Presentació

Centre d'Estudis Vilassarenc

Short communication : Comparing the microbiota diversity from the core, middle part and rind of six Spanish commercial goat cheeses

Altres ajuts: acords transformatius de la UABThe cheese core has a lower oxygen saturation and salinity and a higher acidity than the rind, but there is controversy about the incidence of such factors on the magnitude of microbial diversity. The goal of the current work was to investigate the existence of differences in α-diversity between the core, middle part, and rind of six Spanish commercial cheeses through a sequencing approach. To this end, we have collected rind, middle part, and core samples from fresh (H and M), soft semi-ripened (C and P), hard semi-ripened (B) and semi-hard aged (G) goat cheeses. After purifying deoxyribonucleic acid from these 18 samples, the V3-V4 ultravariable region of the 16S rRNA gene was sequenced. The analysis of microbial composition revealed that lactic acid bacteria from the genera Lactococcus, Lactobacillus, Streptococcus, and Leuconostoc are predominant in all six goat cheeses. Furthermore, we identified several psychrophilic taxa often associated with the post-pasteurization contamination of refrigerated milk. Comparison of three α-diversity estimators (Chao1, Shannon and Faith's phylogenetic diversity indices) of microbiota in the core, middle part, and rind of all six goat cheeses did not reveal substantial differences, being only significant (at the nominal level) the comparison of rind vs middle part for the Shannon index (P-value = 0.031). Moreover, the construction of a dendrogram based on Aitchison distances revealed that cheese samples cluster according to their manufacturing characteristics, with a clear distinction between fresh vs semi-ripened or aged cheeses. We conclude that the magnitude of microbial α-diversity in the cheese core is similar to that in the rind despite their different physicochemical attributes. This result could be because physicochemical differences between cheese compartments are often attenuated during cheese ripening

Detection of homozygous genotypes for a putatively lethal recessive mutation in the porcine argininosuccinate synthase 1 (ASS1) gene

The sequencing of the pig genome revealed the existence of homozygous individuals for a nonsense mutation in the argininosuccinate synthase 1 (ASS1) gene (rs81212146, c.944T>A, L315X). Paradoxically, an AA homozygous genotype for this polymorphism is expected to abolish the function of the ASS1 enzyme that participates in the urea cycle, leading to citrullinemia, hyperammonemia, coma and death. Sequencing of five Duroc boars that sired a population of 350 Duroc barrows revealed the segregation of the c.944T>A polymorphism, so we aimed to investigate its phenotypic consequences. Genotyping of this mutation in the 350 Duroc barrows revealed the existence of seven individuals homozygous (AA) for the nonsense mutation. These AA pigs had a normal weight despite the fact that mild citrullinemia often involves impaired growth. Sequencing of the region surrounding the mutation in TT, TA and AA individuals revealed that the A substitution in the second position of the codon (c.944T>A) is in complete linkage disequilibrium with a C replacement (c.943T>C) in the first position of the codon. This second mutation would compensate for the potentially damaging effect of the c.944T>A replacement. In fact, this is the most probable reason why pigs with homozygous AA genotypes at the 944 site of the ASS1 coding region are alive. Our results illustrate the complexities of predicting the consequences of nonsense mutations on gene function and phenotypes, not only because of annotation issues but also owing to the existence of genetic mechanisms that sometimes limit the penetrance of highly harmful mutations

Lesions i estructures fúngiques en arbustos espontanis de Catalunya. III. Branques i troncs de Buxus sempervirens

Lesions i estructures fúngiques en arbustos espontanis de Catalunya. III. Branques i troncs de Buxus sempervirens. Com una nova aportació al coneixement de la diversitat micològica de Catalunya es presenten i il·lustren 44 tàxons de fongs microscòpics trobats sobre troncs i branques gruixudes de boix (Buxus sempervirens). Les prospeccions, realitzades en 24 localitats, han permès identificar 25 tàxons de Deuteromycotina (14 Hyphomycetes; 11 Coelomycetesy; 16 Ascomycotina; y 3 Basidiomycotina. En comparació amb els fongs identificats anteriorment en fulles i branquillons d'aquest arbust, les formes ascògenes s' han revelat com a més abundants en troncs i branques grosses. Es destaquen les correlacions entre l'estat anamòrfic i el teleomòrfic de diferents tàxons que han aparegut en aquest estudi, ja sigui successivament en el mateix punt de l'hoste, ja en llocs contigus, o bé separats.Lesions and fungal structures on wild shrubs of Catalonia. III On branches and trunks of Buxus sempervirens. As a new contribution to the knowledge of the fungal diversity in Catalonia, 44 taxa are presented and illustrated of microscopic fungi that have been found on trunks and thick branches of box (Buxus sempe rvirensi. The prospecting carried out in 24 sites has resulted in the finding of 25 taxa of Deuteromycotina (14 Hyphomycetes; 11 Coelomycetesy; 16 Ascomycotina; and 3 Basidiomycotina. Compared with previous reports of fungi on the leaves and twigs of this shrub, the ascogenous forms have now been shown to be more abundant on trunks and old branches. The correlations found between the anamorph and the teleomorph states of various taxa are underlined. They have been observed either successively in the same spot of the substrate, in contiguous parts of the host, or separated.Lesiones y estructuras fúngicas en arbustos silvestres de Cataluña. III. Sobre ramas y troncos de Buxus sempervirens. Como nueva aportación al conocimiento de la diversidad micològica de Cataluña, se presentan e ilustran 44 taxones de hongos microscópicos encontrados en troncos y ramas gruesas de boj (Buxus sempervirens). Las prospecciones, llevadas a cabo en 24 localidades, han perrnitido identificar 25 taxones de Deuteromycotina (14 Hyphomycetes; 11 Coelomycetesy; 16 Ascomycotina; y 3 Basidiomycotina. En comparación con los hongos que anteriormente identificamos en hojas y ramitas jóvenes de este arbusto, las formas ascógenas han resultado ser mas abundantes en troncos y ramas gruesas. Se destacan las correlaciones entre los estados anamórficos y teleomórficos de diversos taxones encontrados en este estudio, ya sea sucesivamente en el mismo punto de la planta huésped, ya en sitios contiguos, o bien separados

Lesions i estructures fúngiques en arbustos espontanis de Catalunya. II. Sobre fulles i branquillons de Buxus sempervirens

Lesions i estructures fúngiques en arbustos espontanis de Catalunya. Il. Sobre fulles i branquillons de Buxus sempervirens. Es descriuen diverses lesions i poblacions fúngiques presents en fulles i branquillons de Buxus sempervirens recollits a 25 localitats de Catalunya des de l'octubre de 1994. S'indiquen dates i llocs de recol-Iecci ó, tàxons implicats i la major o menor freqüència de cada un d'ells. En les lesions en què vàrem observar estructures picnidials o ascomàtiques fem constar la presència o absència d'elements fèrtils en les cavitats, dades que relacionem amb l'època de l'any . S'han identificat 22 espècies fúngiques (5 celomicets, 6 hifals, 9 ascomicets i 2 basidiomicets), a més de 2 líquens. Dothiorella candollei, Fusarium buxicola, Sesquicillium buxi , Discosphaerina miribelii , Dothidea puccinioides, Gibberella buxi, Nectria desmazierii i Pseudonectria rousseliana no havien estat trobats fins ara en les nostres recerques. Les fotografies en colors que il·lustren aquest estudi contribueixen a la seva utilitat de cara a la identificació dels tàxons.Lesiones y estructuras fúngicas en arbustos silvestres de Cataluña. II. Sobre hojas y ramitas de Buxus sempervirens. Se describen diversos tipos de lesiones y poblaciones fúngicas presentes en hojas y ramitas de Buxus sempervirens, recogidas en 25 localidades de Cataluña, desde octubre de 1994. Se indican fechas, lugares de recolección, taxones implicados y la mayor o menor frecuencia de cada uno. En las lesiones en que se observan estructuras picnidiales o ascomaticas, se hace constar la presencia o ausencia de elementos fértiles en las cavidades, datos que se relacionan con la época del año. Se han identificado 22 especies fúngicas (5 celomicetes, 6 hifales, 9 ascomicetes y 2 basidiomicetes), mas 2 líquenes. Dothiorella candollei, Fusarium buxicola, Sesquicillium buxi , Discosphaerina miribelii , Dothidea puccinioides, Gibberella buxi, Nectria desmazierii y Pseudonectria rousseliana no habían sido citados hasta ahora en nuestros trabajos. Las fotografías en color que ilustran este estudio contribuyen a su utilidad para la identificación de los taxones.Lesions and fungal structures on wild shrubs of Catalonia. II. On leaves and twigs of Buxus sempervirens. Descriptions are given of different types of lesions and fungal populations observed on leaves and twigs of Buxus sempervirens collected in 25 sites of Catalonia since Oct. 1994. The date, collecting sites, implicated taxa and frequency of each one are indicated. In the lesions showing picnidial or ascomatal cavities, the presence or absence of fertile elements into the cavities is noted and its relationship with the season is stated. Twenty-one fungal species (5 coelomycets, 6 hyphomycetes, 9 ascomycetes and 2 basidiomycetes) and 2 lichens have been identified. Dothiorella candollei, Fusarium buxicola, Sesquicillium buxi , Discosphaerina miribelii , Dothidea puccinioides, Gibberella buxi, Nectria desmazieriiand Pseudonectria rousseliana had not been reported until now in our works. The colour photographs that illustrate this study contribute to its practical utility

An overview of antimicrobial peptides and the latest advances in their development

INTRODUCTION: The recent dramatic increase in the incidence of antimicrobial resistance has been recognized by organizations such as the United Nations and World Health Organization as well as the governments of the USA and several European countries. A relatively new weapon in the fight against severe infections caused by multi-drug resistant bacteria is antimicrobial peptides (AMPs). These include colistin, currently regarded as the last line of antimicrobial therapy against multi-drug resistant microorganisms. Areas covered: Here, the authors provide an overview of the current research on AMPs. The focus is AMPs currently being developed for the treatment of recalcitrant bacterial infections, the synergies of AMPs and antibiotics, and the activity of AMPs against biofilm. This review also includes a brief introduction into the use of AMPs in infections caused by Mycobacterium, fungi, and parasites. Expert opinion: In research into new antimicrobials, AMPs are gaining increasing attention. While many are natural and are produced by a wide variety of organisms, others are being newly designed and chemically synthesized in the laboratory to achieve novel antimicrobial agents. The same strategy to fight infections in nature is thus being effectively exploited to safeguard human and animal health

Efficacy of combinations of colistin with other antimicrobials involves membrane fluidity and efflux machinery

Objective: Despite its use was abandoned several decades ago, the polycationic peptide colistin has become the last hope to treat severe infections caused by multidrug-resistant Gram-negative bacteria. Thus, the development of colistin resistance may seriously compromise the efficacy of treatment. Moreover, colistin has high toxicity being dose dependent. A potentially effective strategy to avoid resistance may be to combine colistin with other antimicrobials. This may help in the rescue of old antimicrobials and in reducing toxic undesired effects. Methods: Antimicrobial susceptibility determination, efflux machinery function measurements in different conditions and measurement of inhibition of the extrusion by colistin were performed. Moreover, modifications of anisotropy of the membranes by using fluorescent dyes was accomplished. Results: Sub-inhibitory concentrations of colistin have a synergistic effect with several antimicrobials that act intracellularly (targeting protein synthesis and DNA replication). This effect was demonstrated through the uptake increases of acridine orange. in Pseudomonas aeruginosa, Escherichia coli and Acinetobacter baumanii but also in an intrinsically colistin-resistant species as Serratia marcescens. Measurements of the anisotropy of bacterial membranes, as a measure of membrane fluidity, showed significant changes indicative of colistin activity. Conclusion: The alterations in the cellular efflux machinery that resulted in higher intracellular concentrations of acridine orange, and likely of other antimicrobials combined with data of membrane fluidity and measured synergism in vitro allow us to envisage the use of these combinations to fight infections caused by multidrug-resistant bact

anti-Tricyclo­[4.2.1.12,5]deca-3,7-diene-9,10-dione

The title compound, C10H8O2, is a precursor to an unusual bis-homoaromatic dication and to heterodiamantanes and other oxa-cage compounds. Two independent mol­ecules, each of which is situated on a center of symmetry, comprise the unit cell. Both mol­ecules are in nearly identical chair conformations