Distribution of Burkholderia cepacia phenotypes by niche, method of isolaiton and pathogenicity of onion

Abstract

Several proposals have been made for the subdivision of the bacterial species Burkholderia cepacia. Data applying these schemes to a collection of 188 strains of B. cepacia, isolated using a variety of methods, from soils, decayed onions, and nosocomial sources are presented. None of the schemes could be shown to be associated with the method of isolation, niche from which a strain was isolated, pectolytic activity, or pathogenicity to onion. Strains isolated by serial dilution on onion slices were much more uniform than were strains isolated using semiselective media. The nutritionally stringent medium of Lumsden and Sasser (US Patent No. 4 588 584) was judged better for the collection of a phenotypically broad sample of B. cepacia than those of Hagedorn, Gould, Bardinelli & Gustavson (1987) and Wu & Thompson (1984), which are based on antibiotic insensitivity. Pectolytic activity and pathogenicity to onion were shown to be highly correlated characters. None of the strains of clinical origin was capable of macerating onion tissue. 277. LA: The Station. Wu B J, Thompson S T. 1984. Selective medium for Pseudomonas cepacia containing 9-chloro-9-(4-diethylaminopheny1)-10-phenylacridan and polymyxin B sulfate. Applied Environmental Microbiology 48:743-746. Yohalem D S. 1993. Characterization of diversity among Pseudomonas cepacia strains isolated from soils, decayed onions, and cEinical sources. Ph.D. Thesis. Cornell University, Ithaca, NY. Yohalem D S, Lorbeer J W. 1994a. Multilocus isoenzyme diversity among strains of Pseudomonas cepacia isolated from decayed onions, soils, and clinical sources. Systematic and Applied Microbiology 17: 116-124. Yohalem D S, Lorbeer J W. 1994. Intraspecific metabolic diversity among strains of Burkholderia cepacia isolated from decayed onions, soils, and the clinical environment. Antonie van Leeuwenhoek 399-1 5. 65: 1 1 1-1 3 1.

Burkholderia cepacia Complex Bacteria from Clinical and Environmental Sources in Italy: Genomovar Status and Distribution of Traits Related to Virulence and Transmissibility

“…In fact, proteolytic activity was found to be equally spread within both groups of isolates, as was onion tissue maceration ability. The latter property, which is related to pathogenicity for plants, was previously thought to be characteristic only of environmental strains (42), but at present most clinical isolates including epidemic strains readily cause soft rot of onions (8). On the contrary, the antibiotic resistance profiles of the B. cepacia complex isolates were associated with their origins; in fact, clinical isolates generally exhibited resistance to larger numbers of antibiotics and a higher degree of resistance to the single antibiotics tested than the environmental isolates did.…”

Culture-Based and Non-Growth-Dependent Detection of the Burkholderia cepacia Complex in Soil Environments

“…It also holds promise as an agent of biocontrol of many plant pathogens (7,8,20) and as a bioremediation organism for the degradation of a wide range of recalcitrant compounds (21,23). Although several attempts have been made to distinguish between benign and human pathogenic strains of Bcc, clear demarcations between environmentally useful and clinically significant strains have not been found (11,28,34,47,49,50). Moreover, a small but steady number of Bcc infections in cystic fibrosis patients each year occur from strains that have not been previously encountered in the clinical setting (26).…”

Identification and Onion Pathogenicity of Burkholderia cepacia Complex Isolates from the Onion Rhizosphere and Onion Field Soil

“…Rhizosphere distribution studies have been conducted on maize and rice (15,38,55), both plant species that are not subject to infection by B. cepacia complex strains. In contrast, onion is a host of B. cepacia; however, only one study has examined the occurrence of B. cepacia populations associated with decayed onions and onion field soil (54), and this work was done prior to the current changes in the taxonomy of the species. Thus, the occurrence and potential pathogenicity of other species of the B. cepacia complex in the onion rhizosphere have not been fully evaluated.…”