E64 treatment reduced lesion size in RGAS053Δ<i>srv</i> infected mice but increased lesion size in MGAS315Δ<i>srv</i> infected mice.

<p>The infecting dose (∼2×10⁸ CFU) of MGAS315, MGAS315Δ<i>srv,</i> RGAS053 or RGAS053Δ<i>srv</i> was resuspended in 333 µM E64 (0.1 ml), and 333 µM E64 (0.1 ml) was injected directly into the abscess each day following infection (n = 3 mice/strain). Lesion development (mm²) and weight were monitored over 8 days. Representative images of subcutaneous infections are shown from 1, 3, and 8 dpi for each strain. (A) No difference was observed between E64 treated (open circles) and untreated (closed circles) RGAS053 infections over 8 dpi. (B) A trend was observed where lesion formation was decreased following E64 treatment of RGAS053Δ<i>srv</i> (open circles) compared to inoculation with RGAS053Δ<i>srv</i> alone (closed circles). (C) No difference was observed between E64 treated (open triangles) and untreated (closed triangles) MGAS315 infections over 8 dpi. (D) Lesion formation was significantly increased following E64 treatment of MGAS315Δ<i>srv</i> (open triangles) compared to untreated infections (closed triangles) (*p≤0.05; unpaired t-test).