Evaluation of Polymerase Chain Reaction for Direct Detection of Escherichia coli Strains in Environmental Samples
Evaluation of Polymerase Chain Reaction for Direct Detection of Escherichia coli Strains in Environmental Samples
No Thumbnail Available
Date
2007
Authors
Safa A. Sherfi
Hamid A. Dirar
Badr E. Hago
Mohamed E. Ahmed
Hassan A. Musa
Hassan Abu Aisha
Imadeldin E. Aradaib
Journal Title
Journal ISSN
Volume Title
Publisher
Academic Journals
Abstract
The potential of the Polymerase Chain Reaction (PCR), as a means of detecting
Escherichia coli (E. col’) DNA in suspected environmental samples, was studied. Using a
pair of outer primers Pl and P2, selected from wdA gene, which encodes £. coli
glucuronidase, the PCR-based assay resulted in amplification of a 486 base pair (bp) PCR
product. £. cofi strains from different environmental sources including recycled and drinking
water as well as stagnant water were detected by this nested PCR-based assay.
Amplification products were visualized on ethidium bromide-stained agarose gel. The
sensitivity of the PCR assay was 100 fg of bacterial DNA with ethidium bromide-stained
agarose gels. Using a pair of internal (nested) primers P3 and P4, the nested PCR produced
a 186 bp PCR product. The nested PCR increased the sensitivity of the PCR assay by 1,000
times and specific PCR products were detected from 0.1 fg of bacterial DNA. Amplification
product was not detected when the nested PCR-based assay was applied to DNA from
other related bacteria including, Salmonella, Pseudomonas and Proteus or nucleic acid-free
water. Application of this nested PCR-based assay to environmental samples resulted in
direct detection of Z. coli DNA from sewage water, tap water, drinking water at Shambat
Campus, University of Khartoum, Sudan. This nested PCR-based assay should provide a
rapid, sensitive and specific assay for direct detection and quantification of £. cofi in
environmental samples suspected to contain the organism.
Description
Keywords
Citation
Aradaib, I.E., 2008. Evaluation of Polymerase Chain Reaction for Direct Detection of Escherichia coli Strains in Environmental Samples.