Table 2.

Competitive index experiments assessing the ratio of lp28-3-deficient spirochetes to wild-type spirochetes in an experimental coinfection model^a

Expt and coinjected mouse	CI result (lp28-3−/wild-type ratio) for:
	Inoculum	Mouse isolates			Larval tick isolates
		2 wk	4 wk	8 wk
Expt 1 (C12/A3 ratio)b
Mouse 1	1:1	NAc	1:2.4	NA	NA
Mouse 2	1:1	NA	1:6.5	NA	NA
Mouse 3	1:1	NA	0:1d	NA	NA
Mouse 4	1:1	NA	1:8.3	NA	NA
Expt 2 (C33/A3 ratio)e
Mouse 1	1:1.25	1.0:7.7	0:1.0d	1.0:2.7	1.0:15.8
Mouse 2	1:1.25	0:1.0d	NDf	ND	0:1.0d
Mouse 3	1:1.25	1.0:7.7	1.0:10.7	0:1.0d	0:1.0d
Mouse 4	1:1.25	1.0:1.0	ND	ND	6.1:1.0
Mouse 5	1:1.25	1.0:10.6	1.0:8.0	1.0:5.0	1.0:11.5

^aThe data used to determine these ratios are provided in Table S2 (CI experiment 1) and Table S3 (CI experiment 2) in the supplemental material.

^bRatio of C12 (lp28-3⁻) to A3 (wild type) determined by enumeration of spirochetes in a Petroff-Hausser chamber prior to preparation of the inoculum. Mice were inoculated with 9 × 10³ spirochetes.

^cNA, not applicable. Samples were not taken at these time points in experiment 1.

^dAll of the tissue isolates screened were positive for the presence of lp28-3 from these samples (for isolate screening data, see Tables S2 and S3 in the supplemental material).

^eRatio of C33 (lp28-3⁻) to A3 (wild type) determined experimentally by PCR screening of colonies for lp28-3 after plating of the inoculum. Mice were inoculated with 1 × 10⁴ spirochetes.

^fND, not determined due to contamination of the reisolation culture.