Coliphage are alternative fecal indicators that may be suitable surrogates for viral pathogens, but a majority of standard detection methods utilize insufficient sample volumes (1-100 mL) for routine detection in environmental waters. Here we compare three somatic and F+ coliphage enumeration methods based on a paired measurement from 1L samples collected from the Great Lakes region (n=74). Methods include: 1) a dead-end hollow fiber ultrafilter combined with single agar layer plaque assay (D-HFUF-SAL); 2) a modified SAL (M-SAL); and 3) a direct membrane filtration (DMF) technique. Overall, D-HFUF-SAL outperformed all other methods as it yielded the lowest frequency of non-detects [(ND); 10.8%] and the highest average coliphage concentrations (2.51 ± 1.02 log10 plaque forming unit/liter (PFU/L) and 0.79 ± 0.71 log10 PFU/L for somatic and F+, respectively). M-SAL yielded 29.7% ND and average concentrations of 2.26 ± 1.15 log10 PFU/L (somatic) and 0.59 ± 0.82 log10 PFU/L (F+). DMF performed worse compared to D-HFUF-SAL and M-SAL methods (ND of 65.6%; average somatic coliphage concentration 1.52 ± 1.32 log10 PFU/L, with no F+ detected), indicating this procedure is unsuitable for 1L surface water sample volumes. This study represents an important step toward the use of a coliphage method for recreational water quality criteria purposes.
This dataset is associated with the following publication:
McMinn, B., E. Rhodes, E. Huff, P. Wanjugi, M. Ware, S. Nappier, M. 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, USA, 261: 63-66, (2018).