Evaluation of a serum-based PCR assay for the diagnosis of canine monocytic ehrlichiosis

Mathios E. Mylonakis , Victoria I. Siarkou , Leonidas Leontides , Eleftheria Bourtzi-Hatzopoulou , Vassilios I. Kontos , Alexander F. Koutinas

The aim of this study was to estimate the relative diagnostic sensitivity and specificity of a polymerase chain reaction (PCR) assay in the serum of dogs with naturally occurring non-myelosuppressive canine monocytic ehrlichiosis (CME), and to investigate the association between PCR positivity and immunofluorescence antibody (IFA) titres for . Serum samples obtained from 38 dogs with non-myelosuppressive CME and 12 healthy dogs were analyzed retrospectively. Each serum sample was analyzed in triplicate using an specific nested PCR assay targeting a 389bp sequence of the 16S rRNA gene. DNA was amplified in 24 of 38 (63.1%) affected dogs; all samples from healthy dogs were negative. A high level of agreement was found among the PCR replicates (<0.0001). Median IFA titre of the 24 PCR-positive dogs was significantly lower than that of the PCR-negative infected dogs (0.0029), indicating that DNA may circulate prior to the development of a high antibody titre. Serum-based PCR analysis is suggested for the early diagnosis of CME when whole blood samples are not available.

Mots clés: Serum; Dog; PCR; 16S rRNA

Mathios E. Mylonakis, Victoria I. Siarkou, Leonidas Leontides, Eleftheria Bourtzi-Hatzopoulou, Vassilios I. Kontos, et al.. Evaluation of a serum-based PCR assay for the diagnosis of canine monocytic ehrlichiosis. Veterinary Microbiology, 2009, 138 (3-4), pp.390. ⟨10.1016/j.vetmic.2009.04.015⟩. ⟨hal-00514610⟩