Can habits and behaviors predict colonization by community-associated MRSA in patients admitted to a Brazilian hospital?

This study aimed to identify factors associated with colonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in adult patients admitted to a Brazilian hospital. This is a cross-sectional study, in which patients underwent a nasal swab and were asked about hygiene behavior, habits, and clinical history. Among the 702 patients, 180 (25.6%) had S. aureus and 21 (2.9%) MRSA. The factors associated with MRSA colonization were attending a gym (OR 4.71; 95% CI; 1.42 - 15.06), smoking habit in the last year (OR 2.37; 95% CI; 0.88 - 6.38), previous hospitalization (OR 2.18; CI 95%; 0.89 - 5.25), and shared personal hygiene items (OR 1.99; 95% CI; 0.71 - 5.55). At the time of admission, colonization by CA-MRSA isolates was higher than that found in the general population. This can be an important public health problem, already endemic in hospitals, whose factors such as those associated with habits (smoking cigarettes) and behaviors (team sports practice and activities in gyms) have been strongly highlighted. These findings may help developing infection control policies, allowing targeting patients on higher-risk populations for MRSA colonization.

Luz UVC como estratégia de desinfecção do ar e superfícies hospitalares / Luz UV-C como estrategia de desinfección del aire y superficies hospitalarias / UVC light as a strategy for disinfection of hospital air and surfaces

Resumo Objetivo Avaliar a eficácia antimicrobiana de um dispositivo fixo emissor de luz UV-C na desinfecção de diferentes superfícies do ambiente hospitalar e sua eficácia antifúngica na qualidade do ar. Métodos Estudo quase-experimental realizado em uma unidade de internação hospitalar, que utilizou o Bioamostrador de ar Andersen® de seis estágios para análise do ar; e na avaliação das superfícies, utilizaram-se três suspensões de microrganismos (Acinetobacter sp. MDR, Escherichia coli e Klebsiella pneumoniae produtora de KPC) para contaminar o ambiente. Para ambos foram feitas coletas pré (controle) e pós-acionamento da luz UV-C (teste). Resultados Na avaliação do ar houve uma redução importante da contagem de colônias após a luz UV-C e não foram encontrados fungos patogênicos ou toxigênicos em nenhum dos dois momentos. Em relação à desinfecção das superfícies, nenhum crescimento bacteriano foi observado após a intervenção da luz, demonstrando 100% de inativação bacteriana nas condições testadas. Conclusão A utilização da tecnologia com emissão de luz UV-C fixa foi eficaz e pode ser considerada uma intervenção promissora para protocolos de desinfecção de superfícies hospitalares.

Resumen Objetivo Evaluar la eficacia antimicrobiana de un dispositivo fijo emisor de luz UV-C para la desinfección de diferentes superficies del ambiente hospitalario y su eficacia antifúngica en la calidad del aire. Métodos Estudio cuasi experimental realizado en una unidad de internación hospitalaria, en que se utilizó el biomuestreador de aire Andersen® de seis etapas para el análisis del aire. En el análisis de las superficies, se utilizaron tres suspensiones de microorganismos (Acinetobacter sp. MDR, Escherichia coli y Klebsiella pneumoniae productora de KPC) para contaminar el ambiente. En ambos se tomó una muestra antes (control) y después de accionar la luz UV-C (prueba). Resultados En el análisis del aire hubo una reducción importante del recuento de colonias después de la luz UV-C y no se encontraron hongos patógenos ni toxigénicos en ninguno de los dos momentos. Con relación a la desinfección de las superficies, no se observó ningún crecimiento bacteriano después de la intervención de la luz, lo que demuestra un 100 % de inactivación bacteriana en las condiciones analizadas. Conclusión El uso de la tecnología con emisión de luz UV-C fija fue eficaz y puede ser considerada una intervención prometedora para protocolos de desinfección de superficies hospitalarias.

Abstract Objective To evaluate a fixed UV-C light emitting device for its antimicrobial effectiveness in the disinfection of distinct surfaces and its antifungal effectiveness on air quality in the hospital environment. Methods This quasi-experimental study was conducted in a hospital inpatient unit, in which a six-stage air Biosampler (Andersen®) was used for air analysis. In the evaluation of surfaces, three suspensions of microorganisms (Acinetobacter sp. multidrug-resistant, Escherichia coli, and KPC-producing Klebsiella pneumoniae) were used to contaminate the environment. In both evaluations, pre- (control) and post-activation of UV-C light (test) collections were made. Results In the air evaluation, an important reduction was observed in the colony count after irradiation with UV-C light, and pathogenic or toxigenic fungi were not found in either of the two moments. Regarding the disinfection of surfaces, no bacterial growth was observed after the application of UV-C light, showing 100% bacterial inactivation under the tested conditions. Conclusion The use of fixed UV-C light emission technology was effective and can be considered a promising intervention for hospital surface disinfection protocols.

Avaliação dos processos de higienização hospitalar através do lean healthcare: estratégias para segurança e qualidade do cuidado em saúde / Evaluation of Hospital hygiene processes through Lean Healthcare: strategies for safety and quality of health care

Este estudo teve o objetivo de indicar estratégias de melhoria contínua dos processos de higienização de superfícies hospitalares de uma unidade de terapia intensiva através de abordagem Lean Healthcare. É um estudo de caráter exploratório, descritivo, observacional, em que a coleta de dados ocorreu no período de julho de 2021 a janeiro de 2022 por observações in loco e entrevistas com cinco profissionais do serviço de higienização. Utilizaram-se as ferramentas: Gemba, mapeamento de fluxo de valor e diagrama do espaguete adaptado, árvore da realidade atual (ARA), Matriz GUT, Matriz de esforço impacto e 5W2H, para levantar, analisar problemas e propor intervenções para futuras melhorias. Como indicador de qualidade do processo optou-se pelo uso de marcadores fluorescentes com análise de 10 higienizações terminais. Para tratamento dos dados utilizou-se o software Miro®, o Excel® e uma planta física projetada da área. Atendeu parcialmente às diretrizes SQUIRE 2.0 através do uso de ferramentas Lean com foco na melhoria da qualidade, segurança e cuidados em saúde. Identificou-se o uso inadequado de desinfetante e de equipamento de proteção individual, manejo incorreto de perfurocortante, além da ordem, técnica e movimentos incorretos. O percentual do indicador completo/correto do processo de higienização terminal foi de 70%. Além disso, o teste do marcador fluorescente demonstrou apenas 33% de conformidade da limpeza, concluindo que não houve padrão em nenhuma higienização terminal observada. Além disso, identificou-se inadequações que comprometeram a qualidade do processo de limpeza e desinfecção de leitos, o que é uma premissa básica para otimização do trabalho e sustentabilidade institucional. Nesse contexto, os resultados sumarizados neste estudo demonstraram que a utilização das ferramentas Lean contribuiu para a proposição de intervenções objetivas baseadas nos reais problemas identificados e analisados.

This study aimed to adjust strategies for continuous improvement of hospital equipment management processes in an intensive care unit through Lean Healthcare approch. It is exploratory, descriptive, observational in which data collection took place from July 2021 to January 2022 through on-site observations and interviews with five professionals from the hygiene service. Use as tools: Gemba, value mapping and adapted flow flow, current reality tree (ARA), GUT Matrix, Impact Effort Matrix and 5W2H, to raise, analyze problems and propose interventions for future improvements. As an indicator of process quality, we chose to use fluorescent indicators with analysis of 10 cleaning terminals. To use Miro® software, Excel® and an area data treatment plant. Attended health services. Inadequate use of disinfectant and personal protective equipment, inadequate sharps, in addition to incorrect order, techniques and movements were identified. The percentage of the indicator/correct in the evaluation process of the complete terminal was 70%. In addition, the fluorescent marker test is only 33% cleaning compliance, concluding that there was no pattern in any terminal cleaning observed. In addition, the necessary adaptations to guarantee the sustainability and quality of the bed cleaning process, which is basic for the optimization of work and institutional infection. In these summaries, in this study, the results are calculated and the use of Lean tools designed to propose objective interventions in real problems and estimates.

Quint points lattice in a driven Belousov-Zhabotinsky reaction model.

We report the discovery of a regular lattice of exceptional quint points in a periodically driven oscillator, namely, in the frequency-amplitude control parameter space of a photochemically periodically perturbed ruthenium-catalyzed Belousov-Zhabotinsky reaction model. Quint points are singular boundary points where five distinct stable oscillatory phases coalesce. While spikes of the activator show a smooth and continuous variation, the spikes of the inhibitor show an intricate but regular branching into a myriad of stable phases that have fivefold contact points. Such boundary points form a wide parameter lattice as a function of the frequency and amplitude of light absorption. These findings revise current knowledge about the topology of the control parameter space of a celebrated prototypical example of an oscillating chemical reaction.

Single cell plasticity and population coding stability in auditory thalamus upon associative learning.

Cortical and limbic brain areas are regarded as centres for learning. However, how thalamic sensory relays participate in plasticity upon associative learning, yet support stable long-term sensory coding remains unknown. Using a miniature microscope imaging approach, we monitor the activity of populations of auditory thalamus (medial geniculate body) neurons in freely moving mice upon fear conditioning. We find that single cells exhibit mixed selectivity and heterogeneous plasticity patterns to auditory and aversive stimuli upon learning, which is conserved in amygdala-projecting medial geniculate body neurons. Activity in auditory thalamus to amygdala-projecting neurons stabilizes single cell plasticity in the total medial geniculate body population and is necessary for fear memory consolidation. In contrast to individual cells, population level encoding of auditory stimuli remained stable across days. Our data identifies auditory thalamus as a site for complex neuronal plasticity in fear learning upstream of the amygdala that is in an ideal position to drive plasticity in cortical and limbic brain areas. These findings suggest that medial geniculate body's role goes beyond a sole relay function by balancing experience-dependent, diverse single cell plasticity with consistent ensemble level representations of the sensory environment to support stable auditory perception with minimal affective bias.

Phase diagrams and dynamical evolution of the triple-pathway electro-oxidation of formic acid on platinum.

Recently, an electro-kinetic model based on a specified reaction scheme for the electro-oxidation of formic acid on platinum was reported. The model evaluated three reaction pathways towards the production of CO2: the dehydrogenation and the dehydration of formic acid, and the third and most active pathway includes fast oxidation of the formate ion. Numerical integrations showed that the model is well-suited to describe the experimental results in voltammetric and oscillatory regimes. In the present paper, we provide detailed stability phase diagrams characterizing the dynamical evolution of this system under galvanostatic and potentiostatic regimes. We find the triple-pathway electro-oxidation of formic acid on platinum to have rather intertwined stability phases and, surprisingly, a total absence of chaotic oscillations. To the best of our knowledge, this is the first study in this direction using a realistic electrochemical model.

Impact of predator dormancy on prey-predator dynamics.

The impact of predator dormancy on the population dynamics of phytoplankton-zooplankton in freshwater ecosystems is investigated using a simple model including dormancy, a strategy to avoid extinction. In addition to recently reported chaos-mediated mixed-mode oscillations, as the carrying capacity grows, we find surprisingly wide phases of nonchaos-mediated mixed-mode oscillations to be present well before the onset of chaos in the system. Nonchaos-mediated cascades display spike-adding sequences, while chaos-mediated cascades show spike-doubling. A host of braided periodic phases with exotic shapes is found embedded in a region of control parameters dominated by chaotic oscillations. We describe the organization of these complicated phases and show how they are interconnected and how their complexity unfolds as control parameters change. The novel nonchaos-mediated phases are found to be large and stable, even for low carrying capacity.

Self-organization of pulsing and bursting in a CO2 laser with opto-electronic feedback.

We report a detailed investigation of the stability of a CO2 laser with feedback as described by a six-dimensional rate-equations model which provides satisfactory agreement between numerical and experimental results. We focus on experimentally accessible parameters, like bias voltage, feedback gain, and the bandwidth of the feedback loop. The impact of decay rates and parameters controlling cavity losses are also investigated as well as control planes which imply changes of the laser physical medium. For several parameter combinations, we report stability diagrams detailing how laser spiking and bursting is organized over extended intervals. Laser pulsations are shown to emerge organized in several hitherto unseen regular and irregular phases and to exhibit a much richer and complex range of behaviors than described thus far. A significant observation is that qualitatively similar organization of laser spiking and bursting can be obtained by tuning rather distinct control parameters, suggesting the existence of unexpected symmetries in the laser control space.

Complex dynamics of a dc glow discharge tube: Experimental modeling and stability diagrams.

We report a detailed experimental study of the complex behavior of a dc low-pressure plasma discharge tube of the type commonly used in commercial illuminated signs, in a microfluidic chip recently proposed for visible analog computing, and other practical devices. Our experiments reveal a clear quasiperiodicity route to chaos, the two competing frequencies being the relaxation frequency and the plasma eigenfrequency. Based on an experimental volt-ampere characterization of the discharge, we propose a macroscopic model of the current flowing in the plasma. The model, governed by four autonomous ordinary differential equations, is used to compute stability diagrams for periodic oscillations of arbitrary period in the control parameter space of the discharge. Such diagrams show self-pulsations to emerge remarkably organized into intricate mosaics of stability phases with extended regions of multistability (overlap). Specific mosaics are predicted for the four dynamical variables of the discharge. Their experimental observation is an open challenge.

Discontinuous spirals of stable periodic oscillations.

We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase orderly without bound. Such complex patterns emerge forming self-similar discontinuous phases that combine in an artful way to produce large discontinuous spirals of stability. This unanticipated discrete accumulation of stability phases was detected experimentally and numerically in a Duffing-like proxy specially designed to bypass noisy spectra conspicuously present in driven oscillators. Discontinuous spirals organize the dynamics over extended parameter intervals around a focal point. They are useful to optimize locking into desired oscillatory modes and to control complex systems. The organization of oscillations into discontinuous spirals is expected to be generic for a class of nonlinear oscillators.

Antiperiodic oscillations.

The investigation of regular and irregular patterns in nonlinear oscillators is an outstanding problem in physics and in all natural sciences. In general, regularity is understood as tantamount to periodicity. However, there is now a flurry of works proving the existence of "antiperiodicity", an unfamiliar type of regularity. Here we report the experimental observation and numerical corroboration of antiperiodic oscillations. In contrast to the isolated solutions presently known, we report infinite hierarchies of antiperiodic waveforms that can be tuned continuously and that form wide spiral-shaped stability phases in the control parameter plane. The waveform complexity increases towards the focal point common to all spirals, a key hub interconnecting them all.

Stern-Brocot trees in the periodicity of mixed-mode oscillations.

We investigate the distribution of mixed-mode oscillations in the control parameter space for two paradigmatic chemical models: a three-variable fourteen-parameter model of the Belousov-Zhabotinsky reaction and a three-variable four-parameter autocatalator. For both systems, several high-resolution phase diagrams show that the number of spikes of their mixed-mode oscillations emerges consistently organized in a surprising and unexpected symmetrical way, forming Stern-Brocot trees. The Stern-Brocot tree is more general and contains the Farey tree as a subtree. We conjecture the Stern-Brocot hierarchical organization to be the archetypal skeleton underlying several systems displaying mixed-mode oscillations.

Non-Shilnikov cascades of spikes and hubs in a semiconductor laser with optoelectronic feedback.

Incomplete homoclinic scenarios were recently measured in a semiconductor laser with optoelectronic feedback. We show here that such a laser contains cascades of spirals of periodic oscillations and hubs which look identical to the familiar ones observed in complete homoclinic scenarios. This means that hubs are far more general than presumed so far, being not limited by Shilnikov's theorem. Laser hubs open the possibility of measuring complex distributions of non-Shilnikov laser oscillations, and we briefly discuss how to do it.

Relative abundance and structure of chaotic behavior: the nonpolynomial Belousov-Zhabotinsky reaction kinetics.

We report a detailed numerical investigation of the relative abundance of periodic and chaotic oscillations in phase diagrams for the Belousov-Zhabotinsky (BZ) reaction as described by a nonpolynomial, autonomous, three-variable model suggested by Gyorgyi and Field [Nature (London) 355, 808 (1992)]. The model contains 14 parameters that may be tuned to produce rich dynamical scenarios. By computing the Lyapunov spectra, we find the structuring of periodic and chaotic phases of the BZ reaction to display unusual global patterns, very distinct from those recently found for gas and semiconductor lasers, for electric circuits, and for a few other familiar nonlinear oscillators. The unusual patterns found for the BZ reaction are surprisingly robust and independent of the parameter explored.

Multistability, phase diagrams, and intransitivity in the Lorenz-84 low-order atmospheric circulation model.

We report phase diagrams detailing the intransitivity observed in the climate scenarios supported by a prototype atmospheric general circulation model, namely, the Lorenz-84 low-order model. So far, this model was known to have a pair of coexisting climates described originally by Lorenz. Bifurcation analysis allows the identification of a remarkably wide parameter region where up to four climates coexist simultaneously. In this region the dynamical behavior depends crucially on subtle and minute tuning of the model parameters. This strong parameter sensitivity makes the Lorenz-84 model a promising candidate of testing ground to validate techniques of assessing the sensitivity of low-order models to perturbations of parameters.

Spatial updating, spatial transients, and regularities of a complex automaton with nonperiodic architecture.

We study the dynamics of patterns exhibited by rule 52, a totalistic cellular automaton displaying intricate behaviors and wide regions of active/inactive synchronization patches. Systematic computer simulations involving 2(30) initial configurations reveal that all complexity in this automaton originates from random juxtaposition of a very small number of interfaces delimiting active/inactive patches. Such interfaces are studied with a sidewise spatial updating algorithm. This novel tool allows us to prove that the interfaces found empirically are the only interfaces possible for these periods, independently of the size of the automata. The spatial updating algorithm provides an alternative way to determine the dynamics of automata of arbitrary size, a way of taking into account the complexity of the connections in the lattice.