Dr. Roberto Vidal
Adjunct Investigator
Universidad de Chile
Our main objective is to determine the Clinical and Molecular Epidemiology of the intestinal infections caused by most frequent isolates of diarrheagenic Escherichia coli (DEC), mainly Shiga-toxin producing E.coli (EHEC/STEC) and enterotoxigenic E.coli (ETEC). Other bacterial pathogens for human or animals like Listeria monocytogenes and Piscirickettsia salmonis also has been included. Currently, our laboratory has been working on the design and evaluation of new molecular techniques for diagnostic (based on mPCR), characterization of virulence factor previously described. Moreover, we are also interested in the search for new virulence factors associated with bacterial adhesion and their interaction with extracellular matrix proteins or other membrane structures in eukaryotic cells. We carry out clonal studies using PFGE protocol, for outbreaks caused by pathogenic strains isolated from Chile and other countries.
In STEC, also we have worked in determined the magnitude of the animal reservoir (bovine and pig) in Chile, characterizing those strains with zoonotic potential. Five years ago, we incorporated immunoproteomics assay (using 2D gel) for searching for protective antigens harbored in STEC strains that would allow their control in the animal reservoir for future vaccine’s studies. Since 2010, in a collaborative study, our laboratory has incorporated several isolates of Adherent-Invasive E.coli (AIEC) (Dra. Marcela Hermoso, Dr. Rodrigo Quera) and microbiota studies in inflammatory bowel disease in Chilean and Spanish patients, adding collaborators such as Dr. Ramón Rossello Mora, Daniel Ginard (IMEDEA-CSIC, Spain), and Fernando Ruiz-Pérez (University of Virginia, USA).
AIEC is a new pathotype of E.coli that has been associated with Inflammatory Bowel Disease (IBD). On the other hand, with less time commitment, we also conduct studies to characterize isolates of Listeria monocytogenes from human and food since 2008 to 2017, and P. Salmonis obtained from sick salmon in the south of Chile. All these studies have been developed in collaboration with the Drs. Angel Onate, Maricel Vidal, Mauricio Farfán, and Betty San Martin (Chile), Alfredo Torres (UTMB, USA), Myron Levine, Karen Kotloff and Colin Stine (CVD, University of Maryland, USA), Jim Nataro (University of Virginia, USA), Jorge Blanco Alvarez (Spain), José Luis Puente- Garciíaa (Universidad Nacional Autoónoma de México, UNAM) and Jorge Girón (Benemérita Universidad de Puebla). In all these topics, we have published manuscript with good impact factor in leading journal for microbiology.