AWWA WQTC71413

This powerpoint presentation begins by presenting study objectives that included the following: validation of a pectin-based agar substitute toeliminate the need of precise temperaturemonitoring for agar during assay;validation of a method to enhance visualization ofviral plaques using a chromogenic substrate and adye; and,validation of pectin-based medium using U.S. Environmental Protection Agency (USEPA)Method 1602. Study procedures included the following: add 10 or 100 mL of water or concentratedsamples from absorption/elution method topectin-based medium;add 0.75 mL bacterial stain; and,add 3 mL log-phase E. coli culture (E. coliFamp or CN13); add antibiotics if necessary[Ampicillin/streptomycin when using E. coli Famp(male-specific coliphages), Nalidixic acid when using E. coli CN-13];swirl the bottle several times to mix well andpour the mixture into the pretreated petri dish; allow the medium mixture to solidify on a horizontal benchfor 45 min., then turn the stacked dishes up side down quicklyand move them to an incubator (36 ± 1 ºC);or,immediately after pour plate, stack up the dishes and carefullymove the dishes to a leveled incubator. Plates can beincubated in upright position. Study conclusions indicate the following: the pectin-based medium is superior to traditional agar-basedmedium - results can be obtained as early as 6 hrs., easy identification by larger blue plaques with excellentcontrast, and better in recovering injured coliphages; convenient and easy to use,temperature control is not required andeliminates preparation, sterilization or melting of agar medium; field deployable; IPR and MS meets USEPA Methods 1602 QCrequirement; detection of male-specific coliphages using pectin-based medium is more sensitive than agar-based medium in filtered sewage and surface water; detection of somatic coliphages using pectin-based medium is as sensitive as agar-based medium; and,the pectin-based medium can be used in direct membrane filtration or possible in DAL. Includes tables, figure.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

30

File Size:

1 file , 1.3 MB