| Abstract [eng] |
Acinetobacter baumannii is a Gram-negative bacteria that have spread in health-care institutions worldwide where it targets individuals with critical conditions and those who have a compromised immune system. The success of the pathogen comes from its highly regulated ability to persist in the environment. In bacteria, gene regulation is commonly performed via two-component systems. Additional mechanism that allows A. baumannii to persist in the environment is the presence of secretion systems. However, very few studies have been performed elucidating the regulatory circuits of the latter. The understanding of how they are regulated and how beneficial they are for the interaction with the environment might aid in the design of potential treating strategies. Here, we showed that the two-component BfmRS system from A. baumannii is required for pellicle formation while at the same time it inhibits motility. Also, we determined that BfmRS represses inter-bacterial competition via contact-dependent growth inhibition system. Moreover, we determined that due to the secretion of a toxic component, which causes target cell growth arrest, A. baumannii does not require a cell-cell contact for the competition. Lastly, we present evidence that capsule plays a protective role against this mechanism. In sum, this work shows that the BfmRS system plays a central role in A. baumannii ability to persist in the environment as well as its ability to perform the inter-bacterial competition. |
