You are here:
Comparison of somatic and F+ coliphage enumeration methods with large volume surface water samples
Citation:
McMinn, B., E. Rhodes, E. Huff, P. Wanjugi, M. Ware, S. Nappier, Mike Cyterski, O. Shanks, K. Oshima, AND A. Korajkic. Comparison of somatic and F+ coliphage enumeration methods with large volume surface water samples. JOURNAL OF VIROLOGICAL METHODS. Elsevier Science Ltd, New York, NY, 261:63-66, (2018). https://doi.org/10.1016/j.jviromet.2018.08.007
Impact/Purpose:
This manuscript describes performance of three culture-based methods for detection and enumeration of somatic and F+ coliphages from large (1L) volumes of surface waters.
Description:
Coliphages are alternative fecal indicators that may be suitable surrogates for viral pathogens, but majority of standard detection methods utilize insufficient volumes for routine detection in environmental waters. We compared three somatic and F+ coliphage methods based on a paired measurement from 1 L samples collected from the Great Lakes (n = 74). Methods include: 1) dead-end hollow fiber ultrafilter with single agar layer (D-HFUF-SAL); 2) modified SAL (M-SAL); and 3) direct membrane filtration (DMF) technique. Overall, D-HFUF-SAL outperformed other methods as it yielded the lowest frequency of non-detects [(ND); 10.8%] and the highest average concentrations of recovered coliphage for positive samples (2.51 ± 1.02 [standard deviation, SD] log10 plaque forming unit/liter (PFU/L) and 0.79 ± 0.71 (SD) log10 PFU/L for somatic and F+, respectively). M-SAL yielded 29.7% ND and average concentrations of 2.26 ± 1.15 (SD) log10 PFU/L (somatic) and 0.59 ± 0.82 (SD) log10 PFU/L (F+). DMF performance was inferior to D-HFUF-SAL and M-SAL methods (ND of 65.6%; average somatic coliphage concentration 1.52 ± 1.32 [SD] log10 PFU/L, no F+ detected), indicating this procedure is unsuitable for 1 L surface water sample volumes. This study represents an important step toward the use of a coliphage method for recreational water quality criteria purposes.
URLs/Downloads:
DOI: Comparison of somatic and F+ coliphage enumeration methods with large volume surface water samples