Présentation
We originally developed genetic tools to study adhesion and biofilm formation in commensal and pathogenic E. coli species. These tools are made freely available to the scientific community upon request.
• pKOBEG Lambda Red plasmids
Based on an initial report by Ken Murphy (U. Massachusetts, USA), we and others developed a rapid PCR-based method using Lambda Red linear DNA recombination to inactivate target genes in E. coli. These methods are now widespread using either K.C. Murphy’ (Murphy 1998), D. Court (Yu et al., 2000), or Barry Wanner (Datsenko and Wanner, 2000) tools or the plasmids (pKOBEG’s) developed in the laboratory.In collaboration with E. Carniel’s group, (Yersiniae Unit, Institut Pasteur), we extended the use of this strategy to the disruption of genes in many commensal and pathogenic enterobacteriacea. All of these tools are available upon request.
Key publications
• Chaveroche, M.K., J.M. Ghigo, and C. d’Enfert. (2000). A rapid method for efficient gene replacement in the filamentous fungus Aspergillus nidulans. Nucleic Acids Research 28:E97.
• Derbise, A ; B. Lesic, D. Dacheux, J.M. Ghigo and E. Carniel . (2003)« A rapid and simple method for inactivating chromosomal genes in Yersinia”. FEMS I. Med Microbiol. Sep 22;38(2):113-6
• RExBAD and RExTET Inactivation/expression tools for plasmid-free study of gene function
We developed a plasmid-free approach enabling both inactivation and modulation of target gene expression. This method combines the lambda-red linear DNA recombination technique with the site-directed insertion of a repression/expression cassette placing a functional and tightly inducible pBAD or Tet promoter upstream of a target gene directly on the chromosome This approach was used in several enterobacteriacea to investigate, at chromosomal monocopy level, the function of large operons, cryptic, essential or unknown function genes. All of these tools are available upon request.
Key publications
• Roux, A., C. Beloin, and J.M. Ghigo. (2005). Combined Inactivation and Expression Strategy To Study Gene Function under Physiological Conditions: Application to Identification of New Escherichia coliAdhesins. Journal of Bacteriology 187:1001-13.
• Da Re, S., B. Le Quere, J.M. Ghigo, and C. Beloin. (2007). Tight modulation of Escherichia coli bacterial biofilm formation through controlled expression of adhesion factors. Applied and Environmental Microbiology 73:3391-403.
• MFDpir improved donor strain for transposon mutagenesis
We constructed a Mu-free donor strain, MFDpir, that is an alternative to the use of the Mu-ridden S17– λ pir and SM10– λ pir strains that are commonly used as donor strains for transposon mutagenesis. The use of MFDpir simplifies the analysis of transposon mutants in E. coli and other Mu-sensitive RP4 host bacteria. Available upon request.
Key publication
• Ferrieres, L., G. Hemery, T. Nham, A.M. Guerout, D. Mazel, C. Beloin, and J.M. Ghigo. (2010). Silent mischief: bacteriophage Mu insertions contaminate products of Escherichia coli random mutagenesis performed using suicidal transposon delivery plasmids mobilized by broad-host-range RP4 conjugative machinery. Journal of Bacteriology 192:6418-27. doi: 10.1128.