1. Institut de Pharmacologie et de Biologie Structurale; Centre National de la Recherche Scientifique; Toulouse France
2. Institut de Pharmacologie et de Biologie Structurale; Univer-sité Paul Sabatier; Université de Toulouse; Toulouse France
3. Division of Infectious Diseases; Department of Medicine; University of Alabama at Birmingham; Birmingham AL USA
4. Department of Microbiology; University of Alabama at Birmingham; Birmingham AL USA