DISTRIBUTION OF BURKHOLDERIA-CEPACIA PHENOTYPES BY NICHE, METHOD OF ISOLATION AND PATHOGENICITY TO ONION

Several proposals have been made for the subdivision of the bacterial species Burkholderia cepacia. Data applying these schemes to a collect ion of 188 strains of B. cepacia, isolated using a variety of methods, from soils, decayed onions, and nosocomial sources are presented. Non e of the schemes could be shown to be associated with the method of is olation, niche from which a strain was isolated, pectolytic activity, or pathogenicity to onion. Strains isolated by serial dilution on onio n slices were much more uniform than were strains isolated using semis elective media. The nutritionally stringent medium of Lumsden and Sass er (US Patent No. 4 588 584) was judged better for the collection of a phenotypically broad sample of B. cepacia than those of Hagedorn, Gou ld, Bardinelli & Gustavson (1987) and Wu & Thompson (1984), which are based on antibiotic insensitivity. Pectolytic activity and pathogenici ty to onion were shown to be highly correlated characters. None of the strains of clinical origin was capable of macerating onion tissue.