Comparative study between two laser scanning cytometers and epifluorescence microscopy for the detection of Cryptosporidium oocysts in water.
BACKGROUND
Cryptosporidium detection in water and environmental samples has increased during the last years, largely due to an increase in the number of reported waterborne outbreaks of cryptosporidiosis and the implementation of new regulations about Cryptosporidium monitoring in water supplies. The aim of this study was to validate and compare the capacity of two laser scanning cytometers commercially available (LSC and ChemScanRDI), against manual microscopic enumeration of Cryptosporidium oocysts in surface water and reference material samples.


METHODS
Reference material and surface water samples were analysed by two laser scanning cytometers methodologies and by manual epifluorescence microscopy. Two mAbs from commercial suppliers were used to evaluate background reduction.


RESULTS
Highly significant correlations were obtain between both cytometers (R(2) = 0.99) and with manual microscopy (R(2) = 0.98), showing that oocysts counts made by cytometers were equivalent to those obtained with conventional methods. We observed a variability in oocysts counts when different antibodies where used with laser scanning cytometers and manual microscopy.


CONCLUSIONS
This study showed the efficacy of the laser scanning technology (LSC and ChemScanRDI), as an automated and a more standardized alternative to manual epifluorescence microscopy examination, for Cryptosporidium detection in water samples. High quality antibodies are needed for automated enumeration as well as for manual microscope observations.
Montemayor
Michel
M
Department of Microbiology, University of Barcelona, Barcelona, Spain.
Galofré
Belén
B
Ribas
Ferrán
F
Lucena
Francisco
F
D000818:Animals; D003458:Cryptosporidium / Q000254:growth & development / Q000302:isolation & purification*; D047569:Laser Scanning Cytometry; D008856:Microscopy, Fluorescence; D033661:Oocysts / Q000254:growth & development*; D014867:Water / Q000469:parasitology*; D014881:Water Supply
D014867:Water