Pneumococcal transformation

Patrice Polard

Directeur de Recherche, CNRS
05 61 33 59 72

Team members

  Researcher emeritus
  • David Lane
  • Nathalie Campo
  • Jean-Pierre Claverys
  • Maud Hertzog
  • Calum Johnston
  • Mathieu Berge
  • Marc Prudhomme
  Technical staff
  • Violette Morales
  • Isabelle Mortier
  • Emeline Vernhes
  • David De Lemos


The pneumococcal transformation team combines complementary approaches to study all aspects of genetic transformation in the human pathogen Streptococcus pneumoniae (the pneumococcus). Transformation is a mechanism of horizontal gene transfer entirely encoded by the recipient cell. It involves capture of exogenous DNA, internalization in the form of single strands and integration into the recipient chromosome by homologous recombination, driven by the recombinase RecA. This process is widespread in the bacterial kingdom and promotes acquisition of new genetic traits. In the pneumococcus, transformation occurs during a short window called competence and can mediate the spread of antibiotics and vaccine escape. Our team combines molecular genetics, cell biology, biochemistry and single molecule analyses to study the pneumococcal transformation process. The main projects of our team focus on:

  • the mechanisms and proteins involved in the transformation process at a molecular level
  • how competence is integrated into and controls the pneumococcal cell cycle
  • how competence and transformation impact chromosome dynamics
  • homologous recombination mediated by RecA and partners using single molecule studies
  • the complex regulatory cascade and sensory cues controlling competence induction

Through these complementary projects, we aim to further our fundamental understanding of this widespread, clinically relevant process.



Chomosome dynamics during pneumococcal competence for transtormation

Pneumococcal competence regulation

Transformation machinery (TRAM)

Single molecule analysis of recombination during transformation (SMART)


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Université Paul Sabatier
118 Route de Narbonne

31062 TOULOUSE Cedex

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