New mechanism for methcillin resistance in Staphylococcus aureus: clinical isolates that lack the PBP 2a gene and contain normal penicillin-binding proteins with modified penicillin-binding capacity - Tomasz,A.; Drugeion,H.B.; de Lencastre,M.H.; Jabes,D.; McDougall,L.; Bille,J. (Antimicrob Agents Chemother, 1989)