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United States Department of Agriculture

Agricultural Research Service

Title: Cryptosporidium Oocysts in Bent Mussells in the Chesapeake Bay

Authors
item Graczyk, T - JOHNS HOPKINS UNIV
item Fayer, Ronald
item Lewis, E - NOAA
item Trout, James
item Farley, C - NOAA

Submitted to: Letters in Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 11, 1998
Publication Date: N/A

Interpretive Summary: Oocysts are the stage in the life cycle of Cryptosporidium parvum that contaminate the environment and lead to infection in humans and animals. We previously demonstrated oocysts in oysters collected from bars in rivers associated with the Chesapeake Bay. While oysters were being collected we observed the presence of large numbers of mussels in the same localities. The present study was undertaken to determine if mussels might also filter oocysts from the water and if they might serve as indicators of environmental contamination with feces. We found oocysts in mussels at the 2 sites we examined and demonstrated that mussels can be useful as indicators of fecal contamination of surface waters.

Technical Abstract: Filter-feeding molluscan shellfish can contain environmentally-derived waterborne pathogens of humans and can be used for sanitary assessment of water quality. In the present study, oocysts of Cryptosporidium were detected in Bent mussels (Ischadium recurvum) at two Chesapeake Bay sites from which Cryptosporidium parvum-contaminated oysters were previously collected. Spiking of Cryptosporidium-free Blue mussel (Mytilus edulis) tissue with C. parvum oocysts showed sensitivity of oocyst detection of 51.1% and the oocyst detection threshold of 19 oocysts per 0.7 ml of mussel tissue homogenate. The results indicate that Bent mussels can serve as biological indicators of water contamination with Cryptosporidium oocysts.

Last Modified: 8/29/2014