|SREL Reprint #1945|
Genetic Structure of a Lotic Population of Burkholderia (Pseudmonas) cepacia
MARK G. WISE,1 LAWRENCE J. SHIMKETS,1 AND J VAUN McARTHUR2
The genetic structure of a population of Burkholderia (Pseudomonas) cepacia
isolated from a southeastern blackwater stream was investigated by using
multilocus enzyme electrophoresis to examine the alielic variation in eight
structural gene loci. Overall, 213 isolates were collected at transect points along
the stream continuum, from both the sediments along the bank and the water
column. Multilocus enzyme electrophoresis analysis revealed 164 distinct
electrophoretic types, and the mean genetic diversity of the entire population was
0.574. Genetic diversity values did not vary spatially along the stream continuum.
From a canonical discriminant analysis, Mahalonobis distances (measurements of
genetic similarity between populations) revealed significant differences among the
subpopulations at the sediment sampling points, suggesting bacterial adaptation to
a heterogeneous (or patchy) microgeographical environment. Multilocus linkage
disequilibrium analysis of the isolates revealed only limited association between
alleles, suggesting frequent recombination, relative to binary fission, in this
population. Furthermore, the dendrogram created from the data of this study and
the allele mismatch distribution are typical of a population characterized by
extensive genetic mixing. We suggest that B. cepacia be added to the growing list
of bacteria that are not obligatorily clonal.
SREL Reprint #1945
Wise, M., L.J. Shimkets, and J.V. McArthur. 1995. Genetic structure of a lotic population of Burkholderia (Psuedomonas) cepacia. Applied and Environmental Microbiology 61:1791-1798.