Molecular‐based assessment of diversity and population structure of Sporothrix spp. clinical isolates from Espírito Santo‐Brazil

Abstract

Background Sporotrichosis is a subcutaneous mycosis caused by Sporothrix species that affects humans and animals. Little information on the genetic diversity and population structure of the pathogen is available for Brazil, which is needed to design effective strategies to tackle the advance of sporotrichosis in endemic areas. Objectives We assessed the genetic diversity and mating‐type distribution of Sporothrix isolates recovered from human and feline cases of sporotrichosis in Espírito Santo‐Brazil to better understand the population structure, epidemiology and diversification of this pathogen, as well as to explore the possible routes of transmission involved in the ongoing outbreaks. Methods In all, 75 Sporothrix isolates were identified with phenotypic characteristics. Then, fungal DNA extraction was performed, and the species‐specific PCR technique was applied, using markers directed to the calmodulin gene. The mating‐type idiomorph of species was identified by PCR using primers targeting the MAT1‐1 and MAT1‐2 loci. Results Among the 75 Sporothrix isolates, 76% were confirmed as S brasiliensis and 24% as S schenckii sensu stricto. S brasiliensis was more prevalent in the metropolitan area and S schenckii s. str. in the mountainous region of the state. In both species, the presence of the two sexual idiomorphs was detected, suggesting that they are heterothallic species. Conclusions Our data suggest that sporotrichosis takes on an epidemic‐urban character involving S brasiliensis. This species in Espírito Santo is likely to originate from Rio de Janeiro, as most isolates harbour the same MAT 1‐2 locus. We confirm that S brasiliensis has significantly broadened its area of occurrence, an essential feature of emerging pathogens.

Exploring genetic diversity, population structure, and phylogeography in Paracoccidioides species using AFLP markers

“…This paradoxical reproduction system has been observed in Sporothrix ( Teixeira et al. 2015 , Rocha et al. 2020 , de Carvalho et al.…”

Current Progress on Epidemiology, Diagnosis, and Treatment of Sporotrichosis and Their Future Trends

“…The isolates obtained can be accurately identified from positive cultures, and antifungal susceptibility testing in vitro and other assays can be performed [ 2 ]. Macroscopically, in media such as malt extract agar (MEA) or potato dextrose agar (PDA), the colonies start to grow as hyaline filamentous fungi and then turn brown to black after a few days, mainly in the colony’s center [ 118 , 188 , 189 ]. Sometimes the mycelium can grow entirely white, designated as an albino [ 118 , 188 , 189 ].…”

“…Macroscopically, in media such as malt extract agar (MEA) or potato dextrose agar (PDA), the colonies start to grow as hyaline filamentous fungi and then turn brown to black after a few days, mainly in the colony’s center [ 118 , 188 , 189 ]. Sometimes the mycelium can grow entirely white, designated as an albino [ 118 , 188 , 189 ]. The Sporothrix colonies’ diameter is smaller, ranging from 19 to 41 mm, compared to other filamentous fungi, such as Aspergillus fumigatus (65–70 mm) [ 118 , 190 ].…”

“…Sometimes the mycelium can grow entirely white, designated as an albino [ 118 , 188 , 189 ]. The Sporothrix colonies’ diameter is smaller, ranging from 19 to 41 mm, compared to other filamentous fungi, such as Aspergillus fumigatus (65–70 mm) [ 118 , 190 ]. Microscopically, the mycelial form is observed as septate, thin, branched, and hyaline hyphae, with conidiogenous cells arising from undifferentiated hyphae, forming conidia thick-walled (hyaline or brown), small (2–3 × 3–6µm), with a different arrangement, such as sympodial form, appearing in small groups of denticles in a slight apical dilation of the conidiophore or as sessile [ 118 , 188 , 189 ].…”

Old and New Insights into Sporothrix schenckii Complex Biology and Identification

“…This might explain not only an adaptive shift of Sporothrix species from a saprobic life in plant materials to a pathogenic life in mammals but also an increase in their pathogenicity during the evolution [ 33 ]. Until now, there is no known sexual stage in Sporothrix species [ 34 ], despite the presence of a set of mating or pheromone-response protein-encoding genes in their genomes [ 35 ].…”