Real-time multiplex PCR assay for detection and differentiation of rickettsiae and orientiae

Abstract

The high incidence of rickettsial diseases in Southeast Asia necessitates rapid and accurate diagnostic tools for a broad range of rickettsial agents, including Orientia tsutsugamushi (scrub typhus) and Rickettsia typhi (murine typhus), but also spotted fever group infections, which are increasingly reported. We present an SYBR-Green-based, real-time multiplex PCR assay for rapid identification and differentiation of scrub typhus group, typhus group and spotted fever group rickettsiae using 47 kDa, gltA and ompB gene targets. Detection limits for amplification of these genes in reference strains ranged from 24 copies/μl, 5 copies/μl and 1 copy/μl in multiplex and 2 copies/μl, 1 copy/μl and 1..