Bacteria can be deep sleepers. These deep sleeping bacteria are called 'persisters' and although their ability to fall into a deep sleep is enviable, persisters are problematic as they can wake up spontaneously causing the return of an infection. As a result they have been implicated in the stubbornness of chronic infections.
A team from VIB-KU Leuven Center for Microbiology is looking into how these cells are able to revert from a dormant to an active state. Their research, published today in Molecular Cell, provides insights into how persisters wake up.
In their research, the scientists used an E. coli model system based on HokB, a peptide that is known to promote the development of persister cells by forming pores in the bacterial cell membrane. This results into a rapid loss of energy, pushing the bacteria into a low energy state or deep sleep. Importantly, this pore formation is only possible when two HokB peptides are linked together. The awakening of these sleeping bacteria is possible only when the link between the peptides is broken. This in turn breaks up the pore. Only when the pore is degraded, cells are able to energize again by consuming available nutrients.
Persister cells are responsible for many chronic infections including urinary tract infections by E. coli, lung infections in cystic fibrosis patients by Pseudomonas aeruginosa, or tuberculosis by Mycobacterium tuberculosis.
According to senior author Jan Michiels, "Results from this work may help us to discover novel molecules and to design new strategies to eradicate persisters. Combinations of molecules stimulating awakening together with classical antibiotics could eradicate chronic infections."