PCR Identification of Escherichia coli Isolated from Bushehr Coastal Water

Abstract

Background: Standard methods of identification have not been able to solve all issues concerning E. coli. With the development of genomic studies, PCR appears promising to deal with the shortcomings. This study aimed to utilize PCR with specific primers for lacZ, uidA, cyd, and lacY gene segments to identify environmental E. coli isolates. Materials and methods: PCR and the aforementioned four primers were used for molecular identification of E. coli on purified genome DNA from 120 environmental E. coli isolates, standard strains of Shigella, and Enterohaemorrhagic E. coli strain as controls. All environmental E. coli isolates were isolated from Bushehr coastal areas and identified in a previous study by standard bacteriological methods and then preserved in -70 ˚C for further studies. Results: The primers successfully showed their ability to identify the targets in environmental isolates and standard strains. It is shown that the four PCR fragments related to lacZ, uidA, cyd, and lacY genes were observed only for E. coli isolates and strains. Conclusion: PCR method proved capable to distinguish E. coli from Shigella as the most phylogenetically related genus and contrary to the classical methods, it could detect enterohaemorrhagic strains as Escherichia coli