Melissococcus plutonius Can Be Effectively and Economically Detected Using Hive Debris and Conventional PCR

SIMPLE SUMMARY: Laboratory diagnostics of the presence of Melissococcus plutonius is necessary for the confirmation of European foulbrood (EFB) in honey bee colonies. Seeking EFB positive colonies is based on inspections performed by beekeepers or authorized inspectors. Bee brood, adult bees, or honey are usually sampled and confirmed by PCR. Here, we tested a new concept of searching suspected colonies by simple and effective collecting hive debris. Conventional PCR detection of M. plutonius in hive debris gives comparable sensitivity and specificity as for adults or honey. The main advantage of testing hive debris combines its effectiveness and costs compared to the sampling of adult bees or honey. Easy and fast collection of hive debris samples in areas with EFB outbreaks could fasten disease early detection and elimination. ABSTRACT: European foulbrood (EFB) is an infectious disease of honey bees caused by the bacterium Melissococcus plutonius. A method for DNA isolation and conventional PCR diagnosis was developed using hive debris, which was non-invasively collected on paper sheets placed on the bottom boards of hives. Field trials utilized 23 honey bee colonies with clinically positive symptoms and 21 colonies without symptoms. Bayes statistics were applied to calculate the comparable parameters for EFB diagnostics when using honey, hive debris, or samples of adult bees. The reliability of the conventional PCR was 100% at 6.7 × 10(3) Colony Forming Unit of M. plutonius in 1 g of debris. The sensitivity of the method for the sampled honey, hive debris, and adult bees was 0.867, 0.714, and 1.000, respectively. The specificity for the tested matrices was 0.842, 0.800, and 0.833. The predictive values for the positive tests from selected populations with 52% prevalence were 0.813, 0.833, and 0.842, and the real accuracies were 0.853, 0.750, and 0.912, for the honey, hive debris, and adult bees, respectively. It was concluded that hive debris can effectively be utilized to non-invasively monitor EFB in honey bee colonies.