Australian researchers close in on Campylobacter

A team from Griffith University has identified a unique sensory structure present on particularly virulent strains of Campylobacter jejuni.

The team from the university’s Institute for Glycomics explained that the ability to cause disease depends on the ability of bacterial cells to move towards their target host cells. This movement is determined by specialised structures on the bacterial cells, called sensory receptors, that sense chemicals in their environment.

In the paper ‘A direct-sensing galactose chemoreceptor recently evolved in invasive strains of Campylobacter jejuni’, published in Nature Communications, the researchers describe the sensory structure that is able to bind host-specific sugar.

Campylobacter bacteria are among the most common cause of foodborne enteritis and have surpassed other food bugs such as Salmonella and Shigella as causes of illness, hospitalisation and lost production in the workplace.

The Campylobacter infection is usually passed to humans from food animals, particularly poultry, through consumption of undercooked meats, unpasteurised milk and contaminated water.

The researchers used chicken models to look at mutant displays with disabled Tlp11 chemosensory receptors and determined that disabling just this one sensor reduces the ability of Campylobacter to colonise chickens.

“This is a very important finding, as sensory structures are very specific to each bacteria and offer high target specificity for design of new antimicrobial compounds,” said research leader Professor Victoria Korolik.

“Essentially, it should be possible to design an antimicrobial drug to target a specific pathogen that will not affect normal flora.

“Targeting sensory apparatus of microbes also reduces risk of development of antimicrobial resistance, since the bacterial cell will not be killed but, rather, have its ability to reach host cells and cause disease disabled.”

Professor Korolik further explained that developing an understanding of how bacterial sensors bind to chemicals has enormous potential for the future. Ultimately, scientists could engineer bacteria with a set of sensors that will selectively direct cancer-killing bacteria towards cancer cells. They could also direct bacteria that degrade chemicals in environmental contamination, such as oil spills, to contaminated areas.