Division of Medical Mycology, Teaching and Research Laboratory in Clinical Analyses, Department of Clinical Analysis of State, University of Maringá, Paraná, Brazil.
Mycopathologia. 2022 Feb;187(1):85-93. doi: 10.1007/s11046-021-00606-5. Epub 2021 Dec 2.
Rhodotorula spp. and Trichosporon spp. are opportunistic pathogens, and although an association between these two species in the same infection appears to be uncommon, it has been reported. This is the first study that aimed to evaluate the pathogenesis of a co-infection by R. mucilaginosa and T. asahii, using a new in vivo model, the Zophobas morio larvae. Suspensions from planktonic and biofilm-recovered cells were injected in the larvae as in monospecies as mixed (a ratio of 1:1 for both agents of a of 10 inoculum). Individual and mixed biofilms of R. mucilaginosa and T. asahii were produced for 24 and 48 h, and they were partially characterized by crystal violet and reduction of tetrazolium salt. When evaluating the impact of the planktonic suspension in vivo we verified that the fungi in monoculture were more able to kill the larvae than those from planktonic mixed suspension. On the other hand, regarding biofilm-recovered cells, there was an increase in the death of larvae infected for mixed suspensions. Moreover, the death rate was more pronounced when the larvae were infected with 48 h biofilm-recovered cells than the 24 h ones. T. asahii was the best producer of total biomass, mainly in 48 h. The metabolic activity for both yeasts organized in biofilm maintained the same pattern between 24 and 48 h. The present study proves a synergistic interaction between R. mucilaginosa and T. asahii after an experience in a mixed biofilm. Our results suggest that both species were benefited from this interaction, acquiring a greater potential for virulence after passing through the biofilm and this ability was acquired by the cells released from the biofilm.
红酵母属和毛孢子菌属是机会致病菌，虽然这两种菌在同一感染中同时出现的情况似乎并不常见，但已有相关报道。本研究旨在利用一种新的活体模型——黄粉虫幼虫，评估粘红酵母和近平滑假丝酵母混合感染的发病机制。将浮游和生物膜回收细胞的悬浮液分别以单种和混合（两种菌的接种物比例为 1:1）的方式注入幼虫体内。单独和混合培养的粘红酵母和近平滑假丝酵母生物膜培养 24 和 48 小时，并通过结晶紫和四唑盐还原对其进行部分表征。在评估浮游悬液在体内的影响时，我们发现与浮游混合悬浮液相比，单培养真菌更能杀死幼虫。另一方面，对于生物膜回收细胞，混合悬浮液感染的幼虫死亡率增加。此外，与 24 小时生物膜回收细胞相比，感染 48 小时生物膜回收细胞的幼虫死亡率更高。在生物量方面，毛孢子菌是总生物量的最佳生产者，主要在 48 小时。两种酵母在生物膜中组织的代谢活性在 24 和 48 小时之间保持相同的模式。本研究证明了粘红酵母和平滑假丝酵母在混合生物膜经历后存在协同相互作用。我们的结果表明，这两种菌都从这种相互作用中受益，在通过生物膜后获得了更大的毒力潜力，这种能力是由从生物膜中释放的细胞获得的。
