TABLE 1.

Characterization of the S. aureus collections used in this study

Collection	Collection code(s)a	Geographic originb	No. of strains	Original purpose for strain collection in this study	Description of collections	Reference(s) or source
1		United States (CDC)a	59		Multicenter collection of MRSA (63%) and MSSA (37%) strains	35
2		Portugal	184		Nationwide disseminated MRSA strains from hospitals	1
3		Worldwide	66	Generation of strain-specific DNA probes	Worldwide collection of MRSA strains	20
4		Italy	49		Genetically unrelated MRSA strains (determined by PFGE), isolated from hospitalized patients (five centers), Sicily, Italy	41
5		Australia	18		Genetically unrelated MRSA strains (determined by PFGE), obtained from four different hospitals	41
6	K2	United States	26	Determination of discriminatory power of the genotyping methods (see Table 4)	Community-acquired MRSA strains	46
7	SA, SB, SC	United States (CDC)	14		Selection of geographically diverse strains from collection 1	35
8	NC	The Netherlands	10	Stability experiment for binary typing probes (see Table 3)	Strains isolated from persistant nasal carriers	43
9	RIVM	The Netherlands	2		Selection of 1 MRSA strain (Va) and 1 MSSA strain (Ia), from collection no. 10
10	RIVM	The Netherlands	49	Epidemiological applications of the diverse genotyping systems (see Table 5)	MRSA and MSSA strains from 10 outbreaks in 10 Dutch hospitals	This study
11		United Kingdom (NCTC)	2	Mapping of the strain-specific DNA probes (see Fig. 1)	S. aureus NCTC 8325 and 8325-4	27, 29

^aK2, community-acquired MRSA strains from a New York City hospital; SA, SB, SC, S. aureus strains from the CDC collection; NC, nasal carrier; RIVM, National Institute of Public Health and the Environment (Bilthoven, The Netherlands). 

^bCDC, Centers for Disease Control and Prevention; NCTC, National Collection of Type Cultures (Central Public Health Laboratory, London, United Kingdom).