Characterization of retinal arteries by adaptive optics ophthalmoscopy image analysis.

OBJECTIVE: This paper aims at quantifying biomarkers from the segmentation of retinal arteries in adaptive optics ophthalmoscopy images (AOO). METHODS: The segmentation is based on the combination of deep learning and knowledge-driven deformable models to achieve a precise segmentation of the vessel walls, with a specific attention to bifurcations. Biomarkers (junction coefficient, branching coefficient, wall to lumen ratio (wlr) are derived from the resulting segmentation. RESULTS: reliable and accurate segmentations (mse = 1.75 ± 1.24 pixel) and measurements are obtained, with high reproducibility with respect to images acquisition and users, and without bias. SIGNIFICANCE: In a preliminary clinical study of patients with a genetic small vessel disease, some of them with vascular risk factors, an increased wlr was found in comparison to a control population. CONCLUSION: The wlr estimated in AOO images with our method (AOV, Adaptive Optics Vessel analysis) seems to be a very robust biomarker as long as the wall is well contrasted.

Reconstrução de hemiatrofia facial com hidroxiapatita de cálcio: relato de uma técnica segura e minimamente invasiva / Reconstruction of facial hemiatrophy using calcium hydroxylapatite filler: report of a safe and minimally invasive technique

Introdução: a hemiatrofia facial progressiva, também conhecida como síndrome de Parry Romberg, é uma forma rara de esclerodermia, cujo manejo de sequelas é desafiador. Objetivo: diante desse desafio, o objetivo deste estudo foi avaliar pela primeira vez na literatura a eficácia do preenchimento da hidroxiapatita de cálcio (CaHa) na reconstrução da mandíbula de um paciente com síndrome de Parry Romberg. Relato do caso: paciente do sexo feminino, 15 anos, com atrofia progressiva do lado direito da face por síndrome de Parry Romberg. Após o controle da doença, a principal queixa da paciente era assimetria facial, principalmente na região mandibular. Discussão: a CaHa é um preenchedor injetável biocompatível, que é gradualmente reabsorvido e substituído por estroma fibrovascular, formado principalmente por novo colágeno, em um processo que ocorre sem qualquer reação imunológica. Este perfil de segurança torna a CaHa uma boa escolha para a correção de sequelas de esclerodermia estável. Conclusão: este relato permite concluir que a biocompatibilidade do preenchimento de CaHa e a adequação para correção da mandíbula também são aplicáveis em procedimentos reconstrutivos para esclerodermia estável, de forma segura e minimamente invasiva, com ótimos resultados estéticos. O procedimento deve ser programado caso a caso, e um acompanhamento regular também é recomendado.

Introduction: Progressive Facial Hemiatrophy, also known as Parry Romberg Syndrome, is a rare form of linear scleroderma. The management of facial atrophy sequelae is challenging. Objective: This study aims to evaluate for the first time in literature the effectiveness of the calcium hydroxylapatite (CaHa) filler in the jawline reshaping of a patient with Parry Romberg Syndrome. Case report: A 15-year-old woman with progressive atrophy of the right side of the face due to Parry Romberg Syndrome. After disease control, the patient's main complaint was facial asymmetry, mainly in the jawline region. Discussion: CaHa is a biocompatible injectable filler that is gradually resorbed and replaced by fibrovascular stroma, mainly formed for new collagen, in a process that occurs without any immunological reaction. This safety profile makes CaHa a good choice for correcting stable scleroderma defects. Conclusion: This report concludes that CaHa filler biocompatibility and suitability for the jawline correction are also applicable in reconstructive procedures for stable scleroderma, safely and minimally invasively, with optimal aesthetic results. The method must be programmed case-by-case, and a regular follow-up is also recommended.

Instrumentos de avaliação da neuropatia periférica induzida por quimioterapia no paciente com mieloma múltiplo / Evaluation instruments of peripheral neuropathy induced by chemotherapy in patients with multiple myeloma

Objetivo: Identificar instrumentos de avaliação da neuropatia periférica induzida por quimioterapia que possam ser traduzidos ou adaptados para monitoramento dessa reação adversa a medicamentos em pacientes com mieloma múltiplo.Método: Revisão narrativa, realizada entre julho de 2018 a maio de 2019. Foram elegíveis artigos publicados em inglês e português, entre junho de 2007 a janeiro de 2019, disponíveis na íntegra de maneira livre ou em periódicos do Portal da CAPES Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Foram excluídos estudos com animais, monografias, guidelines, teses, casos clínicos e estudos que não da área de saúde.Resultados: Foram identificados cinco instrumentos: Patient Neurotoxicity Questionnaire; Funcional Assessment of Cancer Therapy/ Gynecologyc Group – Neurotoxicity; Chemotherapy-Induced Peripheral Neuropathy Assessment Tool; Funcional Assessment Cancer Therapy/Taxane; Indication for Common Toxicity Criteria – Grading of Peripheral Neuropathy Questionnaire (ICPNQ). Após análise de cada ferramenta apresentada, o ICPNQ se mostrou válido e aplicável na prática clínica, porém, encontra-se em língua inglesa.Conclusão: A tradução e validação do instrumento ICPNQ para o português, possibilitaria sua incorporação à prática clínica no monitoramento da neuropatia periférica induzida por quimioterapia em pacientes com Mieloma Múltiplo. (AU)

Objective: To identify instruments for evaluation of peripheral neuropathy induced by chemotherapy that can be translated or adapted to monitor this adverse drug reaction in patients with multiple myeloma.Method: Narrative review, conducted between July 2018 and may 2019. Articles published in English and Portuguese were eligible between June 2007 and January 2019, available in full in a free manner or in periodicals of the CAPES Coordination Portal for Improvement of Level Personnel Higher. Animal studies, monographs, guidelines, theses, clinical cases and non-health studies were excluded.Results: Five instruments were identified: Patient Neurotoxicity Questionnaire; Funcional Assessment of Cancer Therapy/Gynecologyc Group – Neurotoxicity; Chemotherapy-Induced Peripheral Neuropathy Assessment Tool; Funcional Assessment Cancer Therapy/Taxane; Indication for Common Toxicity Criteria – Grading of Peripheral Neuropathy Questionnaire (ICPNQ). After analyzing each tool presented, the ICPNQ proved to be valid and applicable in clinical practice, however, it is in the English language.Conclusion: The translation and validation of the ICPNQ instrument into Portuguese would allow its incorporation into clinical practice in the monitoring of peripheral neuropathy induced by chemotherapy in patients with multiple myeloma. (AU)

COVID-19 lockdown: a rare opportunity to establish baseline pollution level of air pollutants in a megacity, India.

This paper analyses air quality data from megacity Delhi, India, during different periods related to the COVID-19, including pre-lockdown, lockdown and unlocked (post-lockdown) (2018-2020) to determine what baseline levels of air pollutants might be and the level of impact that could be anticipated under the COVID-19 lockdown emission scenario. The results show that air quality improved significantly during the lockdown phases, with the most significant changes occurring in the transportation and industrially dominated areas. A pronounced decline in PM2.5 and PM10 up to 63% and 58%, respectively, was observed during the lockdown compared to the pre-lockdown period in 2020. When compared to 2018 and 2019, they were lower by up to 51% and 61%, respectively, dropping by 56% during unlock. Some pollutants (NOx and CO) dropped significantly during lockdown, while SO2 and O3 declined only slightly. Moreover, when compared between the different phases of lockdown, the maximum decline for most of the pollutants and air quality index occurred during the lockdown phase 1; thus, this period was used to report the COVID-19 baseline threshold values (CBT; threshold value is the upper limit of baseline variation). Of the various statistical methods used median + 2 median absolute deviation (mMAD) was most suitable, indicating CBT values of 143 and 75 ug/m3 for PM10 and PM2.5, respectively. This results although preliminary, but it gives a positive indication that temporary lockdown can be considered as a boon to mitigate the damage we have done to the environment. Also, this baseline levels can be helpful as a first line of information to set future target limits or to develop effiective management policies for achieving better air quality in urban centres like Delhi. Supplementary Information: The online version contains supplementary material available at 10.1007/s13762-021-03142-3.

Evidence for a spin acoustic surface plasmon from inelastic atom scattering.

Closed-shell atoms scattered from a metal surface exchange energy and momentum with surface phonons mostly via the interposed surface valence electrons, i.e., via the creation of virtual electron-hole pairs. The latter can then decay into surface phonons via electron-phonon interaction, as well as into acoustic surface plasmons (ASPs). While the first channel is the basis of the current inelastic atom scattering (IAS) surface-phonon spectroscopy, no attempt to observe ASPs with IAS has been made so far. In this study we provide evidence of ASP in Ni(111) with both Ne atom scattering and He atom scattering. While the former measurements confirm and extend so far unexplained data, the latter illustrate the coupling of ASP with phonons inside the surface-projected phonon continuum, leading to a substantial reduction of the ASP velocity and possibly to avoided crossing with the optical surface phonon branches. The analysis is substantiated by a self-consistent calculation of the surface response function to atom collisions and of the first-principle surface-phonon dynamics of Ni(111). It is shown that in Ni(111) ASP originate from the majority-spin Shockley surface state and are therefore collective oscillation of surface electrons with the same spin, i.e. it represents a new kind of collective quasiparticle: a Spin Acoustic Surface Plasmon (SASP).

Macrophytes as bioindicators of heavy metal pollution in estuarine and coastal environments.

The Derwent estuary, in Tasmania (Australia), is highly contaminated with heavy metals with significant levels in both sediments and benthic fauna. However, little is known about metal content in benthic primary producers. We characterized metal content (Arsenic, Cadmium, Copper, Lead, Selenium and Zinc) in twelve species of macrophyte, including red, green, and brown algae, and seagrasses, from the Derwent. The metals, arsenic, copper, lead, and Zinc were detected in all of the macrophytes assessed, but the levels differed between species. Seagrasses accumulated the highest concentrations of all metals; with Zn levels being particularly high in the seagrass Ruppia megacarpa (from the upper Estuary) and Pb was detected in Zostera muelleri (from the middle estuary). Ulva australis was ubiquitous throughout the middle-lower estuary and accumulated Zn in relatively high concentrations. The findings suggest that analysis of multiple species may be necessary for a comprehensive understanding of estuary-wide metal pollution.

Photosynthetic and ultrastructural responses of Ulva australis to Zn stress.

This research evaluated the effect of zinc (Zn) on the ultrastructure and the photosynthetic efficiency of a common green alga. Ulva australis was grown in the laboratory for 7days under a range of different Zn concentrations (0, 25, 50 and 100µgL-1). Growth rate (Gr), photosynthetic efficiency (Fv/Fm and ETRmax), photosynthetic pigments, and metal accumulation were measured. Samples of 1mm length were taken to analyse the effect of Zn on the ultrastructure using transmission electron microscopy (TEM) and cytochemical responses (TB-O and PAS) were evaluated by light microscopy (LM). There were no significant differences in the growth rate, Fv/Fm, ETRmax and the photosynthetic pigments chlorophyll a, chlorophyll b and carotenoids (p>0.05) after 7days of Zn exposure. However, TEM revealed cytoplasm retraction, compression of cellulose fibrils, dissembled thylakoids and electron-dense bodies suggesting ultrastructural impacts from metal exposure and accumulation. Cytological analysis demonstrated that Zn affected U. australis cells at the three concentrations tested. The main effect was cytoplasm retraction and a decrease on the amount of starch granules, following exposure at 25µgL-1 and 50µgL-1 of Zn. We conclude that concentrations of Zn assessed in U. australis in this research has a short-term cellular effect as revealed by TEM and cytological analysis, demonstrating the importance of measuring a broad suite of endpoints to better understand species responses to environmentally relevant concentrations of Zn. However, U. australis was able to physiologically tolerate adverse conditions, since there was no effect on the photosynthetic performance and growth.

Identification and characterization of the bZIP transcription factor involved in zinc homeostasis in cereals.

Members of the basic leucine zipper family, as bZIP19, are considered to be essential regulators of the adaptation to zinc deficiency. Knowing that this gene as well as its targets are conserved in the plant kingdom, we followed an in silico approach to identify and characterize the bzip19 gene in cereals. Through BLASTp in Phytozome database, 33 bzip19 genes were identified on the genomes of Oryza sativa, Sorghum bicolor, Zea mays, Glycine max, Triticum aestivum, and Brachypodium distachyon. The analysis of conserved motifs and bZIP domains was performed using MEME and PFAM databases. In 25 of these genes, CysHis-motifs at the basic N-terminal region were found. This motif is conserved in group bZIP and suggested to play a role as a Zn-sensor. Regarding their phylogeny, it was possible to infer orthologous groups and explore the evolutionary relationship between these BZIP19 proteins. Data mining allowed us to select eight putative orthologous whose expression profile was analyzed under stress conditions in the Genevestigator platform. The comparison between the expression profiles of these eight putative orthologous and the original Arabidopsis bzip19 also seems to indicate conserved transcriptional regulation. Thus, considering that modified expression of bZIP19 genes has already been confirmed as an efficient tool to improve Arabidopsis tolerance to Zn deficiency, and that these new bZIP orthologous have a high level of conservation when compared to the original bZIP19 sequence, they can be useful for the development of tolerant crops enabling plants to grow in areas of low zinc bioavailability.

Reactivity of O2 on Pd/Ru(0001) and PdRu/Ru(0001) surface alloys.

The reactivity of a Pd monolayer epitaxially grown on Ru(0001) toward O2 has been investigated by molecular beam techniques. O2 initial sticking coefficients were determined using the King and Wells method in the incident energy range of 40-450 meV and for sample temperatures of 100 K and 300 K, and compared to the corresponding values measured on the clean Ru(0001) and Pd(111) surfaces. In contrast to the high reactivity shown by Ru(0001) at 100 K, the Pd/Ru(0001) system exhibits a monotonic decrease in the sticking probability of O2 as a function of normal incident energy. At room temperature, the system was found to be inert. Thermal desorption measurements show that O2 is adsorbed molecularly at 100 K. A completely different behaviour has been measured for the Pd0.95Ru0.05/Ru(0001) surface alloy. On this surface, the O2 sticking probability increases with incident energy and resembles the one observed on the clean Ru(0001) surface, even at 300 K. Thermal desorption measurements point to dissociative adsorption of O2 in this system. Both the charge transfer from the Pd to the Ru substrate and the compressive strain on the Pd monolayer contribute to decrease in the reactivity of the Pd/Ru(0001) system well below those of both Ru(0001) and Pd(111).

Fine-tuning transmission electron microscopy methods to evaluate the cellular architecture of Ulvacean seaweeds (Chlorophyta).

Chemical fixation is a critical step in the analysis of the ultrastructure of seaweeds because the wrong approach can compromise the ability to distinguish fine-scale cellular composition. Fixation agents, fixation time and type of tissue are important factors to consider for transmission electron microscopy (TEM), and not every protocol is suitable for all cell types. We evaluated a range of fixation agents, post-fixation time and dehydration solutions to determine a TEM protocol for seaweeds in the Family Ulvaceae. We assessed Ulva lactuca using 5 protocols. The level of preservation obtained differed markedly between fixation methods The best result was obtained by fixing the sample with 2.5% glutaraldehyde, 0.05M sodium cacodylate buffer and 2% paraformaldehyde overnight, and 8h post-fixation in 1% in osmium tetroxide 1%. This approach and fixation time ensured that the membranes, especially the thylakoid membranes of chloroplasts, remained intact. Ethanol is recommended for dehydration as the use of acetone for dehydration resulted in the collapse of cellular membranes. This new protocol will ensure the ultrastructure of Ulvacean seaweeds can be clearly ascertained in the future.

Serum n-3 polyunsaturated fatty acids are inversely associated with longitudinal changes in depressive symptoms during pregnancy.

BACKGROUNDS: N-3 polyunsaturated fatty acids (PUFAs) have been hypothesised to be protective for depression during pregnancy. However, there are few data and no consensus regarding this association. In this line, we aim to evaluate if the concentration of n-3 and n-6 PUFAs, and their ratio, are associated with depressive symptoms throughout pregnancy. METHOD: A prospective cohort of 172 Brazilian women was followed at 5-13th, 20-26th and 30-36th weeks of gestation. The presence of depressive symptoms was evaluated using the Edinburgh Postnatal Depression Scale (EPDS) at each pregnancy trimester. Depression was defined as an EPDS score ≥11. The concentrations of n-3 [α-linolenic acid; eicosapentaenoic acid (EPA); docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA)] and n-6 PUFAs [linoleic acid; γ linolenic acid; eicosadienoic acid; eicosatrienoic acid; arachidonic acid; docosatetraenoic acid and docosapentaenoic acid] were expressed as absolute (µg/ml) values. The total n-6/n-3 ratio was calculated. Statistical analyses were performed using univariate and adjusted random intercept logistic model for each fatty acid (FA) considering the longitudinal nature of data. Covariates were selected as potential confounders based on their biological plausibility of having an association with the concentration of FA and depressive symptoms during pregnancy. RESULTS: The prevalence of depressive symptoms was high in all pregnancy trimesters (1st = 33.7%; 2nd = 18.9%; 3rd = 17.4%). We did not find differences in means FA concentrations by depressive symptom classification, for each follow-up visit. The women presented a 5% decrease in the odds of having depressive symptoms for each one-week increase in the gestational age. As individual women progressed through pregnancy, higher concentrations of EPA (odds ratio (OR) = 0.92; 95% CI: 0.86-0.99), DHA (OR = 0.96; 95% CI: 0.93-0.99), DPA (OR = 0.87; 95% CI: 0.77-0.99) and total n-3 (OR = 0.98; 95% CI: 0.96-0.99) were associated with a lower odds of depressive symptoms, while higher total n-6/n-3 ratio were associated with greater odds of depressive symptoms (OR = 1.40; 95% CI: 1.09-1.79). We detected a decrease in the probability of depressive symptoms as concentrations of total n-3 FA, α-linolenic acid, DPA, and DHA increased. We also observed a sharper decline for women with initial greater chance of depressive symptoms compared with those with lower chance of having these symptoms. CONCLUSIONS: We found a high prevalence of depressive symptoms in low-income Brazilian pregnant women and no significant associations between n-6 FA and depressive symptoms. Lower serum concentrations of DHA, EPA and DPA and a higher n-6/n-3 ratio at each pregnancy trimester were associated with higher odds of depressive symptoms throughout pregnancy.

Observation of Localized Vibrational Modes of Graphene Nanodomes by Inelastic Atom Scattering.

Inelastic helium atom scattering (HAS) is suitable to determine low-energy (few meV) vibrations spatially localized on structures in the nanometer range. This is illustrated for the nanodomes that appear often on graphene (Gr) epitaxially grown on single crystal metal surfaces. The nature of the inelastic losses observed in Gr/Ru(0001) and Gr/Cu/Ru(0001) has been clarified by intercalation of Cu below the Gr monolayer, which decouples the Gr layer from the Ru substrate and changes substantially the out-of-plane, flexural phonon dispersion of epitaxial Gr, while maintaining the nanodomes and their localized vibrations. He diffraction proves that the Cu-intercalated Gr layer is well ordered structurally, while scanning tunneling microscopy reveals the persistence of the (slightly modified) periodic array of Gr nanodomes. A simple model explains the order of magnitude of the energy losses associated with the Gr nanodomes and their size dependence. The dispersionless, low-energy phonon branches may radically alter the transport of heat in intercalated Gr.

The effect of leptin concentrations and other maternal characteristics on gestational weight gain is different according to pre-gestational BMI: results from a prospective cohort.

OBJECTIVE: To evaluate the effect of leptin and other selected variables on gestational weight gain (GWG) according to pre-gestational body mass index (BMI). DESIGN: Prospective cohort. SETTING: Public Health Center, Rio de Janeiro, Brazil. SAMPLE: Two hundred and twenty-eight pregnant women. METHODS: Women were followed at the 5-13, 20-26 and 30-36th gestational weeks. The effects of independent variables on GWG in normal weight (BMI 18.5-24.9 kg/m(2) ), overweight (BMI 25.0-29.9 kg/m(2) ) and obese (BMI ≥ 30.0 kg/m(2) ) women were assessed using longitudinal linear mixed-effects models. MAIN OUTCOME MEASURE: Maternal body weight (kg) throughout pregnancy. RESULTS: Leptin concentrations were associated with GWG in normal weight (ß = 0.048, P < 0.001) and overweight (ß = 0.023, P = 0.048) women, but not in obese ones (ß = 0.011, P = 0.308). Additionally, the number of hours slept per night decreased the effect of leptin on GWG in OW women (ß = -0.013, P = 0.002). The effect of other maternal characteristics on GWG was different depending on the BMI category. CONCLUSIONS: Leptin concentrations were positively associated with GWG in normal weight and overweight women, but not in obese ones. Maternal height was associated with GWG in all BMI categories, but other variables such as sleep duration, QUICKI values, HDL-c, smoking habit and marital status presented differential effects according to BMI. We encourage further studies to investigate the association between leptin and gestational weight gain, taking into account the pre-pregnancy weight and sleep duration, in order to compare and confirm our results. TWEETABLE ABSTRACT: Leptin is associated with weight gain in normal weight and overweight pregnant women, but not in obese ones.

Lipid changes throughout pregnancy according to pre-pregnancy BMI: results from a prospective cohort.

OBJECTIVE: To evaluate the rate of change in serum lipids and the factors associated with their variations, stratifying for pre-pregnancy body mass index (BMI) categories. DESIGN: Prospective cohort. SETTING: Public Health centre, Rio de Janeiro, Brazil. POPULATION: Two hundred and twenty-five healthy pregnant women recruited between 2009 and 2011. METHODS: Women were evaluated during the three trimesters of pregnancy (5th-13th, 20th-26th and 30th-36th gestational weeks). Pre-pregnancy BMI (kg/m²) was classified as normal weight (NW = 18.5-24.9), overweight (OW = 25.0-29.9) or obese (OB ≥ 30.0). The independent variables included maternal socioeconomic, demographic, biochemical and lifestyle factors. We performed linear mixed-effects models adjusted for gestational age and body weight, reporting coefficient (ß) and 95% confidence interval (95% CI). MAIN OUTCOME MEASURES: Longitudinal total cholesterol (TC), high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c) and triglyceride (TG) measurements. RESULTS: OW and OB women presented higher mean TG, TC and LDL-c compared with their NW counterparts (P < 0.05). The mean HDL-c concentrations were higher in NW than in OB women (P = 0.03). OW and OB women presented lower serum TC (ßOW  = -0.014; 95% CI = -0.026 to -0.002; P = 0.022; ßOB  = -0.015; 95% CI -0.015 to 0.001; P = 0.066) and LDL-c (ßOW  = -0.012; 95% CI = -0.021 to -0.002; P = 0.017; ßOB  = -0.018; 95% CI = -0.031 to -0.005; P = 0.005) rates of change (mmol/l per gestational week) compared with the NW. Pre-gestational BMI was the main factor associated with the rate of changes in TC and LDL-c concentrations. CONCLUSION: Pre-pregnancy BMI was the main factor associated with the rate of change in TC and LDL-c throughout pregnancy, and OW and OB women presented lower rates of change compared with NW controls.

Increased lactate threshold after five weeks of treadmill aerobic training in rats.

The aim of the present study was to analyse the lactate threshold (LT) changes in rats submitted to an aerobic treadmill-training programme. Twenty-five Wistar rats were divided into two groups: a sedentary control group (CG), and a trained group (TG) submitted to an aerobic training during 5 weeks. All the animals were submitted to an incremental treadmill exercise test in order to determine LT. There was an increase in the maximum running speed in the TG (from 32.25 ± 1.27 to 47.75 ± 3.13 m.min-1 - p = 0.001), and running speed at LT (from 26.21 ± 1.15 to 35.30 ± 2.24 m.min-1 - p = 0.004), a part from the reduction in blood lactate at LT. LT can be determined in rats, and aerobic training induced positive oxidative physiological adaptations in the animals.

Environment-driven reactivity of H2 on PdRu surface alloys.

The dissociative adsorption of molecular hydrogen on Pd(x)Ru(1-x)/Ru(0001) (0 ≤ x ≤ 1) has been investigated by means of He atom scattering, Density Functional Theory and quasi-classical trajectory calculations. Regardless of their surroundings, Pd atoms in the alloy are always less reactive than Ru ones. However, the reactivity of Ru atoms is enhanced by the presence of nearest neighbor Pd atoms. This environment-dependent reactivity of the Ru atoms in the alloy provides a sound explanation for the striking step-like dependence of the initial reactive sticking probability as a function of the Pd concentration observed in experiments. Moreover, we show that these environment-dependent effects on the reactivity of H2 on single atoms allow one to get around the usual constraint imposed by the Brønsted-Evans-Polanyi relationship between the reaction barrier and chemisorption energy.

Genetic variability in the ITS and IGS regions of the ribosomal DNA of Acremonium cavaraeanum exhibiting antimicrobial activity.

Endophytic microorganisms represent promising alternatives for obtaining new drugs of biotechnological importance. In this study, the endophytic species Acremonium cavaraeanum (A1a) isolated from Cocos nucifera was cultivated for the production of secondary metabolites, and its extracts and fractions were evaluated by the dilution method (MIC). The EtOAc extracts and MeOH fractions were tested against Gram-positive and -negative bacteria, and had an MIC of 125 µg/mL when evaluated in the EtOAc extract (EBI). The EtOAc extract (EBII) had an MIC of 62.25 µg/mL for Staphylococcus aureus and an MIC between 125 and 250 µg/mL for Gram-negative bacteria. The methanolic fractions showed activity with MIC between 125 and 250 µg/mL for all bacteria tested. The IGS region of the rDNA repeat unit of genomic DNA was analyzed by PCR/RFLPs, including endonucleases PstI, BamHII, HinfI, and EcoRI. The physical maps showed different restriction sites for the 6 Acremonium sp isolates, and revealed 5 RFLP patterns. The results showed that isolates of the same Acremonium species exhibited variation in this specific region. The sequences of ITS1-5.8S-ITS2 regions were aligned by Clustal W using the neighbor joining method, which grouped the isolates into 5 distinct clusters. This study aimed to evaluate the genetic diversity of A. cavaraeanum crops exhibiting antibacterial activity. The results of this study indicate that different fungal genetic isolates have biotechnological potential for the production of active bio-compounds against several human pathogens.