title: Genetic organization of the downstream region of the mecA element in methicillin-resistant Staphylococcus aureus isolates carrying different polymorphisms of this region.
abstract: We describe here the genetic organization of the mec element downstream of the mecA gene in 34 different methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates carrying 13 of the most frequent polymorphisms of mecA and representing the major epidemic clones of MRSA. All polymorphisms carried three common genetic elements: the hypervariable region, a copy of IS431, and a unique 2-kb sequence (downstream constant segment, or dcs) for which no homologous sequences are found in data banks. Polymorphisms of the downstream region were shown to be caused by the presence of linearized plasmids flanked by insertion sequences (pUB110, pT181, and pI258) and the autonomous insertion sequence IS256.
authors.affiliation: Molecular Genetics Unit, Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: D C
authors.initials: DC
authors.lastname: Oliveira
authors.forename: S W
authors.initials: SW
authors.lastname: Wu
authors.forename: H
authors.initials: H
authors.lastname: de Lencastre
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D006602:Hexosyltransferases; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics*; D002267:Muramoylpentapeptide Carboxypeptidase / Q000235:genetics*; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D011110:Polymorphism, Genetic; D013211:Staphylococcus aureus / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase