Clinical and neuroanatomical predictors of post-stroke fatigue

INTRODUCTION

Post-stroke fatigue (PSF) has been described as early exhaustion with tiredness that develops during physical or mental activity and generally does not improve with rest. There are inconsistent findings on the relationship between the characteristics of the ischemic brain lesion and PSF. However, some studies suggest that specific neuroanatomical and neuroplastic changes could explain post-stroke fatigue. The aim was to evaluate the severity of PSF in relation to the location and the size of the ischemic lesion in acute stroke patients to establish possible predictors of PSF.

PATIENTS AND METHODS

We performed a prospective observational study to establish potential early predictors of long-term PSF, which was assessed using the Fatigue Assessment Scale six months after ischemic stroke. After segmenting brain infarcts on Diffusion-Weighted Imaging (DWI) images, we studied the association with PSF using Voxel-Based Lesion-Symptom Mapping (VLSM).

RESULTS

Out of 104 patients, 61 (59 %) reported PSF. Female sex and history of diabetes mellitus were associated with a greater risk of developing PSF. The association of PSF with female sex was confirmed in a replication cohort of 50 patients. The ischemic lesion volume was not associated with PSF, and VBLSM analysis did not identify any specific brain area significantly associated with PSF.

CONCLUSIONS

PSF is frequent in stroke patients, especially women, even after six months. The absence of neuroanatomical correlates of PSF suggests that it is a multifactorial process with biological, psychological, and social risk factors that require further study.

Genomic Insights into the expansion of Carbapenem-Resistant Klebsiella pneumoniae within Portuguese Hospitals

Carbapenem-resistant Klebsiella pneumoniae complex (CR-KP) are a public health concern, causing infections with a high mortality rate, limited therapeutic options and challenging infection control strategies. In Portugal CR-KP rate has increased steeply, but the factors associated to this expansion are poorly explored. To address this question we compared, by phylogenetic and resistome analysis, the draft genomes of 200 CR-KP isolates collected in 2017-2019 from five hospitals in the Lisbon region, Portugal. We found that CR-KP belonged mainly to ST13 (29%), ST17 (15%), ST348 (13%), ST231 (12%) and ST147 (7%). Carbapenem resistance was conferred mostly by KPC-3 (74%) or OXA-181 (18%) presence, which were associated with IncF/IncN and IncX plasmids, respectively. Almost all isolates were multidrug resistant harbouring resistance determinants to aminoglycosides, beta-lactams, trimethoprim, fosfomycin, quinolones and sulphonamides. In addition, 11% of isolates were resistant to colistin. Colonizing and infection isolates were highly related and most colonized patients (89%) reported a previous hospitalization. Moreover, among the 171 events of cross-dissemination identified, by cgMLST data analysis (<5 alleles), 41 occurred between different hospitals and 130 within the same hospital. Our results suggest that CR-KP dissemination in the Lisbon region result from acquisition of carbapenemases in mobile genetic elements, influx of CR-KP into the hospitals by colonized ambulatory patients and transmission of CR-KP within and between hospitals. Our data reinforces that the prudent use of carbapenems, patients screening at hospital entrance, and improvement of infection control will be needed to decrease the burden of CR-KP infection in Portugal.

Clostridioides difficile Sporulation

Some members of the Firmicutes phylum, including many members of the human gut microbiota, are able to differentiate a dormant and highly resistant cell type, the endospore (hereinafter spore for simplicity). Spore-formers can colonize virtually any habitat and, because of their resistance to a wide variety of physical and chemical insults, spores can remain viable in the environment for long periods of time. In the anaerobic enteric pathogen Clostridioides difficile the aetiologic agent is the oxygen-resistant spore, while the toxins produced by actively growing cells are the main cause of the disease symptoms. Here, we review the regulatory circuits that govern entry into sporulation. We also cover the role of spores in the infectious cycle of C. difficile in relation to spore structure and function and the main control points along spore morphogenesis.

A sporulation signature protease is required for assembly of the spore surface layers, germination and host colonization in Clostridioides difficile

A genomic signature for endosporulation includes a gene coding for a protease, YabG, which in the model organism Bacillus subtilis is involved in assembly of the spore coat. We show that in the human pathogen Clostridioidesm difficile, YabG is critical for the assembly of the coat and exosporium layers of spores. YabG is produced during sporulation under the control of the mother cell-specific regulators σE and σK and associates with the spore surface layers. YabG shows an N-terminal SH3-like domain and a C-terminal domain that resembles single domain response regulators, such as CheY, yet is atypical in that the conserved phosphoryl-acceptor residue is absent. Instead, the CheY-like domain carries residues required for activity, including Cys207 and His161, the homologues of which form a catalytic diad in the B. subtilis protein, and also Asp162. The substitution of any of these residues by Ala, eliminates an auto-proteolytic activity as well as interdomain processing of CspBA, a reaction that releases the CspB protease, required for proper spore germination. An in-frame deletion of yabG or an allele coding for an inactive protein, yabGC207A, both cause misassemby of the coat and exosporium and the formation of spores that are more permeable to lysozyme and impaired in germination and host colonization. Furthermore, we show that YabG is required for the expression of at least two σK-dependent genes, cotA, coding for a coat protein, and cdeM, coding for a key determinant of exosporium assembly. Thus, YabG also impinges upon the genetic program of the mother cell possibly by eliminating a transcriptional repressor. Although this activity has not been described for the B. subtilis protein and most of the YabG substrates vary among sporeformers, the general role of the protease in the assembly of the spore surface is likely to be conserved across evolutionary distance.

Genome-wide analysis reveals that the cytochrome P450 family 7 subfamily B member 1 gene is implicated in growth traits in Rasa Aragonesa ewes

Sheep are very well adapted to changing environments and are able to produce and reproduce with low inputs in feed and water better than other domestic ruminants. Indeed, the ewe body condition score (BCS) and live weight (LW) play a significant role in productive and reproductive performance. This work conducts a genome-wide association study (GWAS) to detect genetic variants associated with growth traits in 225 adult ewes of the Rasa Aragonesa breed by using the genotypes from 50 k and HD Illumina Ovine BeadChip. These ewes were measured for LW, BCS and growth rate (GR) for 2 years, from January to September. Corrected phenotypes for BCS, LW and GR were estimated and used as input for the GWAS. Only one single nucleotide polymorphism (SNP) rs425509273 in chromosome 9 (OAR9), associated with the GR, overcame the genome-wise significance level. One, three and nine SNPs were associated at the chromosome-wise level (FDR 10%) for traits BCS, LW and GR, respectively. The cytochrome P450 family 7 subfamily B member 1 (CYP7B1) candidate gene, located 83 kb upstream from SNP rs425509273 in OAR9, was partially isolated and Sanger-sequenced. Fifteen polymorphisms comprising 12 SNPs, two indels and one polyC, were detected in promoter, exon 1, 3, 5, and intron 1-3 region. The SNP association analysis of the polymorphisms located close to the transcription start site (TSS) showed that a 22 bp insertion located at -58 nucleotides from the TSS (indel (-58)), a polyC (-25), and two A/G SNPs (SNP3 (-114) and SNP5 (-63)) were associated with the GR trait, whereas only the indel (-58) was associated with the BCS trait. The haplotype analysis confirmed these results. The functional characterisation of the polymorphisms at CYP7B1 gene in liver by real-time quantitative PCR analysis confirmed that the mutations in the promoter region affected CYP7B1 gene expression. Our results demonstrated the involvement of the CYP7B1 gene promoter on GR and BCS traits in Rasa Aragonesa. These findings suggest that variations in ovine CYP7B1 may serve as potential genetic markers to be used in breeding programmes to improve growth characteristics that could influence reproductive traits.

A new fluorescence-based approach for direct visualization of coat formation during sporulation in Bacillus cereus

The human pathogenic bacteria Bacillus cereus, Bacillus anthracis and the entomopathogenic Bacillus thuringiensis form spores encased in a protein coat surrounded by a balloon-like exosporium. These structures mediate spore interactions with its environment, including the host immune system, control the transit of molecules that trigger germination and thus are essential for the spore life cycle. Formation of the coat and exosporium has been traditionally visualized by transmission electronic microscopy on fixed cells. Recently, we showed that assembly of the exosporium can be directly observed in live B. cereus cells by super resolution-structured illumination microscopy (SR-SIM) using the membrane MitoTrackerGreen (MTG) dye. Here, we demonstrate that the different steps of coat formation can also be visualized by SR-SIM using MTG and SNAP-cell TMR-star dyes during B. cereus sporulation. We used these markers to characterize a subpopulation of engulfment-defective B. cereus cells that develops at a suboptimal sporulation temperature. Importantly, we predicted and confirmed that synthesis and accumulation of coat material, as well as synthesis of the σK-dependent protein BxpB, occur in cells arrested during engulfment. These results suggest that, unlike the well-studied model organism Bacillus subtilis, the activity of σK is not strictly linked to the state of forespore development in B. cereus.

Fungal Planet description sheets: 1436-1477

Novel species of fungi described in this study include those from various countries as follows: Argentina, Colletotrichum araujiae on leaves, stems and fruits of Araujia hortorum. Australia, Agaricus pateritonsus on soil, Curvularia fraserae on dying leaf of Bothriochloa insculpta, Curvularia millisiae from yellowing leaf tips of Cyperus aromaticus, Marasmius brunneolorobustus on well-rotted wood, Nigrospora cooperae from necrotic leaf of Heteropogon contortus, Penicillium tealii from the body of a dead spider, Pseudocercospora robertsiorum from leaf spots of Senna tora, Talaromyces atkinsoniae from gills of Marasmius crinis-equi and Zasmidium pearceae from leaf spots of Smilaxglyciphylla. Brazil, Preussia bezerrensis from air. Chile, Paraconiothyrium kelleni from the rhizosphere of Fragaria chiloensis subsp. chiloensis f. chiloensis. Finland, Inocybe udicola on soil in mixed forest with Betula pendula, Populus tremula, Picea abies and Alnus incana. France, Myrmecridium normannianum on dead culm of unidentified Poaceae. Germany, Vexillomyces fraxinicola from symptomless stem wood of Fraxinus excelsior. India, Diaporthe limoniae on infected fruit of Limonia acidissima, Didymella naikii on leaves of Cajanus cajan, and Fulvifomes mangroviensis on basal trunk of Aegiceras corniculatum. Indonesia, Penicillium ezekielii from Zea mays kernels. Namibia, Neocamarosporium calicoremae and Neocladosporium calicoremae on stems of Calicorema capitata, and Pleiochaeta adenolobi on symptomatic leaves of Adenolobus pechuelii. Netherlands, Chalara pteridii on stems of Pteridium aquilinum, Neomackenziella juncicola (incl. Neomackenziella gen. nov.) and Sporidesmiella junci from dead culms of Juncus effusus. Pakistan, Inocybe longistipitata on soil in a Quercus forest. Poland, Phytophthora viadrina from rhizosphere soil of Quercus robur, and Septoria krystynae on leaf spots of Viscum album. Portugal (Azores), Acrogenospora stellata on dead wood or bark. South Africa, Phyllactinia greyiae on leaves of Greyia sutherlandii and Punctelia anae on bark of Vachellia karroo. Spain, Anteaglonium lusitanicum on decaying wood of Prunus lusitanica subsp. lusitanica, Hawksworthiomyces riparius from fluvial sediments, Lophiostoma carabassense endophytic in roots of Limbarda crithmoides, and Tuber mohedanoi from calcareus soils. Spain (Canary Islands), Mycena laurisilvae on stumps and woody debris. Sweden, Elaphomyces geminus from soil under Quercus robur. Thailand, Lactifluus chiangraiensis on soil under Pinus merkusii, Lactifluus nakhonphanomensis and Xerocomus sisongkhramensis on soil under Dipterocarpus trees. Ukraine, Valsonectria robiniae on dead twigs of Robinia hispida. USA, Spiralomyces americanus (incl. Spiralomyces gen. nov.) from office air. Morphological and culture characteristics are supported by DNA barcodes. Citation: Tan YP, Bishop-Hurley SL, Shivas RG, et al. 2022. Fungal Planet description sheets: 1436-1477. Persoonia 49: 261-350. https://doi.org/10.3767/persoonia.2022.49.08.

Genomic characterization of antifungal Acinetobacter bacteria isolated from the skin of the frogs Agalychnis callidryas and Craugastor fitzingeri

Chytridiomycosis, a lethal fungal disease caused by Batrachochytrium dendrobatidis (Bd), is responsible for population declines and extinctions of amphibians worldwide. However, not all amphibian species are equally susceptible to the disease; some species persist in Bd enzootic regions with no population reductions. Recently, it has been shown that the amphibian skin microbiome plays a crucial role in the defense against Bd. Numerous bacterial isolates with the capacity to inhibit the growth of Batrachochytrium fungi have been isolated from the skin of amphibians. Here, we characterized eight Acinetobacter bacteria isolated from the frogs Agalychnis callidryas and Craugastor fitzingeri at the genomic level. A total of five isolates belonged to Acinetobacter pittii,Acinetobacter radioresistens, or Acinetobactermodestus, and three were not identified as any of the known species, suggesting they are members of new species. We showed that seven isolates inhibited the growth of Bd and that all eight isolates inhibited the growth of the phytopathogen fungus Botrytis cinerea. Finally, we identified the biosynthetic gene clusters that could be involved in the antifungal activity of these isolates. Our results suggest that the frog skin microbiome includes Acinetobacter isolates that are new to science and have broad antifungal functions, perhaps driven by distinct genetic mechanisms.

Oral vaccination of fish against vibriosis using spore-display technology

Oral vaccines are highly demanded by the aquaculture sector, to allow mass delivery of antigens without using the expensive and labor-intensive injectable vaccines. These later require individual handling of fish, provoking stress-related mortalities.

One possible strategy to create injection-free vaccine delivery vehicles is the use of bacterial spores, extremely resistant structures with wide biotechnological applications, including as probiotics, display systems, or adjuvants. Bacterial spores, in particular those of Bacillus subtilis, have been shown to behave as mucosal vaccine adjuvants in mice models. However, such technology has not been extensively explored against fish bacterial disease.

In this study, we used a laboratory strain of B. subtilis, for which a variety of genetic manipulation tools are available, to display at its spores surface either a Vibrio antigenic protein, OmpK, or the green fluorescence protein, GFP. When previously vaccinated by immersion with the OmpK- carrying spores, zebrafish survival upon a bacterial challenge with V. anguillarum and V. parahaemolyticus, increased up to 50 - 90% depending on the pathogen targeted. Further, we were able to detect anti-GFP-antibodies in the serum of European seabass juveniles fed diets containing the GFP-carrying spores and anti-V. anguillarum antibodies in the serum of European seabass juveniles fed the OmpK-carrying spores containing diet. More important, seabass survival was increased from 60 to 86% when previously orally vaccinated with in-feed OmpK- carrying spores. Our results indicate that B. subtilis spores can effectively be used as antigen-carriers for oral vaccine delivery in fish.

Using Whole Genome Sequencing to Investigate a Mock-Outbreak of Carbapenem-Resistant Klebsiella pneumoniae in Real-Time

INTRODUCTION

Healthcare associated infections due to carbapenem-resistant Klebsiella pneumoniae (CRKP) are a major concern in Portuguese hospitals. Whole genome sequencing (WGS) can improve infection control, but this practice is not routinely used by hospital clinical laboratories in Portugal. We simulated the investigation of a CRKP outbreak based on WGS, with the aim of determining, in the minimum possible time, genetic relatedness between CRKP clinical and environmental isolates.

MATERIAL AND METHODS

Ten CRKP clinical isolates routinely obtained in the hospital laboratory were used. Forty environmental samples - from sinks and sink drains of ward rooms - were collected. Environmental samples were plated on selective media and presumptive CRKP colonies were isolated. Total DNA was extracted from all putative CRKP isolates and sequenced. Clonal relatedness was determined by multi-locus sequence typing and core genome single nucleotide polymorphism analysis; the presence of carbapenemase genes was evaluated.

RESULTS

Clinical isolates were characterized in 48 hours: eight strains were confirmed as CRKP, of which six were of ST13 and carried blaKPC-3. Environmental samples results were obtained in six days: eight CRKP were isolated from which five were of ST13 and carried blaKPC-3. Clinical and environmental ST13 isolates were highly related: ten (of 11) isolates differed from each other in < 0.001% of 2 172 367 core nucleotides.

DISCUSSION

WGS can be used as a high-resolution effective tool to investigate healthcare associated infections and track routes of dissemination in real-time.

CONCLUSION

In Portugal, routine use of WGS to improve infection control could thrive through collaborative initiatives between hospitals and research institutes.

A molecular test based on RT-LAMP for rapid, sensitive and inexpensive colorimetric detection of SARS-CoV-2 in clinical samples

Until there is an effective implementation of COVID-19 vaccination program, a robust testing strategy, along with prevention measures, will continue to be the most viable way to control disease spread. Such a strategy should rely on disparate diagnostic tests to prevent a slowdown in testing due to lack of materials and reagents imposed by supply chain problems, which happened at the beginning of the pandemic. In this study, we have established a single-tube test based on RT-LAMP that enables the visual detection of less than 100 viral genome copies of SARS-CoV-2 within 30 min. We benchmarked the assay against the gold standard test for COVID-19 diagnosis, RT-PCR, using 177 nasopharyngeal RNA samples. For viral loads above 100 copies, the RT-LAMP assay had a sensitivity of 100% and a specificity of 96.1%. Additionally, we set up a RNA extraction-free RT-LAMP test capable of detecting SARS-CoV-2 directly from saliva samples, albeit with lower sensitivity. The saliva was self-collected and the collection tube remained closed until inactivation, thereby ensuring the protection of the testing personnel. As expected, RNA extraction from saliva samples increased the sensitivity of the test. To lower the costs associated with RNA extraction, we performed this step using an alternative protocol that uses plasmid DNA extraction columns. We also produced the enzymes needed for the assay and established an in-house-made RT-LAMP test independent of specific distribution channels. Finally, we developed a new colorimetric method that allowed the detection of LAMP products by the visualization of an evident color shift, regardless of the reaction pH.

Liver stiffness change with HCV cure in HIV-infected patients on non-nucleoside analogues

BACKGROUND

Liver stiffness (LS) at sustained viral response (SVR) is strongly associated with a lower incidence of subsequent hepatic events. HIV NNRTIs may have a beneficial impact on fibrogenesis.

OBJECTIVES

Our aim was to analyse the influence of NNRTI-based therapy on the change in LS from starting direct-acting antiviral (DAA) therapy to achieving SVR in HIV/HCV-coinfected patients.

METHODS

Three hundred and thirteen HIV/HCV-coinfected patients who fulfilled the following criteria were included: (i) had achieved SVR with an IFN-free, DAA-including regimen; (ii) LS ≥9.5 kPa before therapy; (iii) LS measurement available at SVR; (iv) seronegative for HBsAg; and (v) ART containing 2 NRTIs plus either 1 NNRTI or 1 integrase inhibitor (INI) or 1-2 NRTIs plus 1 PI. LS changes were assessed.

RESULTS

Seventy-four patients received NNRTI-based combinations [53 (71.6%) rilpivirine and 16 (21.6%) efavirenz] and 239 patients received other regimens. At baseline, the median (IQR) LS was 16.7 kPa (11.8-25.6) in the NNRTI group and 17.3 kPa (11.9-27.4) in the non-NNRTI group (P = 0.278). The median (IQR) percentage of LS decrease from baseline to SVR was 35.2% (18.2%-52.3%) for NNRTI-based therapy and 29.5% (10%-45.9%) for PI- or INI-based therapy (P = 0.018). In multivariate analysis, adjusted for sex, age, HCV genotype, NRTI backbone and propensity score for HIV therapy, NNRTI-based regimen use was associated with a higher LS decrease [β = 11.088 (95% CI = 1.67-20.51); P = 0.021].

CONCLUSIONS

Treatment with NNRTI plus 2 NRTI combinations is associated with a higher LS decline than other ART combinations in HIV/HCV-coinfected patients receiving DAA-based therapy.

CD25890, a conserved protein that modulates sporulation initiation in Clostridioides difficile

Bacteria that reside in the gastrointestinal tract of healthy humans are essential for our health, sustenance and well-being. About 50–60% of those bacteria have the ability to produce resilient spores that are important for the life cycle in the gut and for host-to-host transmission. A genomic signature for sporulation in the human intestine was recently described, which spans both commensals and pathogens such as Clostridioides difficile and contains several genes of unknown function. We report on the characterization of a signature gene, CD25890, which, as we show is involved in the control of sporulation initiation in C. difficile under certain nutritional conditions. Spo0A is the main regulatory protein controlling entry into sporulation and we show that an in-frame deletion of CD25890 results in increased expression of spo0A per cell and increased sporulation. The effect of CD25890 on spo0A is likely indirect and mediated through repression of the sinRR´ operon. Deletion of the CD25890 gene, however, does not alter the expression of the genes coding for the cytotoxins or the genes involved in biofilm formation. Our results suggest that CD25890 acts to modulate sporulation in response to the nutrients present in the environment.

Genome-wide association studies for sperm traits in Assaf sheep breed

Sperm quality traits routinely collected by artificial insemination (AI) center for rams progeny test are related with the capacity to produce sperm doses for AI and, in more or less grade, with males' fertility. Low-quality ejaculates are unuseful to perform AI sperm doses, which suppose high economic loses for the AI center. Moreover, sperm quality traits have low heritability values which make traditional genetic selection little efficient to its improvement. In this work, a genome-wide association study (GWAS) was conducted by using sperm quality traits data and 50 K Affymetrix custom chip genotypes of 429 rams of Assaf breed from OVIGEN AI centre. Furthermore, 47 of these rams were also genotyped with the Illumina HD Ovine BeadChip, and therefore HD genotypes were imputed for all rams with phenotype data. Previous to the GWAS, a linear regression model was fitted including sperm traits as dependent variables; the flock of origin, date of sperm collection, and jump number as fixed effects; rams age at collection in months as covariate; and ram permanent effect as random. Pseudo-phenotypes obtained from this model were used as input for GWAS. Associations at the chromosome-wise level (FDR 10%) of 76 single-nucleotide polymorphisms (SNPs) in 4 chromosomes for ejaculate concentration (CON), 20 SNPs in 3 chromosomes for ejaculate volume (VOL), 32 SNPs in 1 chromosome for ejaculate number of spermatozoa (SPZ), and 23 SNPs for spermatozoa mass motility (MOT) in 17 chromosomes were found. Only SNPs associated with MOT overcame the genome-wide significance level. Some candidate genes for sperm traits variability were SLC9C1 (OAR1), TSN (OAR2), and FUT10 (OAR26) for MOT;. DOCK2, CPLANE1, SPEF2, and RAI14 (OAR16) for CON; SCAPER and PSMA4 (OAR18) for VOL; and PARM1 and LOC101110593 (OAR6) for SPZ. SNPs associated with sperm traits were not found to be correlated with milk production genetic variation; however, the high frequencies of some SNPs with negative effect over sperm traits found in animals at the top milk yield estimated breeding values (EBVs) ranking would allow to exert some selective presure to improve rams sperm performances. Effects and frequencies of some of the SNPs detected over sperm quality traits make these variants good candidates to be used in marker-assisted selection to improve sperm characteristics of Assaf rams and AI center efficiency to produce sperm doses.

Impact of wildfire on granite outcrops in archaeological sites surrounded by different types of vegetation

The lack of scientific information about the effects of wildfire on prehistoric structures and rock art, such as dolmens and petroglyphs, impedes the development of conservation guidelines. In this study, the impact of a recent wildfire (late 2017) on granite outcrops in the San Salvador de Coruxo archaeological site (Vigo, SW Galicia) was evaluated. Samples of the same type of granite were obtained from three sites characterised by different types of vegetation (natural scrub, native deciduous oak and non-native pine-eucalypt forest) in order to determine how the vegetation influences the fire-caused damage to the rock. Three subsamples were taken from each of the granite samples at depths of 1 cm-3 cm to study how fire affects the rock at depth. In all sites, the temperature reached at the granite surface was below 380 °C. No mineralogical changes due to fire exposure were detected, and no physical changes that could be attributed to the effect of the fire on the fissure system of the granite were identified. However, aesthetic colour changes due to the deposition of organic and charred matter, which even penetrated the fissures, were detected. The existence of lignin-derived compounds, lipids and carbohydrates in the samples from the oakwood site indicates greater resistance to fire effects in this type of vegetation than in the other two types. Although preliminary, these findings suggest that oakwoods could act as protective belts around archaeological sites by reducing the wildfire severity, because of their greater resistance to being burnt, and that they could buffer the damaging effects of fire in natural areas where parietal art is found.

A protein phosphorylation module patterns the Bacillus subtilis spore outer coat

Assembly of the Bacillus subtilis spore coat involves over 80 proteins which self-organize into a basal layer, a lamellar inner coat, a striated electrodense outer coat and a more external crust. CotB is an abundant component of the outer coat. The C-terminal moiety of CotB, SKRB , formed by serine-rich repeats, is polyphosphorylated by the Ser/Thr kinase CotH. We show that another coat protein, CotG, with a central serine-repeat region, SKRG , interacts with the C-terminal moiety of CotB and promotes its phosphorylation by CotH in vivo and in a heterologous system. CotG itself is phosphorylated by CotH but phosphorylation is enhanced in the absence of CotB. Spores of a strain producing an inactive form of CotH, like those formed by a cotG deletion mutant, lack the pattern of electrondense outer coat striations, but retain the crust. In contrast, deletion of the SKRB region, has no major impact on outer coat structure. Thus, phosphorylation of CotG by CotH is a key factor establishing the structure of the outer coat. The presence of the cotB/cotH/cotG cluster in several species closely related to B. subtilis hints at the importance of this protein phosphorylation module in the morphogenesis of the spore surface layers.

HIV infection is associated with lower risk of hepatocellular carcinoma after sustained virological response to direct-acting antivirals in hepatitis C infected-patients with advanced fibrosis

BACKGROUND

The aim of this study was to assess the impact of HIV infection on the risk of developing hepatocellular carcinoma (HCC) in HCV-infected patients who achieve sustained virological response (SVR) with direct-acting antiviral (DAA).

METHODS

Multisite prospective cohort study, where HCV-monoinfected patients and HIV/HCV-coinfected individuals were included if they met: 1) SVR with DAA-based combination; 2) Liver stiffness (LS) ≥9.5 kPa previous to treatment; 3) LS measurement at the SVR time-point. The main endpoint was the occurrence of HCC. Propensity score (PS) was calculated to address potential confounders due to unbalanced distribution of baseline characteristics of HIV/HCV-coinfected and HCV-monoinfected patients.

RESULTS

1035 HCV-infected patients were included, 667 (64%) coinfected with HIV. After a median (Q1-Q3) follow-up time of 43 (31-49) months, 19 (1.8%) patients developed HCC [11 (3.0%) HCV-monoinfected, 8(1.2%) HIV/HCV-coinfected individuals; p=0.013]. In the multivariable analysis, HIV co-infection was associated with a lower adjusted risk of developing HCC [sHR=0.27, 95% IC (0.08-0.90); p=0.034]. Predictors of HCC emergence were: HCV genotype 3 [sHR=7.9 (2.5-24.9); p<0.001], MELD score at SVR>10 [sHR=1.37 (1.01-1.86); p=0.043] and LS value at SVR [sHR=1.03 (1.01-1.06) for 1 kPa increase; p=0.011]. Using inverse probability weighting method on the PS, HIV-infected patients had a lower risk of HCC [powered HR=0.33 (0.11-0.85)].

CONCLUSIONS

Among HCV-infected patients with advanced fibrosis, who achieve SVR with DAA, HIV-coinfection seems to be associated with a lower risk of HCC occurrence. The underlying causes for this finding need to be investigated.

Diamond Blackfan anemia is mediated by hyperactive Nemo-like kinase

Diamond Blackfan Anemia (DBA) is a congenital bone marrow failure syndrome associated with ribosomal gene mutations that lead to ribosomal insufficiency. DBA is characterized by anemia, congenital anomalies, and cancer predisposition. Treatment for DBA is associated with significant morbidity. Here, we report the identification of Nemo-like kinase (NLK) as a potential target for DBA therapy. To identify new DBA targets, we screen for small molecules that increase erythroid expansion in mouse models of DBA. This screen identified a compound that inhibits NLK. Chemical and genetic inhibition of NLK increases erythroid expansion in mouse and human progenitors, including bone marrow cells from DBA patients. In DBA models and patient samples, aberrant NLK activation is initiated at the Megakaryocyte/Erythroid Progenitor (MEP) stage of differentiation and is not observed in non-erythroid hematopoietic lineages or healthy erythroblasts. We propose that NLK mediates aberrant erythropoiesis in DBA and is a potential target for therapy.

Diamond Blackfan Anemia (DBA) is a congenital bone marrow failure syndrome that is associated with anemia. Here, the authors examine the role of Nemo-like kinase (NLK) in erythroid cells in the pathogenesis of DBA and as a potential target for therapy.

Auditory training app validation

Introduction One of the main hearing complaints is the difficulty to perceive speech in noisy environments. This complaint gets worse with ageing at which cognitive processing speed slows and/or when hearing loss is present. An auditory training can improve speech perception in adverse environments. The use of auditory training software on various digital platforms is becoming a reality.

Objectives To validate the auditory training app in European Portuguese with individuals aged between 55 and 64 years old with an approximate average of 20dB of hearing thresholds.

Methodology The sample consists in two groups of seven individuals without cognitive problems. One of the groups performed eight auditory training sessions with the application for a period of four weeks and the other group (the control group) did not perform any auditory training session. The evaluation was made in all the individuals with the filtered speech test. The training group was evaluated before, immediately after and after four weeks of the auditory training sessions and the control group was evaluated after four weeks.

Results Statistically there is a significant difference between before and immediately after the auditory training in the filtered speech test (p = 0.018). Four weeks after the end of the training the performance of each individual was the same. In the control group there were no significant differences between the two evaluation moments.

Conclusion The EVOLLU auditory training app promotes an improvement in the perception of the word in adverse environments that continues even after some time. This is a sign that individuals are applying that learning into their day to day living. The Evollu application can and should be used in the auditory training of individuals aged between 55 to 64 years old.

Hearing Screening in Preschool Children of a Rural Community in Portugal - A 10-year Experience

Introduction Preschool hearing screening programmes would identify later onset or progressive hearing losses and conductive hearing loss, due to the high prevalence of otitis media with effusion in childhood. Hearing loss associated with otitis media with effusion can have a great impact on reading, writing, central auditory processing and balance.

Objectives The present study aims at characterising the audiological alterations found in preschool children screened in a rural community in Portugal, and the correlation between audiological findings and otoscopy.

Methodology This is an observational study using the results obtained in a ten year audiological and otological screening of preschool children. Otoscopy, Tympanometry and Audiometry (1, 2 and 4 KHz presented at 40 and 20 dB intensity) were performed at the first stage of the screening and the results were classified as “pass” or “refer”. Every non-normal result of any category would imply a second stage consisting of observation by an ENT specialist at the site and the establishing of a follow-up plan. Written Informed Consent was obtained from the parents prior to initiating the study.

Results 595 children aged 5 and 6 years were screened between 2007 and 2017, of whom 192 (32.3%) required referral to the second stage. The most frequent alteration was found in the tympanogram. The tympanograms showed a significant correlation with the otoscopy performed by the ENT doctor, mainly type B tympanograms. The pass/refer audiometry also showed a statistically significant correlation with the medical otoscopy, although weak in all frequencies studied.

Conclusion It’s extremely important to perform a hearing screening in the age range of 5-6 years (with a high predisposition to middle ear problems), with the main objective of identifying and referring for treatment children who present alterations in order to reduce the consequences of the hearing impairment.

From Root to Tips: Sporulation Evolution and Specialization in Bacillus subtilis and the Intestinal Pathogen Clostridioides difficile

Bacteria of the Firmicutes phylum are able to enter a developmental pathway that culminates with the formation of highly resistant, dormant endospores. Endospores allow environmental persistence, dissemination and for pathogens, are also infection vehicles. In both the model Bacillus subtilis, an aerobic organism, and in the intestinal pathogen Clostridioides difficile, an obligate anaerobe, sporulation mobilizes hundreds of genes. Their expression is coordinated between the forespore and the mother cell, the two cells that participate in the process, and is kept in close register with the course of morphogenesis. The evolutionary mechanisms by which sporulation emerged and evolved in these two species, and more broadly across Firmicutes, remain largely unknown. Here, we trace the origin and evolution of sporulation using the genes known to be involved in the process in B. subtilis and C. difficile, and estimating their gain-loss dynamics in a comprehensive bacterial macroevolutionary framework. We show that sporulation evolution was driven by two major gene gain events, the first at the base of the Firmicutes and the second at the base of the B. subtilis group and within the Peptostreptococcaceae family, which includes C. difficile. We also show that early and late sporulation regulons have been coevolving and that sporulation genes entail greater innovation in B. subtilis with many Bacilli lineage-restricted genes. In contrast, C. difficile more often recruits new sporulation genes by horizontal gene transfer, which reflects both its highly mobile genome, the complexity of the gut microbiota, and an adjustment of sporulation to the gut ecosystem.

P581Electronic health records (EHRs) data validation in atherosclerotic/cardiovascular clinical phenotypes

Background

Research efforts to develop strategies to effectively identify patients and reduce the burden of cardiovascular diseases is essential for the future of the health system. Most research studies have used only coded parts of electronic health records (EHRs) for case-detection obtaining missed data cases, reducing study quality and in some case bias findings. Incorporating information from free-text into case-detection through Big Data and Artificial Intelligence techniques improves research quality. Savana has developed EHRead, a powerful technology that applies Natural Language Processing, Machine Learning and Deep Learning, to analyse and automatically extracts highly valuable medical information from unstructured free text contained in the EHR to support research and practice.

Purpose

We aimed to validate the linguistic accuracy performance of Savana, in terms of Precision (P), Recall (R) and overall performance (F-Score) in the cardiovascular domain since this is one of the most prevalent disease in the general population. This means validating the extent to which the Savana system identifies mentions to atherosclerotic/cardiovascular clinical phenotypes in EHRs.

Methods

The project was conducted in 3 Spanish sites and the system was validated using a corpus that consisted of 739 EHRs, including the emergency, medical and discharge records, written in free text. These EHRs were randomly selected from the total number of clinical documents generated during the period of 2012–2017 and were fully anonymized to comply with legal and ethical requirements. Two physicians per site reviewed records (randomly selected) and annotated all direct references to atherosclerotic/cardiovascular clinical phenotypes, following the annotation guidelines previously developed. A third physician adjudicated discordant annotations. Savana's performance was automatically calculated using as validation resource the gold standard created by the experts.

Results

We found good levels of performance achieved by Savana in the identification of mentions to atherosclerotic/cardiovascular clinical phenotypes, yielding an overall P, R, and F-score of 0.97, 0.92, and 0.94, respectively. We also found that going through all the EHRs and identifying the mentions to atherosclerotic/cardiovascular clinical phenotypes, the expert spent ∼ 60h while Savana ∼ 36 min.

Conclusion(s)

Innovative techniques to identify atherosclerotic/cardiovascular clinical phenotypes could be used to support real world data research and clinical practice. Overall Savana showed a high performance, comparable with those obtained by an expert physician annotator doing the same task. Additionally, a significant reduction of time in using automatic information extraction system was achieved.

Imipenem Resistance in Clostridium difficile Ribotype 017, Portugal

We describe imipenem-resistant and imipenem-susceptible clinical isolates of Clostridium difficile ribotype 017 in Portugal. All ribotype 017 isolates carried an extra penicillin-binding protein gene, pbp5, and the imipenem-resistant isolates had additional substitutions near the transpeptidase active sites of pbp1 and pbp3. These clones could disseminate and contribute to imipenem resistance.

Genomic Study of a Clostridium difficile Multidrug Resistant Outbreak-Related Clone Reveals Novel Determinants of Resistance

Background:Clostridium difficile infection (CDI) is prevalent in healthcare settings. The emergence of hypervirulent and antibiotic resistant strains has led to an increase in CDI incidence and frequent outbreaks. While the main virulence factors are the TcdA and TcdB toxins, antibiotic resistance is thought to play a key role in the infection by and dissemination of C. difficile.

Methods: A CDI outbreak involving 12 patients was detected in a tertiary care hospital, in Lisbon, which extended from January to July, with a peak in February, in 2016. The C. difficile isolates, obtained from anaerobic culture of stool samples, were subjected to antimicrobial susceptibility testing with Etest^®strips against 11 antibiotics, determination of toxin genes profile, PCR-ribotyping, multilocus variable-number tandem-repeat analysis (MLVA) and whole genome sequencing (WGS).

Results: Of the 12 CDI cases detected, 11 isolates from 11 patients were characterized. All isolates were tcdA^-/tcdB⁺ and belonged to ribotype 017, and showed high level resistance to clindamycin, erythromycin, gentamicin, imipenem, moxifloxacin, rifampicin and tetracycline. The isolates belonged to four genetically related MLVA types, with six isolates forming a clonal cluster. Three outbreak isolates, each from a different MLVA type, were selected for WGS. Bioinformatics analysis showed the presence of several antibiotic resistance determinants, including the Thr82Ile substitution in gyrA, conferring moxifloxacin resistance, the substitutions His502Asn and Arg505Lys in rpoB for rifampicin resistance, the tetM gene, associated with tetracycline resistance, and two genes encoding putative aminoglycoside-modifying enzymes, aadE and aac(6′)-aph(2″). Furthermore, a not previously described 61.3 kb putative mobile element was identified, presenting a mosaic structure and containing the genes ermG, mefA/msrD and vat, associated with macrolide, lincosamide and streptogramins resistance. A substitution found in a class B penicillin-binding protein, Cys721Ser, is thought to contribute to imipenem resistance.

Conclusion: We describe an epidemic, tcdA^-/tcdB⁺, multidrug resistant clone of C. difficile from ribotype 017 associated with a hospital outbreak, providing further evidence that the lack of TcdA does not impair the infectious potential of these strains. We identified several determinants of antimicrobial resistance, including new ones located in mobile elements, highlighting the importance of horizontal gene transfer in the pathogenicity and epidemiological success of C. difficile.

The Effect of Cold Stress on Damping-Off of Soybean Caused by Pythium sylvaticum

To improve our understanding of the timing of cold stress and its effect on Pythium damping-off, we performed a factorial experiment with two cold stress temperatures (4 and 10°C); exposure to 96 h of cold stress at 0, 1, 2, 4, 6, and 8 days after planting; and inoculation with Pythium sylvaticum-infested millet or control. Increased susceptibility to damping-off resulting in reduced emergence was found in inoculated plants when the cold stress period began 2 or 4 days after planting. In the noninoculated controls, no effect of cold stress on emergence was observed. Slower seedling growth was observed during the cold stress period and in inoculated plants after exposure to cold stress. Seed exudation, mycelial growth, and sporangia germination of P. sylvaticum was evaluated at 4, 10, and 18°C. The greatest seed exudation was observed at 4°C. Low temperatures delayed mycelial growth of P. sylvaticum, although the pathogen was still able to grow at 4°C. Sporangia incubated for 3 h at 18°C in the presence of seed exudates had higher germination in comparison with sporangia incubated at 10 or 4°C. Moreover, more sporangia germinated in response to seed exudates that were previously collected from seed imbibed for 24 h at low temperatures (4°C). These results suggest that cold stress 2 to 4 days after planting increases soybean susceptibility to damping-off, presumably because of increased seed exudation and delayed seedling growth.

SpoVID functions as a non-competitive hub that connects the modules for assembly of the inner and outer spore coat layers in Bacillus subtilis

During sporulation in Bacillus subtilis, a group of mother cell‐specific proteins guides the assembly of the coat, a multiprotein structure that protects the spore and influences many of its environmental interactions. SafA and CotE behave as party hubs, governing assembly of the inner and outer coat layers. Targeting of coat proteins to the developing spore is followed by encasement. Encasement by SafA and CotE requires E, a region of 11 amino acids in the encasement protein SpoVID, with which CotE interacts directly. Here, we identified two single alanine substitutions in E that prevent binding of SafA, but not of CotE, to SpoVID, and block encasement. The substitutions result in the accumulation of SafA, CotE and their dependent proteins at the mother cell proximal spore pole, phenocopying a spoVID null mutant and suggesting that mislocalized SafA acts as an attractor for the rest of the coat. The requirement for E in SafA binding is bypassed by a peptide with the sequence of E provided in trans. We suggest that E allows binding of SafA to a second region in SpoVID, enabling CotE to interact with E and SpoVID to function as a non‐competitive hub during spore encasement.

Types 1 and 2 Plasminogen Activator lnhibitor and Tirmor Necrosis Factor Alpha in Fatients with Sepsis

We have determined the plasma concentrations of types 1 and 2 of plasminogen activator inhibitor (PAI-1 and PAI-2), tumor necrosis factor (TNF-α) and endotoxin in 47 patients with bacterial infection (22 patients presented with positive blood cultures). Results were compared with those observed in 30 healthy subjects. There was a significant increase in PAI-1 and TNF-α in patients as compared to controls (p <0.0001), whereas no differences for PAI-2 were observed. PAI-1 and TNF-α were significantly higher in 18 patients with gram-negative bacteremia as compared to all other patients (p <0.0001). However, no correlation between the analyzed parameters and either endotoxin or clinical outcome was observed. We conclude that there is an increase of PAI-1 and TNF-α in patients with sepsis, which is not related to the endotoxin concentration. Our results suggest that PAI-1, but not PAI-2, is the main plasminogen activator inhibitor in human sepsis.

Behaviour of polysulfone ultrafiltration membrane for dyes removal

Although ultrafiltration membranes have been used for the separation of macromolecules and colloids from solutions, this process has a limited application in the removal of dyes present in coloured discharges of textile industry, as these typically have much lower molecular weight than the molecular cut-off of the membranes (MWCO). In the present work, we have evaluated the behaviour of a polysulfone ultrafiltration membrane in the removal of different dyes from aqueous solutions (Congo red, methyl green and amaranth). Different variables (tangential flow rate, concentration of dye and pH of the feed) were studied to determine their influence on the separation processes (permeate flux and rejection coefficient). The results show that Congo red is easily removed with a GR60PP membrane (MWCO = 25 kDa), whereas methyl green and amaranth show rejection coefficient values of approximately 25.78% and 13.85%, respectively, at neutral pH. Also, an interesting effect is observed for the rejection coefficient for methyl green at different pH values. In addition, several treatments were performed to the membrane so as to modify its surface, trying to improve the values obtained for permeate flux and rejection rate.

Antiphospholipid syndrome and IgA anti-beta2-glycoprotein I antibodies: when Cinderella becomes a princess

IgA anti-beta2-glycoprotein I (IgA-aB2GPI) antibodies are currently not included as a laboratory criterion of antiphospholipid syndrome (APS). In the 13th International Congress on Antiphospholipid Antibodies, Galveston, TX, (USA) in 2010, these antibodies were accepted as an APS laboratory criterion in patients who had clinical manifestations of APS but were negative for "consensus" antiphospholipid antibodies (aPL) (IgG and IgM isotypes). Consequently, individuals with thrombotic events who are negative for consensus aPL may be undiagnosed for APS. The most recent publications have confirmed that IgA-aB2GPI antibodies are a risk factor for thrombotic events. In this viewpoint, we propose that IgA-aB2GPI antibodies should be included as an APS consensus criterion and that we have to help Cinderella become a princess.

[Hydrocephalus due to hyperplasia of the choroid plexuses in a patient with trisomy 9 mosaicism. A real diagnostic and therapeutic challenge]

INTRODUCTION

Trisomy 9 is an unusual chromosome abnormality in live-born patients, which is frequently accompanied by functional and structural anomalies of the central nervous system. Among many other alterations, several studies have been published in the English-speaking literature that show an association between chromosome 9 abnormality and pathologies affecting the choroid plexuses.

CASE REPORT

We report the case of a 4-month-old male with trisomy 9 mosaicism associated to hydrocephalus secondary to choroid plexus hyperplasia, who was referred due to a clinical picture of intracranial hypertension. The cerebrospinal fluid (CSF) drainage procedure that was initially chosen caused massive ascites due to an excessive production of CSF, and led to a cascade of multiple surgical interventions, which included endoscopic and drainage procedures.

CONCLUSIONS

This is another example of an association between choroid plexus pathologies and chromosome 9 abnormality. Due to its scarce incidence, diagnosis of hydrocephalus secondary to plexus hyperplasia is difficult, as is selecting its most suitable treatment. In this type of hydrocephalus there is a double pathophysiological mechanism, which involves an increase in CSF production and a decrease in its reabsorption. Despite taking these considerations into account, the treatment of hydrocephalus secondary to plexus hyperplasia is a real challenge that usually leads to multiple surgical interventions ranging from plexectomy or coagulation of the choroid plexuses to the implantation of CSF drainage devices.

Albumin-binding domain from Streptococcus zooepidemicus protein Zag as a novel strategy to improve the half-life of therapeutic proteins

Recombinant antibody fragments belong to the promising class of biopharmaceuticals with high potential for future therapeutic applications. However, due to their small size they are rapidly cleared from circulation. Binding to serum proteins can be an effective approach to improve pharmacokinetic properties of short half-life molecules. Herein, we have investigated the Zag albumin-binding domain (ABD) derived from Streptococcus zooepidemicus as a novel strategy to improve the pharmacokinetic properties of therapeutic molecules. To validate our approach, the Zag ABD was fused with an anti-TNFα single-domain antibody (sdAb). Our results demonstrated that the sdAb-Zag fusion protein was highly expressed and specifically recognizes human, rat and mouse serum albumins with affinities in the nanomolar range. Moreover, data also demonstrated that the sdAb activity against the therapeutic target (TNFα) was not affected when fused with Zag ABD. Importantly, the Zag ABD increased the sdAb half-life ∼39-fold (47min for sdAb versus 31h for sdAb-Zag). These findings demonstrate that the Zag ABD fusion is a promising approach to increase the half-life of small recombinant antibodies molecules without affecting their therapeutic efficacy. Moreover, the present study strongly suggests that the Zag ABD fusion strategy can be potentially used as a universal method to improve the pharmokinetics properties of many others therapeutics proteins and peptides in order to improve their dosing schedule and clinical effects.

Week 4 response predicts sustained virological response to all-oral direct-acting antiviral-based therapy in cirrhotic patients with hepatitis C virus genotype 3 infection

OBJECTIVE

The aim of this study was to determine the predictive capacity of response at treatment week (TW) 4 for the achievement of sustained virological response 12 weeks after the scheduled end of therapy date (SVR₁₂) to treatment against hepatitis C virus (HCV) genotype 3 (GT3) infection with all-oral direct-acting antiviral (DAA) -based regimens.

PATIENTS AND METHODS

From a prospective multicohort study, HCV GT3-infected patients who completed a course of currently recommended DAA-based therapy at 33 Spanish hospitals and who had reached the SVR₁₂ evaluation time-point were selected. TW4 HCV-RNA levels were categorized as target-not-detected (TND), below the lower limit of quantification (LLOQ_TD) and ≥LLOQ.

RESULTS

A total of 123 patients were included, 86 (70%) received sofosbuvir/ daclatasvir±ribavirin, 27 (22%) received sofosbuvir/ ledipasvir/ ribavirin and 10 (8.1%) received sofosbuvir/ ribavirin, respectively. In all, 114 (92.7%) of the 123 patients presented SVR₁₂ in an on-treatment approach, but nine (7.3%) patients relapsed, all of them had presented cirrhosis at baseline. In those who achieved TND, LLOQ_TD and ≥LLOQ, SVR₁₂ was observed in 81/83 (98%; 95% CI 91.5%-99.7%), 24/28 (85.7%; 95% CI 67.3%-96%) and 9/12 (75%; 95% CI 42.8%-94.5%), respectively; p_{(linear association)} 0.001. Corresponding numbers for subjects with cirrhosis were: 52/54 (96.3%; 95% CI 87.3%-95.5%), 14/18 (77.8%; 95% CI 52.4%-93.6%) and 7/10 (70%; 95% CI 34.8%-93.3%); p 0.004.

CONCLUSIONS

TW4-response indicates the probability of achieving SVR₁₂ to currently used DAA-based therapy in HCV genotype 3-infected individuals with cirrhosis. This finding may be useful to tailor treatment strategy in this setting.

Study of β2-Glycoprotein I Polymorphisms in Patients With Chronic Renal Failure as a Predisposing Factor for the Development of Anti-β2-Glycoprotein I Auto-Antibodies

BACKGROUND

Immunoglobulin (Ig)A anti-β₂-glycoprotein I (aB2GP1) antibodies are associated with thrombotic events, cardiovascular morbidity, and death in dialysis patients. About 30% of patients with chronic renal disease are positive for IgA aB2GP1; however, the origin of these antibodies is unknown. It has been speculated that dialysis membranes, age, or etiology of renal base disease are possible precipitating factors, although these factors do not appear to be the source of antibodies. B2GP1 is a protein of 326 amino acids grouped into five domains. Eight polymorphisms have been described; the most important are Val/Leu²⁴⁷, which appears to predispose aB2GP1 antibody production in patients with anti-phospholipid syndrome, and Trp/Ser³¹⁶, which appears to have protective antibody production of aB2GP1.

METHODS

DNA samples from 92 patients with renal failure on hemodialysis were randomly collected with a 1:1 ratio for the positivity for IgA aB2GP1. Forty-six samples were positive for IgA aB2GP1 (group 1) and 46 negative for IgA aB2GP1 (group 2). All samples were anonymized to study polymorphism Val/Leu²⁴⁷ and polymorphism Trp/Ser³¹⁶.

RESULTS

No significant differences were observed between those who were positive or negative for IgA aB2GP1 in patients with renal failure treated with hemodialysis and the polymorphism located in codons 247 and 316.

CONCLUSIONS

The two groups of patients have the same prevalence in polymorphisms 247 and 316, and therefore there appears not to be a genetic predisposition in our population. New trigger factors must be studied.

Suicide mortality trends in Galicia, Spain and their relationship with economic indicators

BACKGROUND

Recent research has shown an association between unemployment and suicide, but the mediating factors in this relationship are still unknown. In this study, we investigated the effect of unemployment and economic recession on suicide rates in the Spanish region of Galicia between 1975 and 2012 Method. We analysed age-standardised suicide rates in men and women and in four age groups: less than 25 years, 25-45 years, 45-65 years and more than 65 years and performed a joinpoint analysis to determine trend changes throughout 1975-2012 period. Also we analysed the association between suicide, recession and unemployment by means of a temporal trend model with a Generalised Additive Model.

RESULTS

Suicide rates increased from 145 suicides in 1975 to a high in 1993, with 377 deaths by suicide, representing 1.38% of all causes of death, and thereafter they tend to decrease to 335 suicides in 2012. Joinpoint analyses revealed that suicide rates changed differently across sex and age groups. For men, the annual percentage of change (APC) between 1975 and 1988 (CI 95% 1986-1994) was 5.45 (CI 95% = 3.5, -7.2) but from 1988 the APC became negative [-0.66 (CI 95% = -1.3, -0.1)]. For women, APC between 1974 and 1990 (CI 95% 1986-1992) was 4.86 (CI 95% = 3.2, -6.4) and -1.46 subsequently (CI 95% = -2.2, -0.5). Women aged 24 years or less showed stable suicide rates while men from 45-65 years showed two incidence peaks. When we studied the independent correlation between unemployment, recession and suicide, we found a significant association between unemployment and suicide, but not between recession and suicide for both sexes together and for men while for women there was no significant correlation between suicide and unemployment or recession. Finally, when we studied the effect of the interaction between unemployment and recession on suicide we found economic recession and unemployment interacted with regards to suicide rates (F = 5.902; df = 4.167; p = 0.00098) and after adjusting by sex, the effect was confirmed among men (F = 4.827; df = 2.823; p = 0.0087), but not among women (F = 0.001; df = 1.000; p = 0.979).

CONCLUSIONS

Although suicide rates in Galicia are gradually decreasing in the last decades, there are important sex and age differences. Unemployment was related with suicide during economic recession periods according to our results.

A Recombination Directionality Factor Controls the Cell Type-Specific Activation of σK and the Fidelity of Spore Development in Clostridium difficile

The strict anaerobe Clostridium difficile is the most common cause of nosocomial diarrhea, and the oxygen-resistant spores that it forms have a central role in the infectious cycle. The late stages of sporulation require the mother cell regulatory protein σK. In Bacillus subtilis, the onset of σK activity requires both excision of a prophage-like element (skinBs) inserted in the sigK gene and proteolytical removal of an inhibitory pro-sequence. Importantly, the rearrangement is restricted to the mother cell because the skinBs recombinase is produced specifically in this cell. In C. difficile, σK lacks a pro-sequence but a skinCd element is present. The product of the skinCd gene CD1231 shares similarity with large serine recombinases. We show that CD1231 is necessary for sporulation and skinCd excision. However, contrary to B. subtilis, expression of CD1231 is observed in vegetative cells and in both sporangial compartments. Nevertheless, we show that skinCd excision is under the control of mother cell regulatory proteins σE and SpoIIID. We then demonstrate that σE and SpoIIID control the expression of the skinCd gene CD1234, and that this gene is required for sporulation and skinCd excision. CD1231 and CD1234 appear to interact and both proteins are required for skinCd excision while only CD1231 is necessary for skinCd integration. Thus, CD1234 is a recombination directionality factor that delays and restricts skinCd excision to the terminal mother cell. Finally, while the skinCd element is not essential for sporulation, deletion of skinCd results in premature activity of σK and in spores with altered surface layers. Thus, skinCd excision is a key element controlling the onset of σK activity and the fidelity of spore development.

Note. The ripening of Prunus persica fruits with a dominant flat allele Nota. Maduración de frutos de Prunus persica con un alelo dominante de la forma achatada

The changes of peaches ( Prunus persica, L.) with a predominant flat allele were studied during their ripening on the tree. Physicochemical and physiological parameters were analyzed between days 101 and 121 after fruit set. During this period, the weight ranged from 65 g (corresponding to fruit growth stage III) up to a stabilized weight of 90 g when the fruit was ripe. The color changes that characterized fruit ripening began to appear on day 112 after fruit set, with a decrease in the hue angle value both in the skin and pulp. Firmness diminished along the experience from 6.75 to 3.03 Monet units in ripe state. Ripened fruit was also characterized by a soluble solid content of 13.43 °Brix and 0.178% malic acid as titratable acidity. The ripeness index increased throughout maturation from 25.41 at the outset to 44.42 on day 112 after fruit set, and 75.45 at the end of the experiment. The fruit showed a clear climacteric behavior with increased ethylene production and respiration rate. The onset in both processes started on day 112 after fruit set, reached a maximum on day 116, and decreased thereafter. Changes in the content of free and conjugated 1-aminocyclopropane-1-carboxy lic acid (ACC) were coincident with those of ethylene evolution throughout ripening. In regard to polyamine levels, putrescine showed a peak slightly later than that of ethylene and ACC.