TABLE 4.

Stability of plasmids pIF1, pCM11, and pIF2 carried by S. aureus CIM433 during cheese manufacturing^a

Stage and location	Cell count on BHI + Ery as % of cell count on BHI alone
	CIM433/pIF1	CIM433/pCM11	CIM433/pIF2
Molding for 4 h	114	94	88
Day 1	95	41	55
Day 15
Core	61	63	46
Surface	67	61	60

^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.