Geoscience Reference
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1 4 integrons are found among the E. coli strains all along the estuary,
whereas only the strains isolated in the urban zone around Rouen
possess class 2 integrons. These supplies of antibiotic-resistant E. coli
harboring class 1 integrons are mainly of human origin via the treated
effluent from the WWTP [LAR 09].
Enterococcus spp b
Escherichia coli c
Station
pk (km)
min - max a Geom. mean.
(%) e
Geom.mean.
min - max a
(%) e
Upstream
input
Poses
202
< 1- 3,000
217 (54.2)
34 - 54,130
835 (54.5)
Rouen
243
36-9,300
570 (57.1) 292 - 23,690
2,194 (95.7)
Urban
zone
Croisset
246.6 57 - 23 000
635 (59.1) 350 - 26,700
2,247 (96.3)
Docks
251.3
36 - 9,300
522 (77.3) 160 - 16,620
2,183 (95.5)
Bouille
259.7
15 - 4,300
266 (65.2)
293 - 6,520
1,195 (82.1)
Salinity
boundary
Caudebec
310.5
7 - 2,300
111 (36.4)
38 - 1,126
181 (22.7)
Tancarville
337
10 - 2,300
110 (33.3)
36 - 2,472
154 (15.2)
Mouth of
the
estuary
Berville
346
23 - 600
86 (na)
na
na
Honfleur
355.8
3 - 11,454
171 (54.2)
36 - 4,300
338 (28.1)
Table 2.4(a). Microbiological quality of water along the Seine estuary: a) abundance
of bacteria (UFC.100 ml -1 ) in E. coli (2000-2005, thirty sampling campaigns); na:
not analyzed; percentage of campaigns for which the abundance of E. coli and
Enterococci is greater than the values given in the European directive (2006/7/EC):
respectively 185 and 500 UFC.100 mL -1 [TOU 07]
Water contamination by antibiotic-resistant bacteria was also;
investigated along the medical center-WWTP-river continuum. The
results show that the percentages of strains of E. coli resistant to at
4 Integrons, are genetic supports responsible for the capture of antibiotic resistance
genes. They play a major role in the dissemination of antibiotic resistance genes,
mainly among Gram-negative bacteria.
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