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OBJECTIVE: Pediocin PA-1, an antimicrobial peptide derived from Pediococcus acidilactici PAC1.0, has a potential application as a food preservative thanks to its strong inhibitory activity against the foodborne pathogen L. monocytogenes. This study aimed to produce Pediocin PA-1 from the yeast P. pastoris and evaluate its characteristics. METHODS: Gene encoding Pediocin PA-1 was integrated into P. pastoris X33 genome to establish the strain X33::ped, which could produce and secrete this peptide into culture medium. The antimicrobial activity of Pediocin PA-1 was examined using agar diffusion assay. The stability of pediocin PA-1 was determined based on its remaining antibacterial activity after exposure to proteases and extreme pH and temperatures. The potential use of this bacteriocin in food preservation was demonstrated using the L. monocytogenes infected pork bologna. The anticancer activity of Pediocin PA-1 was also investigated on some cancer cells using MTT assay. RESULTS: We established the yeast P. pastoris X33::ped capable of producing pediocin PA-1 with antimicrobial activity against L. monocytogenes and some other harmful bacteria. Pediocin PA-1 was stable at 100ËC and resistant against pH 1-12 for 1 h, but susceptible to trypsin, α-chymotrypsin, and proteinase K. This peptide could reduce the number of L. monocytogenes in pork bologna by 3.59 log CFU/g after 7 days of storage at 4ËC. Finally, Pediocin PA-1 (25 µg/ml) inhibited the proliferation of A549 and Hela cancer cells. CONCLUSION: We succeeded in producing active Pediocin PA-1 from P. pastoris and demonstrated its potential use in food preservation and pharmaceutical industry.
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Conservación de Alimentos , Listeria monocytogenes , Pediocinas , Pediocinas/farmacología , Pediocinas/genética , Animales , Conservación de Alimentos/métodos , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/genética , Humanos , Antibacterianos/farmacología , Clonación Molecular , Porcinos , Pruebas de Sensibilidad Microbiana , Bacteriocinas/farmacología , Bacteriocinas/genética , Bacteriocinas/metabolismo , Pediococcus acidilactici/genética , Pediococcus acidilactici/metabolismo , Expresión Génica , Saccharomycetales/genética , Saccharomycetales/metabolismo , Saccharomycetales/efectos de los fármacosRESUMEN
Helicobacter pylori is the most common cause of gastroduodenal diseases. The concept that cagA-positive H. pylori is a risk factor for gastric cancer appears to be true only for H. pylori strains from Western countries. Other virulent genes may have a synergistic interaction with cagA during pathogenesis. This study aims to investigate H. pylori cagA, vacA, and iceA prevalence, genotypes, and their association to clinical outcomes in Vietnamese patients. The cagA status and vacA and iceA genotypes were determined using the PCR technique on DNA extracted from gastric biopsies of 141 patients with gastroduodenal diseases. After performing molecular analysis for cagA, vacA, and iceA genes, samples with mixed H. pylori strains, positivity, or negativity for both cagA and cagPAI-empty site, or unidentified genotypes were excluded. Finally, 107 samples were examined. The presence of the cagA, vacA, and iceA genes were detected in 77.6%, 100%, and 80.4% of cases, respectively. Notably, cagA( +) with EPIYA-ABD, vacA s1i1m1, vacA s1i1m2, iceA1, and iceA2 accounted for 73.8%, 44.9%, 33.6%, 48.6%, and 31.8% of cases, respectively. Four iceA2 subtypes (24-aa, 59-aa, 94-aa, and 129-aa variants) were found, with the 59-aa variant the most prevalent (70.6%). The cagA( +)/vacAs1i1m1/iceA1 and cagA( +)/vacAs1i1m2/iceA1 combinations were found in 26.2% and 25.1% of cases, respectively. A multivariable logistic regression analysis was performed, after adjusting for age and gender, with the gastritis group was used as a reference control. Statistically significant associations were found between the vacA s1i1m2 genotype, the iceA1 variant, and the cagA( +)/vacAs1i1m2/iceA1 combination and gastric cancer; the adjusted ORs were estimated as 18.02 (95% CI: 3.39-95.81), 4.09 (95% CI: 1.1-15.08), and 16.19 (95% CI: 3.42-76.66), respectively. Interestingly, for the first time, our study found that vacA s1i1m2, but not vacA s1i1m1, was a risk factor for gastric cancer. This study illustrates the genetic diversity of the H. pylori cagA, vacA, and iceA genes across geographical regions and contributes to understanding the importance of these genotypes for clinical outcomes.
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Antígenos Bacterianos , Proteínas Bacterianas , Genotipo , Infecciones por Helicobacter , Helicobacter pylori , Humanos , Proteínas Bacterianas/genética , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Helicobacter pylori/clasificación , Helicobacter pylori/patogenicidad , Vietnam/epidemiología , Antígenos Bacterianos/genética , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/epidemiología , Estudios Transversales , Masculino , Femenino , Persona de Mediana Edad , Adulto , Proteínas de la Membrana Bacteriana Externa/genética , Anciano , Adulto Joven , Prevalencia , Factores de Virulencia/genéticaRESUMEN
A balanced microbiota-microorganisms that live in the gut-is crucial in the early years of a child's life, while dysbiosis-altered microbiota-has been linked to the development of various diseases. Probiotics, such as Alkalihalobacillus clausii, are commonly used to restore the balance of gut microbiota and have shown additional antimicrobial and immunomodulatory properties. Intake of micronutrients can affect the structure and function of the gut barrier and of the microbiota by having multiple effects on cellular metabolism (e.g., immunomodulation, gene expression, and support structure proteins). An inadequate zinc intake increases the risk of deficiency and associated immune dysfunctions; it is responsible for an increased risk of developing gastrointestinal diseases, respiratory infections, and stunting. Paediatric zinc deficiency is a public health concern in many countries, especially in low-income areas. Currently, zinc supplementation is used to treat childhood diarrhoea. This review examines how combining A. clausii and zinc could improve dysbiosis, gut health, and immunity. It suggests that this combination could be used to prevent and treat infectious diseases and diarrhoea in children up to adolescence.
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Microbioma Gastrointestinal , Probióticos , Humanos , Niño , Zinc/farmacología , Disbiosis , Diarrea/tratamiento farmacológicoRESUMEN
OBJECTIVE: Mucociliary transport function in the airway mucosa is essential for maintaining a clean mucosal surface. This function is impaired in upper and lower airway diseases. Nasal polyps are a noticeable pathological feature that develop in some of the patients with chronic rhinosinusitis. Like ordinary nasal mucosae, nasal polyps have a ciliated pseudostratified epithelium with vigorous ciliary beating. We measured ex vivo Mucociliary Transport Velocity (MCTV) and Ciliary Beat Frequency (CBF) and explored the expressions of Planar Cell Polarity (PCP) proteins in nasal polyps in comparison with turbinate mucosae. METHODS: Inferior turbinates and nasal polyps were surgically collected from patients with chronic rhinosinusitis. Ex vivo MCTV and CBF were measured using a high-speed digital imaging system. Expressions of PCP proteins were explored by fluorescence immunohistochemistry and quantitative RT-PCR. RESULTS: The MCTV of nasal polyps was significantly lower than that of the turbinates (7.43⯱â¯2.01 vs. 14.56⯱â¯2.09⯵m/s; pâ¯=â¯0.0361), whereas CBF did not differ between the two tissues. The MCTV vector was pointed to the posteroinferior direction in all turbinates with an average inclination angle of 41.0 degrees. Immunohistochemical expressions of Dishevelled-1, Dishevelled-3, Frizzled3, Frizzled6, Prickle2 and Vangl2 were lower in the nasal polyps than in the turbinates. Confocal laser scanning microscopy showed that Frizzled3 was localized along the cell junction on the apical surface. The expression levels of mRNAs for Dishevelled-1, Dishevelled-3 and Frizzled3 in the nasal polyps were also decreased in comparison with the turbinates. CONCLUSION: These results indicate that muco ciliary transport in nasal polyps is impaired although vigorous ciliary beating is maintained, and that the impairment may be caused by a decrease in Dishevelled/Frizzled proteins and resultant PCP disarrangement. LEVEL OF EVIDENCE: Level 3.
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Pólipos Nasales , Sinusitis , Humanos , Pólipos Nasales/metabolismo , Depuración Mucociliar , Cilios/metabolismo , Cilios/patología , Mucosa Nasal/metabolismo , Sinusitis/metabolismoRESUMEN
Abstract Objective Mucociliary transport function in the airway mucosa is essential for maintaining a clean mucosal surface. This function is impaired in upper and lower airway diseases. Nasal polyps are a noticeable pathological feature that develop in some of the patients with chronic rhinosinusitis. Like ordinary nasal mucosae, nasal polyps have a ciliated pseudostratified epithelium with vigorous ciliary beating. We measured ex vivo Mucociliary Transport Velocity (MCTV) and Ciliary Beat Frequency (CBF) and explored the expressions of Planar Cell Polarity (PCP) proteins in nasal polyps in comparison with turbinate mucosae. Methods Inferior turbinates and nasal polyps were surgically collected from patients with chronic rhinosinusitis. Ex vivo MCTV and CBF were measured using a high-speed digital imaging system. Expressions of PCP proteins were explored by fluorescence immunohistochemistry and quantitative RT-PCR. Results The MCTV of nasal polyps was significantly lower than that of the turbinates (7.43 ± 2.01 vs. 14.56 ± 2.09 μm/s; p= 0.0361), whereas CBF did not differ between the two tissues. The MCTV vector was pointed to the posteroinferior direction in all turbinates with an average inclination angle of 41.0 degrees. Immunohistochemical expressions of Dishevelled-1, Dishevelled-3, Frizzled3, Frizzled6, Prickle2 and Vangl2 were lower in the nasal polyps than in the turbinates. Confocal laser scanning microscopy showed that Frizzled3 was localized along the cell junction on the apical surface. The expression levels of mRNAs for Dishevelled-1, Dishevelled-3 and Frizzled3 in the nasal polyps were also decreased in comparison with the turbinates. Conclusion These results indicate that muco ciliary transport in nasal polyps is impaired although vigorous ciliary beating is maintained, and that the impairment may be caused by a decrease in Dishevelled/Frizzled proteins and resultant PCP disarrangement. Level of evidence: Level 3.
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Plant diseases caused by phytopathogenic fungi are one of the leading factors affecting crop loss. In the present study, sixty-one Streptomyces strains were screened for their antifungal activity against relevant wide range fungal pathogens prominent in Vietnam, namely Lasiodiplodia theobromae, Fusarium fujikuroi, and Scopulariopsis gossypii. Endophytic strain RC2 was the most effective strain in the mycelial inhibition of the tested fungi. Based on phenotypic characteristics, 16S rDNA gene analysis, and genomic analysis, strain RC2 belonged to Streptomyces albus. An ethyl acetate extract of S. albus RC2 led to the strong growth inhibition of S. gossypii Co1 and F. fujikuroi L3, but not L. theobromae N13. The crude extract also suppressed the spore germination of S. gossypii Co1 and F. fujikuroi L3 to 92.4 ± 3.2% and 87.4% ± 1.9%, respectively. In addition, the RC2 extract displayed potent and broad-spectrum antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and the phytopathogenic bacteria Ralstonia solanacearum and Xanthomonas oryzae. The genome of strain RC2 was sequenced and revealed the presence of 15 biosynthetic gene clusters (BGCs) with similarities ≥ 45% to reference BGCs available in the antiSMASH database. The UPLC-HRMS analysis led to the identification of 8 other secondary metabolites, which have not been reported in S. albus. The present study indicated that RC2 could be a potent biocontrol agent against phytopathogenic fungi. Further attention should be paid to antifungal metabolites without functional annotation, development of product prototypes, and greenhouse experiments to demonstrate effective control of the plant diseases.
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Antifúngicos , Streptomyces , Antifúngicos/farmacología , Genómica , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiologíaRESUMEN
Introduction: Aflatoxins B1 are among the most common poisonous mycotoxins produced by certain fungi that harm animals and crops. Mycotoxins can cause a variety of adverse health effects and pose a serious health threat to humans. The Maximum Residue Limits of aflatoxin B1 in processed cereals and ingredients are 2 parts per billion (ppb) and 5 ppb, respectively. Objectives: To evaluate the status of aflatoxin B1 contamination in rice, corn and staple food produced in Ha Giang province compared with the maximum permitted levels. Methods: A total of 210 rice and maize samples were analyzed to quantify the level of aflatoxin B1. Analysis of mycotoxins was conducted by High Performance Liquid Chromatography using a fluorescence detector. Results: It was found that rice, rice products, maize, and maize products had a mean aflatoxin B1 content of 1.79 ppb, 2.55 ppb, 2.19 ppb, and 6.35 ppb, respectively. The results also showed that 71.9 percent of samples were contaminated with mycotoxins, and 14.28 percent of samples exceeded the maximum allowable limit. Conclusion: The concentration of aflatoxin B1 in 14.28 percent of the samples are over permissible limits by nationwide regulations (AU)
Introducción: La aflatoxina B1 se encuentra entre las micotoxinas más comunes y venenosas producidas por ciertos hongos que dañan a los animales y los cultivos. Las micotoxinas pueden causar una variedad de efectos adversos para la salud y representar una grave amenaza para la salud de los seres humanos. Los límites máximos de residuos de aflatoxina B1en cereales e ingredientes procesados son de 2 ppb y 5 ppb, respectivamente. Objetivos: Evaluar el estado de contaminación por aflatoxina B1 en arroz, maíz y alimentos básicos producidos en la provincia de Ha Giang, en comparación con los niveles máximos permitidos. Métodos: Se analizaron un total de 210 muestras de arroz y maíz para cuantificar el nivel de aflatoxina B1. El análisis de micotoxinas se realizó mediante cromatografía líquida de alta resolución, utilizando un detector de fluorescencia. Resultados: Se encontró que el arroz, los productos de arroz, el maíz y los productos de maíz tenían un contenido medio de aflatoxin B1, de 1,79 ppb, 2,55 ppb, 2,19 ppb y 6,35 ppb, respectivamente. Los resultados también mostraron que el 71,9 por ciento de las muestras estaban contaminadas con micotoxinas y el 14,28 por ciento de las muestras excedieron el límite máximo permitido. Conclusión: La concentración de aflatoxina B1 en el 14,28 por ciento de las muestras está por encima de los límites permisibles por la norma nacional(AU)
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Oryza , Contaminación de Alimentos , Cromatografía Líquida de Alta Presión/métodos , Aflatoxina B1/toxicidad , Zea mays , Micotoxinas/análisis , Producción de Cultivos/métodosRESUMEN
ABSTRACT: This study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg / mL) and CS 625 (C. sinensis extract 625 µg / mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage.
RESUMO: O objetivo deste estudo foi investigar os efeitos do extrato de folhas de chá verde (Camellia sinensis) na qualidade de filés de bagre listrado (Pangasianodon hypophthalmus) durante 18 meses de armazenamento congelado (-20 ± 2 ° C). O estudo incluiu três tratamentos: imersão dos filés de bagre listrado em água fria da torneira como um tratamento de controle, em solução de extrato de Camellia sinensis 7,63 µg / mL e em solução de extrato de Camellia sinensis 625 µg / mL. As amostras foram armazenadas por 18 meses e as coletas foram feitas aos zero, um, três, seis, nove, 12 e 18 meses. Os parâmetros avaliados incluíram contagem viável total, parâmetros físico-químicos (capacidade de retenção de água, nitrogênio básico volátil total, valor de peróxido, substâncias reativas ao ácido tiobarbitúrico, umidade e pH), propriedades sensoriais e medição de cor. Os resultados mostraram que os filés de bagre listrado tratados com extratos de Camellia sinensis reduziram ligeiramente a oxidação de lipídios, inibiram o crescimento de bactérias e aumentaram as propriedades sensoriais em comparação com as amostras não tratadas. Além disso, o tratamento do extrato de Camellia sinensis não afetou o pH, a umidade, a capacidade de retenção de água, o nitrogênio básico volátil total e a cor do filé durante o armazenamento congelado. Com base na contagem viável total, parâmetros físico-químicos e qualidade sensorial, pode-se concluir que filés de bagre listrados não tratados ou tratados com extratos de Camellia sinensis (7,63 e 625 µg / mL) podem ser usados por até 18 meses.
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This study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg / mL) and CS 625 (C. sinensis extract 625 µg / mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage.
O objetivo deste estudo foi investigar os efeitos do extrato de folhas de chá verde (Camellia sinensis) na qualidade de filés de bagre listrado (Pangasianodon hypophthalmus) durante 18 meses de armazenamento congelado (-20 ± 2 ° C). O estudo incluiu três tratamentos: imersão dos filés de bagre listrado em água fria da torneira como um tratamento de controle, em solução de extrato de Camellia sinensis 7,63 µg / mL e em solução de extrato de Camellia sinensis 625 µg / mL. As amostras foram armazenadas por 18 meses e as coletas foram feitas aos zero, um, três, seis, nove, 12 e 18 meses. Os parâmetros avaliados incluíram contagem viável total, parâmetros físico-químicos (capacidade de retenção de água, nitrogênio básico volátil total, valor de peróxido, substâncias reativas ao ácido tiobarbitúrico, umidade e pH), propriedades sensoriais e medição de cor. Os resultados mostraram que os filés de bagre listrado tratados com extratos de Camellia sinensis reduziram ligeiramente a oxidação de lipídios, inibiram o crescimento de bactérias e aumentaram as propriedades sensoriais em comparação com as amostras não tratadas. Além disso, o tratamento do extrato de Camellia sinensis não afetou o pH, a umidade, a capacidade de retenção de água, o nitrogênio básico volátil total e a cor do filé durante o armazenamento congelado. Com base na contagem viável total, parâmetros físico-químicos e qualidade sensorial, pode-se concluir que filés de bagre listrados não tratados ou tratados com extratos de Camellia sinensis (7,63 e 625 µg / mL) podem ser usados ââpor até 18 meses.
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Té , Extractos Vegetales/administración & dosificación , Industria Pesquera , Camellia sinensis , Almacenamiento de Alimentos , CongelaciónRESUMEN
Abstract This study investigated the changes in the ingredients in Fallopia multiflora Thunb. Haraldson (FMT) root after processing it with different methods such as soaking, stewing, and steaming or combined methods. The total polyphenol, 2,3,5,4'-tetrahydroxystilben-2-O-ß-D-glucoside (THSG), and physcion contents in FMT products after processing were determined using high-performance liquid chromatography (HPLC) and ultraviolet-visible (UV-VIS) methods. The results demonstrated that the processing method and time significantly affected the contents of polyphenol, THSG, and physcion. The physcion and total polyphenol content increased or decreased during processing depending upon the processing time, while the THSG content gradually decreased with an increase in the processing time. The content of physcion (a substance that can cause liver toxicity) was analysed, and the suitable conditions for processing of the FMT products were determined as initial soaking in rice swill for 24 h and subsequent stewing with black beans and water for 12 h
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Fallopia multiflora/genética , Métodos , Cromatografía Líquida de Alta Presión/métodos , Polifenoles/agonistas , Hígado/anomalíasRESUMEN
Psoriasis is a common chronic, immune-mediated inflammatory disease of the skin. PSORS1C3 is a non-protein coding gene, of which the RNA transcript is found in psoriatic patients. CARD14 is mainly expressed in epidermal keratinocytes. TLR4 is a transmembrane protein to recognize microbial antigens. Our study aimed to assess the relationship among PSORS1C3, CARD14 and TLR4 polymorphisms, inflammatory expression and psoriasis susceptibility. To the end, 71 patients with psoriasis and 46 healthy individuals with the well-characterized clinical profiles were enrolled. Gene polymorphisms were determined by Sanger DNA sequencing and secretion of cytokines by ELISA. As a result, genetic analysis of PSORS1C3 gene identified nine SNPs and three haplotype blocks. Sequencing of the CARD14 gene determined eight SNPs and one haplotype block. Sequencing of TLR4 gene identified nine SNPs, in which a SNP rs1018673641 was found to exert deleterious effect. The linkage disequilibrium analysis showed that seven variants in PSORS1C3 gene and three SNPs in CARD14 gene were in tightly linked. More importantly, a significant association between IL-6 level and rs1018673641 AT genotype in TLR4 gene was detected in psoriatic patients. In conclusion, the PSORS1C3, CARD14 and TLR4 polymorphisms and haplotypes may be correlated with risk of suffering psoriasis and the IL-6-mediated chronic inflammation in psoriasis could be partially regulated by the TLR4 functional variant.
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Common Palm Civet (Paradoxurus hermaphroditus) is a rare mammal appearing in South and Southeast Asia, first described in 1777. An expensive coffee is made of beans eaten and rejected by civets. In Vietnam, the animals are increasingly captured and kept captive to sell these beans, which has adversely affected their population. Because of the detrimental effects of stress, studying stress responses is important for this wildlife conservation. The stress response of the Common Palm Civet was investigated through the concentration of glucocorticoid hormones in feces under different conditions such as translocation and forced-pairing during the breeding season, among others. This is a non-invasive method for measuring glucocorticoid hormones in captive Common Palm Civet in Vietnam. Our results validated that fecal glucocorticoid metabolites (FGM) accurately reflect circulating glucocorticoid stress hormones in Common Palm Civet. FGM increased under adrenocorticotropic hormone stimulation and during the breeding season (April and NovemberDecember). FGM during estrus and parturition was high as well in female civets. Stress response was also observed in case of forced-pairing or residence change. These data could be useful for research and the conservation of this species.
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Animales , Estrés Fisiológico , Conducta Animal , Corticosterona/fisiología , Hormona Adrenocorticotrópica/análisis , Viverridae/fisiología , Glucocorticoides/análisis , Vietnam , Conservación de los Recursos Naturales , Animales SalvajesRESUMEN
Feather pecking behavior is regarded as the most serious welfare concern in poultry layer production. The cause of feather pecking is partly due to the nutrient-deficient diets that further depletes the tryptophan levels in the animal's system. Tryptophan is an essential amino acid and thus, cannot be synthesized in the body of animals, including poultry. This amino acid can be metabolized through three pathways. Tryptophan metabolism produces important metabolites: serotonin and melatonin. Tryptophan affects hormone secretion in poultry. Thus, it affects poultry's psychological status, which eventually leads to feathers' pecking. The application of tryptophan as a feed additive can improve poultry performance and alleviate feather pecking behavior or stress response in poultry production. This is achieved through indole pathways and mostly through the Tryptophan-Kynurenine pathway. This review paper aims to provide detailed information regarding the performance of tryptophan on feather pecking behavior, particularly in laying poultry animals.
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Animales , Estrés Psicológico/prevención & control , Triptófano/administración & dosificación , Conducta Animal , Pollos , Plumas , Pico , Bienestar del AnimalRESUMEN
Production of indole-3-acetic acid (IAA) is well documented in various studies for the bacteria that inhabit the rhizosphere of plants, but with roots of wet rice, the outstandings have been not yet elucidated. This study began with the isolation of bacteria type strain Azospirillum sp. and developed the investigation to a screening of their ability in IAA production. This screening conducted a selection of only bacteria that was capable of the production of IAA with its content of over 25 µg. mL-1 for sequencing. Of 10 isolates only one resulted from the type strain Azospirillum brasilense (A. brasilense) with a similarity of 100%. Various factors that influence A. brasilense in biosynthesizing IAA such as temperature, pH, nitrogen presence and concentration of tryptophan in the culture medium were examined. The results indicated that the culture conditions were suitable for IAA biosynthesis at pH 6.5, 30 °C, culture media with nitrogen, and 0.1% trytophan. The next survey on the role of the immobilization of this bacteria with microalgae in alginate was highlighted to its support in microalgal growth. With the co-immobilization of bacteria and microalgae, the density of Chlorella vulgaris was significantly increased during 15-day culture, inducing 2.2 times of cell content in culture batch microalgae immobilized A. brasilense higher than that free-bacteria.
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Azospirillum brasilense , Chlorella vulgaris , Microalgas , Oryza , Medios de Cultivo , Ácidos Indolacéticos , Nitrógeno , VietnamRESUMEN
ABSTRACTS Introduction: Milk and dairy products are nutritious and can play a significant role in a healthy diet. The safety of milk decreases with increasing concentration of arsenic. The Maximum Residue Limits of arsenic is 500 parts per billion (ppb). Objectives: To evaluate the status of arsenic contamination of milk and dairy products produced and processed in some provinces and cities of Vietnam. Methods: A total of 367 samples were tested. Samples were digested before analysis to remove organic compounds, and the total arsenic content determined by atomic absorption spectrophotometry. Results: The average concentrations of total arsenic in liquid milk were 139.32 ppb; in yogurt, 169.81 ppb; in cheese, 221.38 ppb; in milk cake, 232.80 ppb; and in milk powder, 35.43 ppb, respectively. Conclusion: The arsenic concentrations in some samples are higher than the maximum permitted levels according to national regulations.
RESUMEN Introducción: La leche y los productos lácteos son nutritivos y pueden desempeñar un papel importante en una dieta saludable. La seguridad de la leche disminuye con el aumento de la concentración de arsénico. Los límites máximos de residuos de arsénico son 500 ppb. Objetivos: Evaluar el estado de contaminación por arsénico de la leche y los productos lácteos producidos y procesados en algunas provincias y ciudades de Vietnam. Métodos: Se analizaron un total de 367 muestras. Las muestras se digirieron antes del análisis, para eliminar los compuestos orgánicos y se determinó el contenido total de arsénico mediante espectrofotometría de absorción atómica. Resultados: Las concentraciones promedio de arsénico total en la leche líquida fueron 139,32 ppb; en el yogur, 169,81 ppb; en el queso, 221,38 ppb; en el pastel de leche, 232,80 ppb; y en la leche en polvo, 35,43 ppb, respectivamente. Conclusión: Las concentraciones de arsénico en algunas muestras superan los niveles máximos permitidos según la normativa nacional.
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Abstract In this paper, the chemical constituents, larvicidal and antimicrobial activities of hydrodistilled essential oils from Zingiber castaneum Škorničk. & Q.B. Nguyễn and Zingiber nitens M.F. Newman were reported. The main constituents of Z. castaneum leaf were bicyclogermacrene (24.8%), germacrene D (12.9%), cis-β-elemene (11.2%) and β-pinene (10.3%), while sabinene (22.9%) and camphene (21.2%) were the significant compounds in the rhizome. However, the dominant compounds in the leaf of Z. nitens includes β-pinene (45.8%) and α-pinene (10.7%). Terpinen-4-ol (77.9%) was the most abundant compound of the rhizome. Z. castaneum rhizome oil displayed larvicidal activity against Aedes aegypti and Culex quinquefasciatus with LC50 values of 121.43 and 88.86 µg/mL, respectively, at 24 h. The leaf oil exhibited activity with LC50 values of 39.30 µg/mL and 84.97 µg/mL, respectively. Also, the leaf and rhizome oils of Z. nitens displayed greater larvicidal action towards Ae. aegypti with LC50 values of 17.58 µg/mL and 29.60 µg/mL, respectively. Only the rhizome oil displayed toxicity against Cx. quinquefasciatus with LC50 value of 64.18 µg/mL. All the studied essential oils inhibited the growth of Pseudomonas aeruginosa ATCC25923 with minimum inhibitory concentration (MIC) value of 50.0 µg/mL. This paper provides information on the larvicidal and antimicrobial potentials of Z. castaneum and Z. nitens essential oils.
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Abstract Endophytic bacteria from weed are emerging as valuable alternatives for biochemical pesticides in sustainable agriculture. This study aims to discover the antagonistic effects of some endophytic bacteria isolated from weed (Lactuca indica) against A. alternata, a casual of stem end rot disease of pitaya. A total of 14 endophytic bacteria were isolated and four of them presented in vitro antagonistic activity against A. alternata. Of four, strain L115 significantly inhibited the pathogenic growth with a mean inhibition diameter of 12.67 ± 0.02 mm, while the other three (strain L110, L111, and L114) showed a weak inhibition. The results indicated that strain L115 could belong to the Bacillaceae family while the other three (strain L110, L111, and L114) had characteristics of the Pseudomonadaceae family. Interestingly, strain L115 showed positive results for phosphate solubilization, indole acetic acid (IAA), and biofilm production, whereas three other strains presented weak capabilities for phosphate solubilization, biofilm production and IAA production. In addition, the filtrate of strain L115 presented antifungal activity on biocontrol tests in vitro. Especially, strain L115 significantly increased seedling biomass of pitaya and tomato compared to the control. Hence, these results suggest strain L115 has the potential to be used as biocontrol agents against A. alternata. More studies should be done in the future to evaluate their efficiency in field conditions.
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Little is known about the genetic diversity of Salmonella enterica serovar Typhi (S. Typhi) circulating in Latin America. It has been observed that typhoid fever is still endemic in this part of the world; however, a lack of standardized blood culture surveillance across Latin American makes estimating the true disease burden problematic. The Colombian National Health Service established a surveillance system for tracking bacterial pathogens, including S. Typhi, in 2006. Here, we characterized 77 representative Colombian S. Typhi isolates collected between 1997 and 2018 using pulse field gel electrophoresis (PFGE; the accepted genotyping method in Latin America) and whole genome sequencing (WGS). We found that the main S. Typhi clades circulating in Colombia were clades 2.5 and 3.5. Notably, the sequenced S. Typhi isolates from Colombia were closely related in a global phylogeny. Consequently, these data suggest that these are endemic clades circulating in Colombia. We found that AMR in S. Typhi in Colombia was uncommon, with a small subset of organisms exhibiting mutations associated with reduced susceptibility to fluoroquinolones. This is the first time that S. Typhi isolated from Colombia have been characterized by WGS, and after comparing these data with those generated using PFGE, we conclude that PFGE is unsuitable for tracking S. Typhi clones and mapping transmission. The genetic diversity of pathogens such as S. Typhi is limited in Latin America and should be targeted for future surveillance studies incorporating WGS.
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Salmonella typhi/genética , Fiebre Tifoidea/epidemiología , Fiebre Tifoidea/microbiología , Antibacterianos/farmacología , Colombia/epidemiología , Farmacorresistencia Bacteriana/genética , Vigilancia de la Población , Salmonella typhi/efectos de los fármacosRESUMEN
Nucleic acid test (NAT), most typically quantitative PCR, is one of the standard methods for species specific flavivirus diagnosis. Semi-comprehensive NATs such as pan-flavivirus PCR which covers genus Flavivirus are also available; however, further specification by sequencing is required for species level differentiation. In this study, a semi-comprehensive detection system that allows species differentiation of flaviviruses was developed by integration of the pan-flavivirus PCR and Nanopore sequencing. In addition, a multiplexing method was established by adding index sequences through the PCR with a streamlined bioinformatics pipeline. This enables defining cut-off values for observed read counts. In the laboratory setting, this approach allowed the detection of up to nine different flaviviruses. Using clinical samples collected in Vietnam and Brazil, seven different flaviviruses were also detected. When compared to a commercial NAT, the sensitivity and specificity of our system were 66.7% and 95.4%, respectively. Conversely, when compared to our system, the sensitivity and specificity of the commercial NAT were 57.1% and 96.9%, respectively. In addition, Nanopore sequencing detected more positive samples (n = 8) compared to the commercial NAT (n = 6). Collectively, our study has established a semi-comprehensive sequencing-based diagnostic system for the detection of flaviviruses at extremely affordable costs, considerable sensitivity, and only requires simple experimental methods.
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Infecciones por Flavivirus/diagnóstico , Infecciones por Flavivirus/virología , Flavivirus/aislamiento & purificación , Secuenciación de Nanoporos/métodos , Brasil , Biología Computacional/métodos , Flavivirus/genética , Humanos , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , VietnamRESUMEN
AIMS: Clinical decision making is challenging in men with metastatic prostate cancer (mPC), as heterogeneity in treatment options and patient characteristics have resulted in multiple scenarios with little or no evidence. The South East Asia Expert Panel 2019 addressed some of these challenges. METHODS: Based on evidence in the literature and expert interviews, 19 statements were formulated for key challenges in the treatment of men with castration-sensitive and -resistant prostate cancer in clinical practice. A modified Delphi process was used to reach consensus among experts in the panel and develop clinical practice recommendations. RESULTS: The majority of the panel preferred a risk-based stratification and recommended abiraterone or enzalutamide as first-line therapy for symptomatic chemotherapy naïve patients. Abiraterone is preferred over enzalutamide as a first-line treatment in these patients. However, the panel did not support the use of abiraterone in high risk lymph-node positive only (N+M0) or in non-metastatic (N0M0) patients. In select patients, low dose abiraterone with food may be used to optimize clinical outcomes. Androgen receptor gene splice variant status may be a useful guide to therapy. In addition, generic versions of approved therapies may improve access to treatment to a broader patient population. The choice of treatment, as well as sequencing are guided by both patient and disease characteristics, preferences, drug access, cost, and compliance. CONCLUSION: Expert recommendations are key to guidance for the optimal management of mPC. Appropriate choice, timing, and sequence of treatment options can help to tailor therapy to maximize outcomes in men with mPC.