Scientists discover key element in bacterial evolution

Scientists at the University of Glasgow have discovered an important element in understanding bacterial evolution and ultimately antibiotic resistance.

The team of researchers identified how certain genetic elements of bacterial pathogens can spread and transform non-pathogenic bacteria into virulent.

Most bacterial pathogens cause disease through the presence of a class of genetic elements called “pathogenicity islands”.

The researchers describe the spread of these pathogenetic islands as “hijacking the hijackers”, the mechanism of which was previously unknown and is thought to be widespread in nature.

Pathogenicity islands are called Phage-Inducible Chromosomal Islands – or PICIs – and represent a novel family of mobile genetic elements found in pathogenic bacteria and which play an important role in bacterial evolution and antimicrobial resistance.

PICIs are clinically important because they carry disease and antibiotic-resistant genes. More so the transfer of these elements greatly impacts on the emergence of increasingly virulent and resistant bugs.

Professor José R Penades, from the University’s Institute of Infection, Immunity and Inflammation, said: “In our discovery, we have seen how pathogenicity islands hijack and block their helper virus, using the virus for themselves to move.

“These pathogenicity islands are smart. One reason they can move so quickly is because they can sense nearby viruses and hijack them. Essentially, we have found another way that bacterial bugs evolve, in what is a very clever mechanism.”

One human health condition in which pathogenetic islands are found is Toxic Shock Syndrome.

The team hope that their discovery could help scientists better understand how antibiotic resistant bugs and inform further crucial research in this area.