Fig 1.
Flowchart of the experimental design and procedures.
Fig 2.
Measurement of lesion diameter in treated and control rabbits.
Lesion diameter (mm) was measured starting 24 hours post-inoculation (day 1) up to day 45. Group 1 rabbits (n = 2, blue) were treated since day 4 post-inoculation, while Group 2 animals (n = 2, green) were treated since day 14. Control animals (orange) received only carrier (an emulsion of water and hydrophilic petrolatum) since day 4 post-inoculation. Days 13 and 23 are underlined to indicate the days on which DFM of lesion aspirates was performed and/or lesion biopsies (LB) were obtained. Within in each group, the lesion diameter from each individual rabbit is designated with a dot or square.
Fig 3.
DFM analysis of lesion aspirates.
Panel A shows pathogen burden at day 13 post-infection in Group 1 animals (treated with GaM since day 4 post-infection) compared to carrier-treated animals (Group 3) and untreated animals (which started treatment the following day and were then identified as Group 2). The untreated animals started GaM treatment on day 14 post-infection. Panel B shows pathogen burden at day 23 post-infection in Group 2 animals (treated with GaM since day 14 post-infection) compared to carrier-treated controls (Group 3). Asterisks indicate statistical significance (p<0.05).
Table 1.
DFM, FTA-ABS, and VDRL results.
Fig 4.
Quantification of treponemal tp0574 mRNA in lesion biopsies.
Treponemal burden in lesion biopsies harvested at day 13 post-inoculation from Group 1 and Group 3 animals (A), day 23 post-inoculation in Groups 2 and 3 rabbits (B), and at day 33 post-inoculation in Groups 2 and 3 rabbits (C). tp0574 copy number is normalized to 100 copies of rabbit HPRT message. Asterisk indicates statistical significance (p<0.05).
Fig 5.
Histological analysis of lesion biopsies.
Hematoxylin-Eosin. (A, B) Hematoxylin/eosin (HE) straining of biopsies obtained from Group 1 rabbits (#125 and #126, treated since day 4 post-inoculation). (C) HE staining of biopsy from a disseminated lesion of one of the Group 1 rabbits. (D, E) CD4/CD8/CD20 specific staining for the disseminated lesion biopsy of rabbit #125 (Group 1) and the injection site biopsy from control rabbit #122 (Group 3, treated since day 4 with carrier only). (F, G) HE staining of biopsies from lesion developed at the injection sites of Group 3 rabbits (#122, and #128), treated with carrier only.