Search

Yersinia pestis, the causative agent of bubonic and pneumonic plague, has undergone detailed study at the molecular level. To further investigate the genomic diversity among this group and to help characterize lineages of the plague organism that have no sequenced members, we present here the genomes of two isolates of the "classical" Antiqua biovar, strains Antiqua and Nepal516. The genomes of Antiqua and Nepal516 are 4.7 Mb and 4.5 Mb and encode 4,138 and 3,956 open reading frames respectively. Though both strains belong to one of the three classical biovars, they represent separate lineages defined by recent phylogenetic studies. We compare all five currently sequenced Y. pestis genomes and the corresponding features in Y. pseudotuberculosis. There are strain-specific rearrangements, insertions, deletions, single nucleotide polymorphisms and a unique distribution of insertion sequences. We found 453 single nucleotide polymorphisms in protein coding regions, which were used to assess evolutionary relationships of these Y. pestis strains. Gene reduction analysis revealed that the gene deletion processes are under selective pressure and many of the inactivations are probably related to the organism s interaction with its host environment. The results presented here clearly demonstrate the differences between the two Antiqua lineages and support the notion that grouping Y. pestis strains based strictly on the classical definition of biovars (predicated upon two biochemical assays) does not accurately reflect the phylogenetic relationships within this species. Comparison of four virulent Y. pestis strains with the human-avirulent strain 91001 provides further insight into the genetic basis of virulence to humans.

Nitrosococcus oceani (ATCC 19707) is one of only two known ammonia-oxidizing bacteria classified as Gammaproteobacteria, while the large majority of isolated ammonia-oxidizing bacteria are classified as Betaproteobacteria. The N. oceani genome contains genes for 13 complete two-component systems, all the genes needed to reconstruct complete central pathways, the tricarboxylic acid cycle, and the Emblem-Mcycrhof-Parnass and pentose phosphate pathways.

Ochrobactrum anthropi is a common soil alphaproteobacterium that colonizes a wide spectrum of organisms and is being increasingly recognized as an opportunistic human pathogen. Potentially life-threatening infections, such as endocarditis, are included in the list of reported O. anthropi infections. These reports, together with the scant number of studies and the organism's phylogenetic proximity to the highly pathogenic brucellae, make O. anthropi an attractive model of bacterial pathogenicity. Here we report the genome sequence of the type strain O. anthropi ATCC 49188, which revealed the presence of two chromosomes and four plasmids. [ABSTRACT FROM AUTHOR]