Table 2. Combined effects of cefazolin (CEZ) and nisin A determined by the checkerboard assay.

Organism	n	FIC index	No. of strains (%)
			Synergism	Additive	Indifferent	Antagonism
			(≤0.5)	( >0.5 to ≤1.0)	( >1.0 to ≤2.0)	( >2.0)
Staphylococcus aureus	20	0.19–0.5	20 (100)	0 (0)	0 (0)	0 (0)
Staphylococcus intermedius	20	0.19–1.0	8 (40)	12 (60)	0 (0)	0 (0)
Streptococcus agalactiae	10	0.63–1.0	0 (0)	10 (100)	0 (0)	0 (0)
Streptococcus dysgalactiae	18	0.56–1.0	0 (0)	18 (100)	0 (0)	0 (0)
Enterococcus faecalis	18	0.19–1.0	13 (72.2)	5 (27.8)	0 (0)	0 (0)
Escherichia coli	18	0.5 –1.0	4 (22.2)	14 (77.8)	0 (0)	0 (0)

The FIC index values were interpreted as follows: ≤0.5, synergistic; >0.5 to ≤1.0, additive; >1.0 to ≤2.0, indifferent; and >2.0, antagonistic effects.