Novel TaqMan PCR Assay for the Quantification of <i>Paenibacillus larvae</i> Spores in Bee-Related Samples

<i>Paenibacillus larvae</i> is the causative agent of American foulbrood (AFB), a devastating disease of honeybees. <i>P. larvae</i> spore counts in bee-related samples correlate with the presence of AFB symptoms and may, therefore, be used to identify at-risk colonies. Here,...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Darja Kušar, Bojan Papić, Urška Zajc, Irena Zdovc, Majda Golob, Lucija Žvokelj, Tanja Knific, Jana Avberšek, Matjaž Ocepek, Metka Pislak Ocepek
Formato: article
Lenguaje:EN
Publicado: MDPI AG 2021
Materias:
Q
Acceso en línea:https://doaj.org/article/e3b7221369b140cd98273e7284ef979c
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
Descripción
Sumario:<i>Paenibacillus larvae</i> is the causative agent of American foulbrood (AFB), a devastating disease of honeybees. <i>P. larvae</i> spore counts in bee-related samples correlate with the presence of AFB symptoms and may, therefore, be used to identify at-risk colonies. Here, we constructed a TaqMan-based real-time PCR (qPCR) assay targeting a single-copy chromosomal metalloproteinase gene for reliable quantification of <i>P. larvae</i>. The assay was calibrated using digital PCR (dPCR) to allow absolute quantification of <i>P. larvae</i> spores in honey and hive debris samples. The limits of detection and quantification were 8 and 58 spores/g for honey and 188 and 707 spores/mL for hive debris, respectively. To assess the association between AFB clinical symptoms and spore counts, we quantified spores in honey and hive debris samples originating from honeybee colonies with known severity of clinical symptoms. Spore counts in AFB-positive colonies were significantly higher than those in asymptomatic colonies but did not differ significantly with regard to the severity of clinical symptoms. For honey, the average spore germination rate was 0.52% (range = 0.04–6.05%), indicating poor and inconsistent in vitro germination. The newly developed qPCR assay allows reliable detection and quantification of <i>P. larvae</i> in honey and hive debris samples but can also be extended to other sample types.