https://hdl.handle.net/20.500.12008/33109 Wed, 17 Jun 2026 10:33:39 GMT 2026-06-17T10:33:39Z https://colibri.udelar.edu.uy:443/jspui/retrieve/168208/Logo IH (1).png https://hdl.handle.net/20.500.12008/33109 https://hdl.handle.net/20.500.12008/55546 Título: Metagenomic analysis of Raphidiopsis raciborskii microbiome: beyond the individual Autor: Vico, Paula; Iriarte, Andrés; Bonilla, Sylvia; Piccini, Claudia Resumen: Raphidiopsis raciborskii is a toxic, invasive bacteria with a defined biogeographic pattern attributed to the generation of ecotypes subjected to local environmental filters and to phenotypic plasticity. The interactions taking place between the cyanobacterium and the other bacteria inhabiting the external polysaccharide-rich matrix surrounding the cells, or phycosphere, may be ecotype-specific and would have different influence on the carbon and nutrient cycling in the ecosystem. Here, we describe the bacterial community or microbiome (assessed by 16S rRNA metagenomics) associated to two R. raciborskii strains that have been described as different ecotypes: the saxitoxin-producer MVCC19 and the non-toxic LB2897. Our results showed that both ecotypes share 50% of their microbiomes and differ in their dominant taxa. The taxon having the highest abundance in the microbiome of MVCC19 was Neorhizobium (22.5% relative abundance), while the dominant taxon in LB2897 was the Planctomycetes SM1A02 (26.2% relative abundance). These groups exhibit different metabolic capabilities regarding nitrogen acquisition (symbiotic nitrogen-fixing in Neorhizobium vs. anammox in SM1A02), suggesting the existence of ecotype-specific microbiomes that play a relevant role in cyanobacterial niche adaptation. In addition, as saxitoxin and analogues are nitrogen-rich (7 atoms per molecule), we hypothesise that saxitoxin-producing R. raciborskii benefits from external sources of nitrogen provided by the microbiome bacteria. Based on these findings, we propose that the mechanisms involved in the assembly of the cyanobacterial microbiome community are ecotype-dependent. Fri, 01 Jan 2021 00:00:00 GMT https://hdl.handle.net/20.500.12008/55546 2021-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/55519 Título: Composition, Acquisition, and Distribution of the Vi Exopolysaccharide-Encoding Salmonella enterica Pathogenicity Island SPI-7 Autor: Pickard, Derek; Wain, John; Baker, Stephen; Line, Alexandra; Chohan, Sonia; Fookes, Maria; Barron, Andrew; Gaora, Peadar O; Chabalgoity, José A.; Thanky, Niren; Scholes, Christoph; Thomson, Nicholas; Quail, Michael; Parkhill, Julian; Dougan, Gordon Resumen: Vi capsular polysaccharide production is encoded by the viaB locus, which has a limited distribution in Salmonella enterica serovars. In S. enterica serovar Typhi, viaB is encoded on a 134-kb pathogenicity island known as SPI-7 that is located between partially duplicated tRNApheU sites. Functional and bioinformatic analysis suggests that SPI-7 has a mosaic structure and may have evolved as a consequence of several independent insertion events. Analysis of viaB-associated DNA in Vi-positive S. enterica serovar Paratyphi C and S. enterica serovar Dublin isolates revealed the presence of similar SPI-7 islands. In S. enterica serovars Paratyphi C and Dublin, the SopE bacteriophage and a 15-kb fragment adjacent to the intact tRNApheU site were absent. In S. enterica serovar Paratyphi C only, a region encoding a type IV pilus involved in the adherence of S. enterica serovar Typhi to host cells was missing. The remainder of the SPI-7 islands investigated exhibited over 99% DNA sequence identity in the three serovars. Of 30 other Salmonella serovars examined, 24 contained no insertions at the equivalent tRNApheU site, 2 had a 3.7-kb insertion, and 4 showed sequence variation at the tRNApheU-phoN junction, which was not analyzed further. Sequence analysis of the SPI-7 region from S. enterica serovar Typhi strain CT18 revealed significant synteny with clusters of genes from a variety of saprophytic bacteria and phytobacteria, including Pseudomonas aeruginosa and Xanthomonas axonopodis pv. citri. This analysis suggested that SPI-7 may be a mobile element, such as a conjugative transposon or an integrated plasmid remnant. Wed, 01 Jan 2003 00:00:00 GMT https://hdl.handle.net/20.500.12008/55519 2003-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/55507 Título: Intranasal Immunization with a Colloid-Formulated Bacterial Extract Induces an Acute Inflammatory Response in the Lungs and Elicits Specific Immune Responses Autor: Rial, A.; Lens, D.; Betancor, L.; Benkiel, H.; Silva, J. S.; Chabalgoity, J. A. Resumen: Nonspecific stimulation of lung defenses by repeated oral administration of immunomodulators, such as bacterial extracts, has shown potential for the prevention of respiratory tract infections. Here, we show that intranasal (i.n.) immunization with a bacterial extract formulated as a colloid induces an acute inflammatory response in the lungs characterized by increased production of CCL and CXCL chemokines and a major influx of dendritic cells (DCs) and neutrophils, with a higher proportion of DCs showing an activated phenotype (high CD80/CD86 expression). Cytokine levels measured in bronchoalveolar-lavage samples showed a small increase in the production of tumor necrosis factor alpha and similar levels of the other cytokines measured (interleukin 10 [IL-10], IL-12, and gamma interferon [IFN-]) in immunized mice compared with control mice. However, the recall response of primed animals after antigenic challenge induced increased expression of IL-12 and IFN-mRNAs in lung homogenates. Overall, all these effects were not due to the lipopolysaccharide content in the bacterial extract. Furthermore, we found that three i.n. doses administered 2 to 3 weeks apart were enough to elicit long-lasting specific serum immunoglobulin G (IgG) and secretory IgA antibody responses. Assessment of IgG subclasses showed a balanced pattern of IgG1-IgG2a responses. The serum total IgE concentrations were also elevated in immunized mice 2 weeks after the third dose, but they significantly decreased soon afterwards. Our results suggest that simple formulations of bacterial extracts administered i.n. are highly immunogenic, eliciting local and systemic immune responses, and may serve as the basis for cost-effective immunotherapies for the prevention and treatment of respiratory infections. Thu, 01 Jan 2004 00:00:00 GMT https://hdl.handle.net/20.500.12008/55507 2004-01-01T00:00:00Z https://hdl.handle.net/20.500.12008/55489 Título: Pharmacoepidemiology of antipsychotic utilization among children and adolescents in Montevideo between 2018 and 2022 Autor: Cabral, Santiago; Catenaccio, Valentina; Herrera, Guadalupe; Grunbaum, Susana; Speranza, Noelia Resumen: Background: The prescription of antipsychotics in the pediatric population has increased worldwide, especially of second generation antipsychotics. Prescription patterns are not homogeneous across populations. Studies demonstrate differences according to sex, age and socioeconomic level. In Uruguay, the available evidence is limited and comes from small, single-center studies and does not provide information on changes over time. Purpose:describe the use of antipsychotics in 1- to 19-year-old children and adolescents in Montevideo between 2018 and 2022, considering differences according to socioeconomic level. Study design: A descriptive observational study of medication use was conducted. Methods: It included children and adolescent users of antipsychotics treated in eight healthcare centers in Montevideo (one public, five collective healthcare institutions, and two private insurance schemes), which together provide coverage to approximately 230,000 children and adolescents in total. Pharmacy dispensing data were analyzed between 1/1/2018 and 12/31/2022. The primary endpoint was the defined daily dose (DDD) per 1,000 inhabitants/day (DDD per 1,000 inhabitants/day), calculated globally and by drug. Temporal variation was evaluated in three periods: pre-pandemic (2018–2019), start of the pandemic (2020) and post-pandemic (2021–2022). Descriptive statistics were used. Findings: The average DDD per 1,000 inhabitants/day in the period was 11.4, with a predominance of risperidone and aripiprazole. The highest utilization was observed among adolescents aged 15–19 years, followed by the group aged 5–14 years, and was higher in males. Although the use of antipsychotics increased over time in all socioeconomic levels, it was higher for providers of care at the low socioeconomic level and lower for providers of care at the high socioeconomic level. Conclusion: This is the first study in Uruguay that describes the use of antipsychotic agents in children and adolescents by socioeconomic level; it showed a steady increase in their use. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/20.500.12008/55489 2026-01-01T00:00:00Z