1. CICS-UBI - Health Sciences Research Centre; University of Beira Interior; Avenida Infante D. Henrique 6200 - 506 Covilhã Portugal
2. National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases; National Institute of Health Dr. Ricardo Jorge; Avenida Padre Cruz 1649-016 Lisboa Portugal
3. Chemistry Department; University of Beira Interior; Covilhã Portugal