TABLE 2.

p66/flaA expression with increasing time in in vitro culture^a

No. of days postinoculation	No. of bacteria per ml (107)	p66/flaA ratio
1	4.48	7.65
2	6.2	3.39
3	8.3	1.77
4	9.48	0.83
6	9.43	0.45
8	6.68	0.35

^aB. burgdorferi strain N40 (clone D10E9) was inoculated into MKP medium and incubated at 34°C for the number of days indicated. The bacteria were enumerated by dark-field microscopy. After reaching saturation, this strain clumps, decreasing the apparent culture density. p66 and flaA transcript levels were quantified by real-time RT-PCR as described for Table 1.