Researchers reveal evolution mechanisms of bacterial predators

A team of researchers have discovered how bacterial predators evolved to kill other bacteria without harming themselves, which might provide new ways of combating antimicrobial resistance, according to a study released Thursday by the University of Birmingham.

Bacterial predators, also known as bacteria-killing bacteria, may assist humans in fighting pathogens in the post-antibiotic era, but how bacterial predators function has been little understood to date.

A joint study by the labs of Dr. Andrew Lovering and Prof Liz Sockett at the University of Birmingham and the University of Nottingham, has shown how bacterial predators protect themselves from the weapons they use in their bacterial killing pathway.

The research, published in the journal Nature Communications, offers insights into early steps in the evolution of bacterial predators.

Researchers observed that a predatory bacterium called "Bdellovibrio bacteriovorus" ate other bacteria. It attacked them from inside out using enzymes that first loosened the cell walls of prey bacteria and then caused them to inflate like pufferfish. But given the predatory bacterium had similar cell walls, theoretically they could have fallen victim to their own attack.

Researchers found that the bacterium used an ankyrin-type protein as a shield. It bound to the tip of the enzyme weapons, nullifying their action until they were safely secreted out of the predatory bacterium and into the prey bacteria.

"Most bacteria are not predatory and so understanding these mechanisms gives us a glimpse of how predation evolved," said Sockett.

Commenting on the potential impact of the study, Lovering said: "If we are to use Bdellovibrio as a therapeutic in the future, we need to understand the mechanisms underpinning prey killing and be sure that any self-protective genes couldn't be acquired by pathogens, causing resistance." Endit