1 Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, UK.
2 Emory University, School of Medicine, Dept. of Microbiology and Immunology, Emory Antibiotic Resistance Center, 1510 Clifton Rd. Room 3023, Atlanta, GA 30322, USA.
3 Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111, USA.