The 5-AA deletion severely impairs the ability of <i>B. burgdorferi</i> to disseminate in immunocompetent mice ^a.

aGroups of 24 BALB/c mice each received a single intradermal/subcutaneous injection of 105 spirochetes of the clone ΔospC/FL/1 or ΔospC/ΔNt5/1. Six animals from each group were euthanized at 1, 2, 3, or 4 weeks post-inoculation; inoculation site (I.S.) and remote site (R.S.) skin, ear, heart, and tibiotarsal joint specimens were harvested for spirochete culture in BSK-H complete medium. The I.S. site was at the chest; therefore the R.S. site was at the back of the mice. bNot determined.