SUBSPECIFIC DIFFERENTIATION OF BURKHOLDERIA-CEPACIA ISOLATES IN CYSTIC-FIBROSIS

Thirty clinical isolates of Burkholderia cepacia from cystic fibrosis (CF) patients in the UK and Denmark were characterised, together with other clinical isolates and laboratory strains of B, cepacia, B, gladi oli and B, vietnamiensis. Outer-membrane protein (OMP) profiles were d etermined, and the organisms were typed genotypically by pulsed-field gel electrophoresis after DNA restriction analyses with XbaI and DraI, This latter method revealed four clusters among the clinical isolates studied; one of these contained isolates of the UK and intercontinent al CF epidemic lineage ET12, a cluster which appeared to contain three subtypes, Each of the four clusters appeared less closely related to laboratory strains of B, cepacia than were laboratory strains of B, vi etnamiensis, but more closely related to both these species than to B, gladioli, Two types of OMP profile were distinguished among the clini cal isolates and strains, and were designated A and B, In type A isola tes the major proteins had mol.wts of 39, 27 and 18 kDa, Type B strain s additionally contained a group of proteins in the size range 80-90 k Da, although detection of these depended upon the conditions for sampl e denaturation. In most cases, the OMP type correlated with the genoty pe, suggesting that examination of OMPs might be of value in the initi al characterisation of isolates.