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ABSTRACT Introduction. Bryophytes (mosses) have long been used to determine the concentration of heavy metals as an alternative to the collection of atmospheric aerosols. Objective. To evaluate the environmental concentration of lead, cadmium, mercury and arsenic in autochthonous species of moss and to analyze some methodological aspects of biomonitoring in Paraguay. Methodology. In an observational study moss samples were obtained from sub rural zone to be transplanted in 5 sites of high vehicular traffic in Asunción city. The samples were left outdoors for 58 days and then collected and subjected to study using the inductive coupling plasma source mass spectrometry technique. The bryophytes were characterized and all the climatological variables during the study period were consigned. Results. Lead concentrations detected in moss explants exposed to the urban environment were higher than mosses from natural forest, while arsenic levels in the latter were higher than those found in bryophytes transferred to the city. No conspicuous levels of cadmium and mercury were found. The bryophytes used belonged to two families: Hypnaceae and Pilotrichaceae. The range of temperature, relative humidity, wind and precipitation did not reach extreme levels during the studied period. Conclusion. The different lead levels measured here, could be surrogates of urban pollution while the notorious arsenic level in natural forest moss points to other sources like wildfires. Several aspects of the biomonitoring methodology are discussed.

RESUMEN Introducción. Las briofitas (musgos) se han utilizado durante mucho tiempo para determinar la concentración de metales pesados como alternativa a la recolección de aerosoles atmosféricos. Objetivo. Evaluar la concentración ambiental de plomo, cadmio, mercurio y arsénico en especies autóctonas de musgo y analizar algunos aspectos metodológicos de la biomonitorización en Paraguay. Metodología. En un estudio observacional se obtuvieron muestras de musgo de una zona sub-rural para ser trasplantadas en cinco sitios de alto tráfico vehicular en Asunción. Las muestras se dejaron a la intemperie durante 58 días y luego se recogieron para la medición de metales pesados por espectrometría de masas con fuente de plasma de acoplamiento inductivo. Se caracterizaron las briofitas y se consignaron todas las variables climatológicas durante el período de estudio. Resultados. Las concentraciones de plomo detectadas en los explantes de musgo expuestos al medio urbano fueron superiores a las de los musgos del bosque natural, mientras que los niveles de arsénico en estos últimos fueron superiores a los encontrados en los briófitos trasladados a la ciudad. No se encontraron niveles llamativos de cadmio y mercurio. Las briofitas utilizadas pertenecían a dos familias: Hypnaceae y Pilotrichaceae. Los rangos de temperatura, humedad relativa, viento y precipitación no alcanzaron niveles extremos durante el periodo estudiado. Conclusión. Los diferentes niveles de plomo medidos podrían ser subrogados de polución urbana mientras que el notorio nivel de arsénico en musgo de bosque natural apunta a otro tipo de fuentes como los incendios forestales. Se discuten varios aspectos de la metodología de biomonitorización.

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OBJECTIVE: To develop a method for the efficient assembly of viral or multimeric proteins into virus-like particles (VLP) or other macro structures. RESULTS: Protein monomers were assembled by eliminating calcium ions through precipitation. The model protein, rotavirus VP6, assembled into stable, long nanotubes with better quality than the assemblies obtained directly from cell culture. Nanotube length was directly proportional to the initial concentration of VP6 monomers, in accordance with the classic nucleation theory of capsid assembly. The quality of the obtained assemblies was confirmed when the nanotubes were functionalized with metals, yielding unique nanobiomaterials. Assembly efficiency was improved in comparison with other previously proposed methods. CONCLUSIONS: The novel method presented here is simpler and faster than other reported methods for the assembly and disassembly of viral proteins, a step needed for most applications.

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OBJECTIVE: To describe the epidemiological, phenotypical and genetic characteristics of clinical isolates carrying the optrA gene identified in antimicrobial resistance surveillance by the laboratory of the National Institute of Health of Colombia. METHODS: Between October 2014 and February 2019, 25 isolates of Enterococcus spp. resistant to linezolid were received. Antimicrobial identification and sensitivity were determined using Vitek 2 and the minimum inhibitory concentration (MIC) to linezolid was established with E-test. The optrA gene was detected by PCR, and the genetic diversity of optrA-positive isolates was tested with Diversilab®. Six isolates were selected to perform whole genome sequencing. RESULTS: The optrA gene was confirmed in 23/25 isolates of E. faecalis from seven departments in Colombia. The isolates presented a MIC to linezolid between 8 and >256µg/mL. Typing by Diversilab® showed a wide genetic variability. All the isolates analyzed by whole genome sequencing showed the resistance genes fexA, ermB, lsaA, tet(M), tet(L) and dfrG in addition to optrA and were negative for other mechanisms of resistance to linezolid. Three type sequences and three optrA variants were identified: ST16 (optrA-2), ST476 (optrA-5) and ST618 (optrA-6). The genetic environment of the optrA-2 (ST16) isolates presented the impB, fex, optrA segment, associated with plasmid, while in two isolates (optrA-6 and optrA-5) the transferable chromosomal element Tn6674-like was found. CONCLUSION: OptrA-positive clinical isolates present a high genetic diversity, with different optrA clones and variants related to two types of structures and different mobile genetic elements.

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Objetivo. Describir las características epidemiológicas, fenotípicas y genéticas de aislamientos clínicos portadores de optrA identificados en la vigilancia de resistencia antimicrobiana por el laboratorio del Instituto Nacional de Salud de Colombia. Métodos. Entre octubre de 2014 y febrero 2019, se recibieron 25 aislamientos de Enterococcus spp. resistentes al linezolid. La identificación y sensibilidad antimicrobiana se determinó con Vitek 2 y la concentración inhibitoria mínima (CIM) al linezolid se estableció con E-test. El gen optrA se detectó mediante PCR. La diversidad genética de aislamientos positivos para optrA se analizó con Diversilab®. Se seleccionaron seis aislamientos para llevar a cabo la secuenciación del genoma completo. Resultados. Se confirmó el gen optrA en 23/25 aislamientos de E. faecalis de siete departamentos de Colombia. Los aislamientos presentaron una CIM al linezolid entre 8 y >256μg/mL. La tipificación por Diversilab® indicó una amplia variabilidad genética. Todos los aislamientos analizados mediante secuenciación del genoma completo, presentaron genes de resistencia fexA, ermB, lsaA, tet(M), tet(L) y dfrG además de optrA y fueron negativos para otros mecanismos de resistencia al linezolid. Se identificaron tres secuencias tipos y tres variantes de optrA: ST16 (optrA-2), ST476 (optrA-5) y ST618 (optrA-6). El entorno genético de los aislamientos optrA-2 (ST16) presentó el segmento impB, fex, optrA, asociado a plásmido, mientras que en dos aislamientos (optrA-6 y optrA-5) se encontró el elemento cromosómico transferible Tn6674-like. Conclusión. Los aislamientos clínicos positivos para optrA presentan una alta diversidad genética, con diferentes clones y variantes de optrA relacionados con dos tipos de estructuras y diferentes elementos genéticos móviles.

Objective. To describe the epidemiological, phenotypical and genetic characteristics of clinical isolates carrying the optrA gene identified in antimicrobial resistance surveillance by the laboratory of the National Institute of Health of Colombia. Methods. Between October 2014 and February 2019, 25 isolates of Enterococcus spp. resistant to linezolid were received. Antimicrobial identification and sensitivity were determined using Vitek 2 and the minimum inhibitory concentration (MIC) to linezolid was established with E-test. The optrA gene was detected by PCR, and the genetic diversity of optrA-positive isolates was tested with Diversilab®. Six isolates were selected to perform whole genome sequencing. Results. The optrA gene was confirmed in 23/25 isolates of E. faecalis from seven departments in Colombia. The isolates presented a MIC to linezolid between 8 and >256μg/mL. Typing by Diversilab® showed a wide genetic variability. All the isolates analyzed by whole genome sequencing showed the resistance genes fexA, ermB, lsaA, tet(M), tet(L) and dfrG in addition to optrA and were negative for other mechanisms of resistance to linezolid. Three type sequences and three optrA variants were identified: ST16 (optrA-2), ST476 (optrA-5) and ST618 (optrA-6). The genetic environment of the optrA-2 (ST16) isolates presented the impB, fex, optrA segment, associated with plasmid, while in two isolates (optrA-6 and optrA-5) the transferable chromosomal element Tn6674-like was found. Conclusion. OptrA-positive clinical isolates present a high genetic diversity, with different optrA clones and variants related to two types of structures and different mobile genetic elements.

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Expansins are encoded by some phytopathogenic bacteria and evidence indicates that they act as virulence factors for host infection. Here we analysed the expression of exl1 by Pectobacterium brasiliense and Pectobacterium atrosepticum. In both, exl1 gene appears to be under quorum sensing control, and protein Exl1 can be observed in culture medium and during plant infection. Expression of exl1 correlates with pathogen virulence, where symptoms are reduced in a Δexl1 mutant strain of P. atrosepticum. As well as Δexl1 exhibiting less maceration of potato plants, fewer bacteria are observed at distance from the inoculation site. However, bacteria infiltrated into the plant tissue are as virulent as the wild type, suggesting that this is due to alterations in the initial invasion of the tissue. Additionally, swarming from colonies grown on MacConkey soft agar was delayed in the mutant in comparison to the wild type. We found that Exl1 acts on the plant tissue, probably by remodelling of a cell wall component or altering the barrier properties of the cell wall inducing a plant defence response, which results in the production of ROS and the induction of marker genes of the JA, ET and SA signalling pathways in Arabidopsis thaliana. Exl1 inactive mutants fail to trigger such responses. This defence response is protective against Pectobacterium brasiliense and Botrytis cinerea in more than one plant species.

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Pectobacterium is a diverse genus of phytopathogenic species from soil and water that cause infection either to restricted or multiple plant hosts. Phylogenetic analysis and metabolic fingerprinting of large numbers of genomes have expanded classification of Pectobacterium members. Pectobacterium brasiliense sp. nov has been elevated to the species level having detached from P. carotovorum. Here we present two P. brasiliense strains BF20 and BF45 isolated in Mexico from Opuntia and tobacco, respectively, which cluster into two different groups in whole genome comparisons with other Pectobacterium. We found that BF20 and BF45 strains are phenotypically different as BF45 showed more severe and rapid symptoms in comparison to BF20 in the host models celery and broccoli. Both strains produced similar levels of the main autoinducers, but BF45 shows an additional low abundant autoinducer compared to strain BF20. The two strains had different levels of c-di-GMP, which regulates the transition from motile to sessile lifestyle. In contrast to BF45, BF20 had the highest levels of c-di-GMP, was more motile (swarming), non-flocculant and less proficient in biofilm formation and exopolysaccharide production. Genomic comparisons revealed that differences in c-di-GMP accumulation and perhaps the associated phenotypes might be due to unique c-di-GMP metabolic genes in these two strains. Our results improve our understanding of the associations between phenotype and genotype and how this has shaped the physiology of Pectobacterium strains.

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The plant xylem is a preferred niche for some important bacterial phytopathogens, some of them encoding expansin proteins, which bind plant cell walls. Yet, the identity of the substrate for bacterial expansins within the plant cell wall and the nature of its interaction with it are poorly known. Here, we determined the localization of two bacterial expansins with differing isoelectric points (and with differing binding patterns to cell wall extracts) on plant tissue through in vitro fluorophore labeling and confocal imaging. Differential localization was observed, in which Exl1 from Pectobacterium carotovorum located into the intercellular spaces between xylem vessels and adjacent cells of the plant xylem, whereas EXLX1 from Bacillus subtilis bound cell walls of most cell types. In isolated vascular tissue, however, both PcExl1 and BsEXLX1 preferentially bound to tracheary elements over the xylem fibers, even though both are composed of secondary cell walls. Fluorescence correlation spectroscopy, employed to analyze the interaction of expansins with isolated xylem, indicates that binding is governed by more than one factor, which could include interaction with more than one type of polymer in the fibers, such as cellulose and hemicellulose or pectin. Binding to different polysaccharides could explain the observed reduction of cellulolytic and xylanolytic activities in the presence of expansin, possibly because of competition for the substrate. Our findings are relevant for the comprehensive understanding of the pathogenesis by P. carotovorum during xylem invasion, a process in which Exl1 might be involved.

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Se realizó un estudio cualitativo de corte longitudinal durante los años 2015 y 2016 en el municipio El Salvador, Guantánamo, con el objetivo de diseñar un curso para disminuir la morbilidad por cáncer de mama, dirigidos a los enfermeros que laboran en la Atención Primaria de Salud perteneciente a dicho municipio. Se seleccionó una muestra de 30 enfermeros y se le aplicó un diagnóstico para identificar las necesidades formativas. Se diseñó el curso y se sometió a criterio del consejo científico del área. En la etapa diagnóstica se encontraron insuficiencias en relación con el tema del cáncer de mama. El curso sirvió para adquirir conocimientos, habilidades y preparar al personal de enfermería que labora en la Atención Primaria de Salud, para que realicen acciones de promoción, prevención que permitan disminuir los factores de riesgos, hacer diagnósticos más tempranos y mejorar la calidad de vida en las féminas(AU)

The professional overcoming of nursing staff in today's society is a challenge, so it is imperative to constantly prepare the staff who works in Primary Health Care to be able to promote favorable lifestyle changes in the Cuban population. To design a course to reduce morbidity due to breast cancer, aimed at nurses working in primary health care belonging to the municipality of El Salvador. Methods: A longitudinal qualitative study was carried out during the years 2015 and 2016 in the Municipality of El Salvador. A sample of 30 nurses was selected and a diagnosis was applied to identify training needs. The course was designed and submitted to the criteria of the scientific council of the area. Results: In the diagnostic stage, shortcomings were found in relation to the breast cancer issue. Conclusions: The course serves to acquire knowledge, skills and prepare nurses working in Primary Health Care, to carry out promotion, prevention actions that reduce risk factors, make diagnoses earlier and improve the quality of life in the females(AU)

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The human epidermal growth factor receptor (HER1) and its partner HER2 are extensively described oncogenes and validated targets for cancer therapy. However, the effectiveness of monospecific therapies targeting these receptors is hampered by resistance emergence, which is frequently associated with the upregulation of other members of HER family. Combined therapies using monoclonal antibodies or tyrosine kinase inhibitors have been suggested as a promising strategy to circumvent this resistance mechanism. We propose an alternative approach based on simultaneous inactivation of HER1 and HER2 by multi-epitope blockade with specific polyclonal antibodies induced by vaccination. Elicited antibodies impaired both receptors activation and induced their degradation, which caused the inhibition of down-signaling cascades. This effect was translated into cell cycle arrest and apoptosis induction of human tumor cells. Elicited antibodies were able to reduce the viability of a panel of human tumor lines with differential expression levels of HER1 and HER2. The most significant effects were obtained in the tumor lines with lower expression levels of both receptors. These new insights would contribute to the rational design of HER receptors targeting multivalent vaccines, as an encouraging approach for the treatment of cancer patients.

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INTRODUCTION: Tuberculosis (TB) is the leading cause of death due to an infectious disease worldwide. Especially in low-income countries, new diagnostic techniques that are accessible, inexpensive and easy-to-use, are needed to shorten transmission time and initiate treatment earlier. OBJECTIVE: We conducted a study with a handheld, point-of-care electronic nose (eNose) device to diagnose TB through exhaled breath. SETTING: This study includes a total of 110 patients and visitors of an expert centre of respiratory diseases in Asunción, Paraguay. TB diagnosis was established by culture of Mycobacterium tuberculosis complex and compared with the eNose results in two phases. RESULTS: The calibration phase, including only culture confirmed TB cases versus healthy people, demonstrated a sensitivity and specificity of 91% and 93% respectively. The confirmation phase, including all participants, showed a sensitivity of 88% and a specificity of 92%. The eNose showed high acceptance rate among participants, and was easy to operate. CONCLUSION: The eNose resulted in a powerful technique to differentiate between healthy people and TB patients. Its comfort, speed and usability promise great potential in vulnerable groups, in remote areas and hospital settings to triage patients with suspicion of TB.

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