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Objective. To evaluate antimicrobial resistance patterns of clinical Streptococcus pyogenes isolates from different regions of Russia during 2014–2017. Materials and Methods. A total of 792 clinical S. pyogenes isolates from 14 Russian cities were included in the study. Susceptibility testing was performed using reference broth microdilution method (ISO 207761:2006). Susceptibility testing results were interpreted using EUCAST v.10.0 breakpoints. Results. Penicillin G was active against all tested isolates with the MIC50–90 values of 0.016 mg/l and the highest MIC value of 0.25 mg/l. No resistance to linezolid, tedizolid and vancomycin were observed. Respiratory fluoroquinolones, moxifloxacin and levofloxacin, showed a high activity with the only 0.3% and 0.8% of resistant isolates, respectively. Almost all isolates (99.9%) were susceptible to trimethoprim/ sulfamethoxazole. The resistance rates to 14- and 15-membered macrolides varied from 12.1% to 17.2%. The only 2.4% of isolates were resistant to clindamycin. Resistance to chloramphenicol was 6.1%, to tetracycline – 17.2%. Conclusions. The comparison of this study results with the previously published Russian data on antimicrobial resistance of S. pyogenes shows there were no significant changes in the susceptibility of this pathogen over the past two decades, with the exception of macrolides. The growing resistance to 14and 15-membered macrolides raises a question on the further use of this antibiotic class for the empiric treatment of streptococcal infections in Russia.

Abstract Background In recent years, planaria have emerged as an important model system for research into stem cells and regeneration. Attention is focused on their unique stem cells, the neoblasts, which can differentiate into any cell type present in the adult organism. Sequencing of the Schmidtea mediterranea genome and some expressed sequence tag projects have generated extensive data on the genetic profile of these cells. However, little information is available on their protein dynamics. Results We developed a proteomic strategy to identify neoblast-specific proteins. Here we describe the method and discuss the results in comparison to the genomic high-throughput analyses carried out in planaria and to proteomic studies using other stem cell systems. We also show functional data for some of the candidate genes selected in our proteomic approach. Conclusions We have developed an accurate and reliable mass-spectra-based proteomics approach to complement previous genomic studies and to further achieve a more accurate understanding and description of the molecular and cellular processes related to the neoblasts.

Abstract Background Freshwater planarians are an attractive model for regeneration and stem cell research and have become a promising tool in the field of regenerative medicine. With the availability of a sequenced planarian genome, the recent application of modern genetic and high-throughput tools has resulted in revitalized interest in these animals, long known for their amazing regenerative capabilities, which enable them to regrow even a new head after decapitation. However, a detailed description of the planarian transcriptome is essential for future investigation into regenerative processes using planarians as a model system. Results In order to complement and improve existing gene annotations, we used a 454 pyrosequencing approach to analyze the transcriptome of the planarian species Schmidtea mediterranea Altogether, 598,435 454-sequencing reads, with an average length of 327 bp, were assembled together with the ~10,000 sequences of the S. mediterranea UniGene set using different similarity cutoffs. The assembly was then mapped onto the current genome data. Remarkably, our Smed454 dataset contains more than 3 million novel transcribed nucleotides sequenced for the first time. A descriptive analysis of planarian splice sites was conducted on those Smed454 contigs that mapped univocally to the current genome assembly. Sequence analysis allowed us to identify genes encoding putative proteins with defined structural properties, such as transmembrane domains. Moreover, we annotated the Smed454 dataset using Gene Ontology, and identified putative homologues of several gene families that may play a key role during regeneration, such as neurotransmitter and hormone receptors, homeobox-containing genes, and genes related to eye function. Conclusions We report the first planarian transcript dataset, Smed454, as an open resource tool that can be accessed via a web interface. Smed454 contains significant novel sequence information about most expressed genes of S. mediterranea. Analysis of the annotated data promises to contribute to identification of gene families poorly characterized at a functional level. The Smed454 transcriptome data will assist in the molecular characterization of S. mediterranea as a model organism, which will be useful to a broad scientific community.

Abstract Background Two commercial interferon gamma release assays (IGRAs) (QuantiFERON®-TB Gold in Tube and T SPOT®-TB) to detect a contact with M. tuberculosis have recently become available. The majority of studies agree that the sensitivity and specificity of these methods are superior to the Tuberculin Skin Tests (TSTs) in detecting an exposure to bacteria in latently infected individuals and in clinical tuberculosis. However, the data in children remains limited. Findings Consecutively collected samples from children (n = 99) representing age range from zero to 18 years were analyzed in a retrospective non-blinded study. The two IGRAs were modified and adapted to the needs of Finland, a country of a low tuberculosis incidence. For 27 children, both tests were performed simultaneously and compared with the TST and clinician's diagnosis. The sensitivity, specificity, and accuracy of both IGRAs was determined. QuantiFERON TB Gold and T SPOT-TB performed (respectively) as follows: sensitivities 0.92 (95% confidence interval, CI, 0.67–0.99) and 0.85 (0.64–0.95); specificities 0.91 (0.77–0.97) and 1.00 (0.93–1.00); accuracies 0.91 (0.80–0.97) and 0.96 (0.88–0.99). This compares favorably to the TST whose known figures are 0.90, 0.95, and 0.95, respectively. The agreement between the IGRAs was high, k = 0.89. Finally, both methods agreed well with the TST, k = 0.86 for TST/QuantiFERON-TB Gold and k = 0.76 for TST/T SPOT-TB. Conclusion The sensitivity and specificity of IGRA methods compares well with the TST without the inconveniences and complications associated with TST, including exaggerated delayed type hypersensitivity reactions. These properties place them as acceptable substitutes for TST.

Background: Malnutrition among inpatients is highly prevalent, and has a negative impact on their clinical outcome. The Working Group for the Study of Malnutrition in Hospitals in Catalonia was created to generate consensus guidelines for the prevention and/or treatment of malnutrition in hospitals in Catalonia, Spain. Aims: The objectives of the study were to determine the prevalence of malnutrition on admission to hospital in Catalonia and to assess relationships between malnutrition, social and demographic data, overall costs, and mortality. Methods: Prospective and multicenter study conducted with 796 patients from 11 hospitals representative of the hospitalized population in Catalonia. Nutritional status was evaluated using the Nutritional Risk Screening 2002 method. Results: Overall, 28.9% of the patients are malnourished or at nutritional risk. Elderly patients, non-manual workers, those admitted to hospital as emergencies and with higher co-morbidities had higher risk of malnutrition. The type of hospital (second level vs. tertiary or University referral) to which they were admitted was also a factor predisposing to malnutrition. Length of hospital stay was longer in malnourished patients (10.5 vs. 7.7 days, p < 0.0001). The need for a convalescent home on leaving hospital was higher as well as the risk of mortality (8.6% malnourished vs. 1.3% nonmalnourished, p < 0.0001). Conclusions: The prevalence of malnutrition is high in patients on admission to hospital in our community, resulting in elevated overall costs and higher risk of mortality. Age, social class and characteristics of the Unit and the Hospital are the main factors involved in hospital malnutrition. [ABSTRACT FROM AUTHOR]

For successful regeneration, the identity of the missing tissue must be specified according to the pre-existing tissue. Planarians are ideal for the study of the mechanisms underlying this process; the same field of cells can regrow a head or a tail according to the missing body part. After amputation, the differential activation of the Wnt/β-catenin signal specifies anterior versus posterior identity. Initially, both wnt1 and notum (Wnt inhibitor) are expressed in all wounds, but 48 hours later they are restricted to posterior or anterior facing wounds, respectively, by an unknown mechanism. Here we show that 12 hours after amputation, the chromatin accessibility of cells in the wound region changes according to the polarity of the pre-existing tissue in a Wnt/β-catenin-dependent manner. Genomic analyses suggest that homeobox transcription factors and chromatin-remodeling proteins are direct Wnt/β-catenin targets, which trigger the expression of posterior effectors. Finally, we identify FoxG as a wnt1 up-stream regulator, probably via binding to its first intron enhancer region., (© 2023. The Author(s).)

The capability to simultaneously apply different molecular tools to visualize a wide variety of changes in genetic expression and tissue composition in Schmidtea mediterranea has always been of great interest. The most commonly used techniques are fluorescent in situ hybridization (FISH) and immunofluorescence (IF) detection. Here, we describe a novel way to perform both protocols together adding the possibility to combine them with fluorescent-conjugated lectin staining to further broaden the detection of tissues. We also present a novel lectin fixation protocol to enhance the signal, which could be useful when single-cell resolution is required., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Forkhead box (Fox) genes belong to the "winged helix" transcription factor superfamily. The function of some Fox genes is well known, such as the role of foxO in controlling metabolism and longevity and foxA in controlling differentiation of endodermal tissues. However, the role of some Fox factors is not yet well characterized. Such is the case of FoxK genes, which are mainly studied in mammals and have been implicated in diverse processes including cell proliferation, tissue differentiation and carcinogenesis. Planarians are free-living flatworms, whose importance in biomedical research lies in their regeneration capacity. Planarians possess a wide population of pluripotent adult stem cells, called neoblasts, which allow them to regenerate any body part after injury. In a recent study, we identified three foxK paralogs in the genome of Schmidtea mediterranea . In this study, we demonstrate that foxK1 inhibition prevents regeneration of the ectodermal tissues, including the nervous system and the epidermis. These results correlate with foxK1 expression in neoblasts and in neural progenitors. Although the triggering of wound genes expression, polarity reestablishment and proliferation was not affected after foxK1 silencing, the apoptotic response was decreased. Altogether, these results suggest that foxK1 would be required for differentiation and maintenance of ectodermal tissues., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Coronel-Córdoba, Molina, Cardona, Fraguas, Pascual-Carreras, Saló, Cebrià and Adell.)

The forkhead box (Fox) genes encode transcription factors that control several key aspects of development. Present in the ancestor of all eukaryotes, Fox genes underwent several duplications followed by loss and diversification events that gave rise to the current 25 families. However, few Fox members have been identified from the Lophotrochozoa clade, and specifically from planarians, which are a unique model for understanding development, due to the striking plasticity of the adult. The aim of this study was to identify and perform evolutionary and functional studies of the Fox genes of lophotrochozoan species and, specifically, of the planarian Schmidtea mediterranea. Generating a pipeline for identifying Forkhead domains and using phylogenetics allowed us the phylogenetic reconstruction of Fox genes. We corrected the annotation for misannotated genes and uncovered a new family, the QD, present in all metazoans. According to the new phylogeny, the 27 Fox genes found in Schmidtea mediterranea were classified into 12 families. In Platyhelminthes, family losses were accompanied by extensive gene diversification and the appearance of specific families, the A(P) and N(P). Among the newly identified planarian Fox genes, we found a single copy of foxO, which shows an evolutionary conserved role in controlling cell death.

An organizer is defined as a group of cells that secrete extracellular proteins that specify the fate of surrounding cells according to their concentration. Their function during embryogenesis is key in patterning new growing tissues. Although organizers should also participate in adult development when new structures are regenerated, their presence in adults has only been identified in a few species with striking regenerative abilities, such as planarians. Planarians provide a unique model to understand the function of adult organizers, since the presence of adult pluripotent stem cells provides them with the ability to regenerate any body part. Previous studies have shown that the differential activation of the WNT/β-catenin signal in each wound is fundamental to establish an anterior or a posterior organizer in the corresponding wound. Here, we identify the receptors that mediate the WNT/β-catenin signal in posterior-facing wounds. We found that Wnt1-Fzd1-LRP5/6 signaling is evolutionarily conserved in executing a WNT/β-catenin signal to specify cell fate and to trigger a proliferative response. Our data allow a better understanding of the mechanism through which organizers signal to a "competent" field of cells and integrate the patterning and growth required during de novo formation of organs and tissues.

Although many examples of simulated and real microgravity demonstrating their profound effect on biological systems are described in literature, few reports deal with hypergravity and vibration effects, the levels of which are severely increased during the launch preceding the desired microgravity period. Here, we used planarians, flatworms that can regenerate any body part in a few days. Planarians are an ideal model to study the impact of launch-related hypergravity and vibration during a regenerative process in a "whole animal" context. Therefore, planarians were subjected to 8.5 minutes of 4 g hypergravity (i.e. a human-rated launch level) in the Large Diameter Centrifuge (LDC) and/or to vibrations (20-2000 Hz, 11.3 G rms ) simulating the conditions of a standard rocket launch. The transcriptional levels of genes (erg-1 , runt-1 , fos, jnk , and yki ) related with the early stress response were quantified through qPCR. The results show that early response genes are severely deregulated after static and dynamic loads but more so after a combined exposure of dynamic (vibration) and static (hypergravity) loads, more closely simulating real launch exposure profiles. Importantly, at least four days after the exposure, the transcriptional levels of those genes are still deregulated. Our results highlight the deep impact that short exposures to hypergravity and vibration have in organisms, and thus the implications that space flight launch could have. These phenomena should be taken into account when planning for well-controlled microgravity studies., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2020.)

Control of cell number is crucial to define body size during animal development and to restrict tumoral transformation. The cell number is determined by the balance between cell proliferation and cell death. Although many genes are known to regulate those processes, the molecular mechanisms underlying the relationship between cell number and body size remain poorly understood. This relationship can be better understood by studying planarians, flatworms that continuously change their body size according to nutrient availability. We identified a novel gene family, blitzschnell ( bls ), that consists of de novo and taxonomically restricted genes that control cell proliferation:cell death ratio. Their silencing promotes faster regeneration and increases cell number during homeostasis. Importantly, this increase in cell number leads to an increase in body size only in a nutrient-rich environment; in starved planarians, silencing results in a decrease in cell size and cell accumulation that ultimately produces overgrowths. bls expression is downregulated after feeding and is related to activity of the insulin/Akt/mTOR network, suggesting that the bls family evolved in planarians as an additional mechanism for restricting cell number in nutrient-fluctuating environments., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

Freshwater planarians are well known for their remarkable plasticity and regenerative capabilities. Most studies of planarian regeneration have specifically examined regeneration after transverse or longitudinal sectioning or during homeostasis in intact adults. However, tissue transplantation, first performed over a century ago, constitutes another important tool in the study of regeneration in planarians, and can be easily performed given this species' extraordinary healing capacity and its lack of a circulatory system. Studies conducted to date have demonstrated the viability of transplantations involving a variety of tissue types of different positional identities, affecting any of the 3 main body axes. Moreover, these grafting experiments have shown that tissues possess axial positional identities, which are retained following transplantation. The confrontation between different positional identities that occurs after any type of tissue transplantation is resolved by the formation of a blastema, consisting of undifferentiated tissue produced by adult pluripotent stem cells (neoblasts). This blastema intercalates the positional identities of the graft and host tissues. The recent discovery of pathways involved in planarian growth, patterning, and organogenesis, as well as corresponding molecular markers, makes tissue transplantation a vital new tool with which to explore pattern formation. Here, we discuss the different grafting approaches used in planarians, and the corresponding intercalary regenerative response, placing particular emphasis on the respective contributions of donor and host tissue. Moreover, we discuss the temporal induction of blastema formation, and present new molecular data on the generation of an ectopic anterior/posterior axis in response to dorsal/ventral confrontations between host and donor tissue., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The possibility of humans to live outside of Earth on another planet has attracted the attention of numerous scientists around the world. One of the greatest difficulties is that humans cannot live in an extra-Earth environment without proper equipment. In addition, the consequences of chronic gravity alterations in human body are not known. Here, we used planarians as a model system to test how gravity fluctuations could affect complex organisms. Planarians are an ideal system, since they can regenerate any missing part and they are continuously renewing their tissues. We performed a transcriptomic analysis of animals submitted to simulated microgravity (Random Positioning Machine, RPM) (s-µg) and hypergravity (8 g), and we observed that the transcriptional levels of several genes are affected. Surprisingly, we found the major differences in the s-µg group. The results obtained in the transcriptomic analysis were validated, demonstrating that our transcriptomic data is reliable. We also found that, in a sensitive environment, as under Hippo signaling silencing, gravity fluctuations potentiate the increase in cell proliferation. Our data revealed that changes in gravity severely affect genetic transcription and that these alterations potentiate molecular disorders that could promote the development of multiple diseases such as cancer.

The Hippo pathway plays a key role in regulating cell turnover in adult tissues, and abnormalities in this pathway are consistently associated with human cancers. Hippo was initially implicated in the control of cell proliferation and death, and its inhibition is linked to the expansion of stem cells and progenitors, leading to larger organ size and tumor formation. To understand the mechanism by which Hippo directs cell renewal and promotes stemness, we studied its function in planarians. These stem cell-based organisms are ideal models for the analysis of the complex cellular events underlying tissue renewal in the whole organism. hippo RNA interference (RNAi) in planarians decreased apoptotic cell death, induced cell cycle arrest, and could promote the dedifferentiation of postmitotic cells. hippo RNAi resulted in extensive undifferentiated areas and overgrowths, with no effect on body size or cell number. We propose an essential role for hippo in controlling cell cycle, restricting cell plasticity, and thereby preventing tumoral transformation.

Tissue transplantation is an important tool for in vivo studies of pattern organization and axis establishment or maintenance in planarians. Further, transplants can inform on cell movements under different regenerative conditions or genetic backgrounds. Here, we detail classical grafting strategies that have been variously employed in planarian research over the last few decades. These protocols remain similarly useful for addressing current and future questions in the field and the step-by-step protocol that we provide allows facile adaptation of this important method into the experimental repertoire of a laboratory.

Why some animals can regenerate and others not has fascinated biologists since the first examples of regeneration were reported. Although many animal phyla include species with some regenerative ability, mainly restricted to particular cell types or tissues, there are some other species capable of regenerating complex structures, such as the vertebrate limb and heart. More remarkably, there are some examples of animals that can regenerate the whole body from a tiny piece of them. Understanding how regeneration is triggered and achieved in these animals is fundamental not only to understand this fascinating primary biological question, but also because of its implications for the field of regenerative medicine. Here, we discuss one of the models with higher regenerative capabilities: the freshwater planarians. Two key features make planarians an attractive model to study regeneration: the presence of adult pluripotent stem cells and the permanent activation of the morphogenetic mechanisms that instruct cell fate. Here, we revise our current knowledge of key events that lead to successful regeneration including: how heterogeneous is the stem cell population; what are the immediate changes at the gene level after amputation and what triggers the regenerative response; how is axial polarity re-established; how do the different cell types differentiate from lineage-committed progenitors and how is size and organ proportionality controlled. Finally, we point out some open questions that the field needs to address in the near future.

How adult stem cells differentiate into different cell types remains one of the most intriguing questions in regenerative medicine. Pioneer factors are transcription factors that can bind to and open chromatin, and are among the first elements involved in cell differentiation. We used the freshwater planarian Schmidtea mediterranea as a model system to study the role of the gata456 family of pioneer factors in gut cell differentiation during both regeneration and maintenance of the digestive system. Our findings reveal the presence of two members of the gata456 family in the Schmidtea mediterranea genome; Smed-gata456-1 and Smed-gata456-2. Our results show that Smed-gata456-1 is the only ortholog with a gut cell-related function. Smed-gata456-1 is essential for the differentiation of precursors into intestinal cells and for the survival of these differentiated cells, indicating a key role in gut regeneration and maintenance. Furthermore, tissues other than the gut appear normal following Smed-gata456-1 RNA interference (RNAi), indicating a gut-specific function. Importantly, different neoblast subtypes are unaffected by Smed-gata456-1(RNAi), suggesting that 1) Smed-gata456-1 is involved in the differentiation and maintenance, but not in the early determination, of gut cells; and 2) that the stem cell compartment is not dependent on a functional gut.