Taxonomy and phylogeny of new wood- and soil-inhabitingSporothrixspecies in theOphiostoma stenoceras-Sporothrix schenckiicomplex

Abstract

Sporothrix, one of the anamorph genera of Ophiostoma, includes the important human pathogen S. schenckii and various fungi associated with insects and sap stain of wood. A survey of fungi from wood utility poles in South Africa yielded two distinct groups of Sporothrix isolates from different geographical areas. DNA sequence and morphological data derived in this study showed that isolates in these groups represent two novel species in the S. schenckii-O. stenoceras species complex. A new species isolated from pine poles and rosebush wood and phylogenetically closely related to S. pallida is described here as Sporothrix stylites. Phylogenetic analyses also confirmed the synonymy of S. albicans and S. nivea with S. pallida. Sporothrix stylites and S. pallida also are related closely to the isolates from soil, previously treated as "environmental" isolates of S. schenckii. Soil isolates are clearly distinct from human isolates of S. schenckii. We describe the former here as Sporothrix humicola. The isolates from eucalypt poles group peripheral to most other species in the S. schenckii-O. stenoceras complex and are newly described as Sporothrix lignivora. Phylogenetic analyses of sequences of isolates from soil and wood together with those of clinical isolates showed that the human-pathogenic strains form an aggregate of several cryptic species.

Characterization of virulence profile, protein secretion and immunogenicity of differentSporothrix schenckii sensu strictoisolates compared withS. globosaandS. brasiliensisspecies

“…The CAL and ITS sequences used as reference for phylogenetic analysis were selected based on sequences deposited by De Beer et al, 36 Kawasaki et al, 37 Watanabe et al, 38 Aghayeva et al, 39 Marimon et al, 11,12 Gujjari et al, 40 De Meyer et al, 41 Madrid et al, 42 Romeo et al 13 and Rodrigues et al 4 Both sequences, ITS and CAL loci of the same reference isolate, were not always available, thus, the data were analyzed separately.…”

“…Some studies have investigated the protein secretion profile of Sporothrix, 43,44 the genetic variability, 11,12,41,42 as well as virulence of some new species. 2,3 This is the first study which evaluates the protein secretion of S. brasiliensis, S. globosa and S. schenckii s. str.…”

“…45 In addition, the ITS region was sequenced using primers ITS1 and ITS4, which amplify the 18S, ITS1, 5.8S, ITS2 and 28S 46 in order to verify if these isolates were similar to other environmental Sporothrix isolates described by De Meyer et al 41 and Madrid et al 42 Amplified products were gel purified with the Wizard SV Gel and PCR Clean-Up System (Promega Corp.), following were in agreement, except for Ss40, Ss47 and Ss141. The Ss40 isolate induced medium fungal loads of all the analyzed organs but the higher inoculum of yeast cells it could induce high mortality as S. brasiliensis (Ss54, CBS 132990).…”

“…Calmodulin sequences (n = 55) from other isolates of S. schenckii (n = 25), S. brasiliensis (n = 8), S. mexicana (n = 5), S. globosa (n = 12), S. pallida (n = 4) and S. luriei (n = 1), as well as ITS sequences (n = 39) from S. schenckii (n = 15), S. brasiliensis (n = 4), S. mexicana (n = 1), S. globosa (n = 4), S. pallida (n = 1), S. luriei (n = 1), S. inflata (n = 1), S. dimorphospora (n = 2), S. stylites (n = 2), S. humicola (n = 2), S. brunneoviolacea (n = 2), S. lignivora (n = 2) and Ophiostoma stenoceras (n = 2) were included in the present study as reference strains for the phylogenetic analysis. These sequences were previously deposited at GenBank (www.ncbi.nlm.nih.gov/genbank) and described by De Beer et al, 36 Kawasaki et al, 37 Watanabe et al, 38 Aghayeva et al, 39 Marimon et al, 11,12 Gujjari et al, 40 De Meyer et al, 41 Madrid et al, 42 Romeo et al 13 and Rodrigues et al 4 Evolutionary analyses were conducted in MEGA5 49 with Maximum Likelihood method. Evolutionary distances were computed using the Kimura 2-parameter method 50 with a discrete Gamma distribution for the CAL data set and Tamura 3-parameter method 51 for ITS data set, with 1,000 bootstrap replicates.…”

Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species

“…stenoceras complex (De Beer et al 2013b), including three of the newly described species. This adds to an already high diversity of species in this complex from southern Africa (De Meyer et al 2008;Kamgan Nkuekam et al 2012;Musvuugwa et al 2015;Roets et al 2007Roets et al , 2009Zhou et al 2006). This complex includes species collected from many different substrates, including mite-associated species from Protea infructescences (Roets et al 2007(Roets et al , 2009), human pathogens (Marimon et al 2007) and subcortical beetle-associated species (Musvuugwa et al 2015).…”