Targeted gene disruption in Candida parapsilosis demonstrates a role for CPAR2_404800 in adhesion to a biotic surface and in a murine model of ascending urinary tract infection
Targeted gene disruption in Candida parapsilosis demonstrates a role for CPAR2_404800 in adhesion to a biotic surface and in a murine model of ascending urinary tract infection
复制标题
DOI：
10.1080/21505594.2015.1112491
复制
发表时间：
2016-02-17
期刊：
影响因子：
5.2
通讯作者：
Tavanti, Arianna
中科院分区：
文献类型：
--
作者：
Bertini, Alessia;Zoppo, Marina;Tavanti, Arianna
近平滑念珠菌是一种新兴的机会性病原体，其频率仅次于白色念珠菌，通常与粘膜和全身感染相关。对生物表面的粘附是真菌病发展的关键步骤。 C. parapsilosis 基因组编码 5 种预测的凝集素样序列蛋白，它们在粘附过程中的精确作用仍有待阐明。在本研究中，我们重点关注假定的粘附素 Cpar2_404800，因为它与白色念珠菌中最重要的粘附分子具有高度同源性。通过位点特异性删除获得了近平滑念珠菌 CPAR2_404800 杂合突变体和无效突变体的两个独立谱系。 CPAR2_404800突变体在体外生长或进行形态发生的能力方面与野生型菌株没有差异。然而，当与生物表面的粘附相比时，CPAR2_404800无效突变体表现出与颊上皮细胞的粘附显着降低（粘附指数降低>60%）。在零背景中重新引入一份 CPAR2_404800 基因可以恢复野生型表型。使用尿路感染的小鼠模型来阐明 CPAR2_404800 的体内贡献。与野生型感染小鼠相比，从感染无效突变体的小鼠获得的膀胱和肾脏中，观察到菌落形成单位数（每克）分别减少了 0.5 和 1 log(10)。总而言之，这些发现为 CPAR2_404800 在近平滑念珠菌粘附到宿主表面中的直接作用提供了第一个证据，并证明了其对小鼠泌尿念珠菌病发病机制的贡献。
Candida parapsilosis is an emerging opportunistic pathogen, second in frequency only to C. albicans and commonly associated with both mucosal and systemic infections. Adhesion to biotic surfaces is a key step for the development of mycoses. The C. parapsilosis genome encodes 5 predicted agglutinin-like sequence proteins and their precise role in the adhesion process still remains to be elucidated. In this study, we focused on the putative adhesin Cpar2_404800, in view of its high homology to the most important adhesion molecule in C. albicans. Two independent lineages of C. parapsilosis CPAR2_404800 heterozygous and null mutants were obtained by site-specific deletion. CPAR2_404800 mutants did not differ from wild-type strain in terms of in vitro growth or in their ability to undergo morphogenesis. However, when compared for adhesion to a biotic surface, CPAR2_404800 null mutants exhibited a marked reduction in their adhesion to buccal epithelial cells (>60% reduction of adhesion index). Reintroduction of one copy of CPAR2_404800 gene in the null background restored wild type phenotype. A murine model of urinary tract infection was used to elucidate the in vivo contribution of CPAR2_404800. A 0.5 and 1 log(10) reduction in colony forming unit numbers (per gram) was observed respectively in bladder and kidneys obtained from mice infected with null mutant compared to wild-type infected ones. Taken together, these findings provide the first evidence for a direct role of CPAR2_404800 in C. parapsilosis adhesion to host surfaces and demonstrate its contribution to the pathogenesis of murine urinary candidiasis.