9 uidA2 0 0 0 0 O40 3 ET 2 uidA4 0 0 0 0 NT 1 ET 3.1 uidA5 0 0 0 0 NT 3 ET 3.2 uidA5 1 0 0 0 NT 4 ET 3.3 uidA5 1 0 1 0 NT 1 ET 3.4 uidA5 1 0 0 0 O7 IWR-1 13 ET 3.5 uidA5 1 0 1 0 O7 2 ET 3.6 uidA5 0 0 1 0 O7 1 ET 3.7 uidA5 1 0 0 0 O88 1 ET 4 uidA11 0 0 1 0 NT 1 ET 5 uidA20 0 0 0 0 NT 1 ET 6 uidA21 0 0 1 0 NT 1 ET 7 uidA22 0 0 0 0 O15 1 ET 8.1 uidA30 0 0 0 0 O7 1 ET 8.2 uidA30 0 0 1 0 O7 1 ET 8.3 uidA30 1 0 0 0 NT 1 ET 9.1 uidA50 0 0 1 0 NT 2 ET 9.2 uidA50 0 0 0 0 O15 1 ET 10.1 uidA55 0 0 0 0 NT 2 ET 10.2 uidA55 0 0 1 0 NT 1 ET 11 uidA57 0 0 0 0 O8 1 ET 12 uidA65 0 0 1 0 NT 4 ET 13 uidA66 0 0 1 0 O26 1 ET

14.1 uidA90 0 0 0 0 O150 8 ET 14.2 uidA90 0 0 0 0 O15 3 ET 14.3 uidA90 0 0 0 1 O26 1 ET 15 uidA103 0 0 0 0 NT 1 ET 16 uidA110 0 0 0 0 NT 3 ET 17.1 uidA111 0 0 0 0 NT 3 ET 17.2 uidA111 0 0 1 1 NT 1 ET 17.3 uidA111 0 1 1 1 NT 1 ET 18 New allele 1 0 0 1 O7 1 aAMX: amoxicillin; CHL: chloramphenicol; TET: tetracyclin; all of epidemiological Screening Library in vitro types of E. coli B1 strains (i.e., number of ETs/total number of B1 isolates for the sampling campaign) was higher (12/15) than in less contaminated water (9/17 in water containing 1.0 ± 0.1 102 CFU/100 ml; 12/39 in water containing 6.2 ± 0.6 102 CFU/100 ml) (Figure 3A). At the peak of the turbidity, E. coli density reached a value of 7.2 102 CFU/100 ml, the diversity of E. coli B1 strains was higher (6/6) than the diversity observed when turbidity and E. coli density decreased (10/29) (Figure 3B). Among the 40 ETs, strains

of the group ET1.1 were present in all samples, regardless of the hydrological condition or the current land use in the watershed. However, they made up a greater proportion of the strains under non-storm conditions: during the dry period (no contribution selleck compound of fecal bacteria from the watershed), 13 ET1.1/39 E. coli B1 were present, and during the wet period (a low contribution of human-derived fecal material, but none from livestock) 6 ET1.1/17 E. coli B1 were present (Figure 3A). In contrast, other ETs were present only under certain hydrological conditions and/or land-use conditions. ET1.7 and ET14.1 were present only during the dry period.