Abstract
To investigate practicability of molecular analysis for testing Cryptosporidium and Giardia in water, these protozoans in raw water obtained from 30 Japanese drinking-water treatment plants were tested by conventional microscopic observation and molecular analysis, and the results were compared. Detection sensitivity of two methods resembles each other if RT-qPCR is used as a molecular analysis method. On the other hand, the quantified concentrations of Cryptosporidium detected in a few raw waters by RT-qPCR were much lower than those by microscopic observation. Molecular analysis revealed that species and/or genotypes of protozoans in raw water are ecologically diverse, and most species and/or genotypes are potentially infectious for humans. Furthermore, it was found that contamination sources of protozoans in water sources can be predicted depending on detected species and/or genotypes by molecular analysis.
