Not as simple as 1+1
Oeiras, 14.10.10
Bacteria live within walls. But instead of concrete and cement, the cell wall of Staphylococcus aureus (and other gram positive bacteria) is made of peptidoglycan, which determines shape, and teichoic acids, important for interaction with the infected host. Contrary to the accepted idea, the synthesis of these two cell wall ingredients is intricately connected to assure that everything takes place at the right time and place. This is the conclusion of a study published this week in Proceedings of the National Academy of Sciences USA by researchers from Bacterial Cell Biology and Bacterial Cell Surfaces and Pathogenesis Laboratories at ITQB.
Bacterial cell walls are far from being ordinary containers. In fact, they are complex and dynamic structures involved in bacterial resistance to harsh environments. Changing cell wall structure is one of the strategies used by bacteria to become resistant to antibiotics or more efficient in causing disease. In the last six decades, society has grown used to antibiotics, often forgetting the devastating consequences of bacterial infections before that. Unfortunately, current circumstances require that all bacterial strategies are carefully studied. Even if this includes staring at a wall.
In the work that is now published in PNAS, researchers demonstrate that preventing bacteria from producing teichoic acids, results in the synthesis of weaker peptidoglycan, as assessed by their ability to resist lysozyme. This enzyme, also present in human tears, is produced by hosts to fight bacterial infections. As it turns out, teichoic acids play an important role in the synthesis of peptidoglycan by assuring that one of the required enzymes is maintained at the right place for the right time, throughout cell wall division, to weave the complex and resistant peptidoglycan structure.
Original Article
Teichoic acids are temporal and spatial regulators of peptydoglycan cross-linking in Staphylococcus aureus
Magda L. Atilano, Pedro M. Pereira, James Yates, Patricia Reed, Helena Veiga, Mariana G. Pinho, and Sérgio R. Filipe
