To improve surveillance for Cryptosporidium oocysts in water, the US
Environmental Protection Agency developed method 1622, which consists of filtration,
concentration, immunomagnetic separation, fluorescent antibody and 4,6-diamidino-2-phenylindole
(DAPI) counter-staining, and microscopic evaluation. Two filters were compared for
analysis of 11 stream water samples collected throughout the United States.
Replicate 10-L stream water samples (unspiked and spiked with 100-250 oocysts)
were tested to evaluate matrix effects. Oocyst recoveries from the stream water samples
averaged 22% (standard deviation [SD] =+/-17%) with a membrane disk and 12%
(SD=+/-19%) with a capsule filter. These results demonstrate that Cryptosporidium
oocysts can be recovered from stream waters using method 1622, but recoveries are
lower than those from reagent-grade water. This research also evaluated concentrations
of indicator bacteria in the stream water samples. Because few samples were oocyst-positive,
relationships between detections of oocysts and concentrations of indicator organisms
could not be determined. Includes 28 references, tables.
| Edition : | Vol. 93 - No. 1 |
| File Size : | 1
file
, 160 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 01/01/2001 |
