title: Is real-time PCR-based diagnosis similar in performance to routine parasitological examination for the identification of Giardia intestinalis, Cryptosporidium parvum/Cryptosporidium hominis and Entamoeba histolytica from stool samples? Evaluation of a new commercial multiplex PCR assay and literature review.
abstract: Microscopy is the reference standard for routine laboratory diagnosis in faecal parasitology but there is growing interest in alternative methods to overcome the limitations of microscopic examination, which is time-consuming and highly dependent on an operator's skills and expertise. Compared with microscopy, DNA detection by PCR is simple and can offer a better turnaround time. However, PCR performances remain difficult to assess as most studies have been conducted on a limited number of positive clinical samples and used in-house PCR methods. Our aim was to evaluate a new multiplex PCR assay (G-DiaParaTrio; Diagenode Diagnostics), targeting Giardia intestinalis, Cryptosporidium parvum/Cryptosporidium hominis and Entamoeba histolytica. To minimize the turnaround time, PCR was coupled with automated DNA extraction (QiaSymphony; Qiagen). The PCR assay was evaluated using a reference panel of 185 samples established by routine microscopic examination using a standardized protocol including Ziehl-Neelsen staining and adhesin detection by ELISA (E. histolytica II; TechLab). This panel, collected from 12 French parasitology laboratories, included 135 positive samples for G. intestinalis (n = 38), C. parvum/C. hominis (n = 26), E. histolytica (n = 5), 21 other gastrointestinal parasites, together with 50 negative samples. In all, the G-DiaParaTrio multiplex PCR assay identified 38 G. intestinalis, 25 C. parvum/C. hominis and five E. histolytica leading to sensitivity/specificity of 92%/100%, 96%/100% and 100%/100% for G. intestinalis, C. parvum/C. hominis and E. histolytica, respectively. This new multiplex PCR assay offers fast and reliable results, similar to microscopy-driven diagnosis for the detection of these gastrointestinal protozoa, allowing its implementation in routine clinical practice.
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Institut de Biologie, CHU Nantes, France.
authors.forename: A
authors.initials: A
authors.lastname: Laude
authors.affiliation: Laboratoire de Parasitologie-Mycologie, CHU de Dijon, France.
authors.forename: S
authors.initials: S
authors.lastname: Valot
authors.affiliation: Service de Parasitologie-Mycologie-Médecine Tropicale, CHU de Tours/CEPR Inserm U1100, équipe 3, Université François-Rabelais de Tours, France.
authors.forename: G
authors.initials: G
authors.lastname: Desoubeaux
authors.affiliation: Laboratoire de Parasitologie-Mycologie, AP-HP, Hôpital Bichat, Paris, France.
authors.forename: N
authors.initials: N
authors.lastname: Argy
authors.affiliation: Laboratoire de Parasitologie-Mycologie, CHU de Clermont-Ferrand, France.
authors.forename: C
authors.initials: C
authors.lastname: Nourrisson
authors.affiliation: Laboratoire de Parasitologie-Mycologie, INSERM, U1065, C3M, CHU de Nice, France.
authors.forename: C
authors.initials: C
authors.lastname: Pomares
authors.affiliation: Laboratoire de Parasitologie-Mycologie, CHU de Nancy, France.
authors.forename: M
authors.initials: M
authors.lastname: Machouart
authors.affiliation: Laboratoire de Parasitologie-Mycologie, CHU d'Angers, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Le Govic
authors.affiliation: Laboratoire de Parasitologie-Mycologie, CHU de Dijon, France.
authors.forename: F
authors.initials: F
authors.lastname: Dalle
authors.affiliation: Laboratoire de Parasitologie-Mycologie, AP-HP Hôpital Henri Mondor, Créteil, France.
authors.forename: F
authors.initials: F
authors.lastname: Botterel
authors.affiliation: Laboratoire de Parasitologie-Mycologie, CHU de Montpellier, France.
authors.forename: N
authors.initials: N
authors.lastname: Bourgeois
authors.affiliation: Laboratoire de Parasitologie-Mycologie, CHU de Poitiers, France.
authors.forename: E
authors.initials: E
authors.lastname: Cateau
authors.affiliation: Laboratoire de Microbiologie, CHD de la Roche-Sur-Yon, France.
authors.forename: M
authors.initials: M
authors.lastname: Leterrier
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Institut de Biologie, CHU Nantes, France.
authors.forename: P
authors.initials: P
authors.lastname: Le Pape
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Institut de Biologie, CHU Nantes, France. Electronic address: florent.morio@chu-nantes.fr.
authors.forename: F
authors.initials: F
authors.lastname: Morio
mesh_terms: D016785:Cryptosporidium parvum / Q000235:genetics / Q000302:isolation & purification*; D004748:Entamoeba histolytica / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000469:parasitology*; D016829:Giardia lamblia / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007411:Intestinal Diseases, Parasitic / Q000175:diagnosis / Q000469:parasitology; D025202:Molecular Diagnostic Techniques; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
keywords: Cryptosporidium hominis; Cryptosporidium parvum; Entamoeba histolytica; Giardia intestinalis; microscopy; multiplex real-time PCR; stool