title: Unveiling electrotransformation of Moraxella catarrhalis as a process of natural transformation.
abstract: The human respiratory tract pathogen Moraxella catarrhalis is a naturally competent microorganism. However, electrotransformation has long been used to introduce foreign DNA into this organism. This study demonstrated that electrotransformants obtained with linear or circular nonreplicating plasmid DNA originated exclusively from natural transformation processes taking place during the recovery phase after the application of current. Only replicating plasmid DNA could be introduced into M. catarrhalis by electrotransformation, in a type IV pilus-independent manner. Electrotransformation with homologous genomic DNA indicated that restriction of double-stranded DNA was independent of type III restriction-methylation systems. Nontransformability of M. catarrhalis by electrotransformation was observed using double- as well as single-stranded DNA. In addition, the study showed that natural competence is a very constant feature of M. catarrhalis.
authors.affiliation: Institute for Infectious Diseases, University of Bern, Bern, Switzerland. patricia.stutzmann@ifik.unibe.ch
authors.forename: Patricia Stutzmann
authors.initials: PS
authors.lastname: Meier
authors.forename: Rolf
authors.initials: R
authors.lastname: Troller
authors.forename: Nadja
authors.initials: N
authors.lastname: Heiniger
authors.forename: John P
authors.initials: JP
authors.lastname: Hays
authors.forename: Alex
authors.initials: A
authors.lastname: van Belkum
authors.forename: Christoph
authors.initials: C
authors.lastname: Aebi
mesh_terms: D004247:DNA / Q000235:genetics / Q000378:metabolism; D015280:DNA Restriction-Modification Enzymes / Q000502:physiology; D004269:DNA, Bacterial / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D018274:Electroporation; D010861:Fimbriae, Bacterial / Q000502:physiology; D001936:Moraxella catarrhalis / Q000235:genetics*; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D014169:Transformation, Bacterial
chemical_list: D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004247:DNA