[1] Univ Nottingham, Sch Mol Med Sci, Div Microbiol & Infect Dis, Nottingham NG7 2RD, England
[2] Univ Nottingham, Sch Community Hlth Sci, Div Primary Care, Nottingham NG7 2RD, England
[3] Queens Med Ctr Trust, Directorate Pathol, Dept Microbiol, Nottingham, England
[4] Univ Nottingham, Sch Community Hlth Sci, Div Publ Hlth Med & Epidemiol, Nottingham NG7 2RD, England
[5] Queens Med Ctr Trust, Directorate Med, Dept Med, Nottingham, England