title: Stability of the cargo regions of the cfr-carrying, multiresistance plasmid pSP01 from Staphylococcus epidermidis.
abstract: This study investigated the stability or instability - i.e. the ability or inability to undergo excision in circular form - of the four cargo regions (cr1 to cr4) of the novel cfr-carrying, multiresistance plasmid pSP01, arboured by a clinical Staphylococcus epidermidis isolate. Only cr4 proved unstable. The stability of cr1 and cr2 was substantially expected. Insertion sequences (ISs) played an important role in the stability of cr3 (the cfr gene context) and in the instability of cr4. Whereas the stability of cfr genetic contexts is associated with the presence of a single IS copy (istAS-istBS in cr3), their instability is associated with two identical, flanking ISs with the same orientation. cr4 is bracketed between two identical IS257 elements, and appears to behave as a composite transposon. Its instability is of interest because of the existence of a closely related cfr plasmid from S. epidermidis (pSP01.1) that differs from pSP01 only by the lack of cr4. An integration/recombination mechanism is suggested to explain how cr4 may have moved to pSP01.1 to form pSP01.
authors.affiliation: Unit of Microbiology, Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School, Ancona, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Brenciani
authors.affiliation: Unit of Microbiology, Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School, Ancona, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Morroni
authors.affiliation: Unit of Microbiology, Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School, Ancona, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Mingoia
authors.affiliation: Unit of Microbiology, Department of Biomedical Sciences and Public Health, Polytechnic University of Marche Medical School, Ancona, Italy. Electronic address: pe.varaldo@univpm.it.
authors.forename: Pietro E
authors.initials: PE
authors.lastname: Varaldo
authors.affiliation: Unit of Microbiology, Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Giovanetti
mesh_terms: D004251:DNA Transposable Elements; D005798:Genes, Bacterial; D042822:Genomic Instability; D006801:Humans; D010957:Plasmids; D011995:Recombination, Genetic; D013203:Staphylococcal Infections; D013212:Staphylococcus epidermidis / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004251:DNA Transposable Elements
keywords: Cargo region stability; Insertion sequences; Minicircles; Multiresistance plasmid; Staphylococcus epidermidis