Evolution of species of the genus sporothrix based on the sequences of vma and prp8 inteins

Author(s)

Alana Lucena Oliveira

• Document type: Master's Dissertation
• Press: Botucatu. 2021-02-02.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
• Defense date: 2020-10-30
• Advisor: Sandra de Moraes Gimenes Bosco; Hans Garcia Garces

Abstract

Sporotrichosis is a fungal disease caused mainly by species of the pathogenic clade of the genus Sporothrix. These species comprise S. schenckii, S. brasiliensis, S. globosa and S. luriei. S. schenckii has a broad worldwide distribution while S. globosa is a common sapronosis in Asia and S. luriei is a very restricted species with very few reports associated with disease. S. brasiliensis is a zoonosis that mainly affects cats and has had a great incidence in Brazil in the last decade, being considered one of the most important emerging mycoses in recent times. In order to eliminate outbreaks, along with prevention campaigns and surveillance measures, it is very important to have low-cost, fast and accurate diagnostic methods, identifying the correct species involved. Standardization and differentiation of the species from the pathogenic clade of the complex genus Sporothrix were carried out by means of molecular biology using specific gene regions of the VMA and PRP8 inteins that have not yet been studied within these species. The VMA and PRP8 intein regions have already been used for the purposes of diagnosis and phylogenetic studies in other fungi, and are thus considered promising regions for the genus Sporothrix. Inteins are protein sequences present in some organisms that have the ability to perform a self-splicing process just after their host protein is translated. Since the existence of both inteins is proven in the majority of all species of the Sporothrix pathogenic clade, we aim to characterize the PRP8 and VMA inteins in order to diagnose these species molecularly and to determine the evolutionary history of the group, including DNA samples from cultivated isolates. Currently, we have 22 strains of clinical isolates (5 S. globosa, 5 S. schenckii, 12 S. brasiliensis) by sequencing the regions with designed primers and one strain of S. luriei that was analyzed by bioinformatics. The PRP8 intein was found in all species while the VMA intein was absent in S. globosa and S. luriei. Inteins was always found in full-length form. Phylogenetic analyses allowed species differentiation by grouping S. schenckii close to S. brasiliensis and S. globosa close to S. luriei when analyzing the sequences of the PRP8 intein. Likewise, the VMA intein showed a separate clustering of the species S. schenckii and S. brasiliensis. The absence of inteins in S. globosa and the polymorphism found in the VMA intein allowed the designing of an additional primer set to differentiate the species S. schenkii, S. brasiliensis and S. globosa thought only a PCR/Eletrophoresis technique without the need for sequencing. (AU)

• FAPESP's process: 19/03489-7 - Sporotrichosis in the region of Botucatu, SP: retrospective study and molecular identification of the etiological agent
• Grantee: Alana Lucena Oliveira
• Support Opportunities: Scholarships in Brazil - Master