Molecular diversity of live-attenuated prototypic vaccine strains and clinical isolates of Staphylococcus aureus

Bovine mastitis Staphylococcus aureus isolates and prototypic live-attenuat ed vaccine strains were analyzed by SmaI pulsed-field gel electrophoresis ( PFGE) typing and automated ribotyping. The discriminatory index of these me thods was 0.91 and 0.69, respectively. SmaI PFGE typing assigned all labora tory strains into cluster Q, which shared 49% similarity with clusters A an d B, and 35% similarity with cluster C. Automated ribotyping placed laborat ory strains within ribogroups different from those of bovine isolates. Thes e methods have 70% concordance and permitted identification of the prototyp ic vaccine background from those of clinical isolates. This information is required before conducting field trials with the vaccine. (C) 2001 Federati on of European Microbiological Societies. Published by Elsevier Science B.V . All rights reserved.