Table 1. List of strains of Staphylococcus aureus used in this study.

Strain or plasmid	Relevant Characteristics	Reference
S. aureus
Newman	NCTC 8178 wildtype	Duthie and Lorenz, 1952
Newman clfA	clfA:: Emr defective in clumping factor A	McDevitt et al 1994.
Newman clfB	Newman clfB:: lacZ Emr defective in clumping factor B	McAleese et al, 2001
Newman spa	Newman spa:: Kar defective in protein A	O'Brien et al, 2002
Newman sdrC	sdrC:: pG+Host Emr defective in Serine aspartate repeat protein C	O'Brien et al, 2002
Newman sdrD	sdrD:: pG+Host Emr defective in Serine aspartate repeat protein D	O'Brien et al, 2002
Newman ΔsdrCDE	ΔsdrCDE:: Tcr. Deletion mutant lacking SdrC SdrD and SdrE	O'Brien et al, 2002
Newman cap	cap:: Tcr defective in capsular polysacccharide	Wann et al, 1999
SH1000	8325-4 with repaired defect in rbsU	Horsburgh et al 2002
SH1000 spa	spa:: Tcr transduced from 8325-4 spa	This study
8325-4	NCTC8325 cured of prophages	Novick 1967
8325-4 spa	spa:: Tcr. Protein a defective mutant	Hartlieb et al, 2000
Newman clfA clfB	clfA:: Emr clfB: Tcr Defective in clumping factors A and B	Ni Eidhin et al, 1998
Plasmids
pCU1spa	Shuttle vector capable of replicating in E. coli and S. aureus. Cmr Apr spa gene cloned into pCU1	This study
pCU1 spaL17A	Expresses spa with an L17A substitution in each IgG binding domain	This study