1. 1Department of Pathology, University Hospital and School of Medicine, Santiago de Compostela, Spain,
2. Department of Gastroenterology, University Hospital and School of Medicine, Santiago de Compostela, Spain
3. Department of Microbiology, University Hospital and School of Medicine, Santiago de Compostela, Spain
4. Department of Pathology, University Hospital and School of Medicine, Santiago de Compostela, Spain