Francisella tularensis subsp. novicida isolated from a human in Arizona

<p>Abstract</p> <p>Background</p> <p><it>Francisella tularensis </it>is the etiologic agent of tularemia and is classified as a select agent by the Centers for Disease Control and Prevention. Currently four known subspecies of <it>F. tularensis </it>that differ in virulence and geographical distribution are recognized:<it>tularensis </it>(type A), <it>holarctica </it>(type B), <it>mediasiatica</it>, and <it>novicida</it>. Because of the Select Agent status and differences in virulence and geographical location, the molecular analysis of any clinical case of tularemia is of particular interest. We analyzed an unusual <it>Francisella </it>clinical isolate from a human infection in Arizona using multiple DNA-based approaches.</p> <p>Findings</p> <p>We report that the isolate is <it>F. tularensis </it>subsp. <it>novicida</it>, a subspecies that is rarely isolated.</p> <p>Conclusion</p> <p>The rarity of this <it>novicida </it>subspecies in clinical settings makes each case study important for our understanding of its role in disease and its genetic relationship with other <it>F. tularensis </it>subspecies.</p

Melt analysis of mismatch amplification mutation assays (melt-MAMA): a functional study of a cost-effective SNP genotyping assay in bacterial models.

Single nucleotide polymorphisms (SNPs) are abundant in genomes of all species and biologically informative markers extensively used across broad scientific disciplines. Newly identified SNP markers are publicly available at an ever-increasing rate due to advancements in sequencing technologies. Efficient, cost-effective SNP genotyping methods to screen sample populations are in great demand in well-equipped laboratories, but also in developing world situations. Dual Probe TaqMan assays are robust but can be cost-prohibitive and require specialized equipment. The Mismatch Amplification Mutation Assay, coupled with melt analysis (Melt-MAMA), is flexible, efficient and cost-effective. However, Melt-MAMA traditionally suffers from high rates of assay design failures and knowledge gaps on assay robustness and sensitivity. In this study, we identified strategies that improved the success of Melt-MAMA. We examined the performance of 185 Melt-MAMAs across eight different pathogens using various optimization parameters. We evaluated the effects of genome size and %GC content on assay development. When used collectively, specific strategies markedly improved the rate of successful assays at the first design attempt from ~50% to ~80%. We observed that Melt-MAMA accurately genotypes across a broad DNA range (~100 ng to ~0.1 pg). Genomic size and %GC content influence the rate of successful assay design in an independent manner. Finally, we demonstrated the versatility of these assays by the creation of a duplex Melt-MAMA real-time PCR (two SNPs) and conversion to a size-based genotyping system, which uses agarose gel electrophoresis. Melt-MAMA is comparable to Dual Probe TaqMan assays in terms of design success rate and accuracy. Although sensitivity is less robust than Dual Probe TaqMan assays, Melt-MAMA is superior in terms of cost-effectiveness, speed of development and versatility. We detail the parameters most important for the successful application of Melt-MAMA, which should prove useful to the wider scientific community

Multidrug-Resistant Staphylococcus aureus in US Meat and Poultry

We characterized the prevalence, antibiotic susceptibility profiles, and genotypes of Staphylococcus aureus among US meat and poultry samples (n = 136). S. aureus contaminated 47% of samples, and multidrug resistance was common among isolates (52%). S. aureus genotypes and resistance profiles differed significantly among sample types, suggesting food animal–specific contamination

Head and neck squamous cell carcinoma cell lines: Established models and rationale for selection

Background. Head and neck squamous cell carcinoma (HNSCC) cell lines are important preclinical models in the search for novel and targeted therapies to treat head and neck cancer. Unlike many other cancer types, a wide variety of primary and metastatic HNSCC cell lines are available. An easily accessible guide that organizes important characteristics of HNSCC cell lines would be valuable for the selection of appropriate HNSCC cell lines for in vitro or in vivo studies. Methods. A literature search was performed. Results. Cell growth and culture parameters from HNSCC cell lines were catalogued into tables or lists of selected characteristics. Methods for establishing cancer cell lines and basic cell culture maintenance techniques were reviewed. Conclusions. A compendium of HNSCC cell line characteristics is useful for organizing the accumulating information regarding cell line characteristics to assist investigators with the development of appropriate preclinical models. © 2006 Wiley Periodicals, Inc. Head Neck, 2006Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55902/1/20478_ftp.pd

Classical nitriding of heat treatable steel

Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steel

Power hardware-in-the-loop setup for stability studies of grid-connected power converters

acceptedVersionPeer reviewe

Chromatographic Separation and Antigenic Analysis of Proteins of the Oncornaviruses IV. Biochemical Typing of Murine Viral Proteins

Tryptic peptide maps were prepared for four purified structural proteins derived from several murine leukemia viruses (MuLV's). Analyses of these peptide maps reveal that the p30 proteins of Rauscher, Moloney, and Gross MuLV's are very similar to each other, as are the p10's obtained from these three viruses. In contrast, the peptide maps of the individual p15's and p12's from the same viruses establish that each of these polypeptides is highly strain specific. For all four polypeptides studied, unique peptides appear in the Rauscher MuLV and Moloney MuLV tryptic profiles that are not present in the corresponding Gross MuLV profile. By this method of analysis it was possible to distinguish the p30's of N-tropic and B-tropic MuLV's derived from the same BALB/c mouse