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ARS Home » Pacific West Area » Riverside, California » Agricultural Water Efficiency and Salinity Research Unit » Research » Publications at this Location » Publication #361308

Research Project: Identifying, Quantifying and Tracking Microbial Contaminants, Antibiotics and Antibiotic Resistance Genes in Order to Protect Food and Water Supplies

Location: Agricultural Water Efficiency and Salinity Research Unit

Title: Soil salinity, pH, and indigenous bacterial community interactively influence the survival of E. coli O157:H7 revealed by multivariate statistics

item ZIMING, HAN - Jilin University
item MA, JINCAI - Jilin University
item YANG, CHING-HONG - University Of Wisconsin
item Ibekwe, Abasiofiok - Mark

Submitted to: Environmental Science and Pollution Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2020
Publication Date: 9/24/2020
Citation: Ziming, H., Ma, J., Yang, C., Ibekwe, A.M. 2020. Soil salinity, pH, and indigenous bacterial community interactively influence the survival of E. coli O157:H7 revealed by multivariate statistics. Environmental Science and Pollution Research. 28:5575-5586.

Interpretive Summary: Escherichia coli O157:H7 is a food-borne pathogen that causes watery diarrhea and sometimes death. Undercooked beef is believed to be the major cause of E. coli O157:H7 infection. However, accumulating evidence suggests that fresh produce serves as an important vehicle for the transmission of this pathogen. In this study, E. coli O157:H7 survival in 32 soils (16 organic, 16 conventional) from California (CA) and Arizona (AZ) was investigated. The survival of E. coli O157:H7 was controlled by multiple factors, with the dominant factor being salinity (EC). However, other biotic (e.g. fungi, protozoa, bacteriophages, etc.) and abiotic (e.g. availability of nutrient and energy sources, temperature, moisture, etc.) factors and their interactions may also affect the survival of E. coli O157:H7. The results of this research will be used by growers, researchers, FSIS, FDA, and different state agencies that are involved in leafy green production.

Technical Abstract: 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.