Antimicrobial resistance profiles of listeria monocytogenes and listeria innocua isolated from ready-to-eat products of animal origin in Spain

The objective of this work was to investigate the antimicrobial resistance in Listeria spp. isolated from food of animal origin. A total of 50 Listeria strains isolated from meat and dairy products, consisting of 7 Listeria monocytogenes and 43 Listeria innocua strains, were characterized for antimicrobial susceptibility against nine antimicrobials. The strains were screened by real-time PCR for the presence of antimicrobial resistance genes: Tet M, tet L, mef A, msr A, erm A, erm B, lnu A, and lnu B. Multidrug resistance was identified in 27 Listeria strains, 4 belonging to L. monocytogenes. Resistance to clindamycin was the most common resistance phenotype and was identified in 45 Listeria strains; the mechanisms of resistance are still unknown. A medium prevalence of resistance to tetracycline (15 and 9 resistant and intermediate strains) and ciprofloxacin (13 resistant strains) was also found. Tet M was detected in Listeria strains with reduced susceptibility to tetracycline, providing evidence that both L. innocua and L. monocytogenes displayed acquired resistance. The presence of antimicrobial resistance genes in L. innocua and L. monocytogenes indicates that these genes may be transferred to commensal and pathogenic bacteria via the food chain; besides this, antibiotic resistance in L. monocytogenes could compromise the effective treatment of listeriosis in humans

Estudio de la calidad del aceite de oliva virgen de Aragón

The chemical composition of virgin olive oils (95 samples) from Aragón (Spain) from two successive crop seasons (1997/98 and 1998/99) and its relationship with quality and oxidative stability is examined. The main characteristics were: free acidity 0.5 (% oleic acid), peroxide value 11.8 meq/kg, K232 1.92, K270 0.13, oxidative stability 51.4 h (Rancimat method), and antioxidant phenolic substances 168.5 mg/kg (as caffeic acid). From the distribution of fatty acids, a high percentage of linoleic acid (9.46 %) and a low level of stearic (2.10 %) and arachidic (0.36 %) acids, is worth noting. The effect of sample origin (7 productive regions from Aragón), olive variety (Empeltre and Arbequina), and the different steps through processing are also investigated. However, the major factor affecting results was the plague of olive flies during 1997/98 crop season.Se ha estudiado la composición química de 95 muestras de aceite de oliva virgen de Aragón procedente de dos campañas sucesivas (1997/98 y 1998/99) y su relación con la calidad y la estabilidad oxidativa. Las principales características fueron una acidez de 0,5 (% ácido oleico), índice de peróxidos 11,8 meq/kg, K232 1,92, K270 0,13, estabilidad a la oxidación 51,4 h (método Rancimat) y contenido en polifenoles antioxidantes 168,5 mg/kg (como ácido caféico). Del perfil de ácidos grasos, destaca el elevado contenido en linoleico (9,46 %) y las bajas tasas de esteárico (2,10 %) y aráquico (0,36 %). Se analiza el efecto de la procedencia de las muestras (7 comarcas productoras de Aragón), de la variedad de la aceituna (Empeltre o Arbequina) y de las distintas fases del procesado del aceite. Se destaca la gran influencia sobre la calidad del aceite de la plaga de mosca sufrida durante la campaña de 1997/98

Meiotic Chromosome Pairing Is Promoted by Telomere-Led Chromosome Movements Independent of Bouquet Formation

Chromosome pairing in meiotic prophase is a prerequisite for the high fidelity of chromosome segregation that haploidizes the genome prior to gamete formation. In the budding yeast Saccharomyces cerevisiae, as in most multicellular eukaryotes, homologous pairing at the cytological level reflects the contemporaneous search for homology at the molecular level, where DNA double-strand broken ends find and interact with templates for repair on homologous chromosomes. Synapsis (synaptonemal complex formation) stabilizes pairing and supports DNA repair. The bouquet stage, where telomeres have formed a transient single cluster early in meiotic prophase, and telomere-promoted rapid meiotic prophase chromosome movements (RPMs) are prominent temporal correlates of pairing and synapsis. The bouquet has long been thought to contribute to the kinetics of pairing, but the individual roles of bouquet and RPMs are difficult to assess because of common dependencies. For example, in budding yeast RPMs and bouquet both require the broadly conserved SUN protein Mps3 as well as Ndj1 and Csm4, which link telomeres to the cytoskeleton through the intact nuclear envelope. We find that mutants in these genes provide a graded series of RPM activity: wild-type>mps3-dCC>mps3-dAR>ndj1Δ>mps3-dNT = csm4Δ. Pairing rates are directly correlated with RPM activity even though only wild-type forms a bouquet, suggesting that RPMs promote homologous pairing directly while the bouquet plays at most a minor role in Saccharomyces cerevisiae. A new collision trap assay demonstrates that RPMs generate homologous and heterologous chromosome collisions in or before the earliest stages of prophase, suggesting that RPMs contribute to pairing by stirring the nuclear contents to aid the recombination-mediated homology search

Institutional shared resources and translational cancer research

The development and maintenance of adequate shared infrastructures is considered a major goal for academic centers promoting translational research programs. Among infrastructures favoring translational research, centralized facilities characterized by shared, multidisciplinary use of expensive laboratory instrumentation, or by complex computer hardware and software and/or by high professional skills are necessary to maintain or improve institutional scientific competitiveness. The success or failure of a shared resource program also depends on the choice of appropriate institutional policies and requires an effective institutional governance regarding decisions on staffing, existence and composition of advisory committees, policies and of defined mechanisms of reporting, budgeting and financial support of each resource. Shared Resources represent a widely diffused model to sustain cancer research; in fact, web sites from an impressive number of research Institutes and Universities in the U.S. contain pages dedicated to the SR that have been established in each Center, making a complete view of the situation impossible. However, a nation-wide overview of how Cancer Centers develop SR programs is available on the web site for NCI-designated Cancer Centers in the U.S., while in Europe, information is available for individual Cancer centers. This article will briefly summarize the institutional policies, the organizational needs, the characteristics, scientific aims, and future developments of SRs necessary to develop effective translational research programs in oncology