Details

Autor(en) / Beteiligte

• Thirumalapura, Nagaraja R.
• Livengood, Julia
• Beeby, John
• Wang, Weihua
• Goodrich, Erin L.
• Goodman, Laura B.
• Erol, Erdal
• Tewari, Deepanker

Titel

Improved molecular detection of Neorickettsia risticii with a duplex real-time PCR assay in the diagnosis of Potomac horse fever

Ist Teil von

• Journal of veterinary diagnostic investigation, 2023-01, Vol.35 (1), p.62-66

Ort / Verlag

Los Angeles, CA: SAGE Publications

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Neorickettsia risticii, an obligate intracellular bacterium, is the causative agent of Potomac horse fever (PHF). Diagnosis of PHF is based on demonstration of serum antibodies, isolation of N. risticii, and/or detection of nucleic acid by a PCR assay. An existing real-time PCR assay targeting the N. risticii 16S rRNA has been validated using blood samples from horses with colitis, and snails; to our knowledge, the performance of the assay for other sample types has not been reported. We describe here a modification of the 16S rRNA gene assay by the addition of a set of primers and probe targeting the N. risticii p51 gene to form a duplex assay. We validated the new assay using diagnostic specimens from 56 horses with suspected PHF. The assay consistently detected down to 5 copies of synthetic targets, and did not show any cross-reaction with common equine enteric pathogens. Although we did not establish the diagnostic sensitivity and specificity of the duplex assay, results for both gene targets were in complete agreement, with the exception of 4 fecal samples that tested positive for the 16S rRNA gene only. Further analysis indicated that testing of fecal samples using our 16S rRNA gene assay alone can produce a false-positive result.