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EFFECTS OF SEEDING PROCEDURES AND WATER QUALITY ON RECOVERY OF CRYPTOSPORIDIUM OOCYSTS FROM STREAM WATER BY USING U.S. ENVIRONMENTAL PROTECTION AGENCY METHOD 1623
Citation:
Francy, D. S., O. D. Simmons, M W. Ware, E. J. Granger, M. D. Sobsey, AND F W. Schaefer III. EFFECTS OF SEEDING PROCEDURES AND WATER QUALITY ON RECOVERY OF CRYPTOSPORIDIUM OOCYSTS FROM STREAM WATER BY USING U.S. ENVIRONMENTAL PROTECTION AGENCY METHOD 1623. APPLIED AND ENVIRONMENTAL MICROBIOLOGY 70(7):4118-4128, (2004).
Impact/Purpose:
1) Refine new, practical methods for the detection of CCL-related and emerging waterborne human protozoa.
2) Perform field tests of devices or methods that have been developed under this task.
3) Evaluate these methods or devices in a variety of water matrices and parasite concentrations.
This work in this task supports CCL2 and 3 and is expected to be completed by 9/07.
Description:
U.S.EPA Methods 1622 and 1623 are used to detect and quantify Cryptosporidium oocysts in water. The protocol consists of filtration, immunomagnetic separation (IMS), staining with a fluorescent antibody, and microscopic analysis. Microscopic analysis includes detection by fluorescent antibody and confirmation by the demonstration of 1-4 sporozoites or nuclei after staining with 4',6-diamidino-2-phenyl indole dihydrochloride (DAPI). The purpose of this study was to evaluate a new IMS dissociation, a 10 minute incubation at 80 ° C. Heat dissociation improved the average oocyst recovery from 41% to 71% in seeded reagent water, and from 10% to 51% in seeded river samples. The average DAPI confirmation rate improved from 49 % to 93% in reagent water, and from 48% to 73% in river samples. This modification improved both oocyst recovery and confirmation.