The evolution of methicillin resistance in Staphylococcus aureus: similarity of genetic backgrounds in historically early methicillin-susceptible and -resistant isolates and contemporary epidemic clones.

ABSTRACT: The key genetic component of methicillin resistance, the mecA determinant, is not native to Staphylococcus aureus. Thus, the evolution of methicillin-resistant S. aureus (MRSA) must have begun with the acquisition of the mecA determinant from an unknown heterologous source some time before the first reported appearance of MRSA isolates in clinical specimens in the U.K. and Denmark (in the early 1960s). We compared the genetic backgrounds and phenotypes of a group of methicillin-susceptible S. aureus (MSSA) isolates to the properties of MRSA strains isolated in Denmark and the U.K. during the same time period, and also to the genetic profiles of contemporary epidemic clones of MRSA. All early MRSA isolates resembled a large group of the early MSSA blood isolates in phenotypic and genetic pr

SUBMITTER: Crisostomo MI 

PROVIDER: S-EPMC55544 | biostudies-literature | 2001 Aug

REPOSITORIES: biostudies-literature