. 2022 Apr 19;12:6454. doi: 10.1038/s41598-022-10393-8

Table 5.

Minimal concentrations of CBD and PB (PB minimal effective antibiotic concentration [MEAC]) required to the antibacterial activity of the combination CBD + PB. Fractional Inhibitory Combination Index (FICI) values, according to checkerboard assay results. CBD showed antibacterial activity against GND, so FICI was calculated, and the effect of the combination was characterized.

Strain	CBD MIC (µg/mL)	Antibacterial activity of the combination CBD + PB (µg/mL)		PB MIC (µg/mL)	FICI	Effect
Strain	CBD MIC (µg/mL)	CBD	PB MEAC	PB MIC (µg/mL)	FICI	Effect
M. catarrhalis ATCC 25238	64	4	0.25	0.5	0.56	Additive
M. catarrhalis ATCC 25238	64	16	0.01	0.5	0.27	Synergic
N. meningitidis ATCC 13077	128	32	2	64	0.28	Synergic
		16	8		0.25
		8	16		0.31
N. gonorrhoeae ATCC 19424	256	32	0.5	16	0.155	Synergic
N. gonorrhoeae ATCC 19424	256	16	4	16	0.31	Synergic