Table 2. Bacterial viability after treatment with auranofin or auranofin-PLGA NPs^a.

Organism (serotype)	Viability after 6 h of treatment withb:
	Auranofin (μM)				PLGA-auranofin (μM)
	DMSO	0.1	0.25	0.5	PLGA	0.1	0.25	0.5
S. pneumoniae
R6 (none)	−	+	+	+++	−	++++	*	*
D39 (2)	−	++	++	+++	−	++++	++++	*
48 (23F)	−	+	+	+++	−	++++	*	*
69 (19F)	−	++	++	+++	−	++++	++++	*
S. pyogenes
Type strain	−	−	−	−	−	−	−	+
SF370 (M1)	−	−	−	+	−	+	++	++

^aBacteria were incubated at 37 °C in PBS (OD₅₅₀ ≈ 0.6) with the indicated compound at 0.1, 0.25 or 0.5 μM. Viability was determined after 6 h of incubation.

^b−, no effect; +, decrease of 1 log in viable cells;++, decrease of 2 logs in viable cells; +++, decrease of 3 logs in viable cells; ++++, decrease of ≥4 logs in viable cells; *, <10 CFU mL⁻¹.