1. Asturias Institute of Biotechnology, Department of Biochemistry and Molecular Biology, University of Oviedo, Oviedo, Spain.
2. Microbiology Service, Laboratory of Virology, Central University Hospital of Asturias, Oviedo, Spain.
3. Department of Microbiology and Virology, Faculty of Biology, University of Havana, Havana, Cuba.
4. Area of Food Technology, Regional Service of Agrofood Research and Development, Villaviciosa, Spain.