The staining was performed as described previously with minor modifications [30 (link)]. Briefly, Borrelia aggregates on the deparaffinized and hydrated BL biopsy sections were stained with aldehyde fuchsine solution (Sigma-Aldrich, 0.5% fuchsine dye, 6% acetaldehyde in 70% ethanol with 1% concentrated hydrochloric acid) for 20 min. After immersing the slides in 70% ethanol for 1 min and having it rinsed with double-distilled water for another minute, the aggregates were sequentially stained with 1% Alcian blue 8GX (Sigma-Aldrich, dissolved in 3% acetic acid, pH 2.5) for 30 min. The slides were rinsed with double distilled water for 3 min and dehydrated using chilled graded ethanol washes (50%, 70%, and 95%, 3 min each). The slides were then immersed in chilled xylene for 2 min and mounted with Permount media (Fisher Scientific). Images were analyzed using different microscopy methods (see Results section).