Performance of viruses and bacteriophages for fecal source determination in a multi-laboratory, comparative study
|Author(s)||Harwood Valerie J.1, Boehm Alexandria B.2, Sassoubre Lauren M.2, Vijayavel Kannappan3, 12, Stewart Jill R.4, Fong Theng-Theng5, Caprais Marie-Paule6, Converse Reagan R.7, Diston David8, Ebdon James9, Fuhrman Jed A.10, Gourmelon Michele6, Gentry-Shields Jennifer4, Griffith John F.11, Kashian Donna R.12, Noble Rachel T.13, Taylor Huw9, Wicki Melanie8|
|Affiliation(s)||1 : Univ S Florida, Dept Integrat Biol, Tampa, FL 33620 USA.
2 : Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA.
3 : Ottawa Cty Hlth Dept, Div Environm Hlth, Holland, MI 49424 USA.
4 : Univ N Carolina, Dept Environm Sci & Engn, Gillings Sch Global Publ Hlth, Chapel Hill, NC 27599 USA.
5 : Tetra Tech Co, Clancy Environm Consultants, St Albans, VT 05478 USA.
6 : IFREMER, Unite Environm Microbiol & Phycotoxines, Dept Ressources Biolog & Environm, Microbiol Lab,MIC LNR, F-29280 Plouzane, France.
7 : Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA.
8 : Fed Off Publ Hlth, CH-3003 Bern, Switzerland.
9 : Univ Brighton, Sch Environm & Technol, Environm & Publ Hlth Res Unit, Brighton BN2 4GJ, E Sussex, England.
10 : Univ So Calif, Dept Biol Sci, Los Angeles, CA 90089 USA.
11 : Southern Calif Coastal Water Res Project, Costa Mesa, CA 92626 USA.
12 : Wayne State Univ, Dept Biol Sci, Detroit, MI 48202 USA.
13 : Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA.
|Source||Water Research (0043-1354) (Pergamon-elsevier Science Ltd), 2013-11 , Vol. 47 , N. 18 , P. 6929-6943|
|WOS© Times Cited||50|
|Keyword(s)||Virus, Bacteriophage, Water quality, Fecal pollution, Validation|
|Abstract||An inter-laboratory study of the accuracy of microbial source tracking (MST) methods was conducted using challenge fecal and sewage samples that were spiked into artificial freshwater and provided as unknowns (blind test samples) to the laboratories. The results of the Source Identification Protocol Project (SIPP) are presented in a series of papers that cover 41 MST methods. This contribution details the results of the virus and bacteriophage methods targeting human fecal or sewage contamination. Human viruses used as source identifiers included adenoviruses (HAdV), enteroviruses (EV), norovirus Groups I and II (NoVI and NoVII), and polyomaviruses (HPyVs). Bacteriophages were also employed, including somatic coliphages and F-specific RNA bacteriophages (FRNAPH) as general indicators of fecal contamination. Bacteriophage methods targeting human fecal sources included genotyping of FRNAPH isolates and plaque formation on bacterial hosts Enterococcus faecium MB-55, Bacteroides HB-73 and Bacteroides GB-124. The use of small sample volumes (<= 50 ml) resulted in relatively insensitive theoretical limits of detection (10-50 gene copies or plaques x 50 ml(-1)) which, coupled with low virus concentrations in samples, resulted in high false-negative rates, low sensitivity, and low negative predictive values. On the other hand, the specificity of the human virus methods was generally close to 100% and positive predictive values were similar to 40-70% with the exception of NoVs, which were not detected. The bacteriophage methods were generally much less specific toward human sewage than virus methods, although FRNAPH II genotyping was relatively successful, with 18% sensitivity and 85% specificity. While the specificity of the human virus methods engenders great confidence in a positive result, better concentration methods and larger sample volumes must be utilized for greater accuracy of negative results, i.e. the prediction that a human contamination source is absent.|