Development of real-time PCR assays for the detection of Moraxella macacae associated with bloody nose syndrome in rhesus (Macaca mulatta) and cynomolgus (Macaca fascicularis) macaques

Background: Moraxella macacae is a recently described bacterial pathogen that causes epistaxis or so-called bloody nose syndrome in captive macaques. The aim of this study was to develop specific molecular diagnostic assays for M. macacae and to determine their performance characteristics. Methods: We developed six real-time PCR assays on the Roche LightCycler. The accuracy, precision, selectivity, and limit of detection (LOD) were determined for each assay, in addition to further validation by testing nasal swabs from macaques presenting with epistaxis at the Tulane National Primate Research Center. Results: All assays exhibited 100% specificity and were highly sensitive with an LOD of 10 fg for chromosomal assays and 1 fg for the plasmid assay. Testing of nasal swabs from 10 symptomatic macaques confirmed the presence of M. macacae in these animals. Conclusions: We developed several accurate, sensitive, and species-specific real-time PCR assays for the detection of M. macacae in captive macaques.