TABLE 2.

Stability of plasmids pIF1 (sgfp without promoter), pCM11 (sarA promoter-driven sgfp), and pIF2 (sed promoter-driven sgfp) carried by S. aureus CIM433 in milk for 24 h^a

Time (h)	Cell count on BHI + Ery as % of cell count on BHI alone
	pIF1	pCM11	pIF2
0	103	105	94
2	101	117	96
4	105	105	103
6	101	116	118
24	86	55	93

^aBacterial cultures were plated in duplicate on BHI and on BHI supplemented with 10 μg/ml erythromycin. Cell counts on BHI with antibiotic selection are expressed as percentages of cell counts on BHI alone.