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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #301271
Title: Comparison of temperature effects on E. coli, Salmonella, and Enterococcus survival in surface waters

Author
item Pachepsky, Yakov
item Blaustein, Ryan
item WHELAN, GENE - Environmental Protection Agency (EPA)
item Shelton, Daniel

Submitted to: Letters in Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2014
Publication Date: 8/20/2014
Citation: Pachepsky, Y.A., Blaustein, R.A., Whelan, G., Shelton, D.R. 2014. Comparison of temperature effects on E. coli, Salmonella, and Enterococcus survival in surface waters. Letters in Applied Microbiology. 59:278-283.

Interpretive Summary: Microbial water quality is of concern, particularly where waters are used for recreation, irrigation, aquaculture or other agricultural purposes. Estimates of microbial water quality are dependent on bacterial die-off rates, and die-off rates are dependent on temperature. Temperature dependencies have been actively studied for E.coli, the microbe that is commonly used to evaluate potential for pathogenic contamination of waters. It is not known whether the same dependencies apply to other microorganisms. Using published data, we developed a database to test the hypothesis that the die-off dependence for E. coli is similar to other indicator organisms such as Enterococci, or the pathogen Salmonella. We found that existing data support using the same temperature dependence for the three organisms in marine waters. However, in lake freshwaters, the die-off of Salmonella was much faster than that of E. coli. Results of this work are important to researchers and practitioners in the fields of watershed management and irrigation information on essential parameters of bacterial fate and transport models that are used to support environmental management decisions, and on the use of surface water resources in agriculture, aquaculture, and recreation.

Technical Abstract: The objective of this study was to compare the dependencies of survival rates on temperature for indicator organisms E. coli and Enterococcus and the pathogen Salmonella in surface waters. A database consisting of 86 survival datasets from peer-reviewed papers on inactivation of E. coli, Salmonella, and Enterococcus in marine waters and of E. coli and Salmonella in lake waters was assembled. The Q10 model was used to express the temperature effect on survival rates obtained from linear sections of semilogarithmic survival graphs. Available data were not sufficient to establish differences in survival rates and temperature dependencies for marine waters, where values of Q10=3 and survival rate of 0.7 day-1 could be applied. The Q10 values of 1.75 in lake waters were substantially lower in marine waters, and Salmonella inactivation in lake water was, on average, twice as fast as that of E. coli. The data on E. coli substantially outnumber data on Enterococcus and Salmonella. The relative increase in the inactivation rate with the increase in temperature is higher in marine waters than in lake water, and differences in inactivation at a given temperature between Salmonella and E. coli were significant in lake water but not in marine waters.