coli bacteriocin producer strains. Further, the prevalence of chloroform sensitive microcins H47 and M [19] was tested in each of the 1181 E. coli strains. The average prevalence of bacteriocinogeny in the set of 1181 E. coli strains was 54.4% (Additional file 1: Table S1). In contrast to other bacteriocin determinants, genes encoding colicins A, E4, E9 and L were not detected in any producer strain. Most of bacteriocin producers were strains producing two or more bacteriocin types (Additional file 1: Table S1). Association between bacteriocin and virulence determinants We found that 28.6% of E. coli strains possessing

no virulence determinant (n = 63) produced bacteriocins PF-573228 and 34% of the strains harboring one virulence determinant (n = 377) produced bacteriocins. In addition, 58.2%

of E. coli encoding two virulence determinants (n = 220) had bacteriocin genes and 70.6% of the strains with 3 to 7 virulence determinants (n = 521) were bacteriocinogenic (Figure 1). Figure 1 Association between number of virulence factors encoded by E. coli strains and bacteriocin production. Frequency of bacteriocinogeny in E. coli strains correlates with number of virulence factors coded by E. coli. The x axis represents the number of virulence factors coded by E. coli strains (n represents the number of strains encoding the appropriate number of virulence factors) and the y axis shows the frequency of bacteriocinogeny. A correspondence analysis (CA) was performed using individual virulence determinants and bacteriocin-encoding genes (Figure 2). In addition to this two-dimensional MK-0457 mouse representation, Fisher’s exact test was used to analyze the association between bacteriocin types and virulence determinants. Genes encoding aerobactin synthesis were (aer, iucC) were significantly associated with genes for microcin V (p < 0.01) and with genes encoding colicins E1 (p < 0.01), Ia (p < 0.01) and S4 (p = 0.01). The α-hly, cnf1, sfa and pap virulence determinants were plotted together and were associated with genes for microcins H47 (p < 0.01) and M (p < 0.01).

Bacteriocin non-producers were associated with afaI (p < 0.01), eaeA/bfpA Enzalutamide nmr (p < 0.01), pCVD432 (p = 0.03) and with strains in which virulence determinants were not detected (p < 0.01) (Figure 2). Figure 2 Correspondence analysis for bacteriocin types and virulence factors. Association between virulence factors (α-hly, afaI, aer, cnf1, sfa, pap, pCVD432, ial, lt, st, bfpA, eaeA, ipaH, iucC, fimA, ehly) and bacteriocin types (B, D, E1, E2-9, Ia, Ib, Js, K, M, N, S4, U/Y, 5/10, mB17, mC7, mH47, mJ25, mL, mM and mV) in 1181 E. coli strains. The x axis accounted for 51.06% of total inertia and the y axis for 24.02%. Please note the close association between virulence determinants pap, sfa, cnf1 and α-hly and genes for microcins H47, M and L.