[1] AFBI, Belfast BT9 5PX, Antrim, North Ireland
[2] Queens Univ Belfast, Belfast City Hosp, Ctr Infect & Immun, Reg Adult Cyst Fibrosis Unit, Belfast BT7 1NN, Antrim, North Ireland
[3] Queens Univ Belfast, Belfast City Hosp, Ctr Infect & Immun, Resp Med Res Grp, Belfast BT7 1NN, Antrim, North Ireland
[4] Univ Ulster, Sch Biomed Sci, Coleraine BT52 1SA, Londonderry, North Ireland