MiRNA-seq analysis of bovine serum miRNAs in response to Mycobacterium avium paratuberculosis infection. miRNA study of MAP infected bovine serum samples

Mycobacterium avium subspecies paratuberculosis (MAP) is capable of causing a chronic enteritis known as Johne’s disease (JD) in ruminants, notably resulting in substantial economic losses within the dairy industry. Prognostic and diagnostic assays that are both sensitive and specific are required to limit the spread of infection. Circulating microRNAs (miRNAs) have shown potential as biomarkers for various pathologies. We had access to a MAP infection model that consisted of serum samples from unchallenged, silent and subclinical phases in cattle collected across a four year period. Hence, the first aim of this study was to determine whether small RNAs could be sequenced from one ml volumes of serum using this model. We sought to identify potential prognostic miRNA biomarkers of MAP infection. We also had the opportunity to confirm the stability and longevity of circulating miRNAs as the serum samples that had been stored at -20°C for approximately 10-15 years.