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.

Volatile profile and micropropagation conditions of Bauhinia forficata Link.

Bauhinia forficata Link. is a native South American plant, which possesses volatile compounds with pharmaceutical and medicinal properties such as antidiabetic and anti-inflammatory effects. However, the conservation and propagation of this plant are complicated by its recalcitrant seeds and delayed flowering transition. Hence, tissue culture is employed for the safe and efficient propagation of B. forficata. However, the optimal conditions for the in vitro cultivation of B. forficata remain unknown. Thus, this study aimed to characterize the volatile profile of adult B. forficata field plants and evaluate the effects of different light intensities (43 and 70 µmol m-2 s-1), gas exchange rates (14 and 25 µL L-1 s-1), and exogenous sucrose concentrations (0, 20, and 30 g L-1) on their in vitro development. The results showed that ß-caryophyllene is the major volatile compound produced by B. forficata. Moreover, culturing in a medium containing 30 g L-1 of sucrose and flasks with membranes that allow CO2 exchange at the rate of 25 µL L-1 s-1 produced vigorous and hardened plants with high survival rates independent of irradiance. This study is the first to report the optimal in vitro culture conditions for B. forficata as a reference for future studies on micropropagation and secondary metabolite production using this species. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03634-8.

Production of biquinho pepper in different growing seasons characterized by the logistic model and its critical points / Produção de pimenta biquinho em diferentes épocas de cultivo caracterizadas pelo modelo logístico e seus pontos críticos

ABSTRACT: The objective of this study was to characterize the production of biquinho pepper through the interpretation of parameter estimates from the logistic model and its critical points obtained by the partial derivatives of the function, and to indicate the best cultivar and growing season for subtropical climate sites. For this, a 2x3 factorial experiment was conducted with two cultivars of biquinho pepper (BRS Moema and Airetama biquinho) in three growing seasons (E1: October 2015, E2: November 2015, E3: January 2016). The logistic non-linear model for fruit mass was specified as a function of the accumulated thermal sum, and the critical points were calculated through the partial derivatives of the model, in order to characterize the productive performance of the crop by the biological interpretation of the estimates of the three set parameters. In E3, temperatures close to 0 ºC during the experiment were lethal to the plants, and a linear regression model was used in this case. The production of the cultivars in E1 and E2 were well characterized by the estimated logistic models, and the most productive cultivar was Airetama biquinho in all evaluated seasons. This cultivar also presented higher concentration of production. The two cultivars did not differ significantly with regards to productive precocity. For E3, it was not possible to interpret the parameters in the same way as for E1 and E2, since the use of the linear model did not allow the same interpretations performed for the nonlinear model, reaffirming its applicability horticultural crops of multiple harvests.

RESUMO: O objetivo deste estudo foi caracterizar a produção de pimenta biquinho através da interpretação dos parâmetros do modelo Logístico e seus pontos críticos obtidos pelas derivadas parciais da função, bem como indicar qual a melhor cultivar e a melhor época de cultivo para locais de clima subtropical. Conduziu-se um experimento em esquema fatorial 2x3 sendo duas cultivares de pimenta biquinho (BRS Moema e Airetama biquinho), em três épocas de cultivo (E1: outubro de 2015, E2: 01 de novembro 2015 e E3: janeiro de 2016). Ajustou-se o modelo logístico para massa de frutos em função da soma térmica acumulada, e calculou-se os pontos críticos através das derivadas parciais do modelo com a finalidade de caracterizar o desempenho produtivo da cultura através da interpretação biológica destes parâmetros. Temperaturas próximas a 0 ºC durante o experimento foram letais às plantas, e por isso, para a época 3, ajustou-se um modelo de regressão linear. A interpretação dos parâmetros do modelo Logístico e seus pontos críticos permitiram que a produção das cultivares nas épocas 1 e 2 fossem caracterizadas, sendo que a cultivar mais produtiva é Airetama biquinho em todas as épocas de transplante. Essa cultivar também apresenta maior concentração de produção no período. Quanto a precocidade produtiva as duas cultivares não diferiram significativamente. Sobre a época 3, não foi possível interpretar da mesma forma, pois o ajuste do modelo linear não permite as mesmas interpretações realizadas para o modelo não linear, reafirmando a sua aplicabilidade em cultura olerícolas de múltiplas colheitas.

Agroforestry systems and understory harvest management: the impact on growth and productivity of dual-purpose wheat.

The objective of the study was to evaluate the growth and production efficiency of forage-grain dual-purpose wheat in two arrangements and four agroforestry systems (Intercrop-I and Intercrop-II), as well as to evaluate crop management for the wheat crops in two planting seasons (Crop Season I-2014 and Crop Season II-2015. The experiment was conducted in a randomized complete block design, factorial scheme 7x2x2, with seven cultivation systems Eucalyptus urophylla x Eucalyptus grandis Intercrop-II and Intercrop-I; Peltophorum dubium Intercrop-II and Intercrop-I; P. rigida Intercrop-I; S. parahyba Intercrop-I; a wheat monoculture with no tree species present; and two harvest management techniques (with and without harvesting of the forage species). Agroforestry systems generated shading for wheat plants, with a higher phyllochron and lower values of leaf area index of those individuals kept under trees with higher crown shading (non-deciduous trees) due to the lower transmissivity of solar radiation. The systems composed with Schizolobium parahyba in Intercrop-I and Parapiptadenia rigida in Intercrop-I provide a minor phyllochron to the wheat, resulting in a higher leaf area index and dry matter yield. Thus, the cultivation of tree species and dual-skilled agricultural crops, such as wheat, provides promising alternatives for the future use of land in tropical countries.

In vitro propagation of lemon verbena: a plant native of South America

In vitropropagation increases the supply and commercialisation of products of interest. For this, optimising the growing conditions and the composition of the culture medium is crucial to benefit the full development of the plants. Thus, the objective was to evaluate the in vitropropagation of Aloysia triphyllaon different culture media, with varying agar and sucrose concentrations. The experiment was conducted as a completely randomised design, 3×3×3 factorial scheme, with three culture media (MS, JADS and WPM), three sucrose concentrations (8, 10 and 12 g L-1) and three agar concentrations (15, 30 and 45 g L-1), with three replicates each and experimental units composed of one plant per replicate. After 25 days of cultivation, the fresh and dry mass of the plants, numbers of leaves, numbers of nodes, plant lengths, numbers of oxidised leaves, hyperhydricity and acclimatization percentages were evaluated. The WPM medium resulted in a reduced fresh mass, reflecting in the low hyperhydricity observed in the explants, and favoured the acclimatization of the plants. Thus, the WPM medium with sucrose (15 g L-1) and agar (12 g L-1) is recommended as the medium most suitable for the in vitroregeneration of Aloysia triphylla.

The diagnosis of multiple opportunistic infections in advanced stage AIDS: when Ockham's Razor doesn't cut it.

In the advanced stage of AIDS, the diagnosis of the opportunistic infections may be challenging due to the high risk of performing invasive diagnostic methods in a patient with a critical clinical condition, as well as the correct interpretation of the results of microbiological exams. One of the challenges for the diagnosis and treatment of the opportunistic infections is that they may occur concomitantly in the same patient and they may mimic each other, leading to a high discrepancy between clinical and autopsy diagnoses. We describe the case of a 52-year-old man who was hospitalized because of weight loss, anemia, cough, and hepatosplenomegaly. During the investigation, the diagnosis of AIDS was made, and the patient developed respiratory failure and died on the fourth day of hospitalization. At autopsy, disseminated non-tuberculosis mycobacteriosis was found, affecting mainly the organs of the reticuloendothelial system. Also, severe and diffuse pneumonia caused by multiple agents (Pneumocystis jirovecii , Histoplasma capsulatum, suppurative bacterial infection, non-tuberculosis mycobacteria, and cytomegalovirus) was seen in a morphological pattern that could be called "collision pneumonia." The lesson from this case, revealed by the autopsy, is that in advanced AIDS, patients often have multiple opportunistic infections, so the principle of Ockham's razor-that a single diagnosis is most likely the best diagnosis-fails in this clinical context.

The diagnosis of multiple opportunistic infections in advanced stage AIDS: when Ockham's Razor doesn't cut it

In the advanced stage of AIDS, the diagnosis of the opportunistic infections may be challenging due to the high risk of performing invasive diagnostic methods in a patient with a critical clinical condition, as well as the correct interpretation of the results of microbiological exams. One of the challenges for the diagnosis and treatment of the opportunistic infections is that they may occur concomitantly in the same patient and they may mimic each other, leading to a high discrepancy between clinical and autopsy diagnoses. We describe the case of a 52-year-old man who was hospitalized because of weight loss, anemia, cough, and hepatosplenomegaly. During the investigation, the diagnosis of AIDS was made, and the patient developed respiratory failure and died on the fourth day of hospitalization. At autopsy, disseminated non-tuberculosis mycobacteriosis was found, affecting mainly the organs of the reticuloendothelial system. Also, severe and diffuse pneumonia caused by multiple agents (Pneumocystis jirovecii, Histoplasma capsulatum, suppurative bacterial infection, non-tuberculosis mycobacteria, and cytomegalovirus) was seen in a morphological pattern that could be called "collision pneumonia." The lesson from this case, revealed by the autopsy, is that in advanced AIDS, patients often have multiple opportunistic infections, so the principle of Ockham's razor­that a single diagnosis is most likely the best diagnosis­fails in this clinical context.

Characteristics of methicillin-resistant Staphylococcus aureus in patients on admission to a teaching hospital in Rio de Janeiro, Brazil.

BACKGROUND: Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are associated with greater mortality and morbidity; however, risk factors for community-acquired infections caused by MRSA have not been established. Therefore, community patients who are admitted to hospitals without the necessary contact precautions and are infected with community-acquired lineages eventually cause these lineages to spread to these settings. The aim of this study was to detect community-acquired lineages of MRSA in patients on admission to a Brazilian teaching hospital. METHODS: The antimicrobial susceptibility of the MRSA isolates from nasal swabs was evaluated as was the molecular characteristics of the staphylococcal cassette chromosome mec (SCCmec). The clonality was determined using pulsed-field gel electrophoresis and multilocus sequence type analysis. RESULTS: A total of 702 patients were evaluated between March 2012 and March 2013; 180 (25%) of them were colonized by S aureus, and 21 (3%) were MRSA. The SCCmec IV/USA1100/sequence type (ST) 30 was the predominant MRSA lineage (42.8%), followed by SCCmec IV/USA800/ST5 (23.8%). CONCLUSIONS: The occurrence of MRSA colonization was very low, and only 1 patient from cardiac surgery developed an infection, which was caused by an SCCmec II/USA100/ST5 isolate. Screening for MRSA colonization on admission does not seem to be productive; however, for populations submitted to specific surgeries, active surveillance should be implemented.

Morpho-histological, histochemical, and molecular evidences related to cellular reprogramming during somatic embryogenesis of the model grass Brachypodium distachyon.

The wild grass species Brachypodium distachyon (L.) has been proposed as a new model for temperate grasses. Among the biotechnological tools already developed for the species, an efficient induction protocol of somatic embryogenesis (SE) using immature zygotic embryos has provided the basis for genetic transformation studies. However, a systematic work to better understanding the basic cellular and molecular mechanisms that underlie the SE process of this grass species is still missing. Here, we present new insights at the morpho-histological, histochemical, and molecular aspects of B. distachyon SE pathway. Somatic embryos arose from embryogenic callus formed by cells derived from the protodermal-dividing cells of the scutellum. These protodermal cells showed typical meristematic features and high protein accumulation which were interpreted as the first observable steps towards the acquisition of a competent state. Starch content decreased along embryogenic callus differentiation supporting the idea that carbohydrate reserves are essential to morphogenetic processes. Interestingly, starch accumulation was also observed at late stages of SE process. Searches in databanks revealed three sequences available annotated as BdSERK, being two copies corresponding to SERK1 and one showing greater identity to SERK2. In silico analysis confirmed the presence of characteristic domains in a B. distachyon Somatic Embryogenesis Receptor Kinase genes candidates (BdSERKs), which suggests SERK functions are conserved in B. distachyon. In situ hybridization demonstrated the presence of transcripts of BdSERK1 in all development since globular until scutellar stages. The results reported in this study convey important information about the morphogenetic events in the embryogenic pathway which has been lacking in B. distachyon. This study also demonstrates that B. distachyon provides a useful model system for investigating the genetic regulation of SE in grass species.

Temperatura base e filocrono em duas cultivares de oliveira / Base temperature and phyllochron in two olive cultivars

O objetivo deste trabalho foi estimar a temperatura base para emissão de folhas e determinar o filocrono em duas cultivares de oliveira, 'Arbequina' e 'MGS ASC315', durante a fase de muda em condições de campo. Foi instalado um experimento na Fazenda Experimental da Empresa de Pesquisa Agropecuária de Minas Gerais, Maria da Fé, MG. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 2x6, sendo duas cultivares e seis épocas de transplantio, com quinze repetições. A temperatura base (Tb) foi estimada usando a metodologia do menor valor do quadrado médio do erro (QME), e o filocrono foi obtido através do inverso do coeficiente angular da regressão linear entre o número de folhas emitidas e a soma térmica acumulada. A Tb estimada para a Arbequina foi de 10,5°C e 11°C para a MGS ASC315. O filocrono diferiu estatisticamente somente entre as cultivares, sendo menor para a 'Arbequina' (21,7°C dia-1 folha-1) quando comparada com a 'MGS ASC315' (41,6°C dia-1 folha-1).

The objective of this work was to estimate the base temperature for leaf appearance and the phyllochron for two cultivars of Olea europaea L. A field experiment was carried out in the experimental area of the Agricultural Research Corporation of Minas Gerais, Maria da Fé, MG. The experimental design was completely randomized with two cultivars and six planting dates. Base temperature (Tb) was estimated by the minimum mean square error (MSE) and the phyllochron was estimated by the inverse of the slope of regression between main stem leaf number and accumulated thermal time. The estimated base temperature was 10.5°C for Arbequina and 11°C for MGS ASC315. The phyllochron was statistically different only between cultivars, lower for 'Arbequina' (21.7°C day-1 leaf-1) compared to 'MGS ASC315' (41.6°C day-1 leaf-1).

Propagação in vitro de genótipos de alface via embriogênese somática / In vitro propagation of lettuce genotypes via somatic embryogenesis

A propagação in vitro via embriogênese somática é uma alternativa eficiente para a propagação em larga escala do material vegetal. No entanto, não há relatos do desenvolvimento de protocolos completos de embriogênese somática, com produção de plantas de alface. O presente trabalho teve como objetivo estabelecer a propagação in vitro de genótipos de alface, Paris White e Red Salad Bowl, avaliando a indução dos calos embriogênicos, regeneração dos embriões somáticos e posterior conversão em plantas. Para a indução de embriogênese somática, duas fontes de explante (folhas cotiledonares inteiras e seccionadas) foram cultivadas em meio MS+10,75µM de ANA+0,89µM de BA. A proliferação dos calos embriogênicos foi realizada em meio MS+24µM de AIA+0,15µM de BA. Para a maturação dos embriões somáticos e conversão em plantas, utilizou-se meio MS sem regulador de crescimento (semi-sólido sem carvão ativado e com carvão ativado e meio líquido). A fonte do explante seccionada foi estatisticamente superior apenas para o genótipo Paris White. Para a regeneração dos embriões somáticos, observou-se que, no genótipo Paris White, o meio líquido foi superior estatisticamente, quando comparado aos meios semi-sólidos e, para o genótipo Red Salad Bowl, foi o meio semi-sólido com acréscimo de carvão ativado. Tendo em vista o potencial da aplicabilidade comercial da embriogênese somática para a produção em larga escala de plântulas de alface do genótipo Paris White, os protocolos de indução, proliferação, maturação dos embriões somáticos e conversão em plantas, foram adequados, em especial, em sistema líquido.

In vitro propagation via somatic embryogenesis is an efficient alternative to large-scale propagation of plant material. Nevertheless, there are no reports of development of complete somatic embryogenesis protocols, with plant production of lettuce. This study aimed to establish lettuce in vitro propagation of Paris White and Red Salad Bowl genotypes, evaluating embryogenic callus induction, somatic embryos regeneration and subsequent conversion into plants. For somatic embryogenesis induction, two sources of explants (whole and sectioned cotyledons) were grown on MS medium containing 10.75µM NAA and 0.89µM BA. Callus proliferation occurred in MS medium supplemented with 24µM AIA and 0.15µM BA. For somatic embryos maturation and conversion into plants, we used MS medium devoid of growth regulator under three conditions: semi-solid medium with and without activated charcoal, and liquid medium. The sectioned explant source was statistically superior only for genotype Paris White. For somatic embryos regeneration, we observed that, in genotype Paris White, the liquid medium was statistically higher than semi-solid media, and for genotype Red Salad Bowl, activated charcoal-added semi-solid medium was the better. Considering the potential commercial applicability of somatic embryogenesis for seedlings mass production of lettuce Paris White genotype, somatic embryos induction, proliferation, maturation and conversion into plants protocols were adequate, especially in liquid system.