Department of Biotechnology and Microbiology, University of Debrecen, Debrecen, Hungary.
Postdoctoral Fellowship Programme of the Hungarian Academy of Sciences (MTA), Budapest, Hungary.
Mol Nutr Food Res. 2017 Nov;61(11). doi: 10.1002/mnfr.201601099. Epub 2017 Aug 29.
Saccharomyces cerevisiae is one of the most important microbes in food industry, but there is growing evidence on its potential pathogenicity as well. Its status as a member of human mycobiome is still not fully understood.
In this study, we characterize clinical S. cerevisiae isolates from Hungarian hospitals along with commercial baking and probiotic strains, and determine their phenotypic parameters, virulence factors, interactions with human macrophages, and pathogenicity. Four of the clinical isolates could be traced back to commercial strains based on genetic fingerprinting. Our observations indicate that the commercial-derived clinical isolates have evolved new phenotypes and show similar, or in two cases, significantly decreased pathogenicity. Furthermore, immunological experiments revealed that the variability in human primary macrophage activation after coincubation with yeasts is largely donor and not isolate dependent.
Isolates in this study offer an interesting insight into the potential microevolution of probiotic and food strains in human hosts. These commensal yeasts display various changes in their phenotypes, indicating that the colonization of the host does not necessarily impose a selective pressure toward higher virulence/pathogenicity.
酿酒酵母是食品工业中最重要的微生物之一，但越来越多的证据表明其具有潜在的致病性。其作为人类真菌组的一部分的地位尚未完全被理解。
在这项研究中，我们对来自匈牙利医院的临床酿酒酵母分离株以及商业烘焙和益生菌菌株进行了表征，并确定了它们的表型参数、毒力因子、与人类巨噬细胞的相互作用以及致病性。根据遗传指纹图谱，其中四个临床分离株可以追溯到商业菌株。我们的观察表明，商业衍生的临床分离株已经进化出了新的表型，并且表现出相似的，或者在两种情况下，显著降低的致病性。此外，免疫学实验表明，在与酵母共同孵育后，人类原代巨噬细胞激活的变异性在很大程度上取决于供体而不是分离株。
本研究中的分离株为益生菌和食品菌株在人类宿主中的潜在微进化提供了一个有趣的视角。这些共生酵母在其表型上显示出各种变化，表明宿主的定植不一定会对更高的毒力/致病性施加选择压力。
