Contribuição das suiniculturas na selecção e disseminação de Enterococcus spp resistentes às tetraciclinas

Apesar dos antibióticos terem sido abolidos na União Europeia como promotores de crescimento, uma elevada percentagem de Enterococcus spp resistentes às tetraciclinas e genes que lhes conferem resistência (tetM, tetL, tetS) foram detectados em amostras animais e ambientais de suiniculturas portuguesas. Estes dados são preocupantes e podem estar associados a um elevado consumo destes antibióticos em medicina veterinária. A presença de tais estirpes em amostras de ar e de estrume usado como fertilizante agrícola pode ainda promover a sua dispersão fora das explorações animais. Although antibiotics were banned from European Union as animal growth promoters, a high percentage of Enterococcus spp resistant to tetracyclines and genes conferring resistance to these agents (tetM, tetL, tetS) were detected in animal and environmental samples collected in Portuguese piggeries. These data are of concern and might be associated to the consumption of high amounts of these antibiotics in veterinary medicine. The presence of such strains in air and manure used as fertilizer in agriculture might promote their dissemination outside the animal production setting

Co-diversification of Enterococcus faecium Core Genomes and PBP5: Evidences of pbp5 Horizontal Transfer

Ampicillin resistance has greatly contributed to the recent dramatic increase of a cluster of human adapted Enterococcus faecium lineages (ST17, ST18, and ST78) in hospital-based infections. Changes in the chromosomal pbp5 gene have been associated with different levels of ampicillin susceptibility, leading to protein variants (designated as PBP5 C-types to keep the nomenclature used in previous works) with diverse degrees of reduction in penicillin affinity. Our goal was to use a comparative genomics approach to evaluate the relationship between the diversity of PBP5 among E. faecium isolates of different phylogenomic groups as well as to assess the pbp5 transferability among isolates of disparate clonal lineages. The analyses of 78 selected E. faecium strains as well as published E. faecium genomes, suggested that the diversity of pbp5 mirrors the phylogenomic diversification of E. faecium. The presence of identical PBP5 C-types as well as similar pbp5 genetic environments in different E. faecium lineages and clones from quite different geographical and environmental origin was also documented and would indicate their horizontal gene transfer among E. faecium populations. This was supported by experimental assays showing transfer of large (≈180–280 kb) chromosomal genetic platforms containing pbp5 alleles, ponA (transglycosilase) and other metabolic and adaptive features, from E. faecium donor isolates to suitable E. faecium recipient strains. Mutation profile analysis of PBP5 from available genomes and strains from this study suggests that the spread of PBP5 C-types might have occurred even in the absence of a significant ampicillin resistance phenotype. In summary, genetic platforms containing pbp5 sequences were stably maintained in particular E. faecium lineages, but were also able to be transferred among E. faecium clones of different origins, emphasizing the growing risk of further spread of ampicillin resistance in this nosocomial pathogen.This work was supported by Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Educacão e Ciência (MEC) through national funds and co-financed by Fundo Europeu de Desenvolvimento Regional (FEDER) under the Partnership Agreement PT2020 with the reference UID/ MULTI/04378/2013–POCI/01/0145/FERDER/007728 to CN and LP, Instituto de Salud Carlos III (Plan Estatal de I+D+i 2013-2016), Grant PI12-01581 and PI15-01307 to TMC and CIBERESP (CB06/02/0053) to FB, European Commission, Seventh Framework Program (EVOTARFP7-HEALTH-282004) to TMC and FB and the Regional Government of Madrid in Spain (PROMPT- S2010/BMD2414) to FB and TMC.Peer reviewedPeer Reviewe

The compound Poisson limit ruling periodic extreme behaviour of non-uniformly hyperbolic dynamics

We prove that the distributional limit of the normalised number of returns to small neighbourhoods of periodic points of non-uniformly hyperbolic dynamical systems is compound Poisson. The returns to small balls around a fixed point in the phase space correspond to the occurrence of rare events, or exceedances of high thresholds, so that there is a connection between the laws of Return Times Statistics and Extreme Value Laws. The fact that the fixed point in the phase space is a repelling periodic point implies that there is a tendency for the exceedances to appear in clusters whose average sizes is given by the Extremal Index, which depends on the expansion of the system at the periodic point. We recall that for generic points, the exceedances, in the limit, are singular and occur at Poisson times. However, around periodic points, the picture is different: the respective point processes of exceedances converge to a compound Poisson process, so instead of single exceedances, we have entire clusters of exceedances occurring at Poisson times with a geometric distribution ruling its multiplicity. The systems to which our results apply include: general piecewise expanding maps of the interval (Rychlik maps), maps with indifferent fixed points (Manneville-Pomeau maps) and Benedicks-Carleson quadratic maps.Comment: To appear in Communications in Mathematical Physic

Evolution of Chlorhexidine Susceptibility and of the EfrEF Operon among Enterococcus faecalis from Diverse Environments, Clones, and Time Spans

Chlorhexidine (CHX) is widely used to control the spread of pathogens (e.g., human/animal clinical settings, ambulatory care, food industry). Enterococcus faecalis, a major nosocomial pathogen, is broadly distributed in diverse hosts and environments facilitating its exposure to CHX over the years. Nevertheless, CHX activity against E. faecalis is understudied. Our goal was to assess CHX activity and the variability of ChlR-EfrEF proteins (associated with CHX tolerance) among 673 field isolates and 1,784 E. faecalis genomes from the PATRIC database from different sources, time spans, clonal lineages, and antibiotic-resistance profiles. The CHX MIC (MICCHX) and minimum bactericidal concentration (MBCCHX) against E. faecalis presented normal distributions (0.5 to 64 mg/L). However, more CHX-tolerant isolates were detected in the food chain and recent human infections, suggesting an adaptability of E. faecalis populations in settings where CHX is heavily used. Heterogeneity in ChlR-EfrEF sequences was identified, with isolates harboring incomplete ChlR-EfrEF proteins, particularly the EfrE identified in the ST40 clonal lineage, showing low MICCHX (= 500 mg/L). However, increased CHX use, combined with concentration gradients occurring in diverse environments, potentially selecting multidrug-resistant strains with different CHX susceptibilities, signals the importance of monitoring the trends of E. faecalis CHX tolerance within a One Health approach. IMPORTANCE Chlorhexidine (CHX) is a disinfectant and antiseptic used since the 1950s and included in the World Health Organization's list of essential medicines. It has been widely applied in hospitals, the community, the food industry, animal husbandry and pets. CHX tolerance in Enterococcus faecalis, a ubiquitous bacterium and one of the leading causes of human hospital-acquired infections, remains underexplored. Our study provides novel and comprehensive insights about CHX susceptibility within the E. faecalis population structure context, revealing more CHX-tolerant subpopulations from the food chain and recent human infections. We further show a detailed analysis of the genetic diversity of the efrEF operon (previously associated with E. faecalis CHX tolerance) and its correlation with CHX phenotypes. The recent strains with a higher tolerance to CHX and the multiple sources where bacteria are exposed to this biocide alert us to the need for the continuous monitoring of E. faecalis adaptation toward CHX tolerance within a One Health approach. Chlorhexidine (CHX) is a disinfectant and antiseptic used since the 1950s and included in the World Health Organization's list of essential medicines. It has been widely applied in hospitals, the community, the food industry, animal husbandry and pets.Peer reviewe

Species-Specific Codon Context Rules Unveil Non-Neutrality Effects of Synonymous Mutations

Codon pair usage (codon context) is a species specific gene primary structure feature whose evolutionary and functional roles are poorly understood. The data available show that codon-context has direct impact on both translation accuracy and efficiency, but one does not yet understand how it affects these two translation variables or whether context biases shape gene evolution.Here we study codon-context biases using a set of 72 orthologous highly conserved genes from bacteria, archaea, fungi and high eukaryotes to identify 7 distinct groups of codon context rules. We show that synonymous mutations, i.e., neutral mutations that occur in synonymous codons of codon-pairs, are selected to maintain context biases and that non-synonymous mutations, i.e., non-neutral mutations that alter protein amino acid sequences, are also under selective pressure to preserve codon-context biases.Since in vivo studies provide evidence for a role of codon context on decoding fidelity in E. coli and for decoding efficiency in mammalian cells, our data support the hypothesis that, like codon usage, codon context modulates the evolution of gene primary structure and fine tunes the structure of open reading frames for high genome translational fidelity and efficiency in the 3 domains of life

Phylogenetic analysis of apicomplexan parasites infecting commercially valuable species from the North-East Atlantic reveals high levels of diversity and insights into the evolution of the group

Background: The Apicomplexa from aquatic environments are understudied relative to their terrestrial counterparts, and the seminal work assessing the phylogenetic relations of fish-infecting lineages is mostly based on freshwater hosts. The taxonomic uncertainty of some apicomplexan groups, such as the coccidia, is high and many genera were recently shown to be paraphyletic, questioning the value of strict morphological and ecological traits for parasite classification. Here, we surveyed the genetic diversity of the Apicomplexa in several commercially valuable vertebrates from the NorthEast Atlantic, including farmed fish. Results: Most of the sequences retrieved were closely related to common fish coccidia of Eimeria, Goussia and Calyptospora. However, some lineages from the shark Scyliorhinus canicula were placed as sister taxa to the Isospora, Caryospora and Schellakia group. Additionally, others from Pagrus caeruleostictus and Solea senegalensis belonged to an unknown apicomplexan group previously found in the Caribbean Sea, where it was sequenced from the water column, corals, and fish. Four distinct parasite lineages were found infecting farmed Dicentrarchus labrax or Sparus aurata. One of the lineages from farmed D. labrax was also found infecting wild counterparts, and another was also recovered from farmed S. aurata and farm-associated Diplodus sargus. Conclusions: Our results show that marine fish apicomplexans are diverse, and we highlight the need for a more extensive assessment of parasite diversity in this phylum. Additionally, parasites recovered from S. canicula were recovered as basal to their piscine counterparts reflecting hosts phylogeny

Prediction of friction degradation in highways with linear mixed models

The development of a linear mixed model to describe the degradation of friction on flexible road pavements to be included in pavement management systems is the aim of this study. It also aims at showing that, at the network level, factors such as temperature, rainfall, hypsometry, type of layer, and geometric alignment features may influence the degradation of friction throughout time. A dataset from six districts of Portugal with 7204 sections was made available by the Ascendi Concession highway network. Linear mixed models with random effects in the intercept were developed for the two-level and three-level datasets involving time, section and district. While the three-level models are region-specific, the two-level models offer the possibility to be adopted to other areas. For both levels, two approaches were made: One integrating into the model only the variables inherent to traffic and climate conditions and the other including also the factors intrinsic to the highway characteristics. The prediction accuracy of the model was improved when the variables hypsometry, geometrical features, and type of layer were considered. Therefore, accurate predictions for friction evolution throughout time are available to assist the network manager to optimize the overall level of road safety.This research was funded by FCT—Fundação para a Ciência e Tecnologia (Foundation for Science and Technology), Grants No. UIDB/04029/2020 and UIDB/00319/2020

Gene expression modulation by paraquat-induced oxidative stress conditions in Paracoccidioides brasiliensis

Paracoccidioides brasiliensis is a thermodimorphic fungus associated with paracoccidioidomycosis (PCM), the most common systemic mycosis in Latin America. the infection is initiated by inhalation of environmentally dispersed conidia produced by the saprophytic phase of the fungus. in the lungs, P. brasiliensis assumes the parasitic yeast form and must cope with the adverse conditions imposed by cells of the host immune system, which includes a harsh environment, highly concentrated in reactive oxygen species (ROS). in this work, we used the ROS-generating agent paraquat to experimentally simulate oxidative stress conditions in order to evaluate the stress-induced modulation of gene expression in cultured P. brasiliensis yeast cells, using a microarray hybridization approach. the large-scale evaluation inherent to microarray-based analyses identified 2070 genes differentially transcribed in response to paraquat exposure, allowing an integrated visualization of the major metabolic changes that constitute the systemic defense mechanism used by the fungus to overcome the deleterious effects of ROS. These include overexpression of detoxifying agents, as well as of molecular scavengers and genes involved in maintenance of the intracellular redox potential. Particularly noteworthy was to verify that the oxidative stress resistance mechanism of P. brasiliensis also involves coordinated overexpression of a series of genes responsible for chitin-biosynthesis, suggesting that this pathway may constitute a specific regulon. Further analyses aiming at confirming and understanding the mechanisms that control such regulon may provide interesting new targets for chemotherapeutic approaches against P. brasiliensis and other pathogenic fungi. (C) 2013 Elsevier Inc. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Mogi das Cruzes, Nucleo Integrado Biotecnol, BR-08780911 Mogi Das Cruzes, SP, BrazilUniversidade Federal de São Paulo, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, SP, BrazilUniv Fed ABC, Ctr Ciencias Nat & Humanidades, BR-09210170 Santo Andre, SP, BrazilUniversidade Federal de São Paulo, Inst Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, SP, BrazilWeb of Scienc

Treacher Collins syndrome with choanal atresia: a case report and review of disease features

SummaryTreacher Collins Syndrome - or mandibulofacial dysostosis – is a rare condition that presents several craniofacial deformities of different levels. This is a congenital malformation involving the first and second branchial arches. Incidence is estimated to range between 1-40,000 to 1-70,000 of live births. The disorder is characterized by abnormalities of the auricular pinna, hypoplasia of facial bones, antimongoloid slanting palpebral fissures with coloboma of the lower eyelids and cleft palate. Treacher Collins Syndrome is rarely associated with choanal atresia. A multidisciplinary team, including craniofacial surgeon, ophthalmologist, speech therapist, dental surgeon and otorhinolaryngologist, is the most appropriate setting to manage these patients. This study reports a rare case of Treacher Collins Syndrome with choanal atresia, presenting literature review and multidisciplinary intervention

Cover woman: contradictions printed in Nova magazine

This paper discusses on ways contradictory representation of female stereotypes of traditional and modern in the brazilian media. From the analysis covers the magazine Nova in two distinct historical moments, we seek to understand the ways in which female magazines represent the social roles, assisting in the construction and dissemination of a social image of woman