Their investigation reveals exactly why the organisms are so dangerous

Jan 27, 2012 08:31 GMT  ·  By
Microbes observed as they became efficient killers through genetic mutations
   Microbes observed as they became efficient killers through genetic mutations

In addition to being extremely dangerous to humans on their own, many microorganisms also display the ability to mutate extremely fast, so that they can adapt to new, unexpected situations at a moment's notice. The capability was observed as scientists monitored microbes in a new experiment.

The research team, which is based at the Michigan State University (MSU), says that the study is one of the first to demonstrate the full evolutionary paths new viruses take in order to become efficient parasites. The work demonstrates just how easy it is for these pathogens to mutate.

That wouldn't be a problem in itself, since numerous mutations occur in all species all the time. Sometimes, though, a few of those mutations may cause more harm than good. This is, for example, one of the causes of cancer in humans.

In viruses, while certain genetic modifications may help them survive more efficiently, they also make them more dangerous to other species, including us, in the process. The thing is, we cannot confront bacteria and microbes in the open.

As always, it all comes down to time, researchers comment. It takes years for new class of antibiotics to be developed and tested, against a particular type of microorganisms. Bacteria and viruses, on the other hand, can mutate in a manner that renders them immune to the actions of a specific drug in as little as two weeks.

Details of the new investigation were published in the latest issue of the top journal Science. During the experiments, the MSU team observed how the Lambda virus developed four separate mutations over a brief period of time. These allowed it to start infecting cells in a new, unusual manner.

MSU graduate student Justin Meyer says that this type of mutations could turn the Lambda virus from something that is now completely harmless to humans into a public health problem. Meyer was one of the coauthors of the new study.

“We were surprised at first to see Lambda evolve this new function, this ability to attack and enter the cell through a new receptor – and it happened so fast. But when we re-ran the evolution experiment, we saw the same thing happen over and over,” the investigator says.

The expert carried out the work with MSU Hannah Distinguished professor of microbiology and molecular genetics, Richard Lenski.

“Natural selection promoted the virus’ evolution because the mutations helped them use both their old and new attacks. The finding raises questions of whether the five bird flu mutations may also have multiple functions, and could they evolve naturally?” Meyer concludes.