title: In vitro phagocytosis of Giardia duodenalis cysts by hemocytes of the Asian freshwater clam Corbicula fluminea.
abstract: Hemocytes of the Asian freshwater clam Corbicula fluminea, phagocytosed in vitro infectious Giardia duodenalis cysts. After 15, 30, 60, 90, and 120 min of incubation an average of 22%, 32%, 43%, 54%, and 72% of the cysts were phagocytosed by 22%, 55%, 63%, 81%, and 86% of the hemocytes, respectively. The number of hemocytes showing phagocytosis and the mean number of cysts ingested per hemocyte increased significantly over time (P < 0.01); the numbers of nonphagocytosed cysts significantly decreased (P < 0.02). Extrapolation reveals that C. fluminea can retain by phagocytosis an average of 1.6 x 10(6) G. duodenalis cysts/ml hemolymph. The phagocytic capacity of C. fluminea hemocytes indicates the applicability of this freshwater benthic bivalve for bioindication of contamination of waste waters and agricultural drainage with Giardia cysts.
authors.affiliation: Johns Hopkins University, School of Hygiene and Public Health, Department of Molecular Microbiology and Immunology, Baltimore, MD 21205, USA. tgraczyk@phnet.sph.jhu.edu
authors.forename: T K
authors.initials: TK
authors.lastname: Graczyk
authors.forename: M R
authors.initials: MR
authors.lastname: Cranfield
authors.forename: D B
authors.initials: DB
authors.lastname: Conn
mesh_terms: D000818:Animals; D001208:Asia; D049872:Bivalvia / Q000276:immunology / Q000469:parasitology*; D002478:Cells, Cultured; D005618:Fresh Water; D005872:Giardia / Q000276:immunology*; D006434:Hemocytes / Q000166:cytology / Q000276:immunology*; D010587:Phagocytosis