1. School of Chemistry, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
2. Birmingham Advanced Light Microscopy Facility, University of Birmingham, Edgbaston, B15 2TT, UK
3. School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
4. Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK