Efficacy of a modified polymerase chain reaction assay for detection of Ehrlichia canis infection

• Published in: Journal of veterinary diagnostic investigation Vol. 12; no. 5; pp. 456 - 459
• Main Authors: Mathew, JS, Ewing, SA, Malayer, , JR, Fox, JC, Kocan, KM
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA J Vet Diagn Invest 01-09-2000; SAGE Publications; American Association of Veterinary Laboratory Diagnosticians
• Subjects: Animal bacterial diseases; Animals; Bacterial diseases; Bacteriological methods and techniques used in bacteriology; Bacteriology; Biological and medical sciences; Biotinylation; DNA Primers; DNA, Bacterial - analysis; DNA, Bacterial - genetics; Dog Diseases - diagnosis; Dog Diseases - microbiology; Dogs; Ehrlichia - genetics; Ehrlichiosis - diagnosis; Ehrlichiosis - genetics; Ehrlichiosis - veterinary; Fundamental and applied biological sciences. Psychology; Infectious diseases; Medical sciences; Microbiology; Polymerase Chain Reaction - veterinary; Sensitivity and Specificity; Ehrlichiaceae; Performance evaluation; Fissipedia; Carnivora; Rickettsialosis; Ehrlichieae; Canis familiaris; Chemical labelling; Method; Infection; Rickettsiales; Polymerase chain reaction; Vertebrata; Mammalia; DNA; Bacteriosis; Bacteria; Diagnosis; Veterinary; Detection; Ehrlichia infection; Ehrlichia canis
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/104063870001200512

College of Veterinary Medicine, Oklahoma State University, Stillwater 74078, USA.
Detection of Ehrlichia canis in acutely infected and convalescent dogs is important for effective treatment and control. However, accurate detection has been difficult to achieve, in part because dogs that have been treated therapeutically often remain seropositive for extended periods. A new method, polymerase chain reaction (PCR) assay using biotinylated E. canis-specific primers (PCR-BP), was developed for detection of E. canis. Four dogs experimentally infected with E. canis by intravenous inoculation of whole blood from carrier dogs and 2 naturally infected convalescent carriers were used to compare the specificity and sensitivity of the new method with that of microscopy/blood smear evaluation, serologic test, and conventional PCR assay using E. canis-specific primers. In experimentally infected animals, infection was detected as early as 7 days post-exposure using PCR-BP. Although the 2 naturally infected dogs were positive by serologic test and PCR-BP, both were negative by conventional PCR. Results suggest that the new method is a sensitive assay for detection of E. canis infection. In addition, results were obtained more rapidly than with other PCR-based assays.