coli isolates belonged was determined by the PCR-based method,
as described previously by Clermont et al. [42]. A learn more total of 112 isolates of E. coli B1 were tested for the virulence factor hly by the PCR amplification method as described by Escobar-Páramo et al. [34] (hly.1: 5′-AGG-TTC-TTG-GGC-ATG-TAT-CCT-3′; hly.2: 5′-TTG-CTT-TGC-AGA-CTG-CAG-GTG-T-3′). All E. coli B2 were tested for the O81 type [10], and all E. coli B1 strains were tested for O7, O8, O15, O26, O40, O45b, O78, O81, O88, O103, O104, O111, O128 and O150 types by using the PCR-based method described by Clermont et al. [43] with the primers shown in [Additional file 1]. These O types have been previously shown to be present in B1 group strains (Clermont and Denamur, personal data). Antibiotic resistance testing Antibiotic resistance was determined by the agar diffusion method using seven antibiotic disks (BioMérieux, France): amoxicillin (AMX), ticarcillin (TIC), chloramphenicol (CHL), tetracycline (TET), trimethoprim + sulfamethoxazole (SXT), ciprofloxacin (CIP), and streptomycin (STR). Among them CHL, TET, STR are used in veterinary medicine. After 24 h of incubation at 37°C, the bacteria were classified as sensitive, intermediate, or resistant according to French national guidelines [44]. The E. coli CIP 7624 (ATCC 25922) was taken as the quality control strain. The data were regrouped as resistant or non-resistant, the latter corresponding to sensitive and intermediate
phenotypes. Allele number selleck screening library attribution of uidA gene of E. coli B1 Partial uidA sequences (600 pb) of 112 E. coli B1 isolates from the stream (17, dry season;
39, wet season; 15, storm during dry period; 41, storm during wet period [6, 6, and 19 5 h AZD2171 chemical structure before the storm, 6 h after the storm, and 19 h after the storm, respectively]) were sequenced after PCR amplification (uidAR: 5′-CCA-TCA-GCA-CGT-TAT-CGA-ATC-CTT-3′; uidAF:5′ CAT-TAC-GGC-AAA-GTG-TGG-GTC-AAT-3′). Thirty-five μl of PCR product, containing an estimated 100 ng/μl of DNA, were sequenced in both forward and reverse directions at Cogenics (Meylan, France). A consensus sequence was determined by aligning the forward sequence with the reverse complement of the reverse sequence. Alleles of uidA were determined by comparison of the uidA sequences found in the MLST database Pasteur http://www.pasteur.fr/cgi-bin/genopole/PF8/mlstdbnet.pl?file=Eco_profiles.xml. DOCK10 Statistical analyses The frequencies of various phylo-groups in the water samples were compared using the chi-square test. Tests were carried out using the XLSTATS version 6.0 (Addinsoft). Acknowledgements MR held a research grant from the “”Conseil Régional de Haute Normandie”" (France). ED was partially supported by the “”Fondation pour la Recherche Médicale”". The authors thank Dr Barbara J. Malher (U.S. Geological Survey) for constructive remarks on the manuscript and help in editing. We would like to thank Dilys Moscato for helping with the English of this manuscript.