Quantification of a bacteriophage in wastewater.

Abstract

An investigation was conducted to estimate qualitatively and quantitatively the content of bacteriophage in wastewater before and after tertiary treatment through Tucson's pilot filter. Preliminary studies on methods to eliminate or reduce bacteria in wastewater, prior to assaying for bacteriophage, included membrane filtration and centrifugation. Membrane filtration was superior to centrifugation but serum pretreatment was necessary to eliminate loss of bacteriophage by adsorption. Five enteric bacteria, including Escherichia coli, Aerobacter cloacae, Proteus vulgaris, Pseudomonas aeruginosa, and Salmonella paratyphi, were isolated from pilot filter influent and subsequently used to assay wastewater filtrates for bacteriophage. The concentration of bacteriophage capable of causing lysis of these bacteria was determined by using a modification of the most probable number method customarily used to estimate coliforms. The concentrations of all five bacteriophages were found to be reduced after tertiary treatment through the pilot filter. A modification of the bacteriophage assay procedure was investigated in an effort to concentrate bacteriophages present in wastewater using an aluminum hydroxide adsorption method recently devised to adsorb human enteroviruses. This procedure yielded good recovery of bacteriophage and with slight modification might be used for direct plaque enumeration of bacteriophages in water rather than the indirect most probable number method used in this study.