Comparison of traditional and molecular analytical methods for detecting biological agents in raw and drinking water following ultrafiltration.
OBJECTIVE
To compare the performance of traditional methods to quantitative polymerase chain reaction (qPCR) for detecting five biological agents in large-volume drinking-water samples concentrated by ultrafiltration (UF).


RESULTS
Drinking-water samples (100 l) were seeded with Bacillus anthracis, Cryptospordium parvum, Francisella tularensis, Salmonella Typhi, and Vibrio cholerae and concentrated by UF. Recoveries by traditional methods were variable between samples and between some replicates; recoveries were not determined by qPCR. Francisella tularensis and V. cholerae were detected in all 14 samples after UF, B. anthracis was detected in 13, and C. parvum was detected in 9 out of 14 samples. Numbers found by qPCR after UF were significantly or nearly related to those found by traditional methods for all organisms except for C. parvum. A qPCR assay for S. Typhi was not available.


CONCLUSIONS
qPCR can be used to rapidly detect biological agents after UF as well as traditional methods, but additional work is needed to improve qPCR assays for several biological agents, determine recoveries by qPCR, and expand the study to other areas.


CONCLUSIONS
To our knowledge, this is the first study to compare the use of traditional and qPCR methods to detect biological agents in large-volume drinking-water samples.
U.S. Geological Survey, Ohio Water Science Center, Columbus, OH 43229, USA. dsfrancy@usgs.gov
D S
DS
Francy
R N
RN
Bushon
A M G
AM
Brady
E E
EE
Bertke
C M
CM
Kephart
C A
CA
Likirdopulos
B E
BE
Mailot
F W
FW
Schaefer
H D Alan
HD
Lindquist
D001408:Bacillus anthracis; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D015169:Colony Count, Microbial / Q000379:methods*; D016785:Cryptosporidium parvum / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D005604:Francisella tularensis; D008856:Microscopy, Fluorescence; D008967:Molecular Biology / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods*; D012485:Salmonella typhi; D014462:Ultrafiltration; D014734:Vibrio cholerae; D014867:Water / Q000469:parasitology*; D014871:Water Microbiology
D004269:DNA, Bacterial; D014867:Water