Automated activity monitoring
Mice were anaesthetised with isoflurane, tagged subcutaneously with individual radio-frequency-identification (RFID) transponders SID 102/A/2 (EURO I.D. Identifikationssysteme, GmbH, Germany) following analgesia with Caprofen. Mice were housed with 3 animals per cage. Cages were placed onto an RFID sensor plate consisting of 2 × 4 RFID sensors positioned in a grid-like formation (Activity Monitor, PhenoSys, Berlin, Germany). The unique RFID tag of each mouse was used to follow the position over time (sampling rate 3 Hz) and data were calculated as the mean daily distance traveled. The activity was calculated as the percentage reduction in activity compared to baseline (average distance traveled during 6 days before infection).