Pg. Hartel et al., Ribotyping to determine the host origin of Escherichia coli isolates in different water samples, WILDLAND HYDROLOGY, PROCEEDINGS, 1999, pp. 377-382
One problem in evaluating water quality is obtaining fecal coliforms in a w
ater sample but not knowing the host origin of these bacteria. One solution
to this problem may be to isolate the bacteria and observe their ribosomal
DNA fingerprints (ribotyping). This may allow isolates to be associated wi
th a particular host. We obtained 35 isolates of Escherichia coli, a fecal
coliform, from cow manure in a pasture, and compared these isolates to 40 i
solates of E. coli from a stream draining that pasture and 44 isolates from
a geographically separated wooded stream remote from domesticated animals
and human habitation. The isolates were ribotyped with a Qualicon RiboPrint
er(TM) with the restriction enzyme EcoRI. Among the 119 isolates, the RiboP
rinter(TM) system identified eight different ribotypes. The wooded stream a
nd the cow manure each contained six ribotypes, while the pasture stream co
ntained all eight. In the wooded stream, 29 of the 44 isolates (66%) were R
ibotypes #6 and #8, while in the cow manure, 19 isolates (54%) were Ribotyp
e #4. Our results suggest that either a limited variation in ribotypes of E
. coli exists among the two streams and the cow manure, or a more discrimin
atory ribotyping system is needed.