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NERL MICROBIAL PROGRAM WITH EMPHASIS ON PROTOZOAN METHODS
Citation:
Lindquist, H.D A. NERL MICROBIAL PROGRAM WITH EMPHASIS ON PROTOZOAN METHODS. Presented at NCER STAR Drinking Water Progress Review Meeting, Silver Springs, MD, February 22-23, 2001.
Impact/Purpose:
1) Refine new molecular and antibody labeling method for the detection of Giardia and Cryptosporidium in water.
2) Determine the occurrence and distribution of Giardia and Cryptosporidium in water supplies
Description:
The National Exposure Research Laboratory's facility in Cincinnati is engated in a variety of microbiological research projects that include studies on bacteria, viruses, fungi and protozoa. One of these was a protzoology project to determine the best way to evaluate methods reported for detecting Cryptosporidium parvum in water. The technology used in preliminary surveys to determine the incidence of this parasite in watersheds has had obvious shortcomings, notably low recovery of organisms and high inherent variability. To improve this technology, a large number of possible alternatives are available. Without a framework to compare these alternative methods, there is no way to select a method or battery of methods that will address basic question of the underlying distribution of C. parvum in the environment. Procedures for evaluating methods have inherent variability and thus, it is difficult to determine if the method, or the procedures for evaluating the method, is the source of variability. To meet this challenge, a set of criteria were developed and tested for use in methods evaluation. One of the primary tools, counting of absolute numbers of organisms by flow cytometry, has enabled more precise method evaluation. An example of an evaluation of four methods using this technique is presented.