Supramolecular structure in the membrane of Staphylococcus aureus

The fundamental processes of life are organized and based on common basic principles. Molecular organizers, often interacting with the membrane, capitalize on cellular polarity to precisely orientate essential processes. The study of organisms lacking apparent polarity or known cellular organizers (e.g., the bacterium Staphylococcus aureus) may enable the elucidation of the primal organizational drive in biology. How does a cell choose from infinite locations in its membrane? We have discovered a structure in the S. aureus membrane that organizes processes indispensable for life and can arise spontaneously from the geometric constraints of protein complexes on membranes. Building on this finding, the most basic cellular positioning system to optimize biological processes, known molecular coordinators could introduce further levels of complexity. All life demands the temporal and spatial control of essential biological functions. In bacteria, the recent discovery of coordinating elements provides a framework to begin to explain cell growth and division. Here we present the discovery of a supramolecular structure in the membrane of the coccal bacterium Staphylococcus aureus, which leads to the formation of a large-scale pattern across the entire cell body; this has been unveiled by studying the distribution of essential proteins involved in lipid metabolism (PlsY and CdsA). The organization is found to require MreD, which determines morphology in rod-shaped cells. The distribution of protein complexes can be explained as a spontaneous pattern formation arising from the competition between the energy cost of bending that they impose on the membrane, their entropy of mixing, and the geometric constraints in the system. Our results provide evidence for the existence of a self-organized and nonpercolating molecular scaffold involving MreD as an organizer for optimal cell function and growth based on the intrinsic self-assembling properties of biological molecules

Surfactant-free purification of membrane protein complexes from bacteria: application to the staphylococcal penicillin-binding protein complex PBP2/PBP2a

Surfactant-mediated removal of proteins from biomembranes invariably results in partial or complete loss of function and disassembly of multi-protein complexes. We determined the capacity of styrene-co-maleic acid (SMA) co-polymer to remove components of the cell division machinery from the membrane of drug-resistant staphylococcal cells. SMA-lipid nanoparticles solubilized FtsZ-PBP2-PBP2a complexes from intact cells, demonstrating the close physical proximity of these proteins within the lipid bilayer. Exposure of bacteria to (-)-epicatechin gallate, a polyphenolic agent that abolishes β-lactam resistance in staphylococci, disrupted the association between PBP2 and PBP2a. Thus, SMA purification provides a means to remove native integral membrane protein assemblages with minimal physical disruption and shows promise as a tool for the interrogation of molecular aspects of bacterial membrane protein structure and function

Pharmaceutical strategies for the treatment of bacterial biofilms in chronic wounds

Biofilms are sessile communities of microorganisms, mainly bacteria, that grow on biotic and abiotic surfaces. These microorganisms are embedded within an extracellular polymeric substance that provides enhanced protection from antimicrobials. Chronic wounds provide an ideal habitat for biofilm formation. Bacteria can easily attach to wound debris and can infect the wound due to an impaired host immune response. This review highlights the mechanism of biofilm formation and the role of biofilms in the pathophysiology of chronic wounds. Our major focus is on various formulation strategies and delivery systems that are employed to eradicate or disperse biofilms, thereby effectively managing acute and chronic wounds. We also discuss clinical research that has studied or is studying the treatment of biofilm-infected chronic wounds

Global Positioning System Analysis of Physical Demands in Elite Women’s Beach Handball Players in an Official Spanish Championship

This cross-sectional study aims to analyze the physical demands of elite beach handball players during an official competition. Nine elite female (mean age: 24.6 ± 4.0 years; body weight: 62.4 ± 4.6 kg; body height: 1.68 ± 0.059 m; training experience: 5 years; training: 6 h/week) beach handball players of the Spanish National Team were recruited for this study. A Global Positioning System was incorporated on each player’s back to analyze their movement patterns. Speed and distance were recorded at a sampling frequency of 15 Hz, whereas acceleration was recorded at 100 Hz by means of a built-in triaxial accelerometer. The main finding of the study is that 53% of the distance travelled is done at speeds between 1.5 and 5 km/h and 30% of the distance is between 9 and 13 km/h (83% of the total distance covered), which shows the intermittent efforts that beach handball involves at high intensity, as reflected in the analysis of the internal load with 62.82 ± 14.73% of the game time above 80% of the maximum heart rate. These data help to orientate training objectives to the physical demands required by the competition in order to optimize the players’ performance

Comprehensive identification of essential Staphylococcus aureus genes using Transposon-Mediated Differential Hybridisation (TMDH).

BACKGROUND: In recent years there has been an increasing problem with Staphylococcus aureus strains that are resistant to treatment with existing antibiotics. An important starting point for the development of new antimicrobial drugs is the identification of "essential" genes that are important for bacterial survival and growth. RESULTS: We have developed a robust microarray and PCR-based method, Transposon-Mediated Differential Hybridisation (TMDH), that uses novel bioinformatics to identify transposon inserts in genome-wide libraries. Following a microarray-based screen, genes lacking transposon inserts are re-tested using a PCR and sequencing-based approach. We carried out a TMDH analysis of the S. aureus genome using a large random mariner transposon library of around a million mutants, and identified a total of 351 S. aureus genes important for survival and growth in culture. A comparison with the essential gene list experimentally derived for Bacillus subtilis highlighted interesting differences in both pathways and individual genes. CONCLUSION: We have determined the first comprehensive list of S. aureus essential genes. This should act as a useful starting point for the identification of potential targets for novel antimicrobial compounds. The TMDH methodology we have developed is generic and could be applied to identify essential genes in other bacterial pathogens.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Stellar Population gradients in galaxy discs from the CALIFA survey

While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at $\sim$2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&

Phenotypic and molecular characterization of IMP-producing Enterobacterales in Spain: Predominance of IMP-8 in Klebsiella pneumoniae and IMP-22 in Enterobacter roggenkampii

Objectives: Little is known about IMP-producing Enterobacterales (IMP-Ent) in Europe. We analyzed at genomic and phenotypic level IMP-Ent isolates circulating in Spain in a 9-year period. Materials and methods: IMP-Ent isolates submitted to our reference laboratory were included. Antibiotic susceptibility was performed using microdilution method (EUCAST), and IMP-carbapenemase activity was measured with carbapenemase inhibitors, the β-CARBA method, the modified Hodge test (MHT), and the modified carbapenemase inhibition method (mCIM). All isolates collected were sequenced for high-resolution single-nucleotide polymorphism (SNP) typing, core genome multilocus sequence typing (cgMLST), and resistome analysis. Results: Fifty IMP-Ent isolates, collected from 19 hospitals in 13 Spanish provinces, were detected: Klebsiella pneumoniae (IMP-Kpn) (24; 48%), Enterobacter roggenkampii (13; 26%), Enterobacter hormaechei (8, 16%), Klebsiella oxytoca (two; 4%), Enterobacter asburiae (one, 2%), Serratia marcescens (one; 2%) and Escherichia coli (one; 2%). All isolates were positive by the MHT and β-CARBA tests; 48 (96%) were mCIM positive; 12 (24%) and 26 (52%) displayed positive inhibition with dipicolinic (meropenem) and EDTA (ertapenem), respectively. Five IMP-carbapenemase types were identified: IMP-8 (22; 44%), IMP-22 (17; 34%), IMP-13 (7; 14%), IMP-28 (two; 4%), and IMP-15 (two; 4%), predominating IMP-8 in K. pneumoniae and IMP-22 in E. roggenkampii. IMP-28 was exclusively identified in K. oxytoca and IMP-15 in E. hormaechei. Predominant STs were ST405 (29.2%), ST15 (25%) and ST464 (20.8%) in IMP-Kpn; ST96 (100%) in E. roggenkampii and ST182 (62.5%) in E. hormachei. Colistin and amikacin were the most active non-carbapenem antibiotics against IMP-Ent. Conclusion: IMP-Ent isolates remain infrequent in Spain, although in recent years have been circulating causing nosocomial outbreaks, being IMP-8-producing K. pneumoniae and IMP-22-producing E. roggenkampii the most frequently detected in this study. Inhibition with EDTA or dipicolinic acid presented false negative results in some IMP-producing strains. Active microbiological and molecular surveillance is essential for a better comprehension and control of IMP-Ent dissemination.This research was supported by grants from the Instituto de Salud Carlos III (numbers PI18CIII/00030 and PI21CIII/00039). This research was also supported by CIBER-Consorcio Centro de Investigación Biomédica en Red (CB21/13/00095 and CB21/13/000968), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea – NextGenerationEU. This work was supported by Plan Nacional de I + D + i 2013–2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía, Industria y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD16CIII/0004/0002 and REIPI RD16/0016/0007) and co-financed by the European Development Regional Fund (EDRF), “A way to achieve Europe,” Operative program Intelligent Growth, 2014–2020.S

El desarrollo municipal, factor estratégico en el posicionamiento de México en los escenarios políticos y sociales del siglo XXI

LA DEMOCRACIA COMO GOBERNABILIDAD IMPLICA, EN UN PRIMER MOMENTO, establecer una revisión periódica del papel interventor del Estado, por ser éste el principal factor de estabilidad y desarrollo democrático. En un segundo punto, de forma simultánea al estudio del papel del Estado en la conformación de un ambiente de estabilidad, crecimiento, desarrollo, orden y gobernabilidad, merece especial atención el papel y funciones cumplidas tradicionalmente por sus ámbitos de gobierno, como instancias que son fundamentales para la transición, democratización, liberalización y para la propia gobernabilidad

ASPECTOS SOBRE AS INFECÇÕES DE SÍTIO CIRÚRGICO DURANTE CIRURGIAS LIMPAS: UMA REVISÃO DE LITERATURA

Objective: To review the literature in order to highlight the main causes of surgical site infection in previously healthy people during clean surgeries, as well as the factor of highest prevalence in infections by multidrug-resistant bacteria, in the sterile surgical context. Methodology: Studies published on the SCIELO, MEDLINE, PUBMED, and LILACS data platforms were selected from 2016 and 2022. The descriptors used were: "Surgical wound infection"; "Prevalence"; "Intraoperative Care"; "Multiple Bacterial Pharmacoresistance" and "Surgical Operative Procedures"; in associated and isolated form . Data collection took place between March and April 2022. Results: The causes of surgical site infections are varied and its most common etiologic agent is Staphylococcus aureus. Moreover, the main risk factors are pre-existing chronic diseases, smoking, blood transfusion and lack of preoperative care, and most cases of SSI occur in countries with low and middle income populations. Final considerations: To reduce the occurrence of SSI, the increase in microbial resistance due to inadequate antibiotic prophylaxis and improper infection control must be combated. It is necessary to implement and carry out health surveillance actions, educate and train professionals, and maintain aseptic techniques.Objetivo: Revisar la literatura para resaltar las principales causas de infección del sitio quirúrgico en personas previamente sanas durante cirugías limpias, así como el factor más prevalente en las infecciones por bacterias multirresistentes, en el contexto quirúrgico estéril. Metodología: Se seleccionaron estudios publicados en las plataformas de datos SCIELO, MEDLINE, PUBMED y LILACS entre 2016 y 2022. Los descriptores utilizados fueron: “Infección de herida quirúrgica”; "Predominio"; "Cuidados intraoperatorios"; "Farmacoresistencia Bacteriana Múltiple" y "Procedimientos Quirúrgicos Operativos"; de forma asociada y aislada. La recolección de datos se realizó entre marzo y abril de 2022. Resultados: Las causas de las infecciones del sitio quirúrgico son variadas y el agente etiológico más frecuente es Staphylococcus aureus. Además, los principales factores de riesgo son las enfermedades crónicas preexistentes, el tabaquismo, las transfusiones de sangre y la falta de cuidados preoperatorios, y la mayoría de los casos de SSI ocurren en países con una mayoría de población de ingresos bajos y medios. Consideraciones finales: Para reducir la ocurrencia de ISQ, se debe combatir el aumento de la resistencia microbiana debido a la inadecuada profilaxis con antibióticos y al inadecuado control de infecciones. Es necesario implementar y realizar acciones de vigilancia de la salud, educación y capacitación de los profesionales, además del mantenimiento de las técnicas de asepsia.Objetivo: Revisar a literatura a fim de evidenciar as principais causas de infecção de sítio cirúrgico em pessoas previamente hígidas durante cirurgias limpas, bem como o fator de maior prevalência em infecções por bactérias multirresistentes, no contexto cirúrgico estéril. Metodologia: Foram selecionados estudos publicados nas plataformas de dados SCIELO, MEDLINE, PUBMED e LILACS, no período de 2016 e 2022. Os descritores utilizados foram: "Infecção de ferida cirúrgica"; "Prevalência"; "Cuidados intraoperatórios"; "Farmacorresistência bacteriana múltipla" e "Procedimentos Cirúrgicos Operatórios"; de forma associada e isolada . A coleta de dados se deu entre março e abril de 2022. Resultados: São variadas as causas de infecções em sítio cirúrgico e seu agente etiológico mais comum é o Staphylococcus aureus. Ademais, os principais fatores de risco são as doenças crônicas pré-existentes, tabagismo, realização de transfusão sanguínea e ausência de pré-operatório, sendo que a maioria dos casos de ISC ocorre em países de maioria populacional de baixa e média renda. Considerações Finais: Para a diminuição da ocorrência de ISCs, deve-se combater o aumento da resistência microbiana por profilaxia inadequada com antibióticos e o controle impróprio de infecções. Sendo necessária a implantação e realização de ações de vigilância em saúde, educação e treinamento de profissionais, além da manutenção de técnicas de assepsia.Objetivo: Revisar a literatura a fim de evidenciar as principais causas de infecção de sítio cirúrgico em pessoas previamente hígidas durante cirurgias limpas, bem como o fator de maior prevalência em infecções por bactérias multirresistentes, no contexto cirúrgico estéril. Metodologia: Foram selecionados estudos publicados nas plataformas de dados SCIELO, MEDLINE, PUBMED e LILACS, no período de 2016 e 2022. Os descritores utilizados foram: "Infecção de ferida cirúrgica"; "Prevalência"; "Cuidados intraoperatórios"; "Farmacorresistência bacteriana múltipla" e "Procedimentos Cirúrgicos Operatórios"; de forma associada e isolada . A coleta de dados se deu entre março e abril de 2022. Resultados: São variadas as causas de infecções em sítio cirúrgico e seu agente etiológico mais comum é o Staphylococcus aureus. Ademais, os principais fatores de risco são as doenças crônicas pré-existentes, tabagismo, realização de transfusão sanguínea e ausência de pré-operatório, sendo que a maioria dos casos de ISC ocorre em países de maioria populacional de baixa e média renda. Considerações Finais: Para a diminuição da ocorrência de ISCs, deve-se combater o aumento da resistência microbiana por profilaxia inadequada com antibióticos e o controle impróprio de infecções. Sendo necessária a implantação e realização de ações de vigilância em saúde, educação e treinamento de profissionais, além da manutenção de técnicas de assepsia

ASPECTOS SOBRE AS INFECÇÕES DE SÍTIO CIRÚRGICO DURANTE CIRURGIAS LIMPAS: UMA REVISÃO DE LITERATURA

Objective: To review the literature in order to highlight the main causes of surgical site infection in previously healthy people during clean surgeries, as well as the factor of highest prevalence in infections by multidrug-resistant bacteria, in the sterile surgical context. Methodology: Studies published on the SCIELO, MEDLINE, PUBMED, and LILACS data platforms were selected from 2016 and 2022. The descriptors used were: "Surgical wound infection"; "Prevalence"; "Intraoperative Care"; "Multiple Bacterial Pharmacoresistance" and "Surgical Operative Procedures"; in associated and isolated form . Data collection took place between March and April 2022. Results: The causes of surgical site infections are varied and its most common etiologic agent is Staphylococcus aureus. Moreover, the main risk factors are pre-existing chronic diseases, smoking, blood transfusion and lack of preoperative care, and most cases of SSI occur in countries with low and middle income populations. Final considerations: To reduce the occurrence of SSI, the increase in microbial resistance due to inadequate antibiotic prophylaxis and improper infection control must be combated. It is necessary to implement and carry out health surveillance actions, educate and train professionals, and maintain aseptic techniques.Objetivo: Revisar la literatura para resaltar las principales causas de infección del sitio quirúrgico en personas previamente sanas durante cirugías limpias, así como el factor más prevalente en las infecciones por bacterias multirresistentes, en el contexto quirúrgico estéril. Metodología: Se seleccionaron estudios publicados en las plataformas de datos SCIELO, MEDLINE, PUBMED y LILACS entre 2016 y 2022. Los descriptores utilizados fueron: “Infección de herida quirúrgica”; "Predominio"; "Cuidados intraoperatorios"; "Farmacoresistencia Bacteriana Múltiple" y "Procedimientos Quirúrgicos Operativos"; de forma asociada y aislada. La recolección de datos se realizó entre marzo y abril de 2022. Resultados: Las causas de las infecciones del sitio quirúrgico son variadas y el agente etiológico más frecuente es Staphylococcus aureus. Además, los principales factores de riesgo son las enfermedades crónicas preexistentes, el tabaquismo, las transfusiones de sangre y la falta de cuidados preoperatorios, y la mayoría de los casos de SSI ocurren en países con una mayoría de población de ingresos bajos y medios. Consideraciones finales: Para reducir la ocurrencia de ISQ, se debe combatir el aumento de la resistencia microbiana debido a la inadecuada profilaxis con antibióticos y al inadecuado control de infecciones. Es necesario implementar y realizar acciones de vigilancia de la salud, educación y capacitación de los profesionales, además del mantenimiento de las técnicas de asepsia.Objetivo: Revisar a literatura a fim de evidenciar as principais causas de infecção de sítio cirúrgico em pessoas previamente hígidas durante cirurgias limpas, bem como o fator de maior prevalência em infecções por bactérias multirresistentes, no contexto cirúrgico estéril. Metodologia: Foram selecionados estudos publicados nas plataformas de dados SCIELO, MEDLINE, PUBMED e LILACS, no período de 2016 e 2022. Os descritores utilizados foram: "Infecção de ferida cirúrgica"; "Prevalência"; "Cuidados intraoperatórios"; "Farmacorresistência bacteriana múltipla" e "Procedimentos Cirúrgicos Operatórios"; de forma associada e isolada . A coleta de dados se deu entre março e abril de 2022. Resultados: São variadas as causas de infecções em sítio cirúrgico e seu agente etiológico mais comum é o Staphylococcus aureus. Ademais, os principais fatores de risco são as doenças crônicas pré-existentes, tabagismo, realização de transfusão sanguínea e ausência de pré-operatório, sendo que a maioria dos casos de ISC ocorre em países de maioria populacional de baixa e média renda. Considerações Finais: Para a diminuição da ocorrência de ISCs, deve-se combater o aumento da resistência microbiana por profilaxia inadequada com antibióticos e o controle impróprio de infecções. Sendo necessária a implantação e realização de ações de vigilância em saúde, educação e treinamento de profissionais, além da manutenção de técnicas de assepsia.Objetivo: Revisar a literatura a fim de evidenciar as principais causas de infecção de sítio cirúrgico em pessoas previamente hígidas durante cirurgias limpas, bem como o fator de maior prevalência em infecções por bactérias multirresistentes, no contexto cirúrgico estéril. Metodologia: Foram selecionados estudos publicados nas plataformas de dados SCIELO, MEDLINE, PUBMED e LILACS, no período de 2016 e 2022. Os descritores utilizados foram: "Infecção de ferida cirúrgica"; "Prevalência"; "Cuidados intraoperatórios"; "Farmacorresistência bacteriana múltipla" e "Procedimentos Cirúrgicos Operatórios"; de forma associada e isolada . A coleta de dados se deu entre março e abril de 2022. Resultados: São variadas as causas de infecções em sítio cirúrgico e seu agente etiológico mais comum é o Staphylococcus aureus. Ademais, os principais fatores de risco são as doenças crônicas pré-existentes, tabagismo, realização de transfusão sanguínea e ausência de pré-operatório, sendo que a maioria dos casos de ISC ocorre em países de maioria populacional de baixa e média renda. Considerações Finais: Para a diminuição da ocorrência de ISCs, deve-se combater o aumento da resistência microbiana por profilaxia inadequada com antibióticos e o controle impróprio de infecções. Sendo necessária a implantação e realização de ações de vigilância em saúde, educação e treinamento de profissionais, além da manutenção de técnicas de assepsia