Establishment of Orientia tsutsugamushi Lc-1 (Rickettsiales: Rickettsiaceae) infection in ICR outbred mice (Rodentia: Muridae) by needle challenge.

[scrub typhus]

Orientia tsutsugamushi is a pathogen transmitted by Leptotrombidium that causes scrub typhus . To develop an infection mouse model , a mite-derived isolate of O . tsutsugamushi was established from a laboratory-maintained colony of Leptotrombidium chiangraiensis (O . tsutsugamushi Lc-1 ). This Lc-1 isolate was initially presented to ICR (CD-1 ) mice by feeding an infected Lc chigger on the ear of a mouse . Once the Lc-1 was adapted to the ICR mice , quantitative real-time polymerase chain reaction was used to investigate O . tsutsugamushi genomic equivalent copies in tissues and sera . Furthermore , times to onset of the signs of infection are reported in this study . This study provides information useful for future research on this host-pathogen interaction and the associated vaccine efficacy trials .