Detection of bird schistosomes in lakes by PCR and filter-hybridization.
Many lakes around the world are contaminated with bird schistosome cercariae, which penetrate into human skin, causing an itching dermatitis called "swimmers' itch." Bathers could be forewarned from exposure to the larvae and ecological examinations could be performed, when a sensitive method to detect the parasites in aquatic systems, where lots of organisms hinder microscopic examinations, would be available. For this purpose we cloned, sequenced, and analyzed a 396 bp tandem repeated DNA sequence from Trichobilharzia ocellata (ToSau3A), and employed it for developing molecular detection assays. It hybridized with less than 100 pg DNA from different Trichobilharzia species (T. ocellata, Trichobilharzia franki, and Trichobilharzia regenti), but not with 10 ng DNA from other related or sympatric trematodes. A PCR assay, amplifying this sequence with the same specificity, detected 100 fg T. ocellata DNA, 1 cercaria in 0.5 g plankton, and 2 cercariae in 0.5 g host snail tissues.
Hertel
Jan
J
Institute for Zoology I, University of Erlangen, Staudtstrasse 5, D-91058 Erlangen, Germany. jhertel@biologie.uni-erlangen.de
Hamburger
Joseph
J
Haberl
Bernhard
B
Haas
Wilfried
W
D000818:Animals; D001483:Base Sequence; D001715:Bird Diseases / Q000469:parasitology; D015139:Blotting, Southern; D003001:Cloning, Molecular; D018509:DNA, Helminth / Q000032:analysis* / Q000737:chemistry; D003872:Dermatitis / Q000469:parasitology / Q000517:prevention & control*; D004372:Ducks / Q000469:parasitology; D005618:Fresh Water / Q000469:parasitology*; D006801:Humans; D008195:Lymnaea / Q000469:parasitology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012551:Schistosomatidae / Q000235:genetics / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D012689:Sequence Homology, Nucleic Acid; D012876:Skin Diseases, Parasitic / Q000517:prevention & control*; D020080:Tandem Repeat Sequences; D014201:Trematode Infections / Q000469:parasitology / Q000517:prevention & control*
D018509:DNA, Helminth