Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Development and validation of an Ehrlichia canis real-time PCR assay

Dissertation (MSc (Veterinary Science Tropical Diseases))--University of Pretoria, 2019.

Saved in:
Bibliographic Details
Other Authors: Quan, Melvyn
Format: Thesis
Language:English
Published: University of Pretoria 2022
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613593840648192
access_status_str Open Access
author2 Quan, Melvyn
author_browse Quan, Melvyn
author_facet Quan, Melvyn
collection Thesis
dc_rights_str_mv © 2021 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc (Veterinary Science Tropical Diseases))--University of Pretoria, 2019.
format Thesis
id oai:repository.up.ac.za:2263/87866
institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:38:36.983Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2022
publishDateRange 2022
publishDateSort 2022
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/87866 Development and validation of an Ehrlichia canis real-time PCR assay Quan, Melvyn faith.nkosi@up.ac.za Oosthuizen, Marinda C. Nkosi, Nokuzola Faith UCTD Dogs Tick-borne disease (TBD) Ehrlichia canis TaqMan Dissertation (MSc (Veterinary Science Tropical Diseases))--University of Pretoria, 2019. Ehrlichiosis is caused by a pleomorphic gram-negative bacteria and is an important zoonotic tick-borne disease, with a potential to be fatal. This bacterium occurs worldwide and species affected by it include humans, domestic and wild animals. Canine monocytic ehrlichiosis develops over a period of about 8-20 days and may progress from an acute phase to subclinical and chronic disease stages. Although direct detection of the bacterial antigen by ELISA has been used successfully to diagnose the disease, a challenge remains in dogs where co-infection of infectious agents is common due to pathogens being transmitted by the same vectors. Cross-reactivity of the serology assays makes it difficult to make species-specific diagnoses. A more sensitive and reliable molecular technique that can detect and identify pathogens at species level is needed to enhance disease diagnosis. In this study, we developed a real-time PCR assay that employs group-specific primers and an Ehrlichia canis TaqMan® minor groove binder probe. The group-specific primers targeted the conserved region of the 16S rRNA gene and the forward primer included redundant base pairs to accommodate other species in this genus. The primer and probe concentrations were optimised to 200 nM and 250 nM respectively. The efficiency of the assay was 93%. The assay was E. canis specific when tested against other canine and livestock pathogens, as no cross-reactivity was observed. The 95% limit of detection was 33 E. canis plasmid copies/µl of blood (95% confidence interval: 23 - 58). Consistent repeatability was observed, where the inter-run standard deviation (SD) ranged between 0.33 - 1.29 and the intra-run SD 0.04 - 1.14. The results for Reverse Line Blot (RLB) hybridization assay and the TaqMan® MGB real-time PCR assay results were compared and found to be in agreement with an exception of three samples out of 121. Diagnostic validation was performed on field samples, the sensitivity of the TaqMan® MGB real-time PCR assay was 90% and the specificity was 92%. This assay will be a useful tool for the early diagnosis of E. canis and this will aid in timely treatment. Veterinary Tropical Diseases MSc (Veterinary Science Tropical Diseases) Unrestricted 2022-10-21T09:36:10Z 2022-10-21T09:36:10Z 2020 2019-12 Dissertation * S2020 https://repository.up.ac.za/handle/2263/87866 en © 2021 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Dogs
Tick-borne disease (TBD)
Ehrlichia canis
TaqMan
Development and validation of an Ehrlichia canis real-time PCR assay
title Development and validation of an Ehrlichia canis real-time PCR assay
title_full Development and validation of an Ehrlichia canis real-time PCR assay
title_fullStr Development and validation of an Ehrlichia canis real-time PCR assay
title_full_unstemmed Development and validation of an Ehrlichia canis real-time PCR assay
title_short Development and validation of an Ehrlichia canis real-time PCR assay
title_sort development and validation of an ehrlichia canis real time pcr assay
topic UCTD
Dogs
Tick-borne disease (TBD)
Ehrlichia canis
TaqMan
url https://repository.up.ac.za/handle/2263/87866