Highly epidemic strains of methicillin-resistant Staphylococcus aureus notdistinguished by capsule formation, protein A content or adherence to HEp-2 cells

In order to investigate whether highly epidemic methicillin-resistant Staph ylococcus aureus (EMRSA) strains possess special properties that favour the ir dissemination and survival, a study was undertaken that examined methici llin-sensitive and methicillin-resistant strains of Staphylococcus aureus i solated in the UK. Included in the study were EMRSA types 1, 2, 3, 15 and 1 6. Phage types EMRSA-15 and -16, in particular, have emerged as significant hospital pathogens in the UK, resisting standard methods of control and sp reading widely, while the incidence of other epidemic types has either decl ined or not changed. All of the strains included in the study were examined for capsule formation, the amount of bound protein A. produced, and quanti tative adherence to the human continuous epithelial cell line HEp-2. Althou gh all of these properties varied amongst the strains examined, there was n o relationship between any of them and methicillin resistance or epidemic t ype and, incidentally, no relationship between cell wall-bound protein A co ntent and adherence.