Inter-laboratory ring trial to compare four quantitative polymerase chain reaction assays employed for detection of Mycobacterium avium subspecies paratuberculosis

Abstract

Our study reports the findings of an inter-laboratory ring trial comparing the performance of four different quantitative polymerase chain reaction (qPCR) assay services for detecting Mycobacterium avium subspecies paratuberculosis (MAP) infection in cattle and sheep. MAP is the causative agent of Johne’s disease (also known as paratuberculosis), a significant production-limiting disease in livestock populations with a worldwide distribution. The content of this paper is significant and novel as it is the first to highlight the marked variation between the diagnostic sensitivity and reproducibility of the three principal commercial laboratories offering MAP qPCR diagnostic and screening services in Great Britain. The low sensitivity and high variability between the laboratories are of great concern and relevance to veterinary practitioners and livestock producers.