Pseudomonas violetae sp. nov. and Pseudomonas emilianonis sp. nov., two new species with the ability to degrade TNT isolated from soil samples at Deception Island, maritime Antarctica.

Two motile, rod-shaped, Gram-stain-negative bacterial strains, TNT11T and TNT19T, were isolated from soil samples collected at Deception Island, Antarctica. According to the 16S rRNA gene sequence similarity, both strains belong to the genus Pseudomonas. Further genomic analyses based on ANI and dDDH suggested that these strains were new species. Growth of strain TNT11T is observed at 0-30 â„ƒ (optimum, 20 â„ƒ), pH 4.0-9.0 (optimum, pH 6.0) and in the presence of 0-5.0% NaCl (optimum, 1% NaCl), while for TNT19T is observed at 0-30 â„ƒ (optimum between 15 and 20 â„ƒ), pH 5.0-9.0 (optimum, pH 6.0) and in the presence of 0-5.0% NaCl (optimum between 0 and 1% NaCl). The fatty acid profile consists of the major compounds; C16:0 and C16:1 ω6 for TNT11T, and C16:0 and C12:0 for TNT19T. Based on the draft genome sequences, the DNA G + C content for TNT11T is 60.43 mol% and 58.60 mol% for TNT19T. Based on this polyphasic study, TNT11T and TNT19T represent two novel species of the genus Pseudomonas, for which the proposed names are Pseudomonas violetae sp. nov. and Pseudomonas emilianonis sp. nov., respectively. The type strains are Pseudomonas violetae TNT11T (= RGM 3443T = LMG 32959T) and Pseudomonas emilianonis TNT19T (= RGM 3442T = LMG 32960T). Strains TNT11T and TNT19T were deposited to CChRGM and BCCM/LMG with entry numbers RGM 3443/LMG 32959 and RGM 3442/LMG 32960, respectively.

Bioinformatics, thermodynamics, and mechanical resistance of the FtsZ-ZipA complex of Escherichia coli supports a highly dynamic protein interaction in the divisome.

In most microorganisms, cell division is guided by the divisome, a multiprotein complex that assembles at the equator of the cell and is responsible for the synthesis of new cell wall material. FtsZ, the first protein to assemble into this complex forms protofilaments in the cytosol which are anchored to the inner side of the cytosolic membrane by the proteins ZipA and FtsA. FtsZ protofilaments generate a force that deforms the cytosolic membrane and may contribute to the constriction force that leads to the septation of the cell. It has not been studied yet how the membrane protein anchors respond to this force generated by FtsZ. Here we studied the effect of force in the FtsZ-ZipA interaction. We used SMD and obtained the distance to the transition state of key interacting amino acids and SASA of FtsZ and ZipA through the dissociation. The SMD mechanism was corroborated by ITC, and the thermodynamic parameters ΔG0, ΔH0 and ΔS0 were obtained. Finally, we used force spectroscopy by optical tweezers to determine the lifetime of the interaction and rupture probability and their dependence on force at single molecule level. We also obtained the transition state distance, and free energy of the interaction. With the gathering of structural, thermodynamic, kinetic and force parameters we conclude that interaction between FtsZ and ZipA proteins is consistence with the highly dynamic treadmilling process and at least seven ZipA molecules are required to bind to a FtsZ protofilaments to transduce a significant force.

Arthrobacter vasquezii sp. nov., isolated from a soil sample from Union Glacier, Antarctica.

A Gram-stain-positive, catalase-positive, non-motile bacteria, with a rod-coccus cycle (designated as EH-1B-1T) was isolated from a soil sample from Union Glacier in Ellsworth Mountains, Antarctica. Strain EH-1B-1T had an optimal growth temperature of 28 °C and grew at pH 7-10. The major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, C16 : 0 and anteiso-C17 : 0. The G+C content based on the whole genome sequence was 63.1 mol%. Strain EH-1B-1T was most closely related to members of the genus Arthrobacter, namely Arthrobacter subterraneus and Arthrobacter tumbae. The strain grew on tryptic soy agar, Reasoner's 2A agar, lysogeny broth agar and nutrient agar. The average nucleotide identity and digital DNA-DNA hybridization values between strain EH-1B-1T and its closest reference type strains ranged from 78 to 88 % and from 20.9 to 36.3 %, respectively. Based on phenotypic, chemotypic and genotypic evidence, it is proposed that strain EH-1B-1T represents a novel species of Arthrobacter, for which the name Arthrobacter vasquezii sp. nov. is proposed, with strain EH-1B-1T (RGM 3386T=LMG 32961T) as the type strain.

Solid medium for the direct isolation of bacterial colonies growing with polycyclic aromatic hydrocarbons or 2,4,6-trinitrotoluene (TNT).

Isolation of hydrocarbon-degrading bacteria is a key step for the study of microbiological diversity, metabolic pathways, and bioremediation. However current strategies lack simplicity and versatility. We developed an easy method for the screening and isolation of bacterial colonies capable of degrading hydrocarbons, such as diesel or polycyclic aromatic hydrocarbons (PAHs), as well as the pollutant explosive, 2,4,6-trinitrotoluene (TNT). The method uses a two-layer solid medium, with a layer of M9 medium, and a second layer containing the carbon source deposited through the evaporation of ethanol. Using this medium we grew hydrocarbon-degrading strains, as well as TNT-degrading isolates. We were able to isolate PAHs-degrading bacterial colonies directly from diesel-polluted soils. As a proof of concept, we used this method to isolate a phenanthrene-degrading bacteria, identified as Acinetobacter sp. and determined its ability to biodegrade this hydrocarbon.

[Diagnostic capacity of neck circumference to evaluate obesity in a young adult population. Data analysis from the second national health survey in Chile, 2009-2010]. / Capacidad diagnóstica de la circunferencia de cuello para evaluar la obesidad en la población adulta joven. Análisis de datos de la segunda Encuesta Nacional de Salud 2009-2010. Chile.

Introduction: Introduction: Chile is among the countries with the highest rate of excess malnutrition, for that reason it is important to have effective tools to evaluate the nutritional status; interest in neck circumference (NC) measurement as a potential prognostic tool that is easy to access and low-cost has increased. Objective: to evaluate the diagnostic capacity of neck circumference to predict obesity in the population aged 15-16 years, using data from the third National Health Survey 2009-2010. Materials and methods: Concurrent Criteria of Diagnostic Validation were used for the study. The sample consisted of 536 people of ages from 15 to 26 years, where BMI data where taken in order to classify obesity versus normality (gold standard), as was NC (measured in centimeters). People with hyperthyroidism were excluded. Indicators of diagnostic accuracy were obtained; the SPSS, version 25 was used for calculations. Results: according to age and gender ranks, the NC cut-off points to classify general obesity showed sensitivities and specificities above 0.85, with an area under the curve over 0.90, all with p < 0.001. Conclusion: there is evidence that supports that NC cutoff points are a suitable tool for diagnosing obesity in this age group.

Introducción: Introducción: Chile está dentro de los países con mayor tasa de malnutrición por exceso, lo que obliga a disponer de herramientas eficaces para evaluar el estado nutricional; así surge nuestro interés por explorar la posibilidad de utilizar la medición de la circunferencia del cuello (CCUE) como herramienta potencial de diagnóstico de fácil obtención y acceso, y bajo costo. Objetivo: evaluar la capacidad diagnóstica de la circunferencia del cuello como predictor de obesidad en la población de 15-26 años de edad. Materiales y métodos: dado que se encuentran disponibles, y son adecuados para nuestra investigación, se utilizarán datos extraídos de la Tercera Encuesta Nacional de Salud 2009-2010. Nuestro estudio se realizó aplicando el Método de Validación Diagnóstica por Criterio Concurrente. La muestra estuvo compuesta por 536 personas cuyas edades fluctuaban entre los 15 y 26 años, de quienes se tomaron los datos de IMC, para clasificarlas en las categorías de obesidad o normalidad (patrón oro), y la CCUE (en centímetros). Se excluyeron las personas con hipertiroidismo. Se obtuvieron indicadores de exactitud diagnóstica y valores predictivos. Se aplicó el SPSS, versión 25. Resultados: según los rangos de edad y el sexo, los puntos de corte de la CCUE para clasificar la obesidad general presentaron sensibilidades y especificidades superiores a 0,85 con una área bajo la curva superior a 0,90, todos con p < 0,001. Conclusión: existe evidencia a favor de que los puntos de corte de la CCUE presentan una adecuada capacidad de diagnosticar la obesidad en este grupo etario.

Capacidad diagnóstica de la circunferencia de cuello para evaluar la obesidad en la población adulta joven. Análisis de datos de la segunda Encuesta Nacional de Salud 2009-2010. Chile / Diagnostic capacity of neck circumference to evaluate obesity in a young adult population. Data analysis from the second national health survey in Chile, 2009-2010

Introducción: Chile está dentro de los países con mayor tasa de malnutrición por exceso, lo que obliga a disponer de herramientas eficaces para evaluar el estado nutricional; así surge nuestro interés por explorar la posibilidad de utilizar la medición de la circunferencia del cuello (CCUE) como herramienta potencial de diagnóstico de fácil obtención y acceso, y bajo costo. Objetivo: evaluar la capacidad diagnóstica de la circunferencia del cuello como predictor de obesidad en la población de 15-26 años de edad. Materiales y métodos: dado que se encuentran disponibles, y son adecuados para nuestra investigación, se utilizarán datos extraídos de la Tercera Encuesta Nacional de Salud 2009-2010. Nuestro estudio se realizó aplicando el Método de Validación Diagnóstica por Criterio Concurrente. La muestra estuvo compuesta por 536 personas cuyas edades fluctuaban entre los 15 y 26 años, de quienes se tomaron los datos de IMC, para clasificarlas en las categorías de obesidad o normalidad (patrón oro), y la CCUE (en centímetros). Se excluyeron las personas con hipertiroidismo. Se obtuvieron indicadores de exactitud diagnóstica y valores predictivos. Se aplicó el SPSS, versión 25. Resultados: según los rangos de edad y el sexo, los puntos de corte de la CCUE para clasificar la obesidad general presentaron sensibilidades y especificidades superiores a 0,85 con una área bajo la curva superior a 0,90, todos con p < 0,001. Conclusión: existe evidencia a favor de que los puntos de corte de la CCUE presentan una adecuada capacidad de diagnosticar la obesidad en este grupo etario. (AU)

Introduction: Chile is among the countries with the highest rate of excess malnutrition, for that reason it is important to have effective tools to evaluate the nutritional status; interest in neck circumference (NC) measurement as a potential prognostic tool that is easy to access and low-cost has increased. Objective: to evaluate the diagnostic capacity of neck circumference to predict obesity in the population aged 15-16 years, using data from the third National Health Survey 2009-2010. Materials and methods: Concurrent Criteria of Diagnostic Validation were used for the study. The sample consisted of 536 people of ages from 15 to 26 years, where BMI data where taken in order to classify obesity versus normality (gold standard), as was NC (measured in centimeters). People with hyperthyroidism were excluded. Indicators of diagnostic accuracy were obtained; the SPSS, version 25 was used for calculations. Results: according to age and gender ranks, the NC cut-off points to classify general obesity showed sensitivities and specificities above 0.85, with an area under the curve over 0.90, all with p < 0.001. Conclusion: there is evidence that supports that NC cutoff points are a suitable tool for diagnosing obesity in this age group. (AU)

Determination of protein-protein interactions at the single-molecule level using optical tweezers.

Biomolecular interactions are at the base of all physical processes within living organisms; the study of these interactions has led to the development of a plethora of different methods. Among these, single-molecule (in singulo) experiments have become relevant in recent years because these studies can give insight into mechanisms and interactions that are hidden for ensemble-based (in multiplo) methods. The focus of this review is on optical tweezer (OT) experiments, which can be used to apply and measure mechanical forces in molecular systems. OTs are based on optical trapping, where a laser is used to exert a force on a dielectric bead; and optically trap the bead at a controllable position in all three dimensions. Different experimental approaches have been developed to study protein­protein interactions using OTs, such as: (1) refolding and unfolding in trans interaction where one protein is tethered between the beads and the other protein is in the solution; (2) constant force in cis interaction where each protein is bound to a bead, and the tension is suddenly increased. The interaction may break after some time, giving information about the lifetime of the binding at that tension. And (3) force ramp in cis interaction where each protein is attached to a bead and a ramp force is applied until the interaction breaks. With these experiments, parameters such as kinetic constants (koff, kon), affinity values (KD), energy to the transition state ΔG≠, distance to the transition state Δx≠ can be obtained. These parameters characterize the energy landscape of the interaction. Some parameters such as distance to the transition state can only be obtained from force spectroscopy experiments such as those described here.

Análisis bibliométrico sobre la producción científica de Chile en Oncología entre los años 2010 y 2019 / Bibliometric analysis of Chilean scientific production about oncology in the period 2010-2019

Esta investigación tuvo como objetivo analizar la producción científica chilena sobre Oncología indexada en Clarivate Web of Science desde el año 2010 hasta 2019. Se realizó un estudio bibliométrico en el que se efectuó la recuperación retrospectiva de documentos, utilizando una estrategia de búsqueda basada en etiquetas de campo de categoría y país, aplicando además el filtro de fechas. Se identificaron 1 266 documentos, 590 de ellos fueron artículos originales. El idioma principal de las publicaciones fue el inglés; se contabilizaron 182 revistas en las que fueron publicados los artículos, entre las cuales Journal of Clinical Oncology presentó la mayor cantidad de trabajos publicados, con 117 documentos. Los autores chilenos han publicado en colaboración con autores de otros 101 países; entre ellos, Estados Unidos fue el que obtuvo el mayor número de colaboraciones (474 publicaciones). La institución chilena con más publicaciones fue la Pontificia Universidad Católica de Chile, con 364 artículos. El tipo de cáncer más estudiado se relacionó con el sistema digestivo. Se concluye que la producción científica chilena en Oncología ha aumentado sistemáticamente en el periodo 2010-2019, y tiende a incrementar en gran medida el número de publicaciones de artículos originales, principalmente en idioma inglés, ya que facilita la colaboración internacional. A pesar de la amplia cooperación de investigadores e instituciones chilenas y la alta productividad en el área, no existen investigadores o instituciones chilenas que sean responsables de los artículos más citados, por lo cual el impacto de la ciencia y de las publicaciones realizadas en Chile sigue siendo bajo, por lo que resulta necesario potenciar el trabajo de los investigadores chilenos(AU)

The purpose of the study was to analyze Chilean scientific production about oncology indexed in Clarivate Web of Science from 2010 to 2019. A bibliometric analysis was performed which included retrospective retrieval of documents applying a search strategy based on field labels for category and country, as well as a date filter. A total 1 266 documents were identified, 590 of which were original articles. English was the most common language of publication. Articles were retrieved from 182 journals, among which the Journal of Clinical Oncology had the largest number of published articles, with 117. Chilean authors have published in collaboration with authors from another 101 countries, the largest number of them from the United States, with 474 publications. The most productive Chilean institution was the Pontifical Catholic University of Chile, with 364 articles. Gastrointestinal cancer was the type most commonly addressed. It is concluded that Chilean scientific production about oncology has systematically increased in the period 2010-2019, and tends to considerably increase the number of original articles published, mainly in English, to foster international collaboration. Despite the great cooperation of Chilean researchers and institutions and the high productivity in the area, articles by Chilean researchers and institutions were not among the most citated, as a result of which the impact of Chilean science and publications continues to be low. It is therefore necessary to strengthen the work of Chilean researchers(AU)

Genetic Variation in MicroRNA-423 Promotes Proliferation, Migration, Invasion, and Chemoresistance in Breast Cancer Cells.

MicroRNA-423 (miR-423) is highly expressed in breast cancer (BC). Previously, our group showed that the SNP rs6505162:C>A located in the pre-miR-423 was significantly associated with increased familial BC risk in patients with a strong family history of BC. Therefore, in this study, we evaluated the functional role of rs6505162 in mammary tumorigenesis in vitro to corroborate the association of this SNP with BC risk. We found that rs6505162:C>A upregulated expression of both mature miR-423 sequences (3p and 5p). Moreover, pre-miR-423-A enhanced proliferation, and promoted cisplatin resistance in BC cell lines. We also showed that pre-miR-423-A expression decreased cisplatin-induced apoptosis, and increased BC cell migration and invasion. We propose that the rs6505162-A allele promotes miR-423 overexpression, and that the rs6505162-A allele induces BC cell proliferation, viability, chemoresistance, migration, and invasion, and decreases cell apoptosis as a consequence. We suggest that rs6505162:C>A is a functional SNP site with potential utility as a marker for early diagnosis, prognosis, and treatment efficacy monitoring in BRCA1/2-negative BC patients, as well as a possible therapeutic target.

Microbiology can be comic.

For microbiologists, the importance of microorganisms in our daily lives and their impact on our well-being is evident. However, microbiology literacy in our society is far from being enough for individuals to make informed choices and to demand actions based on that information. The vaccine hesitation movement and the alarming increase in antimicrobial resistance due to overuse and misuse of antibiotics are just two examples of how much work is needed to make our society literate in topics related to microbiology. Considering the challenges of communicating a discipline surrounded by misconceptions, which studies the role of living organisms that cannot be seen in plain sight, we need to explore different strategies to effectively contribute to microbiology literacy in our society. Here, we will comment on the use of comics for such a task.

Genetic Variants in pre-miR-146a, pre-miR-499, pre-miR-125a, pre-miR-605, and pri-miR-182 Are Associated with Breast Cancer Susceptibility in a South American Population.

Breast cancer (BC) is one of the most frequent tumors affecting women worldwide. microRNAs (miRNAs) single-nucleotide polymorphisms (SNPs) likely contribute to BC susceptibility. We evaluated the association of five SNPs with BC risk in non-carriers of the BRCA1/2-mutation from a South American population. The SNPs were genotyped in 440 Chilean BRCA1/2-negative BC cases and 1048 controls. Our data do not support an association between rs2910164:G>C or rs3746444:A>G and BC risk. The rs12975333:G>T is monomorphic in the Chilean population. The pre-miR-605 rs2043556-C allele was associated with a decreased risk of BC, both in patients with a strong family history of BC and in early-onset non-familial BC (Odds ratio (OR) = 0.5 [95% confidence interval (CI) 0.4⁻0.9] p = 0.006 and OR = 0.6 [95% CI 0.5⁻0.9] p = 0.02, respectively). The rs4541843-T allele is associated with increased risk of familial BC. This is the first association study on rs4541843 and BC risk. Previously, we showed that the TOX3-rs3803662:C>T was significantly associated with increased risk of familial BC. Given that TOX3 mRNA is a target of miR-182, and that both the TOX3 rs3803662-T and pri-miR-182 rs4541843-T alleles are associated with increased BC risk, we evaluated their combined effect. Risk of familial BC increased in a dose-dependent manner with the number of risk alleles (p-trend = 0.0005), indicating an additive effect.

Mutations in BRCA1, BRCA2 and other breast and ovarian cancer susceptibility genes in Central and South American populations.

Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.

Mutations in BRCA1, BRCA2 and other breast and ovarian cancer susceptibility genes in Central and South American populations

Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.

Colon cancer cell invasion is promoted by protein kinase CK2 through increase of endothelin-converting enzyme-1c protein stability.

Endothelin-converting enzyme-1c (ECE-1c) is a membrane metalloprotease involved in endothelin-1 synthesis, which has been shown in vitro to have a role in breast, ovary and prostate cancer cell invasion. N-terminal end of ECE-1c displays three putative phosphorylation sites for the protein kinase CK2. We studied whether CK2 phosphorylates N-terminal end of ECE-1c as well as whether this has a role in migration and invasion of colon cancer cells. CK2 phosphorylated the N-terminal end of ECE-1c and this was precluded upon inhibition of CK2. Inhibition also led to diminished protein levels of both endogen ECE-1 or GFP-fused N-terminal end of ECE-1c in 293T embryonic and DLD-1 colon cancer cells, which highlighted the importance of this motif on UPS-dependent ECE-1c degradation. Full-length ECE-1c mutants designed either to mimic or abrogate CK2-phosphorylation displayed increased or decreased migration/invasion of colon cancer cells, respectively. Moreover, ECE-1c overexpression or its silencing with a siRNA led to increased or diminished cell migration/invasion, respectively. Altogether, these data show that CK2-increased ECE-1c protein stability is related to augmented migration and invasion of colon cancer cells, shedding light on a novel mechanism by which CK2 may promote malignant progression of this disease.