Detección y caracterización de virus emergentes en su ciclo ambiental

Abstract

[eng] Besides classic enteric viruses such hepatitis A virus and norovirus, there are other viruses that can reach water sources without being part of their transmission route. Some of these pathogens are enveloped viruses, which complicates their recovery with the usual concentration methods for the classic naked enteric viruses. Glass wool filtration followed by polyethylene glycol (PEG) 6000 precipitation is cheap and reliable for recovering non-enveloped viruses, but is inefficient for the concentration of enveloped viruses. Thus, the first goal of this Thesis was the optimization of the glass wool filtration method for the recovery of enveloped viruses without losing efficiency for the recovery of naked viruses. Once optimized, this protocol was used to concentrate viruses from multiple water types such drinking water, surface water, well water, wastewater and brackish pond water. The results presented suggest that the optimized glass wool filtration method is useful and reliable for recovering both enveloped and non-enveloped viruses. Of particular interest was the characterization of a norovirus outbreak of gastroenteritis associated to the consumption of bottled water. Remarkably, several emerging viruses, such as non- classical astroviruses, West Nile virus and rat coronaviruses, were detected in samples from Riyadh (Saudi Arabia), and Barcelona. Additionally, a monthly surveillance of enterovirus in the Barcelona wastewater was implemented for the control of the circulation of highly pathogenic species such as Enterovirus A71 and D68. The dominant consensus sequence and the ensemble of major and minor sequences were determined by Sanger and deep sequencing, respectively.