Postgraduate Program in Medicine: Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Postgraduate Program of Agricultural and Environmental Microbiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Antimicrob Agents Chemother. 2021 Jul 16;65(8):e0054621. doi: 10.1128/AAC.00546-21.
Chromoblastomycosis (CBM) is a chronic subcutaneous infection caused by genera of melanized fungi: , , , , and . Melanin is a virulence factor known to influence antifungal susceptibility. A specific inhibitor of melanin biosynthesis is tricyclazole. The aim of this study was to evaluate the effect of melanin inhibition on antifungal susceptibility of chromoblastomycosis agents and describe the susceptibility profiles of some unusual CBM agents. Seventy-six clinical isolates, representing 13 species of the five main genera of CBM agents, were studied. The antifungal susceptibility testing was performed according to the M38-A2 protocol of CLSI (, 3rd ed., , 2017). In the melanin inhibition test, 16 mg/liter of tricyclazole was added to the medium used in the inoculum preparation and the susceptibility assay. CBM agents were less susceptible to amphotericin B than azoles and terbinafine. The unusual species showed similar susceptibility profiles to those of other species of the same genera. With tricyclazole exposure, MICs of terbinafine, posaconazole, and itraconazole for spp. significantly decreased ( < 0.05). For spp., this reduction was significant for posaconazole and itraconazole. For the other genera, there was a reduction in MICs of terbinafine and itraconazole; however, the statistical tests were not significant. Melanin inhibition can increase the antifungal susceptibility of most CBM agents to itraconazole and terbinafine, the main drugs used in the disease treatment. This increased susceptibility may open up new possibilities for therapy in refractory cases of CBM and/or cases caused by resistant fungal strains. Further studies are needed to confirm the same results .
着色芽生菌病（CBM）是一种由黑素真菌属引起的慢性皮下感染：、、、和。黑色素是一种已知影响抗真菌敏感性的毒力因子。黑色素生物合成的一种特定抑制剂是三环唑。本研究旨在评估黑色素抑制对着色芽生菌病病原体抗真菌敏感性的影响，并描述一些不常见的 CBM 病原体的药敏谱。对 76 株临床分离株进行了研究，代表了 CBM 病原体五个主要属的 13 个种。根据 CLSI 的 M38-A2 方案（，第三版，2017 年）进行抗真菌药敏试验。在黑色素抑制试验中，在用于接种物制备和药敏测定的培养基中添加 16mg/L 的三环唑。与唑类和特比萘芬相比，CBM 病原体对两性霉素 B 的敏感性较低。不常见的种与同属的其他种具有相似的药敏谱。暴露于三环唑后， spp. 的特比萘芬、泊沙康唑和伊曲康唑 MIC 值显著降低（<0.05）。对于 spp.，泊沙康唑和伊曲康唑的 MIC 值降低有统计学意义。对于其他属，特比萘芬和伊曲康唑的 MIC 值降低；然而，统计检验不显著。黑色素抑制可以增加大多数 CBM 病原体对两性霉素 B、唑类和特比萘芬的抗真菌敏感性，这些是该疾病治疗中主要使用的药物。这种增加的敏感性可能为 CBM 的难治性病例和/或耐药真菌菌株引起的病例提供新的治疗可能性。需要进一步的研究来证实相同的结果。
