For in vivo bioluminescence imaging, infected mice were injected with 150 mg/kg d-luciferin i.p. anaesthetized using 2.5% (v/v) isoflurane in oxygen for 2-3 minutes, and then imaged using the IVIS Lumina II (Revvity, Hopkinton, MA, USA). Exposure times varied from 10 seconds to 5 minutes, depending on signal intensity. To estimate parasite burden, whole body regions of interest were drawn using Living Image v4.3 to quantify bioluminescence expressed as total flux (photons/second; p/s). The detection threshold was established from uninfected mice.