DAO 59:35-41 (2004)  -  doi:10.3354/dao059035

Use of rDNA polymorphism for identification of Heterophyidae infecting freshwater fishes

R. Dzikowski1,*, M. G. Levy2, M. F. Poore2, J. R. Flowers2, I. Paperna1

1 Department of Animal Sciences, Faculty of Agriculture, Food and Environmental Sciences, Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel
2 Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough St., Raleigh 27606, North Carolina, USA

ABSTRACT: Infections by trematodes are among the most common fish-borne zoonoses. Metacercariae of the Family Heterophyidae in marine and freshwater fishes are nonfastidious in their choice of definitive hosts, and therefore, cause infections in human and domestic animals. In the present study, species-specific polymerase chain reaction (PCR) assays were developed for identifying and differentiating the various species examined. Sequencing and aligning the 18S (SSU) rDNA revealed interspecific variation for which species-specific DNA oligonucleotides were designed and used for the identification of 6 heterophyid species recovered from piscivorous birds. The oligonucleotides were further used to evaluate the various stages (cercariae recovered from snails, metacercariae recovered from fish and adult trematodes) of the digeneans. By applying this method we elucidated for the first time the life cycle of Pygidiopsis genata. The phylogenetic interrelationship among the newly sequenced species of Heterophyidae is outlined.


KEY WORDS: Digenea · Heterophyidae · Birds · Fish · 18S rDNA gene · SSU


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