Polyphasic identification of three new species in Alternaria section Infectoriae causing human cutaneous infection

Abstract

Summary Background Cutaneous phaeohyphomycosis is an emerging disease in immunocompromised patients, being Alternaria one of the most common genera reported as a causative agent. Species identification is not carried out mainly due to the complexity of the genus. Analysis of the ITS barcode has become standard for fungal identification, but in Alternaria it is only able to discriminate among species‐groups or sections. Methods We present three cases of cutaneous infection caused by Alternaria isolates morphologically identified as belonging to section Infectoriae. They have been morphologically characterised and phylogenetically delineated with five molecular markers (ITS, ATPase, gapdh, rpb2 and tef1). Results Mycotic infections have been diagnosed by repeated cultures and histopathological examination in two of the cases. The polyphasic approach has allowed to delineate three new species of Alternaria section Infectoriae, that is A anthropophila, A atrobrunnea and A guarroi. ATPase has been the only locus able to discriminate most of the species (29 out of 31) currently sequenced in this section, including A infectoria the commonest reported species causing alternariosis. Susceptibility test showed different antifungal patterns for the three species, although terbinafine was the most active in vitro drug against these fungi. Conclusions The ATPase gene is recommended as an alternative barcode locus to identify Alternaria clinical isolates in section Infectoriae. Our results reinforce the relevance of identification of Alternaria isolates at the species level and the necessity to carry out antifungal susceptibility testing to determine the most adequate drug for treatment.

Dematiaceous fungal infections in solid organ transplantation: Systematic review and Bayesian meta‐analysis

“…As a result, we reviewed 228 published reports. We identified and included 149 reports on 201 cases of dematiaceous fungal infections in SOT recipients 21–169 . The majority (134/149; 90%) of included reports scored ≥ 2 of three possible points on our bias assessment (Table S4).…”

Characterization of New Small-Spored Alternaria Species Isolated from Solanaceae in Algeria

“…However, such analyses also revealed the high genetic variability of this section compared to others [59]. Using the combined datasets of ITS rDNA, gpd, rpb2, tef1 and ATPase, new species have recently been defined within the section Infectoriae [51,55]. Using similar loci and comparisons with all of the species for which the corresponding sequences were available in databank, we showed that several isolates included in this section clustered independently with little to no statistical support for their phylogenetic position, which is similar to previous observations [54].…”

“…Alternaria species from section Infectoriae were detected as common species in food, the indoor environment and human cutaneous infections [23,51,[60][61][62]. Recent studies have reported the incidence of species belonging to this section on potato plants in the Pacific North-west [58], in Pakistan [63], in Iran [17], in Russia [64], and our inoculation assays have indeed confirmed that the species from this section could be pathogenic to this host as well as to tomatoes.…”

“…However, due to the high similarity between isolates, it was not possible to delineate reliable morpho-groups based solely on morphology within the members of this section. Phylogenetic analyses at five loci (ITS rDNA, gpd, rpb2, tef1 and ATPase) have been used to separate species within the section Infectoriae [51][52][53][54][55]. Sequences were obtained at these five loci for the 12 isolates assigned to section Infectoriae and compared with corresponding sequences from 37 recognized species from section Infectoriae.…”

Pleocatenata chiangraiensis gen. et. sp. nov. (Pleosporales, Dothideomycetes) from medicinal plants in northern Thailand

“…They have a worldwide distribution with diverse lifestyles, including saprobes, pathogens of plants and humans, endophytes, epiphytes and hyperparasites ( Ramesh 2003 ; Kirk et al 2008 ; Zhang et al 2012 ; Hyde et al 2013 ; Sun et al 2019 ; Ferdinandez et al 2021 ). Many species in Alternaria Nee s , Curvularia Boedijn and Corynespora Güssow, can invade medicinal plants and cause leaf spots and other diseases, as economically important plant pathogens ( Mathiyazhagan et al 2004 ; Abtahi and Nourani 2017 ; Zhang et al 2020 ), and some also pose a threat to human health ( Hyde et al 2018 ; Iturrieta-González et al 2020 ). Endophytes in Pleosporales also show important biocontrol value ( Su et al 2014 ; De Silva et al 2019; Hyde et al 2019 ), for example, an extract from Cochliobolus spicifer R.R.…”