Soil salinity, pH, and indigenous bacterial community interactively influence the survival of E. coli O157:H7...

Complexities of biotic-abiotic interactions in soils result in the lack of integrated understanding of environmental variables that restrict the survival of shiga toxin-producing E. coli O157:H7. Herein, we reanalyzed previously published data and highlighted the influence of soil abiotic factors on E. coli O157:H7 survivability and elucidated how these factors took effect indirectly through affecting indigenous bacterial community. Interaction network analysis indicated salinity and pH decreased the relative abundances of some bacterial taxa (e.g., Acidobacteria_Gp4, Acidobacteria_Gp6, and Deltaproteobacteria) which were positively correlated with the survival of E. coli O157:H7 in soils, and vice versa (e.g., Gammaproteobacteria and Flavobacteria) (P < 0.05). An array of multivariate statistical approaches including partial Mantel test, variation partition analysis (VPA), and structural equation model (SEM) further confirmed that biotic and abiotic factors interactively shaped the survival profile of E. coli O157:H7. This study revealed that some bacterial taxa were correlated with survival of E. coli O157:H7 directly, and salinity and pH could affect E. coli O157:H7 survival through changing these bacterial taxa. These findings suggest that salinity in soil might benefit the control of fecal pathogenic E. coli invasion, while soil acidification caused by anthropogenic influences could potentially increase the persistence of E. coli O157:H7 in agro-ecosystem.