Department of Physics, Lehigh University, Bethlehem, Pennsylvania, United States of America.|Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.|Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.|Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.|Department of Physics, Lehigh University, Bethlehem, Pennsylvania, United States of America.