Francisella tularensis contains several highly pathogenic subspecies, including Francisella tularensis subsp. holarctica, whose distribution is circumpolar in the northern hemisphere. The phylogeography of these subspecies and their subclades was examined using whole-genome single nucleotide polymorphism (SNP) analysis, high-density microarray SNP genotyping, and real-time-PCR-based canonical SNP (canSNP) assays. Almost 30,000 SNPs were identified among 13 whole genomes for phylogenetic analysis. We selected 1,655 SNPs to genotype 95 isolates on a high-density microarray platform. Finally, 23 clade-and subclade-specific canSNPs were identified and used to genotype 496 isolates to establish global geographic genetic patterns. We confirm previous findings concerning the four subspecies and two Francisella tularensis subsp. tularensis subpopulations and identify additional structure within these groups. We identify 11 subclades within F. tularensis subsp. holarctica, including a new, genetically distinct subclade that appears intermediate between Japanese F. tularensis subsp. holarctica isolates and the common F. tularensis subsp. holarctica isolates associated with the radiation event (the B radiation) wherein this subspecies spread throughout the northern hemisphere. Phylogenetic analyses suggest a North American origin for this B-radiation clade and multiple dispersal events between North America and Eurasia. These findings indicate a complex transmission history for F. tularensis subsp. holarctica.

Analysis of length polymorphism at short tandem repeat (STR) loci utilizing the polymerase chain reaction (PCR) process has proven to be an ideal assay for human identification purposes. The short length of STR loci coupled with the amplification of target sequence through PCR allows for a robust, sensitive, and specific assay for highly polymorphic markers. A multiplex containing fifteen STR loci plus the gender-determining locus Amelogenin was developed to provide a single amplification/detection of all CODIS (Combined DNA Index System) STR loci (CSF1PO, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, FGA, THO1, TPOX, and vWA) as well as two internationally-accepted STRs (D2S1338 and D19S433). By incorporating five-dye fragment analysis technology and non-nucleotide linkers, previously optimized AmpFℓSTR® kit primer sequences have been maintained. This kit has been developed in accordance with the standards of the forensic community as defined by the DNA Advisory Board. Validation studies were performed to include developmental validation, and the results support the use of the AmpFℓSTR® Identifiler® PCR Amplification Kit for human identity and parentage testing.

Proteus mirabilis urease catalyzes the hydrolysis of urea, initiating the formation of urinary stones. The enzyme is critical for kidney colonization and the development of acute pyelonephritis. Urease is induced by urea and is not controlled by the nitrogen regulatory system (ntr) or catabolite repression. Purified whole-cell RNA from induced and uninduced cultures of P. mirabilis and Escherichia coli harboring cloned urease sequences was probed with a 4.2-kb BglI fragment from within the urease operon. Autoradiographs of slot blots demonstrated 4.2- and 5.8-fold increases, respectively, in urease-specific RNA upon induction with urea. Structural and accessory genes necessary for urease activity, ureD, A, B, C, E, and F, were previously cloned and sequenced (B. D. Jones and H. L. T. Mobley, J. Bacteriol. 171:6414-6422, 1989). A 1.2-kb EcoRV-BamHI restriction fragment upstream of these sequences confers inducibility upon the operon in trans. Nucleotide sequencing of this fragment revealed a single open reading frame of 882 nucleotides, designated ureR, which is transcribed in the direction opposite that of the urease structural and accessory genes and encodes a 293-amino-acid polypeptide predicted to be 33,415 Da in size. Autoradiographs of sodium dodecyl sulfate-polyacrylamide gels of [35S]methionine-labeled polypeptides obtained by in vitro transcription-translation of the PCR fragments carrying only ureR yielded a single band with an apparent molecular size of 32 kDa. Fragments carrying an in-frame deletion within ureR synthesized a truncated product. The predicted UreR amino acid sequence contains a potential helix-turn-helix motif and an associated AraC family signature and is similar to that predicted for a number of DNA-binding proteins, including E. coli proteins that regulate acid phosphatase synthesis (AppY), porin synthesis (EnvY), and rhamnose utilization (RhaR). These data suggest that UreR governs the inducibility of P. mirabilis urease.

Helicobacter pylon has been demonstrated as an etiologic agent of human gastritis and peptic ulcer formation. However, there is no straightforward basis to distinguish different isolates. We used the polymerase chain reaction (PCR) to amplify the urease structural subunit genes, ureA and ureB, which, when digested with appropriate restriction endonucleases, allow the differentiation of patterns on agarose gels. PCR amplification was possible with DNA rapidly extracted from H. pylon by alkaline lysis and phenol-chloroform. The 2.4-kb

Helicobacter pyloni, a gram-negative, microaerophilic, spiral-shaped bacterium, is an etiologic agent of human gastritis and peptic ulceration and is highly restricted to the gastric mucosa of humans. Urease, synthesized at up to 6% of the soluble cell protein, hydrolyzes urea, thereby releasing ammonia, which may neutralize acid, allowing survival of the bacterium and initial colonization of the gastric mucosa. The urease protein is encoded by two subunit genes, ureA and ureB; however, accessory genes are necessary for enzyme activity. H. pylori urease genes were isolated from a cosmid gene bank and subcloned on a 5.8-kb Sau3A partial fragment carrying ureCDAB, corresponding to four open reading frames described by A.