Distinct Morphological Fates of Uropathogenic <i>Escherichia coli</i> Intracellular Bacterial Communities: Dependency on Urine Composition and pH
Gregory Iosifidis, Iain G. Duggin
Abstract
and allows the development and fate of individual cells to be monitored in real time by fluorescence microscopy. The UPEC-infected bladder cells remained alive and mobile in nonconfluent monolayers during the development of intracellular bacterial communities (IBCs). Switching from a flow of growth medium to human urine resulted in immobilization of both uninfected and infected bladder cells. Some IBCs continued to develop and then released many highly filamentous bacteria via an extrusion-like process, whereas other IBCs showed strong UPEC proliferation, and yet no filamentation was detected. The filamentation response was dependent on the weak acidity of human urine and required component(s) in a low molecular-mass (<3,000 Da) fraction from a mildly dehydrated donor. The developmental fate for bacteria therefore appears to be controlled by multiple factors that act at the level of the whole IBC, suggesting that variable local environments or stochastic differentiation pathways influence IBC developmental fates during infection.