Fecal indicator and pathogenic bacteria and their antibiotic resistance in alluvial groundwater of an irrigated agricultural region with dairies

Xunde Li, Edward R Atwill, Elizabeth Antaki, Olin Applegate, Brian Bergamaschi, Ronald F. Bond, Jennifer Chase, Katherine M. Ransom, William Samuels, Naoko Watanabe, Thomas Harter

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Surveys of microbiological groundwater quality were conducted in a region with intensive animal agriculture in California, USA. The survey included monitoring and domestic wells in eight concentrated animal feeding operations (CAFOs) and 200 small (domestic and community supply district) supply wells across the region. Campylobacter was not detected in groundwater, whereas Escherichia coli O157:H7 and Salmonella were each detected in 2 of 190 CAFO monitoring well samples. Nonpathogenic generic E. coli and Enterococcus spp. were detected in 24.2% (46/190) and 97.4% (185/190) groundwater samples from CAFO monitoring wells and in 4.2% (1/24) and 87.5% (21/24) of CAFO domestic wells, respectively. Concentrations of both generic E. coli and Enterococcus spp. were significantly associated with well depth, season, and the type of adjacent land use in the CAFO. No pathogenic bacteria were detected in groundwater from 200 small supply wells in the extended survey. However, 4.5 to 10.3% groundwater samples were positive for generic E. coli and Enterococcus. Concentrations of generic E. coli were not significantly associated with any factors, but concentrations of Enterococcus were significantly associated with proximity to CAFOs, seasons, and concentrations of potassium in water. Among a subset of E. coli and Enterococcus isolates from both surveys, the majority of E. coli (63.6%) and Enterococcus (86.1%) isolates exhibited resistance to multiple (

Original languageEnglish (US)
Pages (from-to)1435-1447
Number of pages13
JournalJournal of Environmental Quality
Volume44
Issue number5
DOIs
StatePublished - 2015

ASJC Scopus subject areas

  • Environmental Engineering
  • Pollution
  • Management, Monitoring, Policy and Law
  • Waste Management and Disposal
  • Water Science and Technology

Fingerprint Dive into the research topics of 'Fecal indicator and pathogenic bacteria and their antibiotic resistance in alluvial groundwater of an irrigated agricultural region with dairies'. Together they form a unique fingerprint.

  • Cite this

    Li, X., Atwill, E. R., Antaki, E., Applegate, O., Bergamaschi, B., Bond, R. F., Chase, J., Ransom, K. M., Samuels, W., Watanabe, N., & Harter, T. (2015). Fecal indicator and pathogenic bacteria and their antibiotic resistance in alluvial groundwater of an irrigated agricultural region with dairies. Journal of Environmental Quality, 44(5), 1435-1447. https://doi.org/10.2134/jeq2015.03.0139