1. Laboratory of Oral Pathology, Postgraduate and Research Division, Dental School, National Autonomous University of Mexico, Coyoacan, México
2. Laboratory of Microbiology, Pathology and Biochemical, Faculty of Stomatology, Autonomous University of San Luis Potosi, San Luis Potosí, México
3. Microbiology area, Health Sciences Center, Autonomous University of Baja California, Valle de las Palmas, Tijuana, Baja California, México