Survival and regrowth of fecal enterococci in desiccated and rewetted sediments

Fecal enterococci are bacteria widely used as indicators of fecal contamination in marine and estuarine waters. One assumption is that these bacteria do not persist or regrow in the environment. Our continuing problems with high numbers of fecal enterococci in sediment suggested that these bacteria may persist and regrow. Therefore, we conducted experiments with fecal enterococci to determine their ability to survive desiccation and to regrow in marine and estuarine sediments from Georgia, New Hampshire, and Puerto Rico after 0, 2, 30, and 60 days. Although numbers of fecal enterococci generally decreased with increased length of drying, many fecal enterococci survived desiccation and regrew in rewetted sediment, violating the assumption that fecal bacteria not persist or regrow in the environment. Because there is not a better alternative to fecal enterococci as fecal indicator bacteria, these results suggest that care should be taken not to disturb the sediment when sampling water for fecal contamination, or if the sediment is already disturbed (e.g., on windy days or during runoff conditions), then the influence of sediment should be considered.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources Facult

Improving Fluorometry as a Source Tracking Method to Detect Human Fecal Contamination in Georgia Waters

Proceedings of the 2007 Georgia Water Resources Conference, March 27-29, 2007, Athens, Georgia.In a continuing effort to develop inexpensive source tracking methods to detect human fecal contamination in environmental waters, we combined targeted sampling with fluorometry. Targeted sampling works by identifying hotspots of fecal contamination through multiple samplings over ever decreasing distances. Fluorometry identifies human fecal contamination by detecting optical brighteners, primarily from laundry detergents. On St. Simons Island, targeted sampling and fluorometry identified two hotspots of fecal contamination. One hotspot was confirmed as fecal contamination from humans, but the other was not, most likely because of background organic matter fluorescence. Adding a 436-nm emission filter to the fluorometer reduced this background fluorescence by >50%, and with this filter in place, the second hotspot was identified as fecal contamination from birds. As long as a fluorometer is equipped with a 436-nm emission filter, targeted sampling combined with fluorometry may be a relatively inexpensive method to identify human fecal contamination in water.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors

Combining targeted sampling and bacterial source tracking (bst) during calm and stormy conditions

In April 2004, high numbers of fecal enterococci triggered a beach advisory on Sea Island, GA. Targeted sampling, which finds fecal contamination much like the children’s game of “hot” and “cold,” was combined with three bacterial source tracking (BST) methods: Enterococcus speciation, the presence or absence of a human virulence factor in Enterococcus faecium, and fluorometry. During calm (i.e non-runoff) conditions, the likely contamination sources were wildlife feces and leaking sewer lines located on a creek of St. Simons Island, GA. Fluorometry quickly identified malfunctioning sewer lines. A test for human virulence factor was positive. During stormflow (i.e. runoff) conditions, the likely contamination sources were wildlife feces and effluent from two pipes. A test for human virulence factor was negative. Because the percentage of Ent. faecalis from the pipes was high (>30%), fecal contamination from wild birds was likely. This is the first report of targeted sampling during stormy conditions, and the first time fluorometry has been combined with targeted sampling.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources Facult

The CMS Barrel Calorimeter Response to Particle Beams from 2 to 350 GeV/c

The response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/c has been measured. To our knowledge, this is the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a detailed discussion of the underlying phenomena are presented. We also show techniques that apply corrections to the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons. Above 5 GeV/c, these corrections improve the energy resolution of the combined system where the stochastic term equals 84.7$\pm$1.6$\%$ and the constant term is 7.4$\pm$0.8$\%$. The corrected mean response remains constant within 1.3$\%$ rms