Title: Use of a nested PCR-enzyme immunoassay with an internal control to detect Chlamydophila psittaci in turkeys
Authors: Van Loock, Marnix ×
Verminnen, Kristel
Messmer, Trudy O
Volckaert, Guido
Goddeeris, Bruno
Vanrompay, Daisy #
Issue Date: 2005
Publisher: Biomed central ltd
Series Title: BMC infectious diseases vol:5 pages:76-85
Abstract: BACKGROUND: Laboratory diagnosis of Chlamydophila psittaci, an important turkey respiratory pathogen, is difficult. To facilitate the diagnosis, a nested PCR-enzyme immunoassay (PCR-EIA) was developed to detect the Cp. psittaci outer membrane protein A (ompA) gene in pharyngeal swabs. METHODS: The fluorescein-biotin labelled PCR products were immobilized on streptavidin-coated microtiter plates and detected with anti-fluorescein peroxidase conjugate and a colorimetric substrate. An internal inhibition control was included to rule out the presence of inhibitors of DNA amplification. The diagnostic value of the ompA nested PCR-EIA in comparison to cell culture and a 16S-rRNA based nested PCR was assessed in pharyngeal turkey swabs from 10 different farms experiencing respiratory disease. RESULTS: The sensitivity of the nested PCR-EIA was established at 0.1 infection forming units (IFU). Specificity was 100%. The ompA nested PCR-EIA was more sensitive than the 16S-rRNA based nested PCR and isolation, revealing 105 out of 200 (52.5%) positives against 13 and 74 for the latter two tests, respectively. Twenty-nine (23.8%) out of 122 ompA PCR-EIA negatives showed the presence of inhibitors of DNA amplification, although 27 of them became positive after diluting (1/10) the specimens in PCR buffer or after phenol-chloroform extraction and subsequent ethanol precipitation. CONCLUSION: The present study stresses the need for an internal control to confirm PCR true-negatives and demonstrates the high prevalence of chlamydiosis in Belgian turkeys and its potential zoonotic risk. The ompA nested PCR-EIA described here is a rapid, highly sensitive and specific diagnostic assay and will help to facilitate the diagnosis of Cp. psittaci infections in both poultry and man.
ISSN: 1471-2334
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Division of Gene Technology (-)
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
Van Loock 2005 BMC Infect Dis.pdf Published 420KbAdobe PDFView/Open


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science