, 1992;

Schueller et al., 2007) and its interaction with amoeba (La Scola et al., 2000). We thank Mr William Bibb very much for sending hybridoma CSD11, an uncharacterized clone that produced a monoclonal antibody to an Afipia antigen, which was identified here as flagellin. We thank Michael F. Minnick for anti-Bartonella flagellin and Dr M.E Kovach for plasmid pBBR1MCS-2. Financial support by a research award from American Gene Therapy Inc. and Prof. A.A. Szalay is gratefully acknowledged. “
“Piscirickettsia salmonis is a novel, aggressive, facultative Gram-negative CP-868596 in vitro bacterium that drastically affects salmon production at different latitudes, with particular impact in southern Chile. Initially, P. salmonis was described as a Rickettsia-like, obligate, intracellular Alphaproteobacteria, but it was reclassified recently as a facultative intracellular Gammaproteobacteria. This designation has prompted the independent growth of the bacterium to a pure state for detailed study of its biology, genetics and epidemiology, properties that are still relatively poorly characterized. The preliminary sequence analysis of a 992-bp fragment of pure P. salmonis DNA allowed us to characterize selleck chemical a novel and complete 863-bp insertion sequence in the bacterial genome (named ISPsa2), which has a novel 16/16 bp perfectly inverted terminal repeat flanking a 726-bp ORF that encodes a putative transposase (Tnp-Psa). The coding sequence

of the enzyme shares similarities to that described in some Bacillus species and particularly to those of the IS6 family. ISPsa2 carries its own promoter with standard −10 and −35 sequences, suggesting an interesting potential for plasticity in this pathogenic bacterium. Additionally, the presence of ISPsa2 Thymidylate synthase was confirmed from three isolates of P. salmonis collected from different epizootics in Chile in 2010. The

sequencing of bacterial genomes from newly discovered species provides exciting opportunities to understand genome organization and evolution. In addition, it provides novel putative ORFs or potential coding sequences (CDSs) as well as signals for gene expression (Siguier et al., 2006). Most bacterial genomes are composed of a core minimal species backbone, but generally and for purposes of plasticity, they are complemented with other features such as mobile genetic elements (MGEs), which include bacteriophages, conjugative transposons, integrons, composite transposons and insertion sequences (ISs). These elements form part of an extensive gene pool that serves to promote gene exchange and reassortment (Craig et al., 2002). The IS elements are small, mobile, non-self-replicating DNA regions that specify only the gene(s) required for their transposition. In accordance with the features involved in the transposition process and the phylogenetic relationship between different transposases, they have been grouped into different families (Gartemann & Eichenlaub, 2001).