Comparison of Methods for the Recovery and Quantitation of Coliphage and Indigenous Bacteriophage from Marine Waters and Sediments

A variety of anthropogenic influences on marine coastal waters introduces populations of human enteric bacteria and their bacteriophage, some of which may be indicators of municipal waste contamination. This work was undertaken to examine methods for recovery and detection of coliphage in marine waters and sediments. Seeded studies were used to compare viradel and Ultrafiltration methods for the recovery and concentration of both indigenous and introduced viruses from seawater. Ultrafiltration recoveries of MS2 averaged 29.3% in artificial seawater. Viradel methods used to concentrate MD1 coliphage averaged 18.7% recovery when used with natural seawater. A variety of eluants were examined for recovery of phage from sediments. Recoveries ranged from 0.8-100% depending on the type of phage and eluant used. No eluant was capable of providing more efficient recoveries over another, however, indigenous phage #16 was isolated more efficiently than introduced tailed phages T2 and MD1. For phage quantitation, plaque assay counts were compared to particle counts using TEM. TEM counts were usually higher than PFUs in artificial seawater concentrates but lower with eluted marine sediments. Environmental surveys revealed that phage could sometimes be isolated from sediments when they could not be detected in the overlying water column. Preliminary data showed phage could be isolated from sea cucumbers and sponges at higher concentrations than in their surrounding habitats. Therefore, with the development of efficient elution and rapid quantitation techniques, sediments and sea organisms are the most appropriate sampling sites for detection of marine phage populations.