Characterization of the bacterial diversity in Indo-West Pacific loliginid and sepiolid squid light organs.

Loliginid and sepiolid squid light organs are known to host a variety of bacterial species from the family Vibrionaceae, yet little is known about the species diversity and characteristics among different host squids. Here we present a broad-ranging molecular and physiological analysis of the bacteria colonizing light organs in loliginid and sepiolid squids from various field locations of the Indo-West Pacific (Australia and Thailand). Our PCR-RFLP analysis, physiological characterization, carbon utilization profiling, and electron microscopy data indicate that loliginid squid in the Indo-West Pacific carry a consortium of bacterial species from the families Vibrionaceae and Photobacteriaceae. This research also confirms our previous report of the presence of Vibrio harveyi as a member of the bacterial population colonizing light organs in loliginid squid. pyrH sequence data were used to confirm isolate identity, and indicates that Vibrio and Photobacterium comprise most of the light organ colonizers of squids from Australia, confirming previous reports for Australian loliginid and sepiolid squids. In addition, combined phylogenetic analysis of PCR-RFLP and 16S rDNA data from Australian and Thai isolates associated both Photobacterium and Vibrio clades with both loliginid and sepiolid strains, providing support that geographical origin does not correlate with their relatedness. These results indicate that both loliginid and sepiolid squids demonstrate symbiont specificity (Vibrionaceae), but their distribution is more likely due to environmental factors that are present during the infection process. This study adds significantly to the growing evidence for complex and dynamic associations in nature and highlights the importance of exploring symbiotic relationships in which non-virulent strains of pathogenic Vibrio species could establish associations with marine invertebrates.

Use of a microgravity analog to explore the effects of simulated microgravity on the development of Escherichia coli K12 biofilms.

The rapid development of space technologies and the increase of human presence in space has brought the discussion of the effects of microgravity on cells into the undergraduate classroom. This paper proposes an idea to simulate microgravity on a bacterial culture, suitable for an introductory microbiology laboratory. For this purpose, we show the use of a 2D clinostat designed for microbial studies, along with traditional microbiology techniques such as optical density, plate counts, and biofilm biomass measurement to test the effect of simulated microgravity on the growth of Escherichia coli K12. This exercise aims to facilitate further discussions on the effects of microgravity on bacteria growth and communication, as well as the use of technology to simulate space and predict physiological changes in cells.

Phenotypic and transcriptional changes in Escherichia coli K12 in response to simulated microgravity on the EagleStat, a new 2D microgravity analog for bacterial studies.

Understanding the impacts of microgravity on bacteria is vital for successful long duration space missions. In this environment, bacteria have been shown to become more virulent, more resistant to antibiotics and to regulate biofilm formation. Since the study of these phenomena under true microgravity is cost- and time challenging, the use of ground-based analogs might allow researchers to test hypotheses before planning and executing experiments in the space environment. We designed and developed a 2D clinostat with capabilities robust enough for bacterial studies to allow for multiple simultaneous replicates of treatment and control conditions, thus permitting the generation of growth curves, in a single run. We used computational fluid dynamics (CFD), biofilm growth measurement and differential gene expression analysis on Escherichia coli cultures grown to late exponential phase (24 h) to validate the system's ability to simulate microgravity conditions. The CFD model with a rotational speed of 8 rpm projected cells growing homogeneously distributed along the tube, while the static condition showed the accumulation of the cells at the bottom of the container. These results were empirically validated with cultures on nutrient broth. Additionally, crystal violet assays showed that higher biofilm biomass grew on the internal walls of the gravity control tubes, compared to the simulated microgravity treatment. In contrast, when cells from both treatments were grown under standard conditions, those exposed to simulated microgravity formed significantly more biofilms than their gravity counterparts. Consistent with this result, transcriptome analysis showed the upregulation of several gene families related to biofilm formation and development such as cells adhesion, aggregation and regulation of cell motility, which provides a potential transcriptional explanation for the differential phenotype observed. Our results show that when operated under parameters for simulated microgravity, our 2D clinostat creates conditions that maintain a proportion of the cells in a constant free-falling state, consistent with the effect of microgravity. Also, the high-throughput nature of our instrument facilitates, significantly, bacterial experiments that require multiple sampling timepoints and small working volumes, making this new instrument extremely efficient.

Memoria del II Congreso Departamental de Responsables Populares de Salud / Memory of the II Departamental Congress of Responsible Popular of Health

Este documento es una memoria del congreso de responsables populares de salud realizado en Santa Cruz, los temas tratados fueron: Muerte materna: vigilancia epidemiológica, seguro básico de salud, lactancia materna y alimentación complementaria, medicamentos esenciales, información, educación, comunicación, capacitación y estrategia de la IEC

Potencial científico y tecnológico de la Universida Mayor de San Simón: indicadores del I+D

En este contexto se inscribe este esfuerzo de valoración del potencial científico y tecnológico de la UMSS. Uno de sus propositos es mostrar , con información actualizada, tanto las capacidades como las limitaciones de la UMSS, a través de la DICyT, dde los Institutos de Investigación y de los diferentes centros de investigación; su vinculación con el entorno local, nacional, internacional y toda la información considerada importante en el ambito investigativo.