Conferencia inaugural/Keynote Address

Julian Davies, Vancouver, Canada

Todo depende de todo lo demás / Everything depends on everything else

My title is a tenet of a NW Canadian Indian Band and it refers to interactions between Humans and Nature. Recently, this concept has been recognized in biology. Everything down to gene sequence is a part of complex biochemical networks; nothing is an independent entity. The knowledge that all biological molecules and cells are contingent and act in a context specific manner is changing traditional concepts of drug screening (single targets) and can be expected to lead to new classes of antibiotics and other drugs.

Estrés ambiental y desarrollo evolutivo en los sistemas microbianos / Environmental stress and evolvability in microbial systems

The robustness of bacterial metabolism, cells, or systems, generally tolerates small (or predictable) fluctuations in the environment. When fluctuations go beyond a certain limit of tolerance, stress occurs and only genetic variability offers new adaptive ways to natural selection. Most genetic changes occur by mutation and recombination (internal recombination or horizontal acquisition of foreign sequences). As any change has a de-stabilizing risk, genetic change should be managed by novel changes and re-adaptations. Because of that, environmental changes are major driving forces for bacterial evolution.

Genomics has unveiled common molecular aspects regarding the establishment and maintenance of symbiotic associations. Several scenarios allowed the evolution of symbiotic associations, from the first stages of free-living bacteria, through facultative symbiosis, towards the stage of obligate endosymbiosis. The process begins with host invasion, using the same molecular machinery used by pathogens, and ends in huge genetic and phenotypic changes. Comparative analyses of reduced symbiotic genomes are of relevance on fields like Systems and Synthetic Bi

Hacia una aproximación ecológica a los antibióticos y los genes de resistencia antibiótica / Towards an ecological approach to antibiotics and antibiotic-resistance genes

Antibiotics have been searched on purpose as bacterial killers. Since a large number of antibiotics have are produced by environmental organisms, it was though that the actual function of these molecules in Nature should be the Darwinian fighting against competitors. Conversely, antibiotic resistance genes should be shields to avoid antibiotic weapons action. We will discuss in this presentation that antibiotics may act as signaling molecules in Nature and that antibiotic resistance genes may have a relevant role in the basic bacterial metabolism. This view provides a new interpretation on the ecological role of antibiotics and antibiotic resistance genes in Nature.

Detección de estrés medioambiental en organismos fúngicos / Fungi sensing

MAP kinase signalling pathways control virulence factors of pathogenic fungi such as the generation of a stable protection by the cell wall, morphogenesis to invade host tissues and resistance to oxidative stress. The functionality of these pathways represents a key element for adaptation to environmental stress. Therefore, MAP kinases are central to a network of pathways that integrate, amplify and modulate protective and adaptive responses.

Impacto del cambio climático sobre la dinámica y evolución de las enfermedades bacterianas / The impact of climate forcing on bacterial disease dynamics and evolution

Many infectious diseases, both bacterial and viral, show within-year and between-year variability in the size of their outbreaks. Furthermore, many of these diseases are caused not by a single pathogenic entity or strain, but by a collection of them which we identify under one name. These strains change in frequency and dominance over the years, such that the gene pool is continuously evolving. Here, I will show how mathematical and statistical models can be used to understand some of these dynamics and evolutionary patterns. Specifically, I will focus on the bacterial pathogen cholera and how its patterns in Bangladesh can, in part, be explained by climate variability. The patterns I will touch on include patterns of biotype replacement caused by long-term changes in seasonal forcing and patterns of interannual disease variability driven by rainfall, river discharge, and the El Niño Southern Oscillation.

Juan-Luis Ramos, Granada, Spain

To analyze bacterial responses to toxic chemicals we have carried out a series of transcriptomic and proteomic analyses. Our results show that with toluene transcription of the flagellar apparatus is inhibited and under those circumstances bacteria use efflux pumps to expel the solvent and induce a specific catabolic pathway to degrade the pollutant. Exposure to pollutants can lead to selective resistance to a wide range of unrelated compounds such as antibiotics, dyes, etc.

Page Caufield, New York, USA

Members of the human indigenous biota, specifically Streptococcus mutans, colonizing the oral cavity, are transmitted vertically, mother to infant. Extending this pattern on a larger scale has demonstrated clustering of clonal types within racial, ethnic and geographic boundaries, suggesting coevolution has occurred between the human host and it’s obligate bacterial parasite. Analysis of polymorphisms among alleles of conserved genes in S. mutans reveal phylogenetic clustering of strains that appear to parallel human racial/geographic cohorts. This approach supports the notion of the “out of Africa” origin of modern humans.

Richard S. Ostfeld, New York, USA

Many zoonotic, wildlife, and plant pathogens can infect several host species. However, hosts differ strongly in their capacity to support population growth of the pathogen. Some hosts act as reservoirs that amplify pathogens, whereas others act as “dilution hosts” that can absorb but do not contribute pathogens. Reservoir hosts tend to be abundant, widespread species that are resilient to human-caused environmental degradation. In contrast, dilution hosts are often sensitive to environmental degradation, disappearing when biodiversity is lost. This presentation will describe case studies of diseases that are exacerbated when human activities cause the loss of biodiversity.

Reguladores globales y adaptación ambiental en los patógenos Gram negativos / Global regulators and environmental adaptation in Gram-negative pathogens

A powerful combination of single-gene studies and whole-genome approaches has provided a wealth of information about the regulatory circuits used by bacteria to adapt to the environmental changes that are encountered during infection. The facultative intracellular pathogen Salmonella enterica will be used to illustrate how global regulators such as the nucleoid-associated proteins Fis and H-NS collaborate with fluctuations in the superhelicity of the DNA template to modify the gene expression profile of the bacterial cell outside and inside the host.

CIENCIA PARA ACTUAR: VIGILANCIA Y BIO-REMEDIACIÓN DE LOS SISTEMAS MICROBIANOS DAÑADOS / SCIENCE FOR INTERVENTION: SURVEILLANCE AND BIOREMEDIATION OF DAMAGED MICROBIAL SYSTEMS

Moderador / Chairperson: Víctor de Lorenzo, Madrid, Spain

Frederick M. Cohan , Connecticut, USA

Cómo la sistemática bacteriana puede ayudar a evaluar las tendencias ecológicas y evolutivas que imponen los cambios ambientales / How bacterial systematics might help to evaluate ecological and evolutionary trends imposed by environmental changes

To track evolutionary responses of bacterial to global change, microbiologists will need a systematics aimed at discovering newly divergent populations with distinct ecological traits (ecotypes). Traditional systematics is not up to this task, as the species it recognizes are generally too broadly defined. Microbial systematists generally cannot anticipate the ecological characteristics distinguishing young ecotypes before the ecotypes are identified; so a universal molecular approach is needed to identify them. What is needed are molecular markers that evolve rapidly enough to distinguish very closely related populations, as well as an algorithm for interpreting which clusters are most likely to correspond to ecotypes. “Ecotype Simulation” analysis of DNA sequences of protein-coding genes in three bacterial systems has demarcated dozens of putative ecotypes, many of which have been confirmed as ecologically distinct; moreover, many such ecotypes are newly divergent enough to be invisible to our current bacterial systematics. For example, analysis of hot springs Synechococcus has identified extremely closely related ecotypes that are subtly distinct in their temperature adaptations. While such a sequence-based approach will not discover extremely young ecotypes, born during the time of global warming, it should be able to track changes in abundance of already existing ecotypes with different temperature and other adaptations. To discover young ecotypes born during global warming, a more rapid molecular marker, such as VNTR, will be required.

Alban Ramette, Bremen, Germany

Impacto del espacio, el tiempo y los ambientes complejos sobre las comunidades microbianas / Impact of space, time and complex environments on microbial communities

Microbial biogeographic analyses address how much historical vs. contemporary factors can explain variation in the diversity patterns of microbial communities. In this context, current work in soil and marine environments will be presented so as to illustrate how microbial communities thriving in different habitats may be studied by a combination of high throughput molecular techniques and powerful multivariate analyses. The main amount of biological variation that can be explained by environmental, temporal and spatial factors is thereby quantified and tested for significance. This synthetic result thus serves as a precious indicator of our current understanding and predictive abilities about changes in the microbial world.

Víctor de Lorenzo, Madrid, Spain

Organismos modificados genéticamente para la reparación medioambiental: Qué se hizo mal y qué se puede hacer aun / GMOs for environmental remediation: What went wrong and what can still be done

MULTI-RESISTENCIA A FÁRMACOS EN TB, MALARIA Y VIH / MULTIDRUG RESISTANCE IN TB, MALARIA AND HIV

Michael Kozal , New Haven, CT, USA

Multirresistencia a fármacos en el VIH / Multidrug resistance in HIV

The development of antiretroviral therapy has led to a major reduction in mortality due to HIV. However, HIV drug resistance has been shown to occur with all antiretroviral agents. HIV drug resistance can affect the response to antiretroviral therapy and is associated with increased mortality. The emergence of HIV drug resistance in persons on therapy and the transmission of drug-resistant HIV strains to newly infected persons are now major public health problems. HIV infection exists as a viral quasispecies (a “swarm” of genetically diverse virus strains) in an infected person. All the viral strains that make up the “swarm” in a person are not detected by the standard resistance assays used in the clinic (current assays are typically restricted to detecting resistant variants that make up >20% of the quasispecies). Recent data suggests that resistant viral variants that make up as little as 1% of the viral population in a HIV-infected person are clinically important as they can rapidly grow under drug selection pressure and lead to therapy failure. This talk will address the epidemiology and biologic mechanisms of HIV drug resistance and the new approaches to detect and combat HIV drug resistance.

Discusión / Discussions General Topics 5

Despedida y Clausura / Farewel & Closure

Ponente: Rafael Cantón , Madrid, Spain

Los genes de resistencia antibiótica en el medio ambiente / Antibiotic resistance genes in the environment

 Soil bacteria may contain antibiotic resistance genes responsible for different mechanisms that permit to overcome the presence of natural antibiotics present in the environment. This gene pool has been recently named resistome and its components can be mobilized into the microbial community affecting humans. Evidences of this transference have been suggested or demonstrated with newly widespread genes in multidrug-resistance bacteria, such as certain extended-spectrum beta-lactamases genes (bla CTX-M), 16s RNA methylases ( armA, rtmB ) and qnr genes.

Ponente: Jordi Vila, Barcelona, Spain

Migraciones y enfermedades infecciosas / Migrations and infectious diseases

Throughout history, the movement of people has played a critical role in the transmission of infectious disease. Overall, migration of humans has been the pathway for disseminating infectious diseases throughout recorded history and will continue to shape the emergence, frequency, and spread of infections in geographic areas and populations. However, globalisation can exacerbate the risk of spreading infectious diseases. These effects are mediated not only through the movement of people but also by the increased mobility of disease vectors, livestock and other animals that may host zoonoses, as well as the greater propensity of food-borne disease.

Conferencias : 30 minutos de conferencia y 30 m inutos de discusión al finalizar cada sesión / 30-minute talk; 30-minute discussion after each session.

Seminarios: Duración, 1 hora: Exposición, 20 min; Coloquio con los asistentes, 40 min.

Grupos reducidos

Fundación Lilly

ENGLISH <> SPANISH : TRADUCCIÓN SIMULTANEA <> SIMULTANEOUS TRANSLATION PROVIDED