Lambda Red-mediated Recombineering in the Attaching and Effacing Pathogen Escherichia albertii

BACKGROUND: The ability to introduce site-specific mutations in bacterial pathogens is essential towards understanding their molecular mechanisms of pathogenicity. This has been greatly facilitated by the genetic engineering technique of recombineering. In recombineering, linear double- or single-stranded DNA molecules with two terminal homology arms are electroporated into hyperrecombinogenic bacteria that express a phage-encoded recombinase. The recombinase catalyzes the replacement of the endogenous allele with the exogenous allele to generate selectable or screenable recombinants. In particular, lambda red recombinase has been instrumental in engineering mutations to characterize the virulence arsenal of the attaching and effacing (A/E) pathogens enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC), and Citrobacter rodentium. Escherichia albertii is another member of this taxon; however, the virulence of E. albertii remains cryptic despite accumulating evidence that E. albertii is an emerging pathogen. Multiple retrospective studies have reported that a substantial number of EPEC and EHEC isolates (~15 %) that were previously incriminated in human outbreaks actually belong to the E. albertii lineage. Thus, there is increased urgency to reliably identify and rapidly engineer mutations in E. albertii to systematically characterize its virulence determinants. To the best of our knowledge not a single chromosomal gene has been altered by targeted mutagenesis in E. albertii since it was first isolated almost 25 years ago. This is disconcerting because an E. albertii outbreak could cause significant morbidity and mortality owing to our inadequate understanding of its virulence program. RESULTS: In this report we describe a modified lambda red recombineering protocol to mutagenize E. albertii. As proof of principle, we successfully deleted three distinct virulence-associated genetic loci - ler, grlRA, and hfq - and replaced each wild type allele by a mutant allele with an encodable drug resistance cassette bracketed by FRT sites. Subsequently, the FRT-site flanked drug resistance marker was evicted by FLP-dependent site-specific recombination to generate excisants containing a solitary FRT site. CONCLUSIONS: Our protocol will enable researchers to construct marked and unmarked genome-wide mutations in E. albertii, which, in turn, will illuminate its molecular mechanisms of pathogenicity and aid in developing appropriate preventative and therapeutic approaches to combat E. albertii outbreaks

Incorporación de aditivos retardantes tipo “b” en un concreto f’c= 210 kg/cm2 para mejorar su resistencia y fraguado, Tarapoto 2022

El estudio presentado “Incorporación de aditivos retardantes tipo “b” en un concreto f’c= 210 kg/cm2 para mejorar su resistencia y fraguado, Tarapoto 2022”, estableció como objetivo principal mejorar la resistencia y fraguado, para el proyecto se consideró una investigación cuantitativa aplicada que se llevó a cabo mediante la recolecciones de datos científicos, contando con un diseño pre experimental correlacional transversal y una muestra de 36 testigos, donde el investigador manipuló la variable independiente “aditivos retardante tipo b” para determinar las consecuencias que produce en la variable dependiente “resistencia y fraguado”. En base a los aditivos retardantes se obtuvo gracias al laboratorio CIRR. Los resultados obtenidos a los días nos indicaron las resistencias al 0% 224.7 kg/cm2, al 0.25% 221.6 kg/cm2, al 0.5% 219.3 kg/cm2 y al 1%218.4 kg/cm2, con respecto al fraguado se hizo el ensayo a las 10 horas donde se obtuvo un resultado de 24.19 kg/cm2, 23.34 kg/cm2, 11.03 kg/cm2, 6.41 kg/cm2, por lo que se tomó como óptima proporción el 0.5% por ser el que mejor comportamiento muestra en base a los dos criterios y relativamente al costo del concreto adicionado con 0.5% resultó más costoso con una diferencia de S/. 15.40

Human Pleural Fluid Elicits Pyruvate and Phenylalanine Metabolism in Acinetobacter baumannii to Enhance Cytotoxicity and Immune Evasion

The CCAAT box-harboring proteins represent a family of heterotrimeric transcription factors which is highly conserved in eukaryotes. In fungi, one of the particularly important homologs of this family is the Hap complex that separates the DNA-binding domain from the activation domain and imposes essential impacts on regulation of a wide range of cellular functions. So far, a comprehensive summary of this complex has been described in filamentous fungi but not in the yeast. In this review, we summarize a number of studies related to the structure and assembly mode of the Hap complex in a list of representative yeasts. Furthermore, we emphasize recent advances in understanding the regulatory functions of this complex, with a special focus on its role in regulating respiration, production of reactive oxygen species (ROS) and iron homeostasis.Fil: Nyah, Rodman. California State University; Estados UnidosFil: Martinez, Jasmine. California State University; Estados UnidosFil: Fung, Sammie. California State University; Estados UnidosFil: Nakanouchi, Jun. California State University; Estados UnidosFil: Myers, Amber L.. California State University; Estados UnidosFil: Harris, Caitlin M.. California State University; Estados UnidosFil: Dang, Emily. California State University; Estados UnidosFil: Fernandez, Jennifer. California State University; Estados UnidosFil: Liu, Christine. California State University; Estados UnidosFil: Mendoza, Anthony M.. California State University; Estados UnidosFil: Jimenez, Verónica. California State University; Estados UnidosFil: Nikolaidis, Nikolas. California State University; Estados UnidosFil: Brennan, Catherine A.. California State University; Estados UnidosFil: Bonomo, Robert A.. Louis Stokes Cleveland Department of Veterans Affairs Medical Cente; Estados Unidos. Center for Antimicrobial Resistance and Epidemiology; Estados Unidos. Case Western Reserve University School of Medicine; Estados UnidosFil: Sieira, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Ramirez, Maria Soledad. California State University; Estados Unido

Human fluids alter DNA-acquisition in Acinetobacter baumannii

Transformation is one of the mechanisms of acquisition of foreign genetic material leading to the emergence of multidrug resistant (MDR) bacteria. Recently, human serum albumin (HSA) was shown to specifically increase transformation frequency in the nosocomial pathogen Acinetobacter baumannii. To further assess the relevance of HSA as a possible modulator of A. baumannii transformation in host-pathogen interactions, in this work we examined the effect of different human fluids. We observed a significant increase in transformation frequencies in the presence of pleural fluid, whole blood cells and liquid ascites, and to a lesser extent with urine. The observed effects correlate with both HSA and bacterial content found in the assayed patient fluids. Taken together, these results are in agreement with our previous findings that highlight HSA as a possible host signal with the ability to trigger natural transformation in A. baumannii.Fil: Martinez, Jasmine. California State University; Estados UnidosFil: Liu, Christine. California State University; Estados UnidosFil: Rodman, Nyah. California State University; Estados UnidosFil: Fernandez, Jennifer S.. California State University; Estados UnidosFil: Barberis, Claudia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Sieira, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Perez, Federico. Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Estados UnidosFil: Bonomo, Robert A.. Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Estados Unidos. Case Western Reserve University; Estados UnidosFil: Ramirez, Maria Soledad. California State University; Estados Unido

Photo Reference and Identification Sample Marker

The Embry-Riddle Aeronautical University (ERAU) Spacesuit Utilization of Innovative Technology Laboratory (S.U.I.T. Lab) specializes in spacesuit operations, testing, and analysis, with a focus on human performance. The lab works to involve students from all disciplines in human spaceflight research. A majority of the lab’s students are studying Spaceflight Operations, Aerospace Engineering, or Human Factors. This proposal, created by undergraduate students at ERAU, seeks to describe the capabilities of the Photo Reference and Identification Sample Marker(PRISM). PRISM is designed as a sample size, color, and location calibration marker for use during lunar surface extravehicular activities (EVAs). This application requires ease of use for astronauts wearing the Exploration Extravehicular Mobility Unit (xEMU) spacesuit, as well as reliability in the lunar dust environment. PRISM can either be configured vertically or horizontally depending on the sample site. The device consists of an outer casing and a slider subassembly. The casing features reference markers for identification and calibration on the exterior. The slider subassembly includes a slider block which is used to deploy the legs for a vertical configuration. There are additional reference markers along the legs, and they can easily be extended to be stable on inclined terrain. PRISM can also simply be placed on surfaces horizontally without deploying the legs if desired. PRISM is a versatile, easy to use, and dust tolerant device designed to streamline science operations on the lunar surface

The H-NS regulator plays a role in the stress induced by carbapenemase expression in acinetobacter baumannii

Disruption of the histone-like nucleoid structuring protein (H-NS) was shown to affect the ability of Gram-negative bacteria to regulate genes associated with virulence, persistence, stress response, quorum sensing, biosynthesis pathways, and cell adhesion. Here, we used the expression of metallo-β-lactamases (MBLs), known to elicit envelope stress by the accumulation of toxic precursors in the periplasm, to interrogate the role of H-NS in Acinetobacter baumannii, together with other stressors. Using a multidrug-resistant A. baumannii strain, we observed that H-NS plays a role in alleviating the stress triggered by MBL toxic precursors and counteracts the effect of DNA-damaging agents, supporting its role in stress response. IMPORTANCE Carbapenem-resistant A. baumannii (CRAB) is recognized as one of the most threatening Gram-negative bacilli. H-NS is known to play a role in controlling the transcription of a variety of different genes, including those associated with the stress response, persistence, and virulence. In the present work, we uncovered a link between the role of H-NS in the A. baumannii stress response and its relationship with the envelope stress response and resistance to DNA-damaging agents. Overall, we posit a new role of H-NS, showing that H-NS serves to endure envelope stress and could also be a mechanism that alleviates the stress induced by MBL expression in A. baumannii. This could be an evolutionary advantage to further resist the action of carbapenems.Fil: Huang, Fanny. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Fitchett, Noelle. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Razo Gutierrez, Chelsea. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Le, Casin. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Martinez, Jasmine. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Ra, Grace. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Lopez, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gonzalez, Lisandro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Sieira, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Vila, Alejandro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Bonomo, Robert A.. Louis Stokes Cleveland Va Medical Center; Estados Unidos. Case Western Reserve University School of Medicine; Estados UnidosFil: Ramirez, Maria Soledad. California State University. College Of Natural Science And Mathematics; Estados Unido

Educational Evaluation, Assessment, & Effectiveness Glossary: A Claremont Graduate University EDUC 445 Fall 2021 Course Publication

This glossary is intended to support professionals who are seeking to understand evaluation, assessment, and effectiveness in the context of K-12 and higher education. The definitions in this e-book represent the shared meanings that were co-created by education professionals in EDUC 445 at the Claremont Graduate University during Fall 2021 under the guidance of Dr. Gwen Garrison, PhD

Live. Tell. Resist.

This edition of First-Gen Voices features the stories and work of 24 first-generation college students at multiple higher education institutions. The aim is to disseminate a story about us, for us, and consequently, the dominant cultures that have yet to learn from our power

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Publisher Copyright: © 2021, The Author(s).Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.Peer reviewe