Researchers Discover How Infectious Bacteria Can Switch Species

Scientists from the Universities of Bath and Exeter have developed a rapid new way of checking for toxic genes in disease-causing bacteria which infect insects and humans. Their findings could in the future lead to new vaccines and antibacterial drugs.

They studied a bacterium called Photorhabdus asymbiotica, which normally infects and kills insects, but which can also cause an unpleasant infection in humans.

By testing groups of genes from the bacteria against three types of invertebrates (insects, worms and amoebae) and mammalian cells, the scientists were able to identify toxins and other molecules, called virulence factors, made by the bacteria that allow it to infect each type of organism.

By pinning down the genes responsible for each of these possible virulence factors and comparing them with the genes of well known bacteria, the scientists have been able to map out which regions of the bacteria’s DNA control its ability to infect and damage invertebrates, and also potentially humans.

The researchers from Bath and Exeter are publishing their findings in the prestigious journal Proceedings of the National Academy of Sciences of the United States of America.