Sensitivity and Specificity of Molecular-Based Pathogen Detection Method in Refillable Drinking Water Samples

Abstract

The existence of refillable drinking water depots helps the community to get affordable and practical drinking water. However, poor quality drinking water will, however, have an effect on health. One of the quality parameters of drinking water that is suitable for consumption is not contaminated by the bacteria Escherichia coli, Salmonella sp. and Escherichia sp. Measurement of the quality of drinking water, in addition to microbiological tests, can be carried out molecularly using PCR (Polymerase Chain Reaction) method. Therefore, the aim of this study was to examine the sensitivity and specificity of PCR for detection of drinking water pathogens. DNA was extracted from cultures of E. coli, Salmonella sp., Escherichia sp. and some non-coliform bacteria. PCR was performed separately using primer pairs of E. coli-AA-Forward and E.coli-AA-Reverse, Salmonella-OY-Forward and Salmonella-OY-Reverse, E. coli-DB-Forward and E. coli-DB-Reverse. The results of the PCR sensitivity showed that the minimum amount of DNA that can be detected by this method were 0.0025 ng/µL, 0,0005 ng/µL, 0,04 ng/µL for E. coli, Salmonella sp., Escherichia sp., respectively. The results of the PCR specificity of each primer pairs indicated that these methods were able to detect each coliform bacterium specifically according to PCR product size of ± 417 bp, ± 559 bp and ± 815 bp for E. coli, Salmonella sp., Escherichia sp., respectively.