Leishmania braziliensis prostaglandin F2α synthase impacts host infection

BACKGROUND: Prostaglandins (PG) are lipid mediators derived from arachidonic acid metabolism. They are involved in cellular processes such as inflammation and tissue homeostasis. PG production is not restricted to multicellular organisms. Trypanosomatids also synthesize several metabolites of arachidonic acid. Nevertheless, their biological role in these early-branching parasites and their role in host-parasite interaction are not well elucidated. Prostaglandin F2α synthase (PGF2S) has been observed in the Leishmania braziliensis secreted proteome and in L. donovani extracellular vesicles. Furthermore, we previously reported a positive correlation between L. braziliensis PGF2S (LbrPGF2S) expression and pathogenicity in mice. METHODS: LbrPGF2S gene expression and PGF2α synthesis in promastigotes were detected and quantified by western blotting and EIA assay kit, respectively. To investigate LbrPGF2S localization in amastigotes during bone marrow-derived macrophage infection, parasites expressing mCherry-LbrPGF2S were generated and followed by time-lapse imaging for 48 h post-infection. PGF2S homolog sequences from Leishmania and humans were analyzed in silico using ClustalW on Geneious v6 and EMBOSS Needle. RESULTS: Leishmania braziliensis promastigotes synthesize prostaglandin F2α in the presence of arachidonic acid, with peak production in the stationary growth phase under heat stress. LbrPGF2S is a cytoplasmic protein enriched in the secretory site of the parasite cell body, the flagellar pocket. It is an enzyme constitutively expressed throughout promastigote development, but overexpression of LbrPGF2S leads to an increase of infectivity in vitro. The data suggest that LbrPGF2S may be released from intracellular amastigotes into the cytoplasm of bone marrow-derived macrophages over a 48-hour infection period, using time-lapse microscopy and mCherry-PGF2S (mChPGF2S)-expressing parasites. CONCLUSIONS: LbrPGF2S, a parasite-derived protein, is targeted to the host cell cytoplasm. The putative transfer of this enzyme, involved in pro-inflammatory lipid mediator synthesis, to the host cell suggests a potential role in host-parasite interaction and may partially explain the increased pathogenicity associated with overexpression of LbrPGF2S in L. braziliensis. Our data provide valuable insights to help understand the importance of parasite-derived lipid mediators in pathogenesis

Bacteriophages have potential to control foaming caused by Rhodococcus erythropolis in WWTP

Activated-sludge is the most widely used biological process to remove pollutants from wastewater worldwide, mainly due to its economic advantages. Bacteria sum up around 95 % of the total microbial community of the activated-sludge, being responsible for most of the water depuration. Filamentous bacteria are normal components of these artificial ecosystems but their excessive growth leads to potential problems, mainly on the sludge settling (filamentous bulking) or on the formation of scums (filamentous foaming), dramatically reducing the efficiency of the wastewater treatment plants (WWTP). Rhodococcus erythropolis is a gram-positive filamentous bacterium previously identified as one of the sources of foams in activated-sludge. The present work aimed at isolating and characterizing phages infecting R. erythropolis, using sewage water and mixed liquor from an urban WWTP as phage source. Two phages were isolated (one from mixed liquor and the other from sewage) and further characterized genetically and biologically. The TEM analysis revealed that both phages belong to the siphovirus morphotype but with different sizes. The one step growth curve, carried at 28 °C in LB medium, revealed that the Rhodococcus phage isolated from mixed liquor and the one isolated from sewage have significant differences with latent periods of 110 min and 35 min, respectively, and burst sizes of 5 PFU/infected and 106 PFU/infected cell, respectively. Both phages were stable between 4 and 28 °C and between pH values from 7 to 10, which suggests good stability in the WWTP environment. Moreover, phages were able to maintain a R. erytropolis suspension at low levels for up to 30 h post-infection, using MOIs of 0.1, 0.5, and 1. Infection with the mixed liquor phage, maintained the bacterial reduction for 48 h in all MOIs tested. These results demonstrate the potential of using phages to control the problem of bacterial foaming in WWTP.info:eu-repo/semantics/publishedVersio

A comparative analysis of genetic diversity in Portuguese grape germplasm from ampelographic collections fit for quality wine production

Grapevine cultivars diversity is vast and full of synonyms and homonyms. Up to few decades ago characterization of grapevine was based on morphological characters. In the last decades, molecular markers were developed and have been used as tools to study genetic diversity in a range of different plant species. Fifty-six Portuguese accessions representative of ‘Vinhos Verdes’ and ‘Douro’ Controlled Designations of Origin (DOC) were analysed through DNA fingerprints generated by Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR). The study aimed to compare the effectiveness of RAPD and ISSR molecular techniques in the detection of synonyms, homonyms and misnames. RAPD and ISSR analysis enabled the detection of 36 different band patterns, reducing in about 36% the initial material. Several accessions grown under different names, between and within collections, were confirmed as the same genotype, namely Gouveio/Verdelho, Sousão Douro/Vinhão and Arinto Oeste/Pedernã. Similarly, some homonyms/misnames were also identified, namely within Azal Tinto and Rabigato accessions. RAPD and ISSR markers revealed to be adequate molecular techniques for grapevine varieties fingerprinting with advantages over other molecular procedures, contributing for a good management of grapevine collections

First comparative genomic characterization of the MSSA ST398 lineage detected in aquaculture and other reservoirs

Staphylococcus aureus ST398 can cause diseases in several different animals. In this study we analyzed ten S. aureus ST398 previously collected in three different reservoirs in Portugal (humans, gilthead seabream from aquaculture and dolphin from a zoo). Strains tested against sixteen antibiotics, by disk diffusion or minimum inhibitory concentration, showed decreased susceptibility to benzylpenicillin (all strains from gilthead seabream and dolphin) and to erythromycin with an iMLSB phenotype (nine strains), and susceptibility to cefoxitin (methicillin-susceptible S. aureus, MSSA). All strains from aquaculture belonged to the same spa type, t2383, whereas strains from the dolphin and humans belonged to spa type t571. A more detailed analysis using single nucleotide polymorphisms (SNPs)-based tree and a heat map, showed that all strains from aquaculture origin were highly related with each other and the strains from dolphin and humans were more distinct, although they were very similar in ARG, VF and MGE content. Mutations F3I and A100V in glpT gene and D278E and E291D in murA gene were identified in nine fosfomycin susceptible strains. The blaZ gene was also detected in six of the seven animal strains. The study of the genetic environment of erm(T)-type (found in nine S. aureus strains) allowed the identification of MGE (rep13-type plasmids and IS431R-type), presumably involved in the mobilization of this gene. All strains showed genes encoding efflux pumps from major facilitator superfamily (e.g., arlR, lmrS-type and norA/B-type), ATP-binding cassettes (ABC; mgrA) and multidrug and toxic compound extrusion (MATE; mepA/R-type) families, all associated to decreased susceptibility to antibiotics/disinfectants. Moreover, genes related with tolerance to heavy metals (cadD), and several VF (e.g., scn, aur, hlgA/B/C and hlb) were also identified. Insertion sequences, prophages, and plasmids made up the mobilome, some of them associated with ARG, VF and genes related with tolerance to heavy metals. This study highlights that S. aureus ST398 can be a reservoir of several ARG, heavy metals resistance genes and VF, which are essential in the adaption and survival of the bacterium in the different environments and an active agent in its dissemination. It makes an important contribution to understanding the extent of the spread of antimicrobial resistance, as well as the virulome, mobilome and resistome of this dangerous lineage.VS has her Ph.D. fellowship granted by FCT (Fundação para a Ciência e a Tecnologia) with the reference SFRH/BD/133100/2017 co-financed by European Social Fund and the Operational Program for Human Capital (POCH), Portugal. This work was financial supported with funding from FCT/MCTES (UIDB/00211/2020) through national funds.info:eu-repo/semantics/publishedVersio

Análise metabolómica dirigida em cogumelos silvestres do género Boletus.

Os cogumelos são muito apreciados pelas suas propriedades organolépticas e nutricionais, mas também pelas suas propriedades medicinais devido à acumulação de metabolitos bioactivos [1,2]. Neste trabalho, apresentaremos uma análise metabolómica dirigida em espécies silvestres do género Boletus provenientes do Nordeste de Portugal: B. aereus, B. edulis, B. reticulatus (comestíveis), B. purpureus, B. satanas e B. rhodoxanthus (não-comestíveis). Foram analisados metabolitos primários incluindo açúcares (cromatografia líquida de alta eficiência acoplada a detecção por índice de refracção, HPLC-RI), ácidos gordos (cromatografia gasosa acoplada a detecção por ionização de chama, GC-FID), tocoferóis (HPLC-fluorescência) e ácido ascórbico (espectrofotometria). Analisaram-se também metabolitos secundários, nomeadamente ácidos fenólicos, por HPLC-DAD). Os metabolitos antioxidantes foram relacionados com a actividade captadora de radicais DPPH (2,2-difenil-1-picril-hidrazilo), poder redutor e inibição da peroxidação lipídica

Achillea millefolium L. hydroethanolic extract inhibits growth of human tumor cell lines by interfering with cell cycle and inducing apoptosis

info:eu-repo/semantics/publishedVersio

Método del papel de filtro para la medida de la succión del suelo

The capillary pressure of the soil (i.e., the pressure difference between air and water components in soil voids) is a key variable in the analysis of the hydro-mechanical behavior of unsaturated soils. Therefore a simple and economical laboratory method for the measurement of the capillary pressure of the soil (also known as soil matric suction, the reference being the atmospheric pressure), even if a degree of approximation is involved, is of considerable value. The filter paper method calculates soil suction indirectly by measuring the gravimetric water content of the filter paper at equilibrium that is related to soil suction through a predetermined calibration curve. The advantages of the method are simplicity, economy and reasonable accuracy. It can be used to measure suctions from 10 to 30000 kPa. In this paper, the authors use the contact filter paper method for matric suction measurements of an unsaturated compacted silty sand (formed by the weathering of granite) which has been used as a building material for a road in the north of Portugal. The matric suctions inferred from filter paper measurements depend on the calibration between the water content of the filter paper and suction. Therefore, three calibration curves proposed at the literature (Chandler et al. 1992; ASTM D 5298; and Oliveira & Marinho 2006) for the Whatman 42 filter paper are used to interpret the measured filter paper gravimetric water contents. The results of these tests are compared to other techniques (i.e., tensiometers, and the osmotic technique) used to measure or control the negative pore water pressure in the compacted soil specimens and the results obtained are reasonably accurate.La presión capilar del suelo (es decir, la diferencia de la presión entre el aire y los componentes del agua en vacíos del suelo) es una variable llave en el análisis del comportamiento hidromecánico de suelos no saturados. Un método por lo tanto simple y económico del laboratorio para la medida de la presión capilar del suelo (también conocido como la succión matrica del suelo, la referencia que es la presión atmosférica), mesmo si un grado de aproximación está implicado, es de valor considerable. El método del papel de filtro calcula la succión indirectamente utilizando curvas de calibración. Las ventajas del método son simplicidad, economía y exactitud razonable. El método del papel de filtro se puede utilizar para medir succiones a partir del 10 al 30000 kPa. En este artículo, los autores utilizan el método del papel de filtro para la medida de la succión matric de una arena limosa compactada no saturada (formada por la meteorización del granito) que se ha utilizado como material de construcción para un camino en el norte de Portugal. Las succiones matric deducidas de medidas del papel de filtro dependen de una calibración entre el humedade del papel de filtro y la succión. Por lo tanto, tres curvas de calibración propuestas en la literatura (Chandler et al. 1992; ASTM D 5298; y Oliveira & Marinho 2006) para el papel de filtro de Whatman 42 se utilizan para interpretar lãs humedades gravimétricas medidas del papel de filtro. Los resultados de los ensayos se comparan a otras técnicas (es decir, tensiómetros, y la técnica osmótica) usadas para medir o controlar la presión negativa en lãs muestras compactadas del suelo y los resultados obtenidos sea razonablemente exacto