Aplicació de tècniques moleculars per a la detecció d’Escherichia coli en diferents tipus d’aigües
Year: 2019
Type: dissertation
Abstract: Traditionally in water quality analysis laboratories it is used classic microbiological techniques following the Reial decrets depending on the type of water. To detect pathogenic microorganisms stand out the seed in specifics culture media for each pathogen. However, the time of incubation of the samples and the subsequent confirmations that must be carried out in some occasions makes it a long process. In the case of water for consumption, the time it takes to obtain the results depends on the microorganism to be detected, the method used, the type of sample and the intended use. In no case exceeds 24 hours. In this TFG we give a possible alternative of the methods of classic microbiology, the application of molecular techniques for a rapid detection of the bacteria Escherichia coli in waters. Specifically, the application of the polymerase chain reaction (PCR) using specific primers to amplify a specific sequence of DNA in this specie. In order to carry the project out, different samples (MilliQ inoculation with different concentrations of E. coli and a residual water sample) were used. DNA extractions were made and the PCRs were then carried out with two pairs of primers. One amplifies the V3-V4 region of 16S rRNA gene, a region that contains the vast majority of microorganisms, and the other amplifies the ybbW gene that is specific to E. coli. In order to compare the results, the analysis was done using classic microbiology techniques: filtration and seed in culture media, as indicated by ISO 9308-1. Those waters whose microbial load was very low, there was no detection with the specific primers of E. Coli, on the other hand, in the environmental sample (residual water) there was a detection in the two pairs of primers. Based on strains of Escherichia coli, Enterococcus faecium and Pseudomonas aeruginosa, the PCR technique was performed from a colony (colony-PCR). With primers that amplified the 16S region, there was an amplification in all colonies, on the other hand, with the primers specific of E. coli there was only an amplification of colonies of E. coli.
Author: Mercè Agramunt Lliberia
Language: Catalan
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2964386796