[1] Univ Hosp Birmingham NHS Fdn Trust, Queen Elizabeth Hosp, Dept Clin Microbiol & Infect Control, Birmingham B15 2TH, W Midlands, England
[2] Univ Hosp Birmingham NHS Fdn Trust, Queen Elizabeth Hosp, Wellcome Trust Clin Res Facil, Birmingham B15 2TH, W Midlands, England
[3] Brown Univ, Rhode Isl Hosp, Dept Epidemiol & Infect Control, Providence, RI 02903 USA
[4] Brown Univ, Dept Med, Warren Alpert Med Sch, Providence, RI 02912 USA