Evaluation of a real-time polymerase chain reaction assay for the laboratory diagnosis of giardiasis.
A real-time polymerase chain reaction (PCR) assay was evaluated in comparison with the combination of conventional methods (microscopic examination and antigen detection assay) during the period 2006 to 2008 on 771 fecal samples belonging to 386 patients to assess its usefulness for an accurate laboratory diagnosis of giardiasis. The real-time PCR assay detected Giardia intestinalis DNA in 195 samples (106 patients), including 26 samples (21 patients) negative by the conventional assays. Among the 21 patients, in 8 cases, giardiasis was previously diagnosed also by conventional methods in additional samples of the same patients, whereas in 13, it would have been undiagnosed if real-time PCR assay was not used. The real-time PCR assay demonstrated a detection limit of 2 cysts per reaction and 100% specificity and sensitivity compared to conventional methods. A genotype analysis targeting the beta-giardin gene allowed to identify 53 samples (23 patients) containing genotype A and 59 samples (45 patients) containing genotype B.
Calderaro
Adriana
A
Department of Pathology and Laboratory Medicine, Section of Microbiology, University Hospital of Parma, 43100 Parma, Italy. adriana.calderaro@unipr.it
Gorrini
Chiara
C
Montecchini
Sara
S
Peruzzi
Simona
S
Piccolo
Giovanna
G
Rossi
Sabina
S
Gargiulo
Franco
F
Manca
Nino
N
Dettori
Giuseppe
G
Chezzi
Carlo
C
D000328:Adult; D015373:Bacterial Typing Techniques / Q000379:methods*; D002648:Child; D003598:Cytoskeletal Proteins / Q000235:genetics; D005243:Feces / Q000469:parasitology; D016829:Giardia lamblia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D005873:Giardiasis / Q000175:diagnosis* / Q000469:parasitology*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000235:genetics*; D012680:Sensitivity and Specificity
D003598:Cytoskeletal Proteins; D015800:Protozoan Proteins