Diversity and significance of Burkholderia species occupying diverse ecological niches

TLDR: An overview of the taxonomic and ecological diversity of the Burkholderia genus with particular emphasis on strains belonging to the Burk holderia cepacia complex is given and the important question whether 'good' and 'bad' strains are actually the same is addressed.

Abstract: Summary Members of the genus Burkholderia are versatile organisms that occupy a surprisingly wide range of ecological niches. These bacteria are exploited for biocontrol, bioremediation and plant growth promotion purposes, but safety issues regarding human infections, especially in cystic fibrosis patients, have not been solved. This minireview gives an overview of the taxonomic and ecological diversity of the genus with particular emphasis on strains belonging to the Burkholderia cepacia complex and addresses the important question whether ‘good’ and ‘bad’ strains are actually the same. The genus Burkholderia contains over 30 species, which occupy remarkably diverse ecological niches, ranging from contaminated soils to the respiratory tract of humans. The Burkholderia cepacia complex is ubiquitous in nature and can be found in soil, water (including sea water), the rhizosphere of plants, in humans and various animal species and in the hospital environment. Burkholderia cepacia complex isolates have been exploited for various purposes, including biological control of plant pathogens, bioremediation of recalcitrant xenobiotics and plant growth promotion. Unfortunately, some Burkholderia species have been involved in human infections, and safety issues regarding these human infections are hampering the wide-spread biotechnological applications. The purpose of this minireview is to give an overview of the remarkable diversity of the genus Burkholderia and to shed some light on the important question whether or not clinical and environmental B. cepacia complex isolates are the same. A phylogenetic tree based on 16S rRNA gene sequences, showing the positions of all of the Burkholderia species and representatives of related genera, is shown in Fig. 1.