Infectivity of the Highly Transformable BBE02− lp56− Mutant of Borrelia burgdorferi, the Lyme Disease Spirochete, via Ticks

DOI: 10.1128/IAI.00043-06

Article Figures & Data

TABLE 1.

Effect of lp56 on survival and proliferation of B. burgdorferi clones 5A1 (lp56⁻) and 5A19 (lp56⁺) in capillary-inoculated ticks^a

B. burgdorferi B31 isolate	Values for effects determined in expt 1
	Before mouse feeding			After mouse feeding
	No. of positive nymphs/total fed nymphs	Mean no. of spirochetes per field ± SD	P	Mouse	No. of positive nymphs/total fed nymphs	Mean no. of spirochetes per field ± SD	P
5A1 (lp56⁻)	5/5	0.64 ± 0.17		S327	14/14	41.84 ± 21.88
				S328	4/5
			0.13020	S329	6/6		0.000001
5A19 (WT)	5/5	0.48 ± 0.13		S330	12/12	92.83 ± 39.51
				S331	4/4
				S332	8/8

↵ a Culture positivity and mean number of spirochetes per field were determined 24 to 25 days after capillary inoculation (before mouse feeding group) or 7 days after mouse feeding (after mouse feeding group). Three and 10 fields were counted for each fed and unfed tick, respectively. Mean values of spirochetes per field were averaged over the total number of fed ticks in the three mice of each group. Student's t test was used to evaluate statistical significance. All mice were culture positive at all tissue sites examined after feeding.

TABLE 2.

Effects of BBE02 inactivation and absence of lp56 and lp28-4 on survival and proliferation of B. burgdorferi clones in capillary-inoculated ticks^a

B. burgdorferi B31 isolate	Values for effects determined in expt 2
	Before mouse feeding			After mouse feeding
	No. of positive nymphs/total fed nymphs	Mean no. of spirochetes per field ± SD	P	Mouse	No. of positive nymphs/total fed nymphs	Mean no. of spirochetes per field ± SD	P
5A18 NP1 (lp56⁻, lp28-4⁻, and BBE02⁻)	5/5	1.3 ± 0.2	0.000063	S642	7/7	42.94 ± 17.72	0.000412
				S643	4/4
				S644	7/7
5A4 NP1 (BBE02⁻)	5/5	4.26 ± 0.84		S645	4/4	79.79 ± 38.42
				S646	9/9
			0.040845	S647	6/6		0.098377
5A4 (WT)	5/5	3.02 ± 0.79		S648	8/8	61.92 ± 19.55
				S649	7/7
				S650	9/9

↵ a Culture positivity and mean number of spirochetes per field were determined 24 to 25 days after capillary inoculation (before mouse feeding group) or 7 days after mouse feeding (after mouse feeding group). Five and 10 fields were counted for each fed and unfed tick, respectively. Mean values of spirochetes per field were averaged over the total number of fed ticks in the three mice of each group. Analysis of variance with Scheffe's post hoc analysis was used to evaluate statistical significance. All mice were culture positive at all tissue sites examined after feeding.