AWWA WQTC71352

This paper presents preliminary results of method development studies of aculture and qPCR method where unstressed and stressed bacteria were inoculated intodifferent matrices at different densities. This type of method offers both a demonstration of viability throughculture, and the detection specificity and sensitivity of qPCR. The study sought a culturemethod that is able to recover stressed bacteria, and has some selectivity for coliformbacteria. The criteria for qPCR detection was that it must be able to detect the targetbacteria in the presence of a natural bacterial background, and be able to detect a wideenough range of target bacterial concentrations to demonstrate that a change in densityhad occurred during incubation. The approach for demonstrating viability of targetbacteria was to conduct an initial (qPCR) analysis at the time that incubation was initiatedand a final qPCR analysis after a period of incubation. The difference in qPCR signal ofsamples taken before and after incubation was seen as evidence of growth. Whereverpossible, the study used commercially available products to minimize method development andpreparation time. Additionally, the paper presents the results of the use ofthis method with natural surface water samples that were taken from streams suspected ofhaving E. coli O157:H7 contamination. Includes 6 references.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

6

File Size:

1 file , 740 KB