1. Service of Microbiology, Pediatric Hospital “Octavio de la Concepción y la Pedraja”, Holguín, Cuba
2. Department of Bacteriology-Mycology, Tropical Medicine Institute “Pedro Kourí”, Havana, Cuba
3. Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan
4. Service of Microbiology, University Hospital Ramón y Cajal, Madrid, Spain