Cm. Davies et Sc. Apte, Field evaluation of a rapid portable test for monitoring fecal coliforms in coastal waters, ENVIRON TOX, 14(3), 1999, pp. 355-359
Two hundred beachwater samples were collected along the New South Wales coa
st, Australia, and analyzed for fecal coliforms in the field using a portab
le, 60 min fluorimetric assay of beta-D-galactosidase activity. The aim of
the study was to evaluate the reliability of the technique alongside a stan
dard membrane filtration procedure to assess fecal contamination of coastal
bathing waters. The assay had a 98% success rate at predicting whether the
coliform concentrations of the samples were greater than, or less than, 30
0 fecal coliforms per 100 ml (the current limit of detection of the method)
. The results over which the two methods were in disagreement comprised les
s than 2% false positives [where the rapid method indicated greater than an
d membrane filtration indicated less than 300 colony-forming units (cfu) pe
r 100 ml] and no false negatives (where the rapid method indicated less tha
n and membrane filtration indicated greater than 300 cfu per 100 ml). The d
escribed assay provides a rapid, simple, and inexpensive method for the det
ection of fecal contamination in marine waters. As analyses can be performe
d in the field, the technique offers great potential for near real-time mon
itoring of water quality and as an "early warning" system for contamination
of bathing waters. (C) 1999 by John Wiley & Sons, Inc.