Clinical Spectrum of Exophiala Infections and a Novel Exophiala Species, Exophiala hongkongensis

Abstract

We characterized 12 Exophiala strains isolated from patients over a 15-year period to the species level using phenotypic tests and internal transcribed spacer (ITS) and Rpb1 sequencing and described the clinical spectrum of the 12 patients. Eight patients had nail or skin infections, two had invasive infections, and two had colonization of the gastrointestinal tract. ITS and Rpb1 sequencing showed that 11 of the 12 strains were known Exophiala species (E. oligosperma, and E. xenobiotica [n ‫؍‬ 1]), which included the first reported cases of onychomycosis caused by E. bergeri and E. oligosperma. The 12th strain (HKU32 T ), isolated from the nail clipping of the right big toe of a 68-year-old female patient with onychomycosis, possessed unique morphological characteristics distinct from other Exophiala species. It grew very slowly and had a velvety colony texture after 28 days, short conidiophores of the same olivaceous color as the supporting hyphae, numerous spores, and no chlamydospore-like cells. ITS, Rpb1, ␤-tubulin, and ␤-actin gene sequencing unambiguously showed that HKU32 T was clustered with but formed branches distinct from other Exophiala species in phylogenetic trees. We propose the new species Exophiala hongkongensis to describe this novel fungus.

New and interesting chaetothyrialean fungi from Spain

“…During our study, the known distribution of this species was expanded to Spain, but it has not been reported outside Europe. Exophiala oligosperma has a widespread, transoceanic geographical distribution and is associated with a broad clinical spectrum, which includes brain abscesses, disseminated infections, onychomycosis, rhinosinusitis, and other clinical manifestations Kan et al 2013;Woo et al 2013;Wen et al 2016). In Spain, a case of subcutaneous infection in a renal transplant recipient was published by González-López et al (2007).…”

A review of melanized (black) fungal contamination in pharmaceutical products-incidence, drug recall and control measures

“…; Woo et al . ). In addition, dried fungal morphotypes, including conidia and mycelia of various genera, may demonstrate prolonged temperature/survival tolerances up to and exceeding 100°C (Suryanarayanan et al .…”

Misidentification of Aspergillus nomius and Aspergillus tamarii as Aspergillus flavus: Characterization by Internal Transcribed Spacer, β-Tubulin, and Calmodulin Gene Sequencing, Metabolic Fingerprinting, and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

“…In the last decade, more widespread use of internal transcribed spacer 1 (ITS1)-5.8S-ITS2 rRNA gene cluster sequencing and sequencing of other conserved DNA regions has proved to be useful for identifying molds (8)(9)(10). In addition, it has led to the discovery of novel pathogenic fungal species (11,12). In the last decade, a number of case reports, with the help of ITS, ␤-tubulin, and calmodulin gene sequencing, have identified Aspergillus nomius and Aspergillus tamarii as causes of human infections (13)(14)(15)(16)(17)(18).…”