January 7, 2009

Bacteria can transfer toxic genes

New York University School of Medicine researchers say they are startled to find bacteria may have the capability to stealthily transfer toxic genes.

In laboratory experiments, scientists John Chen and Dr. Richard Novick, discovered the bacterium Staphylococcus aureus could co-opt viruses that infect bacteria, called bacteriophages, and use them as pipelines to transfer genetic material to another kind of bacteria -- Listeria monocytogenes. This is the first time, the researchers say, that phages have been observed to serve as shuttle vehicles for bacterial toxins between different species.

We have found that a bacteriophage can transfer genetic elements, or DNA, between unrelated bacterial species in a way that was really not expected, Novick says in a statement.

When Chen, a postdoctoral fellow in Novick's laboratory, suggested doing some transfer experiments with bacteriophages. Novick says he had said go ahead, but it won't work. To his surprise, the bacterial viruses did the completely unexpected.

Although the study, published in Science, uncovered only transfer to Listeria, Novick says the relatively high efficiency suggests that other cases may well exist in nature.

Novick says the transfer is happening by stealth, silently, without anyone noticing.