The three transfer RNAs occupying the A, P and E sites on the ribosome are involved in viral programmed -1 ribosomal frameshift

The -1 programmed ribosomal frameshifts (PRF), which are used by many viruses, occur at a heptanucleotide slippery sequence and are currently thought to involve the tRNAs interacting with the ribosomal P- and A-site codons. We investigated here whether the tRNA occupying the ribosomal E site that precedes a slippery site influences -1 PRF. Using the human immunodeficiency virus type 1 (HIV-1) frameshift region, we found that mutating the E-site codon altered the -1 PRF efficiency. When the HIV-1 slippery sequence was replaced with other viral slippery sequences, mutating the E-site codon also altered the -1 PRF efficiency. Because HIV-1 -1 PRF can be recapitulated in bacteria, we used a bacterial ribosome system to select, by random mutagenesis, 16S ribosomal RNA (rRNA) mutations that modify the expression of a reporter requiring HIV-1 -1 PRF. Three mutants were isolated, which are located in helices 21 and 22 of 16S rRNA, a region involved in translocation and E-site tRNA binding. We propose a novel model where -1 PRF is triggered by an incomplete translocation and depends not only on the tRNAs interacting with the P- and A-site codons, but also on the tRNA occupying the E site

Alteromonas Myovirus V22 Represents a New Genus of Marine Bacteriophages Requiring a Tail Fiber Chaperone for Host Recognition

Marine phages play a variety of critical roles in regulating the microbial composition of our oceans. Despite constituting the majority of genetic diversity within these environments, there are relatively few isolates with complete genome sequences or in-depth analyses of their host interaction mechanisms, such as characterization of their receptor binding proteins (RBPs). Here, we present the 92,760-bp genome of the Alteromonas-targeting phage V22. Genomic and morphological analyses identify V22 as a myovirus; however, due to a lack of sequence similarity to any other known myoviruses, we propose that V22 be classified as the type phage of a new Myoalterovirus genus within the Myoviridae family. V22 shows gene homology and synteny with two different subfamilies of phages infecting enterobacteria, specifically within the structural region of its genome. To improve our understanding of the V22 adsorption process, we identified putative RBPs (gp23, gp24, and gp26) and tested their ability to decorate the V22 propagation strain, Alteromonas mediterranea PT11, as recombinant green fluorescent protein (GFP)-tagged constructs. Only GFP-gp26 was capable of bacterial recognition and identified as the V22 RBP. Interestingly, production of functional GFP-gp26 required coexpression with the downstream protein gp27. GFP-gp26 could be expressed alone but was incapable of host recognition. By combining size-exclusion chromatography with fluorescence microscopy, we reveal how gp27 is not a component of the final RBP complex but instead is identified as a new type of phage-encoded intermolecular chaperone that is essential for maturation of the gp26 RBP.This work was supported by grants ‘VIREVO’ CGL2016‐76273‐P (MCI/AEI/FEDER, EU) (cofounded with FEDER funds) from the Spanish Ministerio de Ciencia e Innovación and ‘HIDRAS3’ PROMETEU/2019/009 from Generalitat Valenciana. R.G.-S. was supported by a predoctoral fellowship from the Valencian Consellería de Educació, Investigació, Cultura i Esport (ACIF/2016/050) and was also a beneficiary of the BEFPI 2019 fellowship for predoctoral stays from Generalitat Valenciana and The European Social Fund. F.R.-V. was a beneficiary of the 5top100 program of the Ministry for Science and Education of Russia

Systemic application of bone-targeting peptidoglycan hydrolases as a novel treatment approach for staphylococcal bone infection

The rising prevalence of antimicrobial resistance in S. aureus has rendered treatment of staphylococcal infections increasingly difficult, making the discovery of alternative treatment options a high priority. Peptidoglycan hydrolases, a diverse group of bacteriolytic enzymes, show high promise as such alternatives due to their rapid and specific lysis of bacterial cells, independent of antibiotic resistance profiles. However, using these enzymes for the systemic treatment of local infections, such as osteomyelitis foci, needs improvement, as the therapeutic distributes throughout the whole host, resulting in low concentrations at the actual infection site. In addition, the occurrence of intracellularly persisting bacteria can lead to relapsing infections. Here, we describe an approach using tissue-targeting to increase the local concentration of therapeutic enzymes in the infected bone. The enzymes were modified with a short targeting moiety that mediated accumulation of the therapeutic in osteoblasts and additionally enables targeting of intracellularly surviving bacteria

Variability and decadal trends in the Isfjorden (Svalbard) ocean climate and circulation – An indicator for climate change in the European Arctic

Isfjorden, a broad Arctic fjord in western Spitsbergen, has shown significant changes in hydrography and inflow of Atlantic Water (AW) the last decades that only recently have been observed in the Arctic Ocean north of Svalbard. Variability and trends in this fjord’s climate and circulation are therefore analysed from observational and reanalysis data during 1987 to 2017. Isfjorden experienced a shift in summer ocean structure in 2006, from AW generally in the bottom layer to AW (with increasing thickness) higher up in the water column. This shift, and a concomitant shift to less fast ice in Isfjorden are linked to positive trends in the mean sea surface temperature (SST) and volume weighted mean temperature (VT) in winter (SSTw/VTw: 0.7 ± 0.1/0.9 ± 0.3 °C 10 yr−1) and summer (SSTS/VTS: 0.7 ± 0.1/0.6 ± 0.1 °C 10 yr−1). Hence, the local mean air temperature shows similar trends in winter (1.9 ± 0.4 °C 10 yr−1) and summer (0.7 ± 0.1 °C 10 yr−1). Positive trends in volume weighted mean salinity in winter (0.21 ± 0.06 10 yr−1) and summer (0.07 ± 0.05 10 yr−1) suggest increased AW advection as a main reason for Isfjorden’s climate change. Local mean air temperature correlates significantly with sea ice cover, SST, and VT, revealing the fjord’s impact on the local terrestrial climate. In line with the shift in summer ocean structure, Isfjorden has changed from an Arctic type fjord dominated by Winter Deep and Winter Intermediate thermal and haline convection, to a fjord dominated by deep thermal convection of Atlantic type water (Winter Open). AW indexes for the mouth and Isfjorden proper show that AW influence has been common in winter over the last decade. Alternating occurrence of Arctic and Atlantic type water at the mouth mirrors the geostrophic control imposed by the Spitsbergen Polar Current (carrying Arctic Water) relative to the strength of the Spitsbergen Trough Current (carrying AW). During high AW impact events, Atlantic type water propagates into the fjord according to the cyclonic circulation along isobaths corresponding to the winter convection. Tides play a minor role in the variance in the currents, but are important in the side fjords where exchange with the warmer Isfjorden proper occurs in winter. This study demonstrates that Isfjorden and its ocean climate can be used as an indicator for climate change in the Arctic Ocean. The used methods may constitute a set of helpful tools for future studies also outside the Svalbard Archipelago.publishedVersio

ÁLBUM SERIADO – ESTRATÉGIA PARA CAPACITAR AGENTES COMUNITÁRIOS DE SAÚDE

O egresso de odontologia pode atuar na atenção à saúde bucal tanto nos setores público e privado. Ele pode integrar equipes de saúde, participando da elaboração de estratégias e políticas de saúde bucal, portanto deve estar preparado para essas atividades. Uma dessas atividades é a capacitação dos agentes comunitários de saúde (ACS), na educação em saúde da população. Com o objetivo de capacitar os ACSs idealizou-se a realização da uma atividade educativa que utiliza uma ferramenta intitulada de álbum seriado, nessa atividade os acadêmicos do curso de odontologia da UNOESC/Joaçaba/SC (8° fase) desenvolvem um livreto com temas relacionados à saúde bucal que será utilizado na capacitação dos ACSs e posteriormente será utilizado como ferramenta na educação em saúde bucal na sua área de atuação. A elaboração do álbum seriado é baseada em informações científicas, com uma linguagem informal e imagens que auxiliem os ACSs na propagação das informações junto à comunidade. A atividade com o ACS proporciona uma socialização da informação com a comunidade, possibilita uma formação continuada para esses profissionais envolvidos diretamente na educação e prevenção em saúde, além disso, eles se sentem valorizados. A educação em saúde aplicada à população através da utilização do álbum seriado vem se mostrando eficaz na transmissão de informação para a comunidade em geral. A busca por novos métodos de transmissão e acesso à informação é importante, pois a prevenção é acompanhada de informação, portanto a utilização dessa ferramenta educativa auxilia na melhorar da saúde da comunidade

PLoS Genet

To generate highly specific and adapted immune responses, B cells diversify their antibody repertoire through mechanisms involving the generation of programmed DNA damage. Somatic hypermutation (SHM) and class switch recombination (CSR) are initiated by the recruitment of activation-induced cytidine deaminase (AID) to immunoglobulin loci and by the subsequent generation of DNA lesions, which are differentially processed to mutations during SHM or to double-stranded DNA break intermediates during CSR. The latter activate the DNA damage response and mobilize multiple DNA repair factors, including Parp1 and Parp2, to promote DNA repair and long-range recombination. We examined the contribution of Parp3 in CSR and SHM. We find that deficiency in Parp3 results in enhanced CSR, while SHM remains unaffected. Mechanistically, this is due to increased occupancy of AID at the donor (Smu) switch region. We also find evidence of increased levels of DNA damage at switch region junctions and a bias towards alternative end joining in the absence of Parp3. We propose that Parp3 plays a CSR-specific role by controlling AID levels at switch regions during CSR

Myocardial ultrasonic tissue characterization in patients with thyroid dysfunction

<p>Abstract</p> <p>Background</p> <p>Structural myocardial abnormalities have been extensively documented in hypothyroidism. Experimental studies in animal models have also shown involvement of thyroid hormones in gene expression of myocardial collagen. This study was planned to investigate the ability of ultrasonic tissue characterization, as evaluated by integrated backscatter (IBS), to early identify myocardial involvement in thyroid dysfunction.</p> <p>Patients and Methods</p> <p>We studied 15 patients with hyperthyroidism (HYPER), 8 patients with hypothyroidism (HYPO), 14 patients with subclinical hypothyroidism (SCH) and 19 normal (N) subjects, who had normal LV systolic function. After treatment, 10 HYPER, 6 HYPO, and 8 SCH patients were reevaluated. IBS images were obtained and analyzed in parasternal short axis (papillary muscle level) view, at left ventricular (LV) posterior wall. The following IBS variables were analyzed: 1) the corrected coefficient (CC) of IBS, obtained by dividing IBS intensity by IBS intensity measured in a rubber phantom, using the same equipment adjustments, at the same depth; 2) cardiac cyclic variation (CV) of IBS - peak-to-peak difference between maximal and minimal values of IBS during cardiac cycle; 3) cardiac cyclic variation index (CVI) of IBS - percentual relationship between the cyclic variation (CV) and the mean value of IBS intensity.</p> <p>Results</p> <p>CC of IBS was significantly larger (p < 0.05) in HYPER (1.57 ± 0.6) and HYPO (1.53 ± 0.3) as compared to SCH (1.32 ± 0.3) or N (1.15 ± 0.27). The CV (dB) (HYPO: 7.5 ± 2.4; SCH: 8.2 ± 3.1; HYPER: 8.2 ± 2.0) and the CVI (HYPO: 35.6 ± 19.7%; SCH: 34.7 ± 17.5%; HYPER: 37.8 ± 11.6%) were not significantly different in patients with thyroid dysfunction as compared to N (7.0 ± 2.0 and 44.5 ± 15.1%).</p> <p>Conclusions</p> <p>CC of IBS was able to differentiate cardiac involvement in patients with overt HYPO and HYPER who had normal LV systolic function. These early myocardial structural abnormalities were partially reversed by drug therapy in HYPER group. On the other hand, although mean IBS intensity tended to be slightly larger in patients with SCH as compared to N, this difference was not statistical significant.</p

Correction to: The tree that hides the forest : cryptic diversity and phylogenetic relationships in the Palaearctic vector Obsoletus/Scoticus complex (Diptera: Ceratopogonidae) at the European level

An amendment to this paper has been published and can be accessed via the original article

The tree that hides the forest: cryptic diversity and phylogenetic relationships in the Palaearctic vector Obsoletus/Scoticus Complex (Diptera: Ceratopogonidae) at the European level

Abstract Background Culicoides obsoletus is an abundant and widely distributed Holarctic biting midge species, involved in the transmission of bluetongue virus (BTV) and Schmallenberg virus (SBV) to wild and domestic ruminants. Females of this vector species are often reported jointly with two morphologically very close species, C. scoticus and C. montanus, forming the Obsoletus/Scoticus Complex. Recently, cryptic diversity within C. obsoletus was reported in geographically distant sites. Clear delineation of species and characterization of genetic variability is mandatory to revise their taxonomic status and assess the vector role of each taxonomic entity. Our objectives were to characterize and map the cryptic diversity within the Obsoletus/Scoticus Complex. Methods Portion of the cox1 mitochondrial gene of 3763 individuals belonging to the Obsoletus/Scoticus Complex was sequenced. Populations from 20 countries along a Palaearctic Mediterranean transect covering Scandinavia to Canary islands (North to South) and Canary islands to Turkey (West to East) were included. Genetic diversity based on cox1 barcoding was supported by 16S rDNA mitochondrial gene sequences and a gene coding for ribosomal 28S rDNA. Species delimitation using a multi-marker methodology was used to revise the current taxonomic scheme of the Obsoletus/Scoticus Complex. Results Our analysis showed the existence of three phylogenetic clades (C. obsoletus clade O2, C. obsoletus clade dark and one not yet named and identified) within C. obsoletus. These analyses also revealed two intra-specific clades within C. scoticus and raised questions about the taxonomic status of C. montanus. Conclusions To our knowledge, our study provides the first genetic characterization of the Obsoletus/Scoticus Complex on a large geographical scale and allows a revision of the current taxonomic classification for an important group of vector species of livestock viruses in the Palaearctic region