TABLE 1.

Comparative growth of B. burgdorferi in two culture media

Inoculum dilutiona	Growthb after:
	2 days		4 days		7 days		14 days		21 days
	BSK	MPM	BSK	MPM	BSK	MPM	BSK	MPM	BSK	MPM
1/10	+++	+++	+++	−−−	+++	−−	+	−	±	0
1/100	++	+±	+++	−	+++	−	+	−	±	0
1/1,000	+	+	+++	0	+++	0	+±	0	±	0
1/10,000	0	0	+	0	+++	0	++	0	±	0
1/100,000	0	0	0	0	+++	0	+++	0	0	0
1/1,000,000	0	0	0	0	+	0	+	0	0	0

^aTenfold dilution series of a suspension of B. burgdorferi HB19. 

^bCultures were observed by AO staining. +, the organism stains orange, ±, a mixture of orange and green organisms; −, only green-staining organisms; 0, no organisms were seen. Where the same symbol is listed multiple times, it refers to the estimate of the number of organisms per slide.