Multiplex detection of "Candidatus Liberibacter asiaticus" and Spiroplasma citri by qPCR and droplet digital PCR.
Journal
PloS one
ISSN: 1932-6203
Titre abrégé: PLoS One
Pays: United States
ID NLM: 101285081
Informations de publication
Date de publication:
2021
2021
Historique:
received:
30
10
2020
accepted:
03
03
2021
entrez:
17
3
2021
pubmed:
18
3
2021
medline:
1
9
2021
Statut:
epublish
Résumé
"Candidatus Liberibacter asiaticus" (CLas) and Spiroplasma citri are phloem-limited bacteria that infect citrus and are transmitted by insect vectors. S. citri causes citrus stubborn disease (CSD) and is vectored by the beet leafhopper in California. CLas is associated with the devastating citrus disease, Huanglongbing (HLB), and is vectored by the Asian citrus psyllid. CLas is a regulatory pathogen spreading in citrus on residential properties in southern California and is an imminent threat to spread to commercial citrus plantings. CSD is endemic in California and has symptoms in citrus that can be easily confused with HLB. Therefore, the objective of this study was to develop a multiplex qPCR and duplex droplet digital PCR (ddPCR) assay for simultaneous detection of CLas and S. citri to be used where both pathogens can co-exist. The multiplex qPCR assay was designed to detect multicopy genes of CLas-RNR (5 copies) and S. citri-SPV1 ORF1 (13 copies), respectively, and citrus cytochrome oxidase (COX) as internal positive control. Absolute quantitation of these pathogens was achieved by duplex ddPCR as a supplement for marginal qPCR results. Duplex ddPCR allowed higher sensitivity than qPCR for detection of CLas and S. citri. ddPCR showed higher tolerance to inhibitors and yielded highly reproducible results. The multiplex qPCR assay has the benefit of testing both pathogens at reduced cost and can serve to augment the official regulatory protocol for CLas detection in California. Moreover, the ddPCR provided unambiguous absolute detection of CLas and S. citri at very low concentrations without any standards for pathogen titer.
Identifiants
pubmed: 33730040
doi: 10.1371/journal.pone.0242392
pii: PONE-D-20-34072
pmc: PMC7968697
doi:
Substances chimiques
DNA, Bacterial
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Langues
eng
Sous-ensembles de citation
IM
Pagination
e0242392Déclaration de conflit d'intérêts
The authors have declared that no competing interests exist.
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