Relación entre la resistencia a antibióticos y la producción de biofilm de aislados de Staphylococcus aureus provenientes de mastitis bovina

The objective was to analyze the relationship between the antibiotic-resistance profile and the biofilm formation of S. aureus isolates from bovine mastitis. Thirty (30) isolates of S. aureus from cases of subclinical mastitis in dairy farms in semi-intensive production and backyard production systems, located in the states of Guanajuato and Michoacán, Mexico, were analyzed. An antibiogram was performed by the Kirbi-Bauer disc-diffusion method. Biofilm formation was determined by the violet crystal staining method. For the evaluation of antibiotic resistance genes and biofilm formation, genomic DNA was obtained from a colony for the identification of the genes: blaZ, mecA, tetK, tetM, gyrA and gyrB, and icaA and icaD. The results showed that 100 % of the isolates were resistant to penicillin and dicloxacillin, followed by cefotaxime (86.6 %), ampicillin and cephalotin (83.3 %) and ceftazidime (80.0 %), while a 36.6 % resistance to oxacillin was observed. It was identified that all isolates of S. aureus had the ability to form biofilm with a range between 20 to 98 %. It was also observed that isolates with a high multi-resistance presented a greater formation of biofilm, establishing a significant positive correlation. In conclusion, S. aureus isolates from bovine mastitis presented high levels of antibiotic resistance; as well as an important biofilm-forming capacity, demonstrating the existence of a positive correlation between these two factors.El objetivo fue analizar la relación entre el perfil de resistencia a antibióticos y la formación de biofilm de aislados de S. aureus provenientes de mastitis bovina. Se analizaron 30 aislados de S. aureus procedentes de casos de mastitis subclínica en granjas lecheras en sistemas de producción semi-intensivo y de traspatio ubicadas en los estados de Guanajuato y Michoacán, México. Se realizó un antibiograma por el método de difusión en disco Kirbi Bauer. La formación de biofilm se determinó por el método de tinción con cristal violeta. Para la evaluación de genes de resistencia a antibióticos y de formación de biofilm se obtuvo ADN genómico de una colonia para la identificación de los genes: blaZ, mecA, tetK, tetM, gyrA y gyrB, y icaA e icaD. Los resultados mostraron que el 100 % de los aislados fueron resistentes a penicilina  y dicloxacilina, seguidos  por cefotaxima  (86.6 %),  ampicilina y cefalotina (83.3 %) y ceftazidima (80.0 %), mientras que se observó un 36.6 % de resistencia a oxacilina. Se identificó que todos los aislados de S. aureus presentaron la capacidad de formar biofilm con un rango del 20 a 98 %. Se observó además que los aislados con una multirresistencia elevada presentaron una mayor formación de biofilm; estableciéndose una correlación positiva significativa. En conclusión, los aislados de S. aureus provenientes de mastitis bovina presentaron elevados niveles de resistencia a antibióticos; así como una importante capacidad formadora de biofilm, demostrando la existencia de una correlación positiva entre estos dos factores

Selenite downregulates STAT3 expression and provokes lymphocytosis in the liver of chronically exposed Syrian golden hamsters

Arsenic is considered a worldwide pollutant that can be present in drinking water. Arsenic exposure is associated with various diseases, including cancer. Antioxidants as selenite and α-tocopherol-succinate have been shown to modulate arsenic toxic effects. Since changes in STAT3 and PSMD10 gene expression have been associated with carcinogenesis, the aim of this study was to evaluate the effect of arsenic exposure and co-treatments with selenite or α-tocopherol-succinate on the expression of these genes, in the livers of chronically exposed Syrian golden hamsters. Animals were divided into six groups: (i) control, (ii) chronically treated with 100 ppm arsenic, (iii) treated with 6 ppm α-tocopherol-succinate (α-TOS), (iv) treated with 8.5 ppm selenite, (v) treated with arsenic + α-TOS, and (vi) treated with arsenic + selenite. Urine samples and livers were collected after 20 weeks of continuous exposure. The urine samples were analyzed for arsenic species by atomic absorption spectrophotometry, and real-time RT-qPCR analysis was performed for gene expression evaluation. A reduction in STAT3 expression was observed in the selenite-treated group. No differences in PSMD10 expression were found among groups. Histopathological analysis revealed hepatic lymphocytosis in selenite-treated animals. As a conclusion, long-term exposure to arsenic does not significantly alter the expression of STAT3 and PSMD10 oncogenes in the livers of hamsters; however, selenite down-regulates STAT3 expression and provokes lymphocytosis

Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 13

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 13 de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada, de acceso abierto a todas las áreas del conocimiento, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico. Con esta colección, se aspira contribuir con el cultivo, la comprensión, la recopilación y la apropiación social del conocimiento en cuanto a patrimonio intangible de la humanidad, con el propósito de hacer aportes con la transformación de las relaciones socioculturales que sustentan la construcción social de los saberes y su reconocimiento como bien público. El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 13, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR) - Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTFAG) - Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kléber Ramírez (UPTM) - Mérida - Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (CABBOPP) - Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE) - Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia – Venezuela; Centro de Investigaciones Internacionales SAS (CEDINTER) - Antioquia – Colombia y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

Cucurbitaceae Seed Protein Hydrolysates as a Potential Source of Bioactive Peptides with Functional Properties

Seeds from Cucurbitaceae plants (squashes, pumpkins, melons, etc.) have been used both as protein-rich food ingredients and nutraceutical agents by many indigenous cultures for millennia. However, relatively little is known about the bioactive components (e.g., peptides) of the Cucurbitaceae seed proteins (CSP) and their specific effects on human health. Therefore, this paper aims to provide a comprehensive review of latest research on bioactive and functional properties of CSP isolates and hydrolysates. Enzymatic hydrolysis can introduce a series of changes to the CSP structure and improve its bioactive and functional properties, including the enhanced protein solubility over a wide range of pH values. Small-sized peptides in CSP hydrolysates seem to enhance their bioactive properties but adversely affect their functional properties. Therefore, medium degrees of hydrolysis seem to benefit the overall improvement of bioactive and functional properties of CSP hydrolysates. Among the reported bioactive properties of CSP isolates and hydrolysates, their antioxidant, antihypertensive, and antihyperglycaemic activities stand out. Therefore, they could potentially substitute synthetic antioxidants and drugs which might have adverse secondary effects on human health. CSP isolates and hydrolysates could also be implemented as functional food ingredients, thanks to their favorable amino acid composition and good emulsifying and foaming properties

Vía de señalización Notch y nuevas estrategias para el tratamiento de cáncer Notch signaling pathway and new strategies in cancer treatment

La vía de señalización Notch desempeña un papel fundamental en las diferentes etapas del desarrollo celular como la proliferación, crecimiento, diferenciación y apoptosis. Estudios recientes han demostrado que, dependiendo del nivel de expresión y del contexto celular, los receptores de membrana Notch contribuyen en la resistencia a apoptosis en células tumorales. Estos descubrimientos sugieren que componentes de la vía de señalización Notch son un blanco potencial para el desarrollo de terapias más efectivas contra el cáncer. Esta revisión describe la función de la vía Notch y nuevas estrategias utilizadas en la modulación de su señal.<br>The Notch signaling pathway plays a crucial role at different stages of cell development, such as proliferation, growth, differentiation, and apoptosis. Recent studies demonstrate that depending on the expression level and cellular context, the Notch receptors play a role in apoptosis resistance in malignant cells. These findings suggest that Notch signaling components may be a potential target in the development of new cancer therapies. This review describes the function of the Notch pathway and new strategies in the modulation of its signal

Vía de señalización Notch y nuevas estrategias para el tratamiento de cáncer

La vía de señalización Notch desempeña un papel fundamental en las diferentes etapas del desarrollo celular como la proliferación, crecimiento, diferenciación y apoptosis. Estudios recientes han demostrado que, dependiendo del nivel de expresión y del contexto celular, los receptores de membrana Notch contribuyen en la resistencia a apoptosis en células tumorales. Estos descubrimientos sugieren que componentes de la vía de señalización Notch son un blanco potencial para el desarrollo de terapias más efectivas contra el cáncer. Esta revisión describe la función de la vía Notch y nuevas estrategias utilizadas en la modulación de su señal

VIRUS FITOPATÓGENOS EN INSECTOS ASOCIADOS AL AJO

La propagación vegetativa del ajo ( Allium sativum ) es la principal vía de transmisión de virus para este cultivo. No obs - tante, no se debe descartar la dispersión por insectos vectores. El objetivo del presente estudio fue detectar, mediante la prueba de ELISA, la presencia de virus en insectos colectados en plantas de ajo. El experimento se llevó a cabo durante el ciclo Otoño-Invierno 2008-2009. La toma de muestras de insectos se realizó en tres fechas después de la siembra. La identificación de las especies de insectos se realizó utilizando un estereomicroscopio Zeiss de 30X y claves taxonómicas. La detección de virus fue mediante la técnica de DAS-ELISA para los potyvirus Virus del rayado amarillo del puerro ( Leek yellow spot virus : LYSV) y Virus del enanismo amarillo de la cebolla ( Onion yellow dwarf virus: OYDV); los carlavirus Virus latente común del ajo ( Garlic common latent virus : GCLV) y Virus latente del chalote ( Shallot latent virus : SLV); y el tospovirus Virus del manchado amarillo del iris ( Iris yellow spot virus : IYSV). Se identificaron 19 especies de insectos, de los que destacaron Thrips tabaci Lindeman, como positivo en 18 muestras para GCLV y dos muestras para IYSV, y Collops quadrimaculatus , como positivo en una muestra para GCLV

Characterization and Identification of Cryptic Biopeptides in Carya illinoinensis (Wangenh K. Koch) Storage Proteins

The objective of this research was to identify and characterize the encoded peptides present in nut storage proteins of Carya illinoinensis. It was found, through in silico prediction, proteomic analysis, and MS spectrometry, that bioactive peptides were mainly found in albumin and glutelin fractions. Glutelin was the major fraction with ~53% of the nut storage proteins containing at least 21 peptides with different putative biological activities, including antihypertensives, antioxidants, immunomodulators, protease inhibitors, and inhibitors of cell cycle progression in cancer cells. Data showed that using 50 μg/mL tryptic digests of enriched peptides obtained from nut glutelins is able to induce up to 19% of apoptosis in both HeLa and CasKi cervical cancer cells. To our knowledge, this is the first report that shows the potential value of the nut-encoded peptides to be considered as adjuvants in cancer therapies

<b>Molecular and biochemical</b><b> characterization of extracellular tannin acyl hydrolase activity from a Mexican isolate of <i style="">Aspergillus niger</i></b>

942-947Microbial tannase, a hydrolysable tannin-degrading enzyme, is extensively used in manufacture of instant tea, beer, wine, and gallic acid. Aspergillus niger strain, obtained from a Mexican tannery wastewaters rich in gallic acid [Quebracho Phenolics-rich Tannery Wastewaters, (QPTW)], displayed a good growth and tannase activity in a minimal medium added with 1% (w/v) QPTW (Kr= 0.451 mm.h-1). Using PCR and RACE 3´ and 5´methodologies, a complete cDNA of a tannase was cloned from this isolate.Nucleotide sequence of complete cDNA was of 4690 bp with a complete ORF of 1833 bp encoding 611 amino acids. Transcriptionalinduction was observed in mineral medium added with carbon sources as tannic acid alone (1 and 10 g/l), as well as mix of glucose(1 and 10 g/l) and tannic acid (1 g/l) in the media. However, neither glucose (1 and 10 g/l) and sucrose (1 and 10 g/l) nor (+)-catechin(1 and 10 g/l) as sole carbon sources displayed gene induction in in vitro assays. A. niger-GTO is a new strain with interesting characteristics for industrial tannase production purposes

Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

Thirty-two farms (n=535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM P<0.01, and correlations between udder quarters from the CMT were around 0.49 P<0.01. Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study