Bacteriophages are parasitic viruses that replicate exclusively in their host, with remarkable specificity. For almost a century, phage suspensions have been used therapeutically in certain Eastern European countries (Russia and Georgia) as an antibiotic treatment. Today, phages are incorporated into some food packaging or wound dressings to reduce the proliferation of bacteria such as
Escherichia coli,
Listeria and
Salmonella.
More recently, bacteriophages have been used as a biosensing element for diagnostic purposes. But they need to be produced in large quantities, and then immobilized on a sensor. To this end, scientists at IRIG have developed a phage purification method to obtain active viral particles in large numbers. They also tested various chemical modifications of the bacteriophages to physically immobilize them on the gold surface of a biosensor, while maintaining their infectivity. The bio-active devices thus obtained show the highest phage density ever described in the literature.
Several biosensors have been produced with different bacteriophages to demonstrate their specificity with respect to their host bacteria.
These results could lead to miniaturized devices, functionalized with different bacteriophages, enabling the sensitivity of a pathogenic bacterium to a specific virus to be tested more rapidly, in just a few hours.
And since we are faced with a growing number of antibiotic-resistant strains, phages represent a serious alternative as an antibiotic treatment, provided they can be produced on a large scale, and in a characterized and reproducible manner for therapeutic purposes.
Artist view showing bacteria blasting after bacteriophage infection. © Larry O C’onnell
Scanning electronic microscopy image of bacteriophages on the gold-coated surface.