Detection and identification of Giardia species using real-time PCR and sequencing

doi:10.1016/j.mimet.2021.106279

Journal of Microbiological Methods

Volume 189, October 2021, 106279

https://doi.org/10.1016/j.mimet.2021.106279 Get rights and content

Highlights

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Rapid, sensitive qPCR screening method for the detection of Giardia spp.
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Direct sequencing of PCR product allows for identification of major species of Giardia.
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Assay may be useful for the detection of low levels of Giardia in clinical and environmental samples.

Abstract

We report a specific region of Giardia spp. 18S ribosomal RNA (18S rDNA) that serves as an ideal target for quantitative PCR (qPCR) detection and sequencing to identify Giardia species, including the clinically-relevant G. duodenalis, in clinical and environmental samples. The presence of multiple copies of the 18S rDNA gene and variations in the selected 18S genomic region enabled the development of a rapid, sensitive qPCR screening method for the detection of Giardia spp. The analytical sensitivity of the Giardia qPCR assay was determined to be a cyst equivalent of 0.4 G. duodenalis cysts per PCR reaction. Amplicon sequencing of the PCR product confirmed Giardia spp. detection and among the 35 sequences obtained, 31, 3 and 1 isolates were classified as belonging to G. duodenalis, G. microti and G. muris, respectively. The TaqMan assay reported here may be useful for the detection of low levels of Giardia in clinical and environmental samples, and further enables the effective use of direct sequencing of the PCR product for Giardia confirmation and to identify major species of Giardia, including G. duodenalis.

Section snippets

Declaration of Competing Interest

The authors declare no conflict of interest.

Acknowledgments

The authors would like to thank Dr. Xiao Lihua, Hunter Seabolt, Jeff Mercante, and Dawn Roellig for the DNA extracts of Giardia specimens and for review of the manuscript. The findings and conclusions in this report are those of the authors and do not necessarily represent those of the CDC. Use of trade names and commercial sources is for identification only and does not imply endorsement by CDC or the U.S. Department of Health and Human Services.

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Citation Excerpt :
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NoteDetection and identification of Giardia species using real-time PCR and sequencing

Highlights

Abstract

Section snippets

Declaration of Competing Interest

Acknowledgments

Int. J. Parasitol.

Acta Trop.

Infect. Genet. Evol.

Int. J. Parasitol.

Int. J. Parasitol.

Acta Trop.

Detection and genotyping by real-time PCR/RFLP analyses of Giardia duodenalis from human faeces

J. Med. Microbiol.

Giardia duodenalis infection in the context of a community-based deworming and water, sanitation and hygiene trial in Timor-Leste

Parasit. Vectors

Case-case analyses of cryptosporidiosis and giardiasis using routine national surveillance data in the United States - 2005-2015

Epidemiol. Infect.

Diagnosis of Giardia infections by PCR-based methods in children of an endemic area

J. Venom. Anim. Toxins Incl. Trop. Dis.

Zoonotic potential and molecular epidemiology of Giardia species and giardiasis

Clin. Microbiol. Rev.

Identification of genotypes of Giardia intestinalis of human isolates in Egypt

Parasitol. Res.

Real-time PCR assay for detection and genotype differentiation of Giardia lamblia in stool specimens

J. Clin. Microbiol.

Note
Detection and identification of Giardia species using real-time PCR and sequencing