The role of GpsB in <i>Staphylococcus aureus</i> cell morphogenesis

Abstract

<i>Staphylococcus aureus</i> is a Gram-positive clinical pathogen, which is currently the second cause of death by antibiotic-resistant infections worldwide. For decades, <i>S. aureus</i> cells were thought to be spherical and lack the ability to undergo elongation. However, super-resolution microscopy techniques allowed us to observe the minor morphological changes that occur during the cell cycle of this pathogen, including cell elongation. <i>S. aureus</i> elongation is not required for normal growth in laboratory conditions. However, it seems to be essential in the context of some infections, such as osteomyelitis, during which <i>S. aureus</i> cells apparently elongate to invade small channels in the bones. In this work, we uncovered new determinants required for <i>S. aureus</i> cell elongation. In particular, we show that GpsB has an important role in the spatio-temporal regulation of PBP2 and PBP4, two proteins involved in peptidoglycan synthesis, contributing to the maintenance of the correct cell morphology in <i>S. aureus</i>.