1. Internal Medicine Service, University Hospital Marqués de Valdecilla-IDIVAL, 39008 Santander, Spain
2. Microbiology Service, University Hospital Marqués de Valdecilla-IDIVAL, 39008 Santander, Spain
3. Nephrology Service, University Hospital Marqués de Valdecilla-IDIVAL, 39008 Santander, Spain
4. Microbiology Service, University Hospital Marqués de Valdecilla-IDIVAL-CIBERINFEC, 39008 Santander, Spain