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Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only Publication Acceptance Date: 12/14/2005 Publication Date: 7/10/2006 Citation: Bolster, C.H., Cook, K.L. 2006. Is escherichaia coli a good indicator of the transport of campylobacter jejuni in ground water environments. ASABE Annual International Meeting. Interpretive Summary: Technical Abstract: The infiltration of fecal material into the subsurface can be a significant source of contamination of groundwater supplies by enteropathogenic microorganisms resulting in serious gastrointestinal illnesses in both humans and livestock. Due to the difficulties in testing for specific pathogens, water samples are tested for the presence of nonpathogenic indicator organisms to determine whether a water supply has been contaminated by fecal material; yet surprisingly few studies have been conducted which directly compare the transport behavior of indicator organisms with pathogenic microorganisms in groundwater environments. In this study we compared the cell properties and transport behavior of Escherichia coli (E. coli), a commonly used indicator organism, and Campylobacter jejuni (C. jejuni), an important enteropathogen commonly found in agricultural wastes. Differences in cell properties were determined by measuring cell size and shape, hydrophobicity, and electrophoretic mobility. Transport differences were determined by conducting miscible displacement experiments in laboratory columns containing either metal-oxyhydroxide coated quartz sand or uncoated quartz sand. Under the experimental conditions tested, C. jejuni was much more negatively charged than E. coli. Cell size and shape differed significantly between the two microorganisms as well. The differences in cell properties between these two microorganisms resulted in significant differences in transport behavior. Under conditions favoring high bacterial attachment to sand grains (i.e., columns packed with metal-oxyhydroxide coated sand), the removal of C. jejuni exceeded that of E. coli. Under conditions favoring low bacterial attachment rates (i.e., columns packed with uncoated quartz sand), however, the removal of E. coli exceeded that of C. jejuni resulting in greater transport of C. jejuni compared to E. coli. Our results call into question the effectiveness of using E. coli as an indicator organism for this important pathogen under certain environmental conditions. |
