Microbiologists John Govan and Peter Vandamme once said something that caught my attention: “What better microbial challenge to unite agricultural and medical microbiologists than a microorganism that reduces an onion to a macerated pulp, protects crops from diseases, devastates the health and social life of cystic fibrosis patients, and not only is resistant to the most famous antibiotic, penicillin, but can use it as a nutrient!". They were speaking about bacteria from the genus Burkholderia!
This genus accommodates around one hundred and twenty species that colonize a wide range of ecological niches and interact with different hosts. For instance, B. cenocepacia is an opportunistic pathogen that produces severe infections in cystic fibrosis and immunocompromised patients, and which is usually resistant to many antibiotic treatments. Other species are environmental/soil commensals/saprophytes that are rarely pathogenic (B. thailandensis). Finally, some species such as B. phytofirmans and B. caledonica are mutualists that are beneficial to plants and could be potentially exploited in biotechnological processes, although the agricultural use of these beneficial species as plant growth promoting bacteria (PGPB) is severely being restrained due to the potential threat that a few opportunistic pathogenic strains pose to human health.
In the last years, a lot of effort has been invested into discriminating between the beneficial environmental (the “good”) and the clinical (the “bad”) Burkholderia strains, and several approaches have been used with this aim. For instance, phylogenetic and taxonomic analyses have given evidence that members of the genus Burkholderia can be separated into several lineages which agree more or less with their different lifestyles. One clade comprises animal and plant pathogens; and other, recently proposed as the novel genus Paraburkholderia, comprises environmental and plant-beneficial PGPB Burkholderia spp.
Good or bad bugs? Friends or foes? The global aim of this project is to unravel the differences between mutualism and pathogenicity in Burkholderia and Paraburkholderia. The goal is to study different ecological states of a group of species and to unravel the mechanisms that lead to mutualism or pathogenicity in different hosts. We hypothesize that the dissimilarities in the genomes of the Burkholderia and Paraburkholderia species allow them to interact with different types of hosts, leading to mutualism, opportunism, and/or pathogenicity.
The importance of achieving the ability to discern between the two of them and understand their colonization fitness genes concerns mainly two fields: public health/medicine and agriculture. Identifying the genes involved in animal and plant colonization will facilitate 1) the development of disease tools against pathogenic Burkholderia, and 2) the identification of targets to increase plant colonization by the beneficial Paraburkholderia.
