<p>(A) THP1 cells were infected with <i>S</i>. <i>aureus</i> Newman... more <p>(A) THP1 cells were infected with <i>S</i>. <i>aureus</i> Newman strains at an MOI of 10 for 120 min under non-phagocytosing conditions (extracellular infection; see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004970#sec011" target="_blank">methods</a>), stained with the fixable viability dye eFluor 450, a membrane damage and cell death marker, and analyzed by flow cytometry. Representative histogram is shown. (B-D) THP1 shRNA cells were infected with <i>S</i>. <i>aureus</i> Newman, MOI 10 for 120 min, followed by flow cytometry analysis for maximal eFluor 450 staining (B) and FLICA-1 activation (C). (D) Culture supernatants were collected from extracellular infections and analyzed for IL-1β secretion. (E and F) THP1 cells were infected with GFP-expressing <i>S</i>. <i>aureus</i> Newman strains at an MOI of 10 for 45 min under phagocytosing conditions (intracellular infection; see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004970#sec011" target="_blank">methods</a>). (E) THP1 cells were stained with the fixable viability dye eFluor 450. After infection, THP1 cells were analyzed by flow cytometry and GFP-positive THP1 cells were selected, indicative of <i>S</i>. <i>aureus</i> phagocytosis. Maximal eFluor 450 incorporation was gated among GFP-positive cells, indicative of THP1 death by intracellular <i>S</i>. <i>aureus</i>. Very few cells appear in the first plot corresponding to the background autofluorescent uninfected cells. Representative plots are shown. (F) Representative histogram of GFP fluorescence in <i>S</i>. <i>aureus</i> infected and uninfected THP1 cells is shown. (G-H) Purified primary CD14+ human monocytes were infected with <i>S</i>. <i>aureus</i> Newman and USA300-BK18807 strains, along with respective isogenic <i>lukAB</i> mutants, at an MOI of 5 for 45 min then stained with eFluor 450 (G) or FLICA-1 (H), and analyzed by flow cytometry. Graphs reflect the fraction of cells that were GFP positive. (I-L) THP1 shRNA cells were infected under phagocytosing conditions with <i>S</i>. <i>aureus</i> Newman, MOI 10 for 45 min, and analyzed by flow cytometry for (I) GFP fluorescence indicating phagocytosis; (J) maximal eFluor 450 staining indicating cell death; and (K) FLICA-1 activation. (L) Culture supernatants were collected and analyzed for IL-1β secretion. Bars represent the mean ± standard error of the mean for at least two independent experiments, each performed in triplicate. Experiments with primary cell experiments include at least three independent donors. Asterisks indicate significance at a <i>p</i>-value of ≤ 0.05 by Tukey’s multiple comparisons post-test for 1-way or 2-way ANOVA, as appropriate.</p
... Barcelona, España. Pág.274. 7 Idem. 8 Escamilla de los Santos, José Guadalupe. Introducción a... more ... Barcelona, España. Pág.274. 7 Idem. 8 Escamilla de los Santos, José Guadalupe. Introducción al uso de la computadora e Internet. Ed. Trillas. ... incursión de nuevas tecnologías. 25 Cfr. Serrano Santoyo, Arturo y Martinez Martinez, Evelio La brecha digital. Mitos y Realidades. ...
Racial disparity in disciplinary actions has long been an issue in American public education. The... more Racial disparity in disciplinary actions has long been an issue in American public education. The United States Department of Education has collected data on this for over 35 years. Wright, Weekes and McGlaughlin (2000) claim, “research evidence indicates that those who are at disproportionate risk of exclusion are African-Caribbean boys of both primary and secondary schooling age.” With a closer focus on Michigan public schools, national research will also support data collected on racial disciplinary disparity rates by the American Civil Liberties Union of Michigan. In addition, contributing factors and issues associated with unfair disciplinary sanctions on minorities will be examined to determine their effect on multi-cultural education.
El nuevo cultivo de papa “Enrica” es adecuado para la industria de las hojuelas, fue desarrollado... more El nuevo cultivo de papa “Enrica” es adecuado para la industria de las hojuelas, fue desarrollado en la estación de investigación del INIFAP en la sierra de Arteaga, como resultado de una cruza entre “Atlantic” e “Ireri” en 1991. Este nuevo cultivo tiene un ciclo de crecimiento de 100 a 110 días después de germinación, con diez días más tardía que el cvAtlantic. Enrica tiene tubérculos con yemas superficiales, con piel de color amarillo, de tipo áspera; la pulpa es de color blanco con un 20 a 22% de sólidos solubles y de un 98 a 100% de hojuelas de alta aptitud para la industria. Enrica es de excelente calidad de hojuelas y ha demostrado tener altosnivelesdeproducciónenlasierradeArteaga,Coahuila; Valle de Navidad, Nuevo León; y León, Guanajuato.
In this work we obtain an anisotropic neutron star solution by gravitational decoupling starting ... more In this work we obtain an anisotropic neutron star solution by gravitational decoupling starting from a perfect fluid configuration which has been used to model the compact object PSR J0348+0432. Additionally, we consider the same solution to model the Binary Pulsar SAX J1808.4-3658 and X-ray Binaries Her X-1 and Cen X-3 ones. We study the acceptability conditions and obtain that the MGD-deformed solution obey the same physical requirements as its isotropic counterpart. Finally, we conclude that the most stable solutions, according to the adiabatic index and gravitational cracking criterion, are those with the smallest compactness parameters, namely SAX J1808.4-3658 and Her X-1.
Antigen-presenting cells such as dendritic cells (DCs) fulfill an indispensable role in the devel... more Antigen-presenting cells such as dendritic cells (DCs) fulfill an indispensable role in the development of adaptive immunity by producing proinflammatory cytokines and presenting microbial antigens to lymphocytes to trigger a faster, specific, and long-lasting immune response. Here, we studied the effect of Staphylococcus aureus toxins on human DCs. We discovered that the leukocidin LukAB hinders the development of adaptive immunity by targeting human DCs. The ability of S. aureus to blunt the function of DCs could help explain the high frequency of recurrent S. aureus infections. Taken together, the results from this study suggest that therapeutically targeting the S. aureus leukocidins may boost effective innate and adaptive immune responses by protecting innate leukocytes, enabling proper antigen presentation and T cell activation.
Staphylococcus aureus is a versatile bacterial pathogen that can cause significant disease burden... more Staphylococcus aureus is a versatile bacterial pathogen that can cause significant disease burden and mortality. Like other pathogens, S. aureus must adapt to its environment to produce virulence factors to survive the immune responses evoked by infection. Despite the importance of environmental signals for S. aureus pathogenicity, only a limited number of these signals have been investigated in detail for their ability to modulate virulence. Here we show that pyruvate, a central metabolite, causes alterations in the overall metabolic flux of S. aureus and enhances its pathogenicity. We demonstrate that pyruvate induces the production of virulence factors such as the pore-forming leucocidins and that this induction results in increased virulence of community-acquired methicillin-resistant S. aureus (CA-MRSA) clone USA300. Specifically, we show that an efficient "pyruvate response" requires the activation of S. aureus master regulators AgrAC and SaeRS as well as the ArlRS t...
La determinación de adecuadas láminas de riego es importante para el manejo del agua en la agricu... more La determinación de adecuadas láminas de riego es importante para el manejo del agua en la agricultura y para garantizar la sostenibilidad de los sistemas productivos. El objetivo de este trabajo fue evaluar diferentes láminas de riego calculadas a partir de coeficientes multiplicadores de la evapotranspiración, aplicadas a un cultivo de Estevia (Stevia Rebaudiana Bert.). Se utilizó un diseño completamente aleatorio realizado en condiciones controladas con 5 tratamientos correspondientes a los coeficientes multiplicadores de la evapotranspiración (0,9, 1,0, 1,1, 1,2 y 1,3) a partir de los cuales fueron calculadas las láminas de riego que fueron aplicadas a las plantas. Cada tratamiento tuvo cinco repeticiones para un total de 25 unidades experimentales. Se evaluaron el número de hojas por planta, el peso fresco y seco, el porcentaje de materia seca, la longitud de raíz, el diámetro de tallo, el contenido relativo de agua en las hojas y el rendimiento del cultivo. No se encontraron d...
Staphylococcus aureus is a major human pathogen that imposes a great burden on the healthcare sys... more Staphylococcus aureus is a major human pathogen that imposes a great burden on the healthcare system. In the development of anti-staphylococcal modalities intended to reduce the burden of staphylococcal disease, it is imperative to select appropriate models of S. aureus strains when assessing the efficacy of novel agents. Here, using whole genome sequencing, we reveal that the commonly used strain Newman D2C from the American Type Culture Collection (ATCC) contains mutations that render the strain essentially avirulent. Importantly, Newman D2C is often inaccurately referred to as simply “Newman” in many publications, leading investigators to believe this is the well-described pathogenic strain Newman. This study reveals that Newman D2C carries a stop mutation in the open reading frame of the virulence gene regulator, agrA . In addition, Newman D2C carries a single nucleotide polymorphism in the global virulence regulator saeR that results in loss of protein function. This loss of fu...
Staphylococcus aureus is a major bacterial pathogen that causes disease worldwide. The emergence ... more Staphylococcus aureus is a major bacterial pathogen that causes disease worldwide. The emergence of strains that are resistant to commonly used antibiotics and the failure of vaccine development have resulted in a renewed interest in the pathophysiology of this bacterium. Staphylococcal leukocidins are a family of bi-component pore-forming toxins that are important virulence factors. During the past five years, cellular receptors have been identified for all of the bi-component leukocidins. The identification of the leukocidin receptors explains the cellular tropism and species specificity that is exhibited by these toxins, which has important biological consequences. In this Review, we summarize the recent discoveries that have reignited interest in these toxins and provide an outlook for future research.
Staphylococcus aureus (Sa) is the leading cause of a variety of bacterial infections ranging from... more Staphylococcus aureus (Sa) is the leading cause of a variety of bacterial infections ranging from superficial skin infections to invasive and life threatening diseases such as septic bacteremia, necrotizing pneumonia, and endocarditis. The success of Sa as a human pathogen is due to its ability to adapt to the environment by changing expression, production, or secretion of virulence factors. Although Sa immune evasion is well-studied, the regulation of virulence factors under different nutrient and growth conditions is still not well understood. Here, we used label-free quantitative mass spectrometry to quantify and compare the secreted Sa proteins (i.e. exoproteomes) of master regulator mutants or established reference strains. Different environmental conditions were addressed by growing the bacteria in rich or minimal media at different phases of growth. We observed clear differences in the composition of the exoproteomes depending on the genetic background or growth conditions. T...
Leukocidin ED (LukED) is a bicomponent pore-forming toxin produced by Staphylococcus aureus that ... more Leukocidin ED (LukED) is a bicomponent pore-forming toxin produced by Staphylococcus aureus that lyses host cells by targeting the chemokine receptors CC chemokine receptor type 5 (CCR5), CXCR1, CXCR2, and DARC. In addition to its role as a receptor for LukED, CCR5 is the major coreceptor for primary isolates of human immunodeficiency virus type 1 (HIV-1) and has been extensively studied. To compare how LukED and HIV-1 target CCR5, we analyzed their respective abilities to use CCR5/CCR2b chimeras to mediate cytotoxicity and virus entry. These analyses showed that the second and third extracellular loops (ECL) of CCR5 are necessary and sufficient for LukED to target the receptor and promote cell lysis. In contrast, the second ECL of CCR5 is necessary but not sufficient for HIV-1 infectivity. The analysis of CCR5 point mutations showed that glycine-163 is critical for HIV-1 infectivity, while arginine-274 and aspartic acid-276 are critical for LukED cytotoxicity. Point mutations in EC...
<p>(A) THP1 cells were infected with <i>S</i>. <i>aureus</i> Newman... more <p>(A) THP1 cells were infected with <i>S</i>. <i>aureus</i> Newman strains at an MOI of 10 for 120 min under non-phagocytosing conditions (extracellular infection; see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004970#sec011" target="_blank">methods</a>), stained with the fixable viability dye eFluor 450, a membrane damage and cell death marker, and analyzed by flow cytometry. Representative histogram is shown. (B-D) THP1 shRNA cells were infected with <i>S</i>. <i>aureus</i> Newman, MOI 10 for 120 min, followed by flow cytometry analysis for maximal eFluor 450 staining (B) and FLICA-1 activation (C). (D) Culture supernatants were collected from extracellular infections and analyzed for IL-1β secretion. (E and F) THP1 cells were infected with GFP-expressing <i>S</i>. <i>aureus</i> Newman strains at an MOI of 10 for 45 min under phagocytosing conditions (intracellular infection; see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004970#sec011" target="_blank">methods</a>). (E) THP1 cells were stained with the fixable viability dye eFluor 450. After infection, THP1 cells were analyzed by flow cytometry and GFP-positive THP1 cells were selected, indicative of <i>S</i>. <i>aureus</i> phagocytosis. Maximal eFluor 450 incorporation was gated among GFP-positive cells, indicative of THP1 death by intracellular <i>S</i>. <i>aureus</i>. Very few cells appear in the first plot corresponding to the background autofluorescent uninfected cells. Representative plots are shown. (F) Representative histogram of GFP fluorescence in <i>S</i>. <i>aureus</i> infected and uninfected THP1 cells is shown. (G-H) Purified primary CD14+ human monocytes were infected with <i>S</i>. <i>aureus</i> Newman and USA300-BK18807 strains, along with respective isogenic <i>lukAB</i> mutants, at an MOI of 5 for 45 min then stained with eFluor 450 (G) or FLICA-1 (H), and analyzed by flow cytometry. Graphs reflect the fraction of cells that were GFP positive. (I-L) THP1 shRNA cells were infected under phagocytosing conditions with <i>S</i>. <i>aureus</i> Newman, MOI 10 for 45 min, and analyzed by flow cytometry for (I) GFP fluorescence indicating phagocytosis; (J) maximal eFluor 450 staining indicating cell death; and (K) FLICA-1 activation. (L) Culture supernatants were collected and analyzed for IL-1β secretion. Bars represent the mean ± standard error of the mean for at least two independent experiments, each performed in triplicate. Experiments with primary cell experiments include at least three independent donors. Asterisks indicate significance at a <i>p</i>-value of ≤ 0.05 by Tukey’s multiple comparisons post-test for 1-way or 2-way ANOVA, as appropriate.</p
... Barcelona, España. Pág.274. 7 Idem. 8 Escamilla de los Santos, José Guadalupe. Introducción a... more ... Barcelona, España. Pág.274. 7 Idem. 8 Escamilla de los Santos, José Guadalupe. Introducción al uso de la computadora e Internet. Ed. Trillas. ... incursión de nuevas tecnologías. 25 Cfr. Serrano Santoyo, Arturo y Martinez Martinez, Evelio La brecha digital. Mitos y Realidades. ...
Racial disparity in disciplinary actions has long been an issue in American public education. The... more Racial disparity in disciplinary actions has long been an issue in American public education. The United States Department of Education has collected data on this for over 35 years. Wright, Weekes and McGlaughlin (2000) claim, “research evidence indicates that those who are at disproportionate risk of exclusion are African-Caribbean boys of both primary and secondary schooling age.” With a closer focus on Michigan public schools, national research will also support data collected on racial disciplinary disparity rates by the American Civil Liberties Union of Michigan. In addition, contributing factors and issues associated with unfair disciplinary sanctions on minorities will be examined to determine their effect on multi-cultural education.
El nuevo cultivo de papa “Enrica” es adecuado para la industria de las hojuelas, fue desarrollado... more El nuevo cultivo de papa “Enrica” es adecuado para la industria de las hojuelas, fue desarrollado en la estación de investigación del INIFAP en la sierra de Arteaga, como resultado de una cruza entre “Atlantic” e “Ireri” en 1991. Este nuevo cultivo tiene un ciclo de crecimiento de 100 a 110 días después de germinación, con diez días más tardía que el cvAtlantic. Enrica tiene tubérculos con yemas superficiales, con piel de color amarillo, de tipo áspera; la pulpa es de color blanco con un 20 a 22% de sólidos solubles y de un 98 a 100% de hojuelas de alta aptitud para la industria. Enrica es de excelente calidad de hojuelas y ha demostrado tener altosnivelesdeproducciónenlasierradeArteaga,Coahuila; Valle de Navidad, Nuevo León; y León, Guanajuato.
In this work we obtain an anisotropic neutron star solution by gravitational decoupling starting ... more In this work we obtain an anisotropic neutron star solution by gravitational decoupling starting from a perfect fluid configuration which has been used to model the compact object PSR J0348+0432. Additionally, we consider the same solution to model the Binary Pulsar SAX J1808.4-3658 and X-ray Binaries Her X-1 and Cen X-3 ones. We study the acceptability conditions and obtain that the MGD-deformed solution obey the same physical requirements as its isotropic counterpart. Finally, we conclude that the most stable solutions, according to the adiabatic index and gravitational cracking criterion, are those with the smallest compactness parameters, namely SAX J1808.4-3658 and Her X-1.
Antigen-presenting cells such as dendritic cells (DCs) fulfill an indispensable role in the devel... more Antigen-presenting cells such as dendritic cells (DCs) fulfill an indispensable role in the development of adaptive immunity by producing proinflammatory cytokines and presenting microbial antigens to lymphocytes to trigger a faster, specific, and long-lasting immune response. Here, we studied the effect of Staphylococcus aureus toxins on human DCs. We discovered that the leukocidin LukAB hinders the development of adaptive immunity by targeting human DCs. The ability of S. aureus to blunt the function of DCs could help explain the high frequency of recurrent S. aureus infections. Taken together, the results from this study suggest that therapeutically targeting the S. aureus leukocidins may boost effective innate and adaptive immune responses by protecting innate leukocytes, enabling proper antigen presentation and T cell activation.
Staphylococcus aureus is a versatile bacterial pathogen that can cause significant disease burden... more Staphylococcus aureus is a versatile bacterial pathogen that can cause significant disease burden and mortality. Like other pathogens, S. aureus must adapt to its environment to produce virulence factors to survive the immune responses evoked by infection. Despite the importance of environmental signals for S. aureus pathogenicity, only a limited number of these signals have been investigated in detail for their ability to modulate virulence. Here we show that pyruvate, a central metabolite, causes alterations in the overall metabolic flux of S. aureus and enhances its pathogenicity. We demonstrate that pyruvate induces the production of virulence factors such as the pore-forming leucocidins and that this induction results in increased virulence of community-acquired methicillin-resistant S. aureus (CA-MRSA) clone USA300. Specifically, we show that an efficient "pyruvate response" requires the activation of S. aureus master regulators AgrAC and SaeRS as well as the ArlRS t...
La determinación de adecuadas láminas de riego es importante para el manejo del agua en la agricu... more La determinación de adecuadas láminas de riego es importante para el manejo del agua en la agricultura y para garantizar la sostenibilidad de los sistemas productivos. El objetivo de este trabajo fue evaluar diferentes láminas de riego calculadas a partir de coeficientes multiplicadores de la evapotranspiración, aplicadas a un cultivo de Estevia (Stevia Rebaudiana Bert.). Se utilizó un diseño completamente aleatorio realizado en condiciones controladas con 5 tratamientos correspondientes a los coeficientes multiplicadores de la evapotranspiración (0,9, 1,0, 1,1, 1,2 y 1,3) a partir de los cuales fueron calculadas las láminas de riego que fueron aplicadas a las plantas. Cada tratamiento tuvo cinco repeticiones para un total de 25 unidades experimentales. Se evaluaron el número de hojas por planta, el peso fresco y seco, el porcentaje de materia seca, la longitud de raíz, el diámetro de tallo, el contenido relativo de agua en las hojas y el rendimiento del cultivo. No se encontraron d...
Staphylococcus aureus is a major human pathogen that imposes a great burden on the healthcare sys... more Staphylococcus aureus is a major human pathogen that imposes a great burden on the healthcare system. In the development of anti-staphylococcal modalities intended to reduce the burden of staphylococcal disease, it is imperative to select appropriate models of S. aureus strains when assessing the efficacy of novel agents. Here, using whole genome sequencing, we reveal that the commonly used strain Newman D2C from the American Type Culture Collection (ATCC) contains mutations that render the strain essentially avirulent. Importantly, Newman D2C is often inaccurately referred to as simply “Newman” in many publications, leading investigators to believe this is the well-described pathogenic strain Newman. This study reveals that Newman D2C carries a stop mutation in the open reading frame of the virulence gene regulator, agrA . In addition, Newman D2C carries a single nucleotide polymorphism in the global virulence regulator saeR that results in loss of protein function. This loss of fu...
Staphylococcus aureus is a major bacterial pathogen that causes disease worldwide. The emergence ... more Staphylococcus aureus is a major bacterial pathogen that causes disease worldwide. The emergence of strains that are resistant to commonly used antibiotics and the failure of vaccine development have resulted in a renewed interest in the pathophysiology of this bacterium. Staphylococcal leukocidins are a family of bi-component pore-forming toxins that are important virulence factors. During the past five years, cellular receptors have been identified for all of the bi-component leukocidins. The identification of the leukocidin receptors explains the cellular tropism and species specificity that is exhibited by these toxins, which has important biological consequences. In this Review, we summarize the recent discoveries that have reignited interest in these toxins and provide an outlook for future research.
Staphylococcus aureus (Sa) is the leading cause of a variety of bacterial infections ranging from... more Staphylococcus aureus (Sa) is the leading cause of a variety of bacterial infections ranging from superficial skin infections to invasive and life threatening diseases such as septic bacteremia, necrotizing pneumonia, and endocarditis. The success of Sa as a human pathogen is due to its ability to adapt to the environment by changing expression, production, or secretion of virulence factors. Although Sa immune evasion is well-studied, the regulation of virulence factors under different nutrient and growth conditions is still not well understood. Here, we used label-free quantitative mass spectrometry to quantify and compare the secreted Sa proteins (i.e. exoproteomes) of master regulator mutants or established reference strains. Different environmental conditions were addressed by growing the bacteria in rich or minimal media at different phases of growth. We observed clear differences in the composition of the exoproteomes depending on the genetic background or growth conditions. T...
Leukocidin ED (LukED) is a bicomponent pore-forming toxin produced by Staphylococcus aureus that ... more Leukocidin ED (LukED) is a bicomponent pore-forming toxin produced by Staphylococcus aureus that lyses host cells by targeting the chemokine receptors CC chemokine receptor type 5 (CCR5), CXCR1, CXCR2, and DARC. In addition to its role as a receptor for LukED, CCR5 is the major coreceptor for primary isolates of human immunodeficiency virus type 1 (HIV-1) and has been extensively studied. To compare how LukED and HIV-1 target CCR5, we analyzed their respective abilities to use CCR5/CCR2b chimeras to mediate cytotoxicity and virus entry. These analyses showed that the second and third extracellular loops (ECL) of CCR5 are necessary and sufficient for LukED to target the receptor and promote cell lysis. In contrast, the second ECL of CCR5 is necessary but not sufficient for HIV-1 infectivity. The analysis of CCR5 point mutations showed that glycine-163 is critical for HIV-1 infectivity, while arginine-274 and aspartic acid-276 are critical for LukED cytotoxicity. Point mutations in EC...
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