Clinical Microbiology: Open Access

Piscirickettsia salmonis genome reveals the presence of components for multiple mechanisms for iron acquisition

3^rd International Conference on Clinical Microbiology & Microbial Genomics

September 24-26, 2014 Valencia Convention Centre, Spain

Rodrigo Pulgar, Travisany Dante, Maass Alejandro and Cambiazo Veronica

Posters: Clin Microbial

Abstract:

Piscirickettsia salmonis is the etiologic agent of Piscirickettsiosis, the most important infectious disease in Chilean salmonid industry. P. salmonis is an intracellular bacterium that infects replicates and survives within salmon macrophages; however their pathogenic mechanisms have not been described. With the aim of identifying genetic components associated with pathogenesis, we sequenced the genome of P. salmonis (ATCC reference strain). The results were filtered and assembled, it allow us to estimate a genome size of 2.99 Mb and GC content of 38.6%. The genome annotation allows us the identification of 3,237 ORFs, of which 70% have a putative function. Among these, there are putative virulence factors related to secretion systems, adhesion, invasion and iron acquisition. Given the importance of iron for the pathogenesis, we identified and characterized genes that encode for proteins related to iron acquisition systems in P. salmonis. The results indicate the presence of orthologous genes related to synthesis and uptake of heme group and siderophores, energy system for iron-siderophore transport, ferrous iron uptake system and transcriptional regulation by Fur (ferric uptake repressor). To gain insight on the possible transcripcional regulation of these genes by Fur, we sought for putative Fur binding sites in the whole genome of P. salmonis using a bioinformatic strategy; identifying two hundred ORFs with at least one Fur binding site. To test experimentally whether the ORF identified to respond to different iron concentration in culture, we designed and produced a microarray, which allow us validate the bioinformatic predicted information.

Biography :

Rodrigo Pulgar is a Biotechnology Engineer and has completed his PhD from University of Chile. His Postdoctoral studies have been realized in the Institute of Nutrition and Food Technology (INTA) from the same University. He is the Director of Research of Centre for Applied Genomics of INTA and member of Genome Regulation Centre (FONDAP).