Table 1.

The effect of lidocaine on B. afzelii strain NE4049 in vitro.

Compounds	Concentration	Day 1	Day 7
Control		++++	++++
Lidocaine (mg/ml)	5	0	0
	2.5	0	0
	1.25	++	++
	0.62	++	++
	0.31	++++	++
	0.15	++++	++++
	0.078	++++	++++
	0.039	++++	++++
	0.019	++++	++++
	0.009	++++	++++
	0.0048	++++	++++
	0.002	++++	++++
	0.001	++++	++++
	0.0006	++++	++++
Gentamicin (µg/ml)	100	0	0
	50	0	0
	25	0	0
	12.5	++	0
	6.25	++	+
	3.12	++++	++
	1.56	++++	++++
	0.78	++++	++++
	0.39	++++	++++
	0.19	++++	++++
	0.09	++++	++++
	0.048	++++	++++

Borrelia motility and numbers were evaluated by observation and counting using Petroff-Hausser chamber under a dark-field microscope. Gentamicin was used as a positive control.

Key used: +: detectable viable B. afzelii in culture by microscopy; ++: at least one spirochete/field of view; +++: at least 10 spirochetes per field of view, ++++: an average of > 100 spirochetes per field of view).