Development and evaluation of a real-time PCR assay for quantification of Giardia and Cryptosporidium in sewage samples.
Cryptosporidium and Giardia are major causes of diarrheal disease in humans worldwide and are major causes of protozoan waterborne diseases. Two DNA TaqMan PCR-based Giardia and Cryptosporidium methods targeting a 74-bp sequence of the β-giardin Giardia gene and a 151-bp sequence of the COWP Cryptosporidium gene, respectively, were used as models to compare two different LNA/DNA TaqMan probes to improve the detection limit in a real-time PCR assay. The LNA probes were the most sensitive resulting in 0.96 to 1.57 lower C t values than a DNA Giardia TaqMan probe and 0.56 to 2.21 lower than a DNA Cryptosporidium TaqMan probe. Evaluation of TaqMan Giardia and Cryptosporidium probes with LNA substitutions resulted in real-time PCR curves with an earlier C t values than conventional DNA TaqMan probes. In conclusion, the LNA probes could be useful for more sensitive detection limits.
Instituto de Ingeniería del Agua y Medio Ambiente, Ciudad Politécnica de la Innovación, Ed. 8G, Acceso D, planta 2, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain. jalonso@ihdr.upv.es
José L
JL
Alonso
Inmaculada
I
Amorós
Irene
I
Cañigral
D003458:Cryptosporidium / Q000302:isolation & purification*; D003598:Cytoskeletal Proteins / Q000235:genetics; D005872:Giardia / Q000302:isolation & purification*; D006801:Humans; D015345:Oligonucleotide Probes / Q000235:genetics; D010274:Parasitology / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D015800:Protozoan Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D012722:Sewage / Q000469:parasitology*
D003598:Cytoskeletal Proteins; D015345:Oligonucleotide Probes; D015800:Protozoan Proteins; D012722:Sewage; C038207:giardin protein, Giardia lamblia; C106305:oocyst wall protein, Cryptosporidium