Development and validation of a real-time PCR for Chlamydia suis diagnosis in swine and humans

Kristien De Puysseleyr; Leentje De Puysseleyr; Julie Geldhof; Eric Cox; Daisy Vanrompay

doi:10.1371/journal.pone.0096704

Development and validation of a real-time PCR for Chlamydia suis diagnosis in swine and humans

PLoS One. 2014 May 9;9(5):e96704. doi: 10.1371/journal.pone.0096704. eCollection 2014.

Authors

Kristien De Puysseleyr¹, Leentje De Puysseleyr¹, Julie Geldhof¹, Eric Cox², Daisy Vanrompay¹

Affiliations

¹ Department of Molecular Biotechnology, Faculty of Bioscience Engineering, University of Ghent, Ghent, Belgium.
² Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, University of Ghent, Ghent, Belgium.

Abstract

Pigs are the natural host for Chlamydia suis, a pathogen which is phylogenetically highly related to the human pathogen C. trachomatis. Chlamydia suis infections are generally treated with tetracyclines. In 1998, tetracyline resistant C. suis strains emerged on U.S. pig farms and they are currently present in the Belgian, Cypriote, German, Israeli, Italian and Swiss pig industry. Infections with tetracycline resistant C. suis strains are mainly associated with severe reproductive failure leading to marked economical loss. We developed a sensitive and specific TaqMan probe-based C. suis real-time PCR for examining clinical samples of both pigs and humans. The analytical sensitivity of the real-time PCR is 10 rDNA copies/reaction without cross-amplifying DNA of other Chlamydia species. The PCR was successfully validated using conjunctival, pharyngeal and stool samples of slaughterhouse employees, as well as porcine samples from two farms with evidence of reproductive failure and one farm without clinical disease. Chlamydia suis was only detected in diseased pigs and in the eyes of humans. Positive humans had no clinical complaints. PCR results were confirmed by culture in McCoy cells. In addition, Chlamydia suis isolates were also examined by the tet(C) PCR, designed for demonstrating the tetracycline resistance gene tet(C). The tet(C) gene was only present in porcine C. suis isolates.

Publication types

Research Support, Non-U.S. Gov't
Validation Study

MeSH terms

Animals
Chlamydia / genetics*
Chlamydia / isolation & purification*
DNA Primers / genetics
DNA Probes / genetics
Female
Humans
Real-Time Polymerase Chain Reaction / methods*
Species Specificity
Swine*

Substances

DNA Primers
DNA Probes

Grants and funding

This study was funded by the Federal Public Service of Health, Safety of the Food Chain and Environment (convention RF-10/6234; http://www.health.belgium.be/eportal?fodnlang=en), Ghent University (IOF/STARTT/002) and MSD Animal Health (Boxmeer, The Netherlands; http://nl.msd-animal-health.be/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.