Identificação polifásica e diversidade genética de sporothrix spp. isolados de humanos e felinos no Estado do Espírito Santo

Abstract

Sporotrichosis is a subcutaneous fungal infection that affects humans and animals caused by species of the genus Sporothrix spp. Information about genetic diversity and the population structure of the pathogen is necessary to devise effective strategies to face the advance of sporotrichosis in endemic areas. Therefore, this study aimed to evaluate the genetic diversity and population structure of Sporothrix species, to better understand their epidemiology, distribution, and diversity, and explore possible transmission routes involved in the ongoing outbreaks. In the study, 262 samples were investigated, 142 from humans and 120 from felines in the period from 2016 to 2021. The isolates were identified according to morphological (macro and micromorphology) and molecular characteristics. Then, the fungal DNA extraction was performed and the species-specific PCR was applied using markers directed to the calmodulin gene. Sexual idiomorphs were identified by mating-type PCR using primers targeted to the MAT1-1 and MAT1-2 loci. The technique of amplified fragment length polymorphism (AFLP) was used to assess the dynamics of the disease, genetic variability, and origin of the isolates. Finally, the antifungal susceptibility test was performed following the CLSI M32-A2 protocol, with amphotericin B, itraconazole, posaconazole, and terbinafine. In isolates from human samples, 125 were identified as S. brasiliensis and 17 as S. schenckii s. str. On the other side, all the feline isolates were identified as S. brasiliensis. In both species, the presence of two sexual idiomorphs was detected; however, MAT1-2 was predominant, suggesting that the isolates from the state of Espírito Santo may have originated from Rio de Janeiro state. In recent years, sporotrichosis has taken an abruptly urban-epidemic characteristic due to the species S. brasiliensis. In addition, terbinafine proved to be the antifungal with the best results in vitro, although in clinical practice itraconazole remains the first choice of treatment. Sporotrichosis continues to advance in the state; therefore, strategies to contain the disease must be outlined by the health system, to avoid containing future epidemics of sporotrichosis.