title: Two-step PCR in the evaluation of antibiotic treatment for Ehrlichia platys infection.
abstract: We evaluated the feasibility of using the two-step polymerase chain reaction (PCR) in determining the withdrawal time of antibiotic treatment for Ehrlichia platys infection. We also present experimental evidence of a dog remaining a carrier after treatment with tetracycline. Canine infectious cyclic thrombocytopenia (CICT) was induced in 3 dogs by intravenous inoculation of blood infected with E. platys. Tetracycline was administered to one of the dogs for 2 weeks when parasitemia appeared. Although the hematologic abnormality of cyclic thrombocytopenia soon disappeared, a few parasitized platelets reappeared after the withdrawal of treatment, and the dog thus remained as a carrier. The other dogs were treated with doxycycline when parasitemic episodes first developed. The durations of antibiotic regimens were determined by the results of two-step PCR in which the 16S rDNA of E. platys was amplified from blood samples. Doxycycline was withdrawn after 8 days of treatment, and the follow-up monitoring continued for 3 weeks. The platelet counts of the 2 dogs remained within the normal range, and the etiologic agent of CICT was not found either by Giemsa staining or by the two-step PCR, indicating complete elimination of the agent.
authors.affiliation: Graduate Institute of Veterinary Medicine, College of Agriculture, National Taiwan University, Taipei, Taiwan, ROC.
authors.forename: W L
authors.initials: WL
authors.lastname: Chang
authors.forename: W L
authors.initials: WL
authors.lastname: Su
authors.forename: M J
authors.initials: MJ
authors.lastname: Pan
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004269:DNA, Bacterial / Q000235:genetics; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000008:administration & dosage / Q000627:therapeutic use*; D004536:Ehrlichia / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D016873:Ehrlichiosis / Q000150:complications / Q000188:drug therapy / Q000662:veterinary*; D005260:Female; D008297:Male; D010976:Platelet Count; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D013752:Tetracycline / Q000008:administration & dosage / Q000627:therapeutic use*; D013921:Thrombocytopenia / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D013752:Tetracycline; D004318:Doxycycline