Rickettsia prowazekiiand Real-time Polymerase Chain Reaction

Sanela Svraka,Didier Raoult,John Gatabazi,Yassina Bechah,Jean-Marc Rolain

doi:10.3201/eid1203.050888

Abstract

Rickettsia prowazekii is the causative agent of epidemic typhus and a potential bioterrorism agent. Sensitive and specific rapid assays are needed to complement existing methods of detecting this organism. We developed a real-time quantitative polymerase chain reaction assay by using a species-specific probe targeting the gltA gene. This assay, which was rapid, specific for R. prowazekii only, and sensitive (cutoff detection of 1 to 5 copies per sample), detected and directly identified R. prowazekii in blood of 12 experimentally infected mice sampled at day 3 and 6 postinfection or in naturally or experimentally infected lice. Because our assay is highly standardized and easily adaptable, it could improve epidemic typhus surveillance in public health programs, especially for countries with underdiagnosed or unrecognized human cases.

Highlights

Rickettsia prowazekii is the causative agent of epidemic typhus and a potential bioterrorism agent
Rickettsia prowazekii is the causative agent of epidemic or louseborne typhus, which is transmitted by the human body louse
The aim of our study was to develop a real-time quantitative polymerase chain reaction (PCR) assay by using a species-specific probe that is rapid, sensitive, and specific for detecting R. prowazekii in clinical samples or in body lice in outbreaks of epidemic typhus

Summary

Introduction

Rickettsia prowazekii is the causative agent of epidemic typhus and a potential bioterrorism agent. A definite diagnosis of epidemic typhus is often delayed because the sensitivity of cell culture and polymerase chain reaction (PCR) methods is low [13], and serologic diagnosis can be obtained only by using advanced serologic methods such as Western blot analysis after cross-adsorptions. These methods are restricted to laboratories with biosafety level 3 (BSL-3) facilities and trained technicians [14]. The aim of our study was to develop a real-time quantitative PCR assay by using a species-specific probe that is rapid, sensitive, and specific for detecting R. prowazekii in clinical samples or in body lice in outbreaks of epidemic typhus

Objectives

Methods

Results

Conclusion