New effect of antibiotics on microbial ressistance

[Prebe]

Looks like antibiotics do more than just increase selective pressure on microorganisms:

Antibiotic Stress Induces Genetic Transformability in the Human Pathogen Streptococcus pneumoniae
Marc Prudhomme,* Laetitia Attaiech,* Guillaume Sanchez, Bernard Martin, Jean-Pierre Claverys
Natural transformation is a widespread mechanism for genetic exchange in bacteria. Aminoglycoside and fluoroquinolone antibiotics, as well as mitomycin C, a DNA-damaging agent, induced transformation in Streptococcus pneumoniae. This induction required an intact competence regulatory cascade. Furthermore, mitomycin C induction of recA was strictly dependent on the development of competence. In response to antibiotic stress, S. pneumoniae, which lacks an SOS-like system, exhibited genetic transformation. The design of antibiotherapy should take into consideration this potential of a major human pathogen to increase its rate of genetic exchange in response to antibiotics.

[Avatar]

So in English, what it's saying is that antibiotics can actually improve the ability of micro-organisms to mutate (evolve)?

--A

[Prebe]

Exactly! Only transformation is bigger than your average mutation. It is actual exchange of genetic material between organisms. A form of recombination if you will (if I understand correctly).

This paper explains the mechanisms.

[Xar]

From a scientific point of view, it's fascinating... basically, it means that, under antibiotic pressure, these bacteria start exchanging DNA among themselves at a heightened pace, which, coupled with the selective pressure they also suffer due to the antibiotics, basically means they can evolve much faster than previously thought. In fact, these two mechanisms together might lead to speciation much faster than either could do it alone!

[The Laughing Man]

is this called "molecular fear" or "pathogen panic"?

[stonemaybe]

Surely this is no different to the fact that during war, science develops at a faster rate? We're in danger, we try harder to survive.

[Prebe]

That is most likely an excellent anaolgy Stonemaybe.