FhlA 依赖性氢化酶的去酸化作用参与了尿路致病性奇异变形杆菌的脲酶活性和尿路结石形成。

Deacidification by FhlA-dependent hydrogenase is involved in urease activity and urinary stone formation in uropathogenic Proteus mirabilis.

机构信息

Department and Graduate Institute of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, No. 1, Chang-Te Street, Taipei, 10016, Taiwan, ROC.

Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University, Taipei, Taiwan, Republic of China.

出版信息

Sci Rep. 2020 Nov 11;10(1):19546. doi: 10.1038/s41598-020-76561-w.

DOI:10.1038/s41598-020-76561-w

PMID:33177598

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7658346/

Abstract

Proteus mirabilis is an important uropathogen, featured with urinary stone formation. Formate hydrogenlyase (FHL), consisting of formate dehydrogenase H and hydrogenase for converting proton to hydrogen, has been implicated in virulence. In this study, we investigated the role of P. mirabilis FHL hydrogenase and the FHL activator, FhlA. fhlA and hyfG (encoding hydrogenase large subunit) displayed a defect in acid resistance. fhlA and hyfG mutants displayed a delay in medium deacidification compared to wild-type and ureC mutant failed to deacidify the medium. In addition, loss of fhlA or hyfG decreased urease activity in the pH range of 5-8. The reduction of urease activities in fhlA and hyfG mutants subsided gradually over the pH range and disappeared at pH 9. Furthermore, mutation of fhlA or hyfG resulted in a decrease in urinary stone formation in synthetic urine. These indicate fhlA- and hyf-mediated deacidification affected urease activity and stone formation. Finally, fhlA and hyfG mutants exhibited attenuated colonization in mice. Altogether, we found expression of fhlA and hyf confers medium deacidification via facilitating urease activity, thereby urinary stone formation and mouse colonization. The link of acid resistance to urease activity provides a potential strategy for counteracting urinary tract infections by P. mirabilis.

摘要

奇异变形杆菌是一种重要的尿路病原体，其特征是尿路结石形成。甲酸氢酶（FHL）由甲酸脱氢酶 H 和将质子转化为氢气的氢化酶组成，与毒力有关。在这项研究中，我们研究了奇异变形杆菌 FHL 氢化酶和 FHL 激活剂 FhlA 的作用。fhlA 和 hyfG（编码氢化酶大亚基）在耐酸性方面存在缺陷。与野生型相比，fhlA 和 hyfG 突变体的培养基酸化速度较慢，而 ureC 突变体无法使培养基酸化。此外，fhlA 或 hyfG 的缺失降低了 pH 值在 5-8 范围内的脲酶活性。fhlA 和 hyfG 突变体中的脲酶活性逐渐降低，在 pH 值为 9 时消失。此外，fhlA 或 hyfG 的突变导致合成尿液中的结石形成减少。这些表明 fhlA 和 hyf 介导的酸化作用影响脲酶活性和结石形成。最后，fhlA 和 hyfG 突变体在小鼠中的定植能力减弱。总之，我们发现 fhlA 和 hyf 的表达通过促进脲酶活性来实现培养基酸化，从而导致尿路结石形成和小鼠定植。耐酸性与脲酶活性的联系为对抗奇异变形杆菌引起的尿路感染提供了一种潜在策略。