Table 1.

Colonization of separate nostrils of healthy volunteers by distinct S. aureus strains^a

S. aureus and colonization of nostrils	No. of volunteers (no. of isolates with characteristic) unless specified otherwise
Total S. aureus
Colonized in both nostrils
100% PFGE identity between strains	28 (56)
<95% PFGE identity between strains	7 (14)
Colonized in only one nostril
Only the right nostril colonized	26 (26)
Only the left nostril colonized	27 (27)
Total no. of volunteers colonized (total no. of isolates)	88 (123)
MRSA (mecA positive)
Colonized in both nostrils
MRSA in both nostrils	0 (0)
MRSA in one nostril and MSSA in the other nostril	3 (3)
Colonized in only one nostril
Only the right nostril colonized	1 (1)
Only the left nostril colonized	4 (4)
Total no. of volunteers colonized (total no. of MRSA isolates)	8 (8)
pvl-positive S. aureus
Colonized in both nostrils
pvl-positive strain in both nostrils	2 (4)
pvl-positive strain in one nostril and pvl-negative strain in the other nostril	1 (1)
Colonized in only one nostril
Only the right nostril colonized	2 (2)
Only the left nostril colonized	3 (3)
Total no. of volunteers colonized (total no. of pvl-positive isolates)	8 (10)

^aThere were a total of 251 healthy volunteers in this study.