No abstract

Lipopeptide biosurfactants (LBs) are biological molecules with low toxicity that have aroused growing interest in the pharmaceutical industry. Their chemical structure confers antimicrobial and antibiofilm properties against different species. Despite their potential, few studies have demonstrated their capability against Malassezia spp., commensal yeasts which can cause dermatitis and serious infections. Thus, the aim of this study was to evaluate the antifungal activity of biosurfactants produced by new strains of Bacillus subtilis TIM10 and B. vallismortis TIM68 against M. furfur and their potential for removal and inhibition of yeast biofilms. Biosurfactants were classified as lipopeptides by FTIR, and their composition was characterised by ESI-Q-TOF/MS, showing ions for iturin, fengycin, and surfactin, with a greater abundance of surfactin. Through the broth microdilution method, both biosurfactants inhibited the growth of clinical M. furfur strains. Biosurfactant TIM10 showed greater capacity for growth inhibition, with no statistical difference compared to those obtained by the commercial antifungal fluconazole for M. furfur 153DR5 and 154DR8 strains. At minimal inhibitory concentrations (MIC-2), TIM10 and TIM68 were able to inhibit biofilm formation, especially TIM10, with an inhibition rate of approximately 90%. In addition, both biosurfactants were able to remove pre-formed biofilm. Both biosurfactants showed no toxicity against murine fibroblasts, even at concentrations above MIC-2. Our results show the effectiveness of LBs in controlling the growth and biofilm formation of M. furfur clinical strains and highlight the potential of these agents to compose new formulations for the treatment of these fungi.

Objective: Perform genotyping of SNPs in the promoter region of the SMO gene in BCC samples from patients from northeastern Brazil, and to determine if there is an association of these SNPs of the gene in question with the susceptibility to the development of the BCC. Methods: 100 samples of paraffined tissue from patients with histopathological diagnosis of BCC and 100 control samples were analyzed for each polymorphism by a newly developed genotyping method, the Dideoxy Single Allele Specific -PCR. The software Bioestat -version 5.3 and Haploview 4.2 were used for the statistical analysis. For all tests a P-value <0.05 was considered significant. Results: The SNP rs538312246 is the Hardy-Weinberg equilibrium, therefore, it did not present significant association with the BCC (X² =2.343 and P<0.158). However, the CpG-SNPs rs375350898 and rs75827493 were significantly associated to the BCC in the analyzed samples (X 2 = 27,740/21,500 and P <0001), the SNP rs75827493 showed a significant association with the BCC of the nodular subtype (P <0.0069). Therefore, our results suggest that SNPs rs375350898 and rs75827493 are potential molecular markers for susceptibility to BCC. Conclusion: The ability to detect SNP in a population, especially in promoter regions, has profoundly changed human genetic studies. This study allowed the understanding of the relationship between the presence of SNPs in CpG islands of the promoter region of the SMO gene can modify the methylation pattern and provide susceptibility to BCC in the population.

Background: Basal cell carcinoma (BCC) is the common neoplasm in humans and its main etiological factor is exposure to solar radiation. Mutations in repair genes can lead to tumor progression and loss of cell integrity leading to the onset of cancer. Nucleotide excision repair (NER) is an important mechanism primarily used to repair injuries caused by UV. Objective: To evaluate and describe for the first time the single nucleotide polymorphisms rs745769173, rs761106780 and rs535425175 and risk of developing BCC. Methods: The present study analyzed 100 samples of paraffin-embedded tissue from patients with histopathological diagnosis of BCC and 100 control samples. The results were obtained by genotyping method, Dideoxy Unique Allele Specific – PCR (DSASP) and molecular modeling. Results: The SNP rs535425175 of the XPC gene showed a significant association with the BCC in the analyzed samples (P <0.005) and molecular docking showed different binding energy of the complex between the XPC region 99-156 and the PH domain of TFIIH p62, being more negative, -710.53 kcal/mol, with the Asn residue at position 108 and less negative, -611.10 kcal/mol, with Lys residue related to the polymorphism. Conclusion: The results suggest that the SNP rs535425175 of the XPC gene, which causes mutation at codon 108 of the XPC protein, which consists of replacing the Ans residue with the Lys, may be considered a risk factor associated with the development of BCC.