El Khatib Mariam, Tran Que-Tien, Nasrallah Chady, Lopes Julie, Bolla Jean-Michel, Vivaudou Michel, Pagès Jean-Marie, Colletier Jacques-Philippe
Institut de Biologie Structurale, Université Grenoble Alpes - Commissariat à l'Énergie Atomique - Centre National de la Recherche Scientifique, Grenoble, France.
School of Biophysics, Jacobs University of Bremen, Bremen, Germany.
PLoS One. 2017 Mar 23;12(3):e0174213. doi: 10.1371/journal.pone.0174213. eCollection 2017.
Biofilms are organized communities of bacterial cells that are responsible for the majority of human chronic bacterial infections. Providencia stuartii is a Gram-negative biofilm-forming bacterium involved in high incidence of urinary tract infections in catheterized patients. Yet, the structuration of these biofilms, and their resistance to environmental insults remain poorly understood. Here, we report on planktonic cell growth and biofilm formation by P. stuartii, in conditions that mimic its most common pathophysiological habitat in humans, i.e. the urinary tract. We observed that, in the planktonic state, P. stuartii forms floating communities of cells, prior to attachment to a surface and subsequent adoption of the biofilm phenotype. P. stuartii planktonic and biofilm cells are remarkably resistant to calcium, magnesium and to high concentrations of urea, and show the ability to grow over a wide range of pHs. Experiments conducted on a P. stuartii strain knocked-out for the Omp-Pst2 porin sheds light on the role it plays in the early stages of growth, as well as in the adaptation to high concentration of urea and to varying pH.
生物膜是由细菌细胞组成的有组织的群落，它们是大多数人类慢性细菌感染的元凶。斯氏普罗威登斯菌是一种革兰氏阴性生物膜形成菌，在导尿患者中尿路感染的发生率很高。然而，这些生物膜的结构及其对环境损伤的抵抗力仍知之甚少。在此，我们报告了斯氏普罗威登斯菌在模拟其在人类中最常见病理生理栖息地（即尿路）的条件下的浮游细胞生长和生物膜形成情况。我们观察到，在浮游状态下，斯氏普罗威登斯菌在附着于表面并随后呈现生物膜表型之前，会形成细胞漂浮群落。斯氏普罗威登斯菌的浮游细胞和生物膜细胞对钙、镁以及高浓度尿素具有显著的抗性，并显示出在广泛的pH值范围内生长的能力。对缺失Omp-Pst2孔蛋白的斯氏普罗威登斯菌菌株进行的实验揭示了该孔蛋白在生长早期以及对高浓度尿素和不同pH值适应过程中所起的作用。
