Integrons: Sex, drugs and recombination

Datum

24.01.2012

Zeit

14:00 - 15:00

Sprecher

Didier Mazel

Zugehörigkeit

Unité Plasticité du Génome Bactérien, Institut Pasteur, Paris, France

Sprache

en

Hauptthema

Biologie

Andere Themen

Biologie

Host

Michael Schlierf

Beschreibung

In most gram-negative species, the multi-drug resistance phenotype development and spread is linked to the presence of integrons. Working as natural genetic engineering platforms, these elements are able to incorporate open-reading frames and convert them to functional genes by ensuring their correct expression. We have previously shown that cassette recruitment involved a novel mode of recombination using single stranded DNA substrates, which likely accounts for the unique aptitude of this site-specific recombination system to recombine distantly related sequences. We have recently shown that the SOS response controls expression of the integrase, and as a result, the gene cassette recruitment process. We have also shown that general horizontal gene transfer mechanisms, such as conjugation and transformation, also induce the SOS response. These observations point to single strand DNA being a central metabolite for the adaptive response of bacteria, especially for integrons and antibiotics. The fact that antibiotics, especially those inducing the SOS response, trigger for the resistance cassette recruitment, resulting in a vicious circle favoring the development of resistance, is of particular concern. I will present an integrated model of cassette dynamics taking into account our most recent results.

Letztmalig verändert: 05.01.2012, 10:54:23