iBB

RNA-binding proteins (RBPs) are important regulators of cellular functions, playing critical roles on the survival of bacteria and in the case of pathogens, on their interaction with the host. RBPs are involved in transcriptional, post-transcriptional, and translational processes. However, except for model organisms like Escherichia coli, there is little information about the identification or characterization of RBPs in other bacteria, namely in members of the Burkholderia cepacia complex (Bcc). Bcc is a group of bacterial species associated with a poor clinical prognosis in cystic fibrosis patients. These species have some of the largest bacterial genomes, and except for the presence of two-distinct Hfq-like proteins, their RBP repertoire has not been analyzed so far. Using in silico approaches, we identified 186 conventional putative RBPs in Burkholderia cenocepacia J2315, an epidemic and multidrug resistant pathogen of cystic fibrosis patients. In a work recently published in the journal GENES, Joana Feliciano, António Seixas, Tiago Pita and Jorge H. Leitão described the comparative genomics and phylogenetic analysis of RBPs present in multiple copies and predicted to play a role in transcription, protein synthesis, and RNA decay in Bcc bacteria. The analysis suggest the existence, in B. cenocepacia and in other Bcc bacteria, of some extra and unexplored functions for the mentioned RBPs, as well as of alternative mechanisms involved in RNA regulation and metabolism in these bacteria.

Cystic fibrosis (CF) is the most life-limiting autosomal recessive disorder in Caucasians, with chronic bacterial airway infections representing the major cause of early decease. Pseudomonas aeruginosa and bacteria from the Burkholderia cepacia complex (Bcc) are the leading pathogens of CF patients’ airways. A wide array of virulence factors is responsible for infections caused by these bacteria, which have tightly regulated responses to the host environment. Small noncoding RNAs (sRNAs) are major regulatory molecules in these bacteria. Several approaches have been developed to study P. aeruginosa sRNAs, many of which are involved in the virulence. On the other hand, the knowledge on Bcc sRNAs remains far behind. In a review published on International Journal of Molecular Sciences, Tiago Pita, Joana Feliciano and Jorge H. Leitão from BSRG-iBB updated the knowledge on characterized sRNAs involved in P. aeruginosa virulence, compiled data so far achieved on sRNAs from the Bcc and discuss their possible roles on bacteria virulence.

Bacteria of the Burkholderia cepacia complex (Bcc) are ubiquitous multidrug resistant organisms and opportunistic pathogens capable of causing life threatening lung infections among cystic fibrosis (CF) patients. No effective therapies are available to eradicate Bcc bacteria from CF patients, as these organisms are inherently resistant to most clinically available antimicrobials. In a collaborative research work headed by BSRG members JH Leitão and SA Sousa, in collaboration with the CBMA (UMinho) team headed by Pedro Santos, and the Cystic Fibrosis center (HSM) headed by MDs C Barreto and L Pereira, an immunoproteomics approach was used to identify Bcc proteins that stimulate the humoral immune response of the CF host. The work was published in the journal New Biotechnology and reports for the first time the identification of 19 proteins as immunogenic. Ten proteins were predicted as extracytoplasmic, 9 of them being conserved in Bcc genomes. The immunogenic Bcc extracytoplasmic proteins are potential targets for development of novel therapeutic strategies and diagnostic tools to protect patients against the onset of chronic Bcc lung infections.