00001). None of the genotypes was common GS-9973 nmr to all three collections of strains as shown in Figure 3B. However, 87.8%, 87% and 76% of the strains had genotypes specific to SW, DM and P sources, respectively. In the MK0683 mw environmental collection, 0.8% and 11.4% of the strains had genotypes common to DM and

P sets, respectively. The genotypes recovered only in both animal sources represented 10.9% and 4.5% of the DM and P sets, respectively. Quinolone resistant isolates as defined by the C257T mutation Overall, 43.4% and 17.4% of C. coli and C. jejuni, respectively, were classified as resistant to quinolones according to the C257T mutation (i.e. the peptide shift Thr86Ile). Quinolone resistance was significantly higher in isolates of poultry origin (P < 0.001) for both C. coli (67.9%) and C. jejuni (38.7%). By comparison,

22.7% and 16.7% of the isolates (including both species) originating from the domestic mammals and surface waters, respectively, were quinolone-resistant. Discussion Sequencing of gyrA indicated that this locus was informative in several different ways for characterizing Campylobacter isolates. First, the alleles of the 496 nucleotide fragments were suitably different in sequence identity between C. selleckchem jejuni and C. coli to be assigned to one or the other of these species. The distribution of these alleles confirmed that recombination events between species occur rather infrequently and in an asymmetric gene flow [33]: one C. jejuni had a typical C. coli allele whereas 4 C. coli had a typical C. jejuni allele. Two other studies using PCR and sequencing data targeting gyrA also identified a C. jejuni segment within a C. coli isolate [34,35], supporting previous findings that gene flow is rather unidirectional from C. jejuni to C. coli [33,36]. Sequencing of gyrA revealed a similar population structure

as that obtained by MLST or rMLST (Ribosomal Multilocus Sequence Typing, [37]). In particular, the phylogenetic analysis clearly organized C. coli into 3 distinct clades as previously described by Sheppard et al. [33,36] (Figure 1). Furthermore, peptide groups 301A and 302 in our study (Table 2) contain alleles commonly Elongation factor 2 kinase found in domestic animals, and they correspond to the agricultural C. coli lineage of the evolutionary scenario proposed by Sheppard et al. [38]. In addition, peptide groups 301B and 301C (Table 2) match with the clades 2 and 3 observed by Sheppard et al. [38] including only alleles recovered from environmental isolates, i.e. from surface waters in our study. In contrast to C. jejuni, the C. coli assigned alleles are predominated by synonymous mutations. As a result, the peptide group 301C is characterized by alleles with a higher GC content (Figure 2A) generated by nucleotide changes only located in the third positions of codons. This trend was also reflected in genotypes linked to this peptide group 301C i.e.