34 research outputs found
Effect of Polydextrose on the Growth of Pediococcus pentosaceus as Well as Lactic Acid and Bacteriocin-like Inhibitory Substances (BLIS) Production
Pediococcus pentosaceus was cultivated in MRS medium supplemented or not with polydextrose under different conditions in order to evaluate its effect on cell growth, lactic acid and bacteriocin-like inhibitory substance (BLIS) production. Independent variables were pH (4.0, 5.0, 6.0), rotational speed (50, 100, 150 rpm), polydextrose concentration (0.5, 1.0, 1.5%) and temperature (25, 30, 35 °C), while cell concentration and productivity after 24 h, maximum specific growth rate, specific rate of substrate (glucose) consumption, volumetric and specific lactic acid productivities, yields of biomass and lactic acid on consumed substrate were the dependent . The maximum cell concentration (10.24 ± 0.16 gX L−1) and productivity (0.42 ± 0.01gX L−1 h−1) were achieved at pH 6.0, 35 °C, 150 rpm using 1.5% polydextrose, while the maximum specific growth rate (0.99 ± 0.01 h−1) and yield of biomass (2.96 ± 0.34gX gS−1) were achieved at the same pH and polydextrose concentration, but at 25 °C and 50 rpm. The specific substrate consumption rate (0.09 ± 0.02 gS gX−1 h−1) and the volumetric lactic acid productivity (0.44 ± 0.02 gP L−1 h−1) were maximized at pH 6.0, 35 °C, 50 rpm and 0.5% polydextrose. BLIS produced in this last run displayed the highest antibacterial activity against Escherichia coli, while the same activity was displayed against Enterococcus faecium using 1.5% polydextrose. These results appear to be quite promising in view of possible production of this BLIS as an antibacterial agent in the food industr
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Dual antibacterial mechanism of [K4K15]CZS-1 against Salmonella Typhimurium: a membrane active and intracellular-targeting antimicrobial peptide
Salmonella genus is a leading cause of food-borne infections with strong public health impact and economic ramifications. The development of antimicrobial resistance added complexity to this scenario and turned the antibiotic drug discovery into a highly important challenge. The screening of peptides has served as a successful discovery platform to design new antibiotic candidates. Motivated by this, the antimicrobial and cytotoxic properties of three cruzioseptins against Salmonella Typhimurium and RAW 264.7 murine macrophage cells, respectively, were investigated. [K4K15]CZS-1 was the most potent antimicrobial peptide identified in the screening step with a minimum inhibitory concentration (MIC) of 16 μg/mL (7.26 μM) and moderate cytotoxicity. From a structural point of view, in vitro and in silico techniques evidenced that [K4K15]CZS-1 is a α-helical cationic antimicrobial peptide. In order to capture mechanistic details and fully decipher their antibacterial action, we adopted a multidimensional approach, including spectroscopy, electron microscopy and omics analysis. In general lines, [K4K15]CZS-1 caused membrane damage, intracellular alterations in Salmonella and modulated metabolic pathways, such as the tricarboxylic acid (TCA) cycle, fatty acid biosynthesis, and lipid metabolism. Overall, these findings provide deeper insights into the antibacterial properties and multidimensional mode of action of [K4K15]CZS-1 against Salmonella Typhimurium. In summary, this study represents a first step toward the screening of membrane-acting and intracellular-targeting peptides as potential bio-preservatives to prevent foodborne outbreaks caused by Salmonella
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study
: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Worldwide trends in population-based survival for children, adolescents, and young adults diagnosed with leukaemia, by subtype, during 2000–14 (CONCORD-3) : analysis of individual data from 258 cancer registries in 61 countries
Background Leukaemias comprise a heterogenous group of haematological malignancies. In CONCORD-3, we analysed
data for children (aged 0–14 years) and adults (aged 15–99 years) diagnosed with a haematological malignancy
during 2000–14 in 61 countries. Here, we aimed to examine worldwide trends in survival from leukaemia, by age and
morphology, in young patients (aged 0–24 years).
Methods We analysed data from 258 population-based cancer registries in 61 countries participating in CONCORD-3
that submitted data on patients diagnosed with leukaemia. We grouped patients by age as children (0–14 years),
adolescents (15–19 years), and young adults (20–24 years). We categorised leukaemia subtypes according to the
International Classification of Childhood Cancer (ICCC-3), updated with International Classification of Diseases
for Oncology, third edition (ICD-O-3) codes. We estimated 5-year net survival by age and morphology, with 95% CIs,
using the non-parametric Pohar-Perme estimator. To control for background mortality, we used life tables by
country or region, single year of age, single calendar year and sex, and, where possible, by race or ethnicity. All-age
survival estimates were standardised to the marginal distribution of young people with leukaemia included in the
analysis.
Findings 164563 young people were included in this analysis: 121328 (73·7%) children, 22963 (14·0%) adolescents, and
20272 (12·3%) young adults. In 2010–14, the most common subtypes were lymphoid leukaemia (28205 [68·2%] patients)
and acute myeloid leukaemia (7863 [19·0%] patients). Age-standardised 5-year net survival in children, adolescents, and
young adults for all leukaemias combined during 2010–14 varied widely, ranging from 46% in Mexico to more than
85% in Canada, Cyprus, Belgium, Denmark, Finland, and Australia. Individuals with lymphoid leukaemia had better
age-standardised survival (from 43% in Ecuador to ≥80% in parts of Europe, North America, Oceania, and Asia) than
those with acute myeloid leukaemia (from 32% in Peru to ≥70% in most high-income countries in Europe,
North America, and Oceania). Throughout 2000–14, survival from all leukaemias combined remained consistently
higher for children than adolescents and young adults, and minimal improvement was seen for adolescents and young
adults in most countries.
Interpretation This study offers the first worldwide picture of population-based survival from leukaemia in children,
adolescents, and young adults. Adolescents and young adults diagnosed with leukaemia continue to have lower
survival than children. Trends in survival from leukaemia for adolescents and young adults are important indicators
of the quality of cancer management in this age group.peer-reviewe
Otimização do rendimento de substância semelhante a bacteriocina (BLIS) produzido por Pediococcus pentosaceus e sua aplicação como bioconservante de alimentos.
Bacteriocins are peptides produced by various species of bacteria, especially lactic acid bacteria (LABs), which exhibit a large spectrum of action against spoilage bacteria and foodborne pathogens. However, when this bacteriocin has not been completely characterized regarding its amino acid and the nucleotide sequences of the corresponding gene, the qualified term bacteriocin-like inhibitory substance (BLIS) is recommended. In order to increase the antimicrobial activity of bacteriocins, the ability of probiotics LABs, such as Pediococcus pentosaceus, to ferment different carbon and nitrogen sources has been studied. For the development of an improved culture medium, carbon and nitrogen sources must be considered as nutrients responsible for cell growth and bacteriocin production. The best condition, after 48 h of cultivation, for growth (3.420 g/L) and for BLIS production by Pediococcus pentosaceus ATCC 43200 was in Man, Rogosa and Sharp (MRS) culture medium supplemented with 1.5% peptone, initial pH 6.0 and under the following culture conditions: anaerobiosis, 30oC and agitation of 200 rpm. Compared with control (MRS without supplement), the growth of Pediococcus was significantly lower (1.995 g/L) as well as it reduced significantly its generation time from 2.05 h (control) to 1.28 h (MRS supplemented), a reduction of approximately 62.5%. Moreover, addiction of peptone to MRS medium promoted reduction of 4 h to the Pediococcus exponential phase onset. Regarding BLIS antimicrobial activity, addition of nitrogen source to MRS medium was also quite significant. Through the agar diffusion method, BLIS showed inhibition halos between 12.50 and 19.50 mm against LABs strains (Lactobacillus sakei ATCC 15521, Lactobacillus plantarum CECT 221 and Carnobacterium piscicola CECT 4020). Against Listeria strains (Listeria innocua NCTC 111288 and Listeria seeligeri NCTC 11289), their antimicrobial activity was better detected in liquid medium assay, evaluating the minimal inhibitory concentration of 50%. BLIS was able to inhibit 60 and 100% of L. seeligeri and L. innocua, respectively, as well as, diluted 1x (v/v) in water was able to inhibit 100% growth of both Listeria. BLIS 17 showed also good results as food preservative when applied in ready-to-eat pork ham artificially contaminated with L. seeligeri in vacuum-package at 4oC during shelf life of 10 days. BLIS was able to maintain low Listeria multiplication, lower samples weight loss, low lipid peroxidation and good color parameters during samples storage. Results demonstrated the importance of optimizing the culture medium to increase microbial mass, to produce and to improve the activity of this antimicrobial molecule. Moreover, results also suggest the possible application of BLIS as a natural food preservative.Bacteriocinas são peptídeos produzidos por várias espécies de bactérias, especialmente bactérias ácido-láticas (BALs) e apresentam um amplo espectro de ação contra bactérias deteriorantes e patógenos de origem alimentar. Entretanto, quando estas bacteriocinas não foram completamente caracterizadas quanto a sequência de seus nucleotídeos e do seu gene correspondente, é recomendada a denominação de substância semelhante a bacteriocina (BLIS). Para aumentar a atividade antimicrobiana de bacteriocinas, a habilidade de BALs probióticas, como Pediococcus pentosaceus, em fermentar diferentes fontes de carbono e nitrogênio tem sido estudado. Para o desenvolvimento de um meio de cultura melhorado, fontes de carbono e nitrogênio devem ser consideradas como nutrientes responsáveis pelo crescimento celular e pela produção de bacteriocina. A melhor condição, após 48 h de cultivo, para o crescimento (3,420 g/L) e para a produção de BLIS por P. pentosaceus ATCC 43200 foi em meio de cultivo Man, Rogosa e Sharp (MRS) suplementado com 1,5% de peptona, pH inicial 6,0 e sob as seguintes condições de cultivo: anaerobiose, 30oC e agitação de 200 rpm. Comparado ao controle (MRS sem suplementação), o crescimento de Pediococcus foi significativamente menor (1,995 g/L) assim, como também, reduziu significativamente o tempo de geração de 2,05 h (controle) para 1,28 h (MRS suplementado), uma redução de aproximadamente 62,5%. Além disso, a adição de peptona ao meio MRS promoveu redução de 4 h para o início da fase exponencial de Pediococcus. Quanto a atividade antimicrobiana de BLIS, a adição de fonte de nitrogênio ao meio MRS também foi bastante significativa. Através do método ágar difusão, BLIS apresentou halos de inibição entre 12,50 a 19,50 mm contra cepas de BALs (Lactobacillus sakei ATCC 15521, Lactobacillus plantarum CECT 221 e Carnobacterium piscicola CECT 4020). Contra cepas de Listeria (Listeria innocua NCTC 11288 e Listeria seeligeri NCTC 11289), a sua atividade inibitória foi melhor detectada em meio líquido, através da determinação da concentração mínima inibitória de 50%. BLIS sem diluição foi capaz de inibir 60 e 100% de L. seeligeri e L. innocua, 15 respectivamente, assim como, diluído 1x (v/v) em água foi capaz de inibir 100% o crescimento de ambas Listeria. BLIS também apresentou bons resultados como conservante de alimento quando aplicado em presunto contaminado artificialmente com L. seeligeri e armazenado a 4oC a vácuo por 10 dias. BLIS foi capaz de manter baixa a multiplicação de Listeria, menor perda de peso das amostras, baixa peroxidação lipídica e bons parâmetros de cor durante o armazenamento das amostras. Os resultados demonstraram a importância de se otimizar meio de cultivo tanto para o aumento da massa microbiana como para a produção e melhoramento da atividade desta molécula antimicrobiana. Além disso, os resultados também sugerem a possível aplicação de BLIS como conservante natural de alimentos