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Updated: February 7, 2022 at 19:00 IST
Wurzburg [Germany]ANI, February 7, 2007: It is well-known that bacteria are very resourceful in adapting to their environment. A team of researchers has discovered a new technique bacteria uses: a sponge that absorbs certain messengers.
The study was recently published by the journal Molecular Cell.
The study was part of research at the Institute for Molecular Infection Biology of the University of Wurzburg (IMIB), and at Helmholtz Institute for RNA based Infection Research. The laboratory of Professor Jorg Vogel was the Chair of Molecular Infection Biology I and Managing Director at the HIRI. He also discovered new details about these signalling pathways.
A previous study published in “The Lancet” revealed that at least 1.27million people die each year from infections with bacteria that is resistant to standard antibiotics. The authors were concerned that this number could rise up to ten millions by 2050.
This made it urgent to search for new compounds that are effective against resistant bacterial strains. One possible approach was to develop programmable RNA-based antibiotics. This required a deep understanding of the key RNA signalling pathways and mechanisms that are involved in an infection.
Gianluca Matera is a Ph.D. student from the IMIB and provided additional information about the background of the paper he coauthored with Jorg Vogel. He explained, “Most bacteria, such as Salmonella enterica or Escherichiacoli have a cell envelope that consists of an outer and inner membrane.” This envelope has two main functions: to protect the bacteria from their environment and to allow them to get nutrients.
Many RNA entities work together to control which substances can be passed through the cell envelope at any given time. This allows the bacteria to defend themselves against antibiotics. Researchers have identified an “RNA sponge” as a new protagonist in Salmonella enterica.
These sponges are part of the “small RNA” class. The Wurzburg study demonstrated that OppX mimicked a specific sRNA binding target, the MicF sRNA in the bacterial membrane, intercepting it before reaching its destination. It absorbed it like an sponge.
The MicF sRNA was a key component of the processes within the bacterial envelope. “The outer membrane and inner membranes of a bacterial envelope cannot function independently. They must communicate with each other, so there must be mechanisms to do this. Gianluca Mattera explained that MicF, a small non-codingRNA, is one type of such regulators.
The Hebrew University of Jerusalem developed a new technique that allowed the junior scientist to identify all the interacting partners of all the sRNAs in Salmonella. This was done in one step.
Matera explained that OppX is a process that increases membrane permeability. It does this by increasing the expression of one of the main pores of the bacterial outer membrane. OmpF is the scientific term for this pore.
If the OppX sponge is missing, the bacterium’s growth will be limited, especially in a nutrient poor environment. If OppX is present in sufficient quantities, the OmpF pores of the membrane become more active, increasing the uptake and reducing the need for nutrients.
OmpF pores also play a critical role when bacteria are attacked with antibiotics. They act as the main entry points into the cell. Matera stated that OppX could indirectly have an effect on antibiotic efficacy by increasing OmpF production and therefore the uptake of antibiotics.
OppX is known to be the first regulator of MicF activity. The newly published data supports the idea that OppX may be the most important, if certainly the only, sponge for MicF sRNA. According to the study authors, it is important to understand the cellular activity MicF.
These new findings were based upon studies of bacteria grown in vitro in laboratory conditions. Scientists believe the next challenge will be to extend these experiments to more “realistic” conditions.
Jorg Vogel explained that the first step was already made in this direction: “We are currently decoding RNA interactomes of Salmonella infection in infected host cells,” Jorg Vogel said. “Antibiotic resistance is one the most serious health threats of our times. That’s why our basic research strives for the development of new therapeutics.” (ANI)