Necropolis, Egypt

Most of the rock-inhabiting fungi are meristematic and melanized microorganisms often associated with monument biodeterioration. In previous microbial profiling of the Egyptian Djoser pyramid, a Pseudotaeniolina globosa isolate was found. The current study aimed to characterize the P. globosa isolated from the Djoser pyramid compared with an Italian isolate at morphological, physiological, and molecular levels. Experiments were carried out to test temperature, salinity, and pH preferences, as well as stress tolerance to UV radiation and high temperature, in addition to a multi-locus genotyping using ITS, nrSSU or 18S, nrLSU or 28S, BT2, and RPB2 markers. Morphological and molecular data confirmed the con-specificity of the two isolates. However, the Egyptian isolate showed a wider range of growth at different environmental conditions being much more tolerant to a wider range of temperature (4–37 °C) and pH values (3.0–9.0 pH) than the Italian (10–30 °C, 4.0–6.0 pH), and more tolerant to extreme salinity levels (5 M NaCl), compared to the lowest in the Italian isolate (0.2 M NaCl). Besides, the Egyptian isolate was more tolerant to high temperature than the Italian isolate since it was able to survive after exposure to up to 85 °C for 5 min, and was not affected for up to 9 h of UV exposure, while the Italian one could not regrow after the same treatments. The Pseudotaeniolina globosa species was attributed to the family Teratosphaeriaceae of the order Capnodiales, class Dothideomycetes. Our results demonstrated that the Egyptian isolate could be considered an ecotype well adapted to harsh and extreme environments. Its potential bio-deteriorating effect on such an important cultural heritage requires special attention to design and conservation plans and solutions to limit its presence and extension in the studied pyramid and surrounding archaeological sites.

Drought meets acid: three new genera in a dothidealean clade of extremotolerant fungi

Fungal strains isolated from rocks and lichens collected in the Antarctic ice-free area of the Victoria Land, one of the coldest and driest habitats on earth, were found in two phylogenetically isolated positions within the subclass Dothideomycetidae. They are here reported as new genera and species, Recurvomyces mirabilisgen. nov., sp. nov. and Elasticomyces elasticusgen. nov., sp. nov. The nearest neighbours within the clades were other rock-inhabiting fungi from dry environments, either cold or hot. Plant-associated Mycosphaerella-like species, known as invaders of leathery leaves in semi-arid climates, are also phylogenetically related with the new taxa. The clusters are also related to the halophilic species Hortaea werneckii, as well as to acidophilic fungi. One of the latter, able to grow at pH 0, is Scytalidium acidophilum, which is ascribed here to the newly validated genus Acidomyces. The ecological implications of this finding are discussed.

Identification of Candida fabianii as a cause of lethal septicaemia

Infections caused by rare fungal species of low pathogenic potential become increasingly common in hospital settings. The identification of these species presents a major challenge for the clinical mycology laboratory. We describe a case of fatal septicaemia caused by Candida fabianii. The use of common biochemical approaches led to misidentification of the isolate as Candida utilis. Sequencing of the internal transcribed spacer regions (ITS1 and ITS2) allowed unequivocal species identification.