Validation of a point-of-care polymerase chain reaction assay for detection of Streptococcus equi subspecies equi in rostral nasal swabs from horses with suspected strangles.

This study aimed to validate a point-of-care polymerase chain reaction (PCR) assay for detection of Streptococcus equi subsp. equi (S. equi) in rostral nasal swabs from horses with suspected acute strangles and to compare the results against the molecular gold standard of quantitative polymerase chain reaction (qPCR). Two hundred thirty-two individual swabs of rostral nasal passages were characterized by qPCR as S. equi positive, S. equi subsp. zooepidemicus (S. zooepidemicus) positive, or S. equi and S. zooepidemicus negative. The specificity and sensitivity of the point-of-care PCR assay were 89% and 84%, respectively. The limits of detection of the qPCR assay and the point-of-care PCR analyzer were 3 and 277 eqbE target genes of S. equi, respectively. Overall agreement and short turnaround time make the point-of-care PCR assay a potential molecular diagnostic platform that will enhance the capability of equine veterinarians to timely support a diagnosis of strangles and institute proper biosecurity protocols. Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.