Development of Conventional and Real-Time Quantitative PCR Assays for Diagnosis and Monitoring of Scabies

Copyright © 2015, American Society for Microbiology. All Rights Reserved..

Scabies remains the most prevalent, endemic, and neglected ectoparasitic infestation globally and can cause institutional outbreaks. The sensitivity of routine microscopy for demonstration of Sarcoptes scabiei mites or eggs in skin scrapings is only about 50%. Except for three studies using conventional or two-tube nested PCR on a small number of cases, no systematic study has been performed to improve the laboratory diagnosis of this important infection. We developed a conventional and a real-time quantitative PCR (qPCR) assay based on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of S. scabiei. The cox1 gene is relatively well conserved, with its sequence having no high levels of similarity to the sequences of other human skin mites, pathogenic zoonotic mites, or common house dust mite species. This mitochondrial gene is also present in large quantities in arthropod cells, potentially improving the sensitivity of a PCR-based assay. In our study, both assays were specific and were more sensitive than microscopy in diagnosing scabies, with positive and negative predictive values of 100%. The S. scabiei DNA copy number in the microscopy-positive specimens was significantly higher than that in the microscopy-negative specimens (median S. scabiei DNA copy number, 3.604 versus 2.457 log10 copies per reaction; P = 0.0213). In the patient with crusted scabies, the qPCR assay performed on lesional skin swabs instead of scrapings revealed that the parasite DNA load took about 2 weeks to become negative after treatment. The utility of using lesional skin swabs as an alternative sample for diagnosis of scabies by PCR should be further evaluated.

Medienart:

E-Artikel

Erscheinungsjahr:

2015

Erschienen:

2015

Enthalten in:

Zur Gesamtaufnahme - volume:53

Enthalten in:

Journal of clinical microbiology - 53(2015), 7 vom: 10. Juli, Seite 2095-102

Sprache:

Englisch

Beteiligte Personen:

Wong, Samson S Y [VerfasserIn]
Poon, Rosana W S [VerfasserIn]
Chau, Sandy [VerfasserIn]
Wong, Sally C Y [VerfasserIn]
To, Kelvin K W [VerfasserIn]
Cheng, Vincent C C [VerfasserIn]
Fung, Kitty S C [VerfasserIn]
Yuen, K Y [VerfasserIn]

Links:

Volltext

Themen:

EC 1.9.3.1
Electron Transport Complex IV
Evaluation Study
Journal Article

Anmerkungen:

Date Completed 11.03.2016

Date Revised 18.03.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1128/JCM.00073-15

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM248340158