Interactions between phage and bacteria have been identified

In a paper published earlier this year in the journal Natural microbiology, The research team discovered that this communication system involves a complex network of antagonistic interactions between phage proteins and host bacteria. This discovery deepens our knowledge of the phage communication system, a promising tool for fighting antibiotic-resistant superbugs.

A curious phage-bacterium communication system

Phages have an amazing social life. In 2017, it was revealed that they were using a communication system called arbitration, what do they use to decide What life cycle do they acquire after infection? host, lytic or lysogenic.

He stone It generates multiple copies of the virus inside the bacteria, which ends in the death of the infected bacteria (lysis) and thus the release of the phages. During the cycle lysogenic, The genetic material of the phage is integrated into the bacterial chromosome and, thus, remaining in a dormant state, is copied and transmitted to the offspring when the bacteria multiply.

To create copies or not to create copies

Until now it was believed that this system arbitration He worked with just two proteins and a small RNA. One of the proteins is a regulator (AimR), and the other is a signaler (AimP), which accumulates depending on the population (the more cells infected with the phage, the more signaling). The production of small RNA (AimX) is critical when deciding which life cycle a phage will follow. “If there are few infected cells, there will be few signals and a lot of RNA, so the phage begins the lytic cycle, generating many copies and lysing the bacteria so that the released phages can infect others,” he describes. Alberto MarinaCSIC Research Professor at IBV-CSIC and one of the main authors of the study.

On the contrary, “if there are many phages and therefore many signals are generated, it is difficult for new bacteria to find free bacteria and it is difficult for them to reproduce. Under these conditions, it is better to integrate into the bacterial genome and remain dormant until the ratio of bacteria to phages becomes high again,” continues the Valencian researcher. In his opinion, this is just iceberg peak other, more complex mechanisms of communication between phages and bacteria. Now together with the researchers Jose R. Penades (Imperial College London) and Avigdor Eldar (Tel Aviv University), Marina develops the project TalkingFages

to dive deeper into these microbial communication systems.

Interaction network

Near Wilfried J. J. Meyerfrom the Center for Molecular Biology of Severo Ochoa (CBM-CSIC-UAM), the teams of Marina and Penades have just published in Natural microbiology work that shows that the original description arbitration presented a very simplified model.

“We have now shown that life cycle decisions involve more phage proteins and, above all, the bacteria’s own proteins.” Marina emphasizes. In the updated model, “the decision about one life cycle or another is established through a complex network of antagonistic interactions involving phage proteins such as SroB, described in the previous article, and YosL, as well as the toxin system. The bacterial antitoxin MazE-MazF, which is essentially a key player in the decision.”

Biotech and biomedical utilities

Thus, “the balance between all these proteins regulates the life cycle of the phage, which shows that this decision is very complex and requires the participation of the host,” says the IBV-CSIC scientist. “This would mean that The phage and its host have a deeper relationship. and that phages are not selfish agents who try to reproduce only at the expense of their hosts,” Marina concludes. This is what they want to test with the project TalkingFages, which received more than eight million euros in one of the latest Synergy grants from the European Research Council (ERC). They are now discovering the molecular basis of the system. arbitration

in context with the host cell.

The use of phages may have important biotechnological and biomedical benefits. Actually, This is one strategy being studied to combat antibiotic-resistant bacteria. It is a pressing health problem that could become the leading cause of death from disease in 2050, according to the World Health Organization. Thus, interfering with the phage life cycle may have health applications in the medium to long term.

Help Articles:

Antagonistic interactions between phage and host factors control arbitration synthesis and lysogeny decision.

Arbitrium communication controls phage lysogeny through non-lethal modulation of the host toxin-antitoxin defense system.