Feleucins: Novel Bombinin Precursor-Encoded Nonapeptide Amides from the Skin Secretion of Bombina variegata

Table 3

Summary of the combinational effects of the three novel AMPs (bombinin, feleucin-BV1, and feleucin-BV2) described in this study against S.  aureus. FIC indices are shown in the top panel and raw data in the lower panel.

(a)

Peptide combination	FIC index	Result of combination
Feleucin-BV1 + feleucin-BV2	1	Additive
Bombinin + feleucin-BV1	0.5	Synergistic
Bombinin + feleucin-BV2	0.625	Additive

(b)

Microorganism	Lowest FIC index ([A]/[B] in mg/L)
	Peptide A + peptide B	Peptide A + peptide C	Peptide B + peptide C
S.  aureus	0.5 (2/64)	0.625 (4/16)	1 (128/64)

Peptide A is bombinin.
Peptide B is feleucin-BV1.
Peptide C is feleucin-BV2.
[A] and [B] are the MIC fractions or multiples in combination.