Bessaiah Hicham, Pokharel Pravil, Loucif Hamza, Kulbay Merve, Sasseville Charles, Habouria Hajer, Houle Sébastien, Bernier Jacques, Massé Éric, Van Grevenynghe Julien, Dozois Charles M
INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Québec, Canada.
CRIPA-Centre de recherche en infectiologie porcine et avicole, Saint-Hyacinthe, Québec, Canada.
PLoS Pathog. 2021 May 27;17(5):e1009617. doi: 10.1371/journal.ppat.1009617. eCollection 2021 May.
Urinary tract infections (UTIs) are a common bacterial infectious disease in humans, and strains of uropathogenic Escherichia coli (UPEC) are the most frequent cause of UTIs. During infection, UPEC must cope with a variety of stressful conditions in the urinary tract. Here, we demonstrate that the small RNA (sRNA) RyfA of UPEC strains is required for resistance to oxidative and osmotic stresses. Transcriptomic analysis of the ryfA mutant showed changes in expression of genes associated with general stress responses, metabolism, biofilm formation and genes coding for cell surface proteins. Inactivation of ryfA in UPEC strain CFT073 decreased urinary tract colonization in mice and the ryfA mutant also had reduced production of type 1 and P fimbriae (pili), adhesins which are known to be important for UTI. Furthermore, loss of ryfA also reduced UPEC survival in human macrophages. Thus, ryfA plays a key regulatory role in UPEC adaptation to stress, which contributes to UTI and survival in macrophages.
尿路感染（UTIs）是人类常见的细菌性传染病，尿路致病性大肠杆菌（UPEC）菌株是UTIs最常见的病因。在感染过程中，UPEC必须应对尿路中的各种应激条件。在此，我们证明UPEC菌株的小RNA（sRNA）RyfA是抵抗氧化应激和渗透应激所必需的。对ryfA突变体的转录组分析显示，与一般应激反应、代谢、生物膜形成以及编码细胞表面蛋白的基因相关的基因表达发生了变化。UPEC菌株CFT073中ryfA的失活降低了其在小鼠尿路中的定殖能力，ryfA突变体的1型菌毛和P菌毛（菌毛）产量也有所降低，已知这些粘附素对UTI很重要。此外，ryfA的缺失也降低了UPEC在人巨噬细胞中的存活率。因此，ryfA在UPEC适应应激中起关键调节作用，这有助于UTI的发生以及在巨噬细胞中的存活。
