A transcriptional complex of NGATHA and bHLH transcription factors directs stigma development in Arabidopsis.

The stigma is an angiosperm-specific tissue that is essential for pollination. In the last two decades, several transcription factors with key roles in stigma development in Arabidopsis thaliana have been identified. However, genetic analyses have thus far been unable to unravel the precise regulatory interactions among these transcription factors or the molecular basis for their selective roles in different spatial and temporal domains. Here, we show that the NGATHA (NGA) and HECATE (HEC) transcription factors, which are involved in different developmental processes but are both essential for stigma development, require each other to perform this function. This relationship is likely mediated by their physical interaction in the apical gynoecium. NGA/HEC transcription factors subsequently upregulate INDEHISCENT (IND) and SPATULA and are indispensable for the binding of IND to some of its targets to allow stigma differentiation. Our findings support a nonhierarchical regulatory scenario in which the combinatorial action of different transcription factors provides exquisite temporal and spatial specificity of their developmental outputs.

Neutralization of Staphylococcus aureus Protein A Prevents Exacerbated Osteoclast Activity and Bone Loss during Osteomyelitis.

Osteomyelitis caused by Staphylococcus aureus is an important and current health care problem worldwide. Treatment of this infection frequently fails not only due to the increasing incidence of antimicrobial-resistant isolates but also because of the ability of S. aureus to evade the immune system, adapt to the bone microenvironment, and persist within this tissue for decades. We have previously demonstrated the role of staphylococcal protein A (SpA) in the induction of exacerbated osteoclastogenesis and increased bone matrix degradation during osteomyelitis. The aim of this study was to evaluate the potential of using anti-SpA antibodies as an adjunctive therapy to control inflammation and bone damage. By using an experimental in vivo model of osteomyelitis, we demonstrated that the administration of an anti-SpA antibody by the intraperitoneal route prevented excessive inflammatory responses in the bone upon challenge with S. aureus. Ex vivo assays indicated that blocking SpA reduced the priming of osteoclast precursors and their response to RANKL. Moreover, the neutralization of SpA was able to prevent the differentiation and activation of osteoclasts in vivo, leading to reduced expression levels of cathepsin K, reduced expression of markers associated with abnormal bone formation, and decreased trabecular bone loss during osteomyelitis. Taken together, these results demonstrate the feasibility of using anti-SpA antibodies as an antivirulence adjunctive therapy that may prevent the development of pathological conditions that not only damage the bone but also favor bacterial escape from antimicrobials and the immune system.

Changes in the epidemiology of invasive fungal disease in a Pediatric Hematology and Oncology Unit: the relevance of breakthrough infections.

BACKGROUND: Invasive fungal disease (IFD) is a significant cause of morbimortality in children under chemotherapy or hematopoietic stem cell transplant (HSCT). The purpose of this study is to describe the changes in the IFD epidemiology that occurred in a Pediatric Hematology-Oncology Unit (PHOU) with an increasing activity over time. METHODS: Retrospective revision of the medical records of children (from 6 months to 18 years old) diagnosed with IFD in the PHOU of a tertiary hospital in Madrid (Spain), between 2006 and 2019. IFD definitions were performed according to the EORTC revised criteria. Prevalence, epidemiological, diagnostic and therapeutic parameters were described. Comparative analyses were conducted using Chi-square, Mann-Whitney and Kruskal-Wallis tests, according to three time periods, the type of infection (yeast vs mold infections) and the outcome. RESULTS: Twenty-eight episodes of IFD occurred in 27 out of 471 children at risk (50% males; median age of 9.8 years old, [IQR 4.9-15.1]), resulting in an overall global prevalence of 5.9%. Five episodes of candidemia and 23 bronchopulmonary mold diseases were registered. Six (21.4%), eight (28.6%) and 14 (50%) episodes met criteria for proven, probable and possible IFD, respectively. 71.4% of patients had a breakthrough infection, 28.6% required intensive care and 21.4% died during treatment. Over time, bronchopulmonary mold infections and breakthrough IFD increased (p=0.002 and p=0.012, respectively), occurring in children with more IFD host factors (p=0.028) and high-risk underlying disorders (p=0.012). A 64% increase in the number of admissions in the PHOU (p<0.001) and a 277% increase in the number of HSCT (p=0.008) were not followed by rising rates of mortality or IFD/1000 admissions (p=0.674). CONCLUSIONS: In this study, we found that yeast infections decreased, while mold infections increased over time, being most of them breakthrough infections. These changes are probably related to the rising activity in our PHOU and an increase in the complexity of the baseline pathologies of patients. Fortunately, these facts were not followed by an increase in IFD prevalence or mortality rates.

Acute Epstein-Barr virus infection: Diagnostic challenge in young children, risk factors for hospitalisation and cytomegalovirus co-detection.

AIM: Acute Epstein-Barr virus (aEBV) and cytomegalovirus (CMV) infections frequently have similar manifestations. We aim to evaluate the characteristics of aEBV infection, risk factors for hospitalisation and differences according to CMV IgM detection (EBV-CMV co-detection) in children. METHODS: Retrospective, single-centre study including patients <16 years diagnosed with aEBV infection (positive anti-EBV IgM/Paul-Bunnell test and acute symptomatology). EBV-CMV co-detection was defined as positive CMV IgM. Factors associated with age, hospitalisation and EBV-CMV co-detection were analysed in a multivariate analysis. RESULTS: A total of 149 patients were included (median age 4.6 years). Most frequent manifestations were fever (77%), cervical lymphadenopathy (64%) and elevated liver enzymes (54%). Younger children had lower rate of positive Paul-Bunnell test (35% vs. 87%; p < 0.01), but higher rate of EBV-CMV co-detection (54% vs. 29%; p = 0.03). These children tended to have less typical symptoms of infectious mononucleosis and higher hospitalisation rate. The overall antibiotic prescription was 49%. Hospitalisation (27 children; 18%) was independently associated with prior antibiotic therapy and anaemia. Sixty-two cases (42%) had EBV-CMV co-detection, which was independently associated with elevated liver enzymes and younger age. CONCLUSION: In this study, younger children with aEBV infection presented more frequently with atypical clinical symptoms, had higher EBV-CMV co-detection rates and were more often hospitalised. Hospitalisation was associated with prior antibiotic prescription.

Daily very low UV dose exposure enhances adaptive immunity, compared with a single high-dose exposure. Consequences for the control of a skin infection.

Ultraviolet radiation (UVr) promotes several well-known molecular changes, which may ultimately impact on health. Some of these effects are detrimental, like inflammation, carcinogenesis and immunosuppression. On the other hand, UVr also promotes vitamin D synthesis and other beneficial effects. We recently demonstrated that exposure to very low doses of UVr on four consecutive days [repetitive low UVd (rlUVd)] does not promote an inflammatory state, nor the recruitment of neutrophils or lymphocytes, as the exposure to a single high UV dose (shUVd) does. Moreover, rlUVd reinforce the epithelium by increasing antimicrobial peptides transcription and epidermal thickness. The aim of this study was to evaluate the adaptive immune response after shUVd and rlUVd, determining T-cell and B-cell responses. Finally, we challenged animals exposed to both irradiation procedures with Staphylococcus aureus to study the overall effects of both innate and adaptive immunity during a cutaneous infection. We observed, as expected, a marked suppression of T-cell and B-cell responses after exposure to an shUVd but a novel and significant increase in both specific responses after exposure to rlUVd. However, the control of the cutaneous S. aureus infection was defective in this last group, suggesting that responses against pathogens cannot be ruled out from isolated stimuli.

High virulence of methicillin resistant Staphylococcus aureus ST30-SCCmecIVc-spat019, the dominant community-associated clone in Argentina.

Community-acquired methicillin resistant Staphylococcus aureus emerged as a worldwide health problem in the last few years. In Argentina, it is found in 70% of skin and skin structure infections in previously healthy adult patients and causes severe invasive diseases. The ST30-SCCmecIVc-spat019 clone is predominant in adult infections and has displaced the previously prevalent ST5-SCCmecIVa-spat311 clone in community settings. In the present work we compared the virulence of both clones in order to explain the displacement, and found that ST30-IVc is associated with invasive infections in adult patients from Argentina and possesses a different virulence-associated genes profile compared to ST5-IVa. A representative strain of ST30 lineage has a more aggressive behavior in animal models of infection and expresses higher level of Fibronectin binding protein A coding gene, which could enhance the bacterial invasion capacity.

Treatment in vitro with PPARα and PPARγ ligands drives M1-to-M2 polarization of macrophages from T. cruzi-infected mice.

Trypanosoma cruzi, the etiological agent of Chagas' disease, induces a persistent inflammatory response. Macrophages are a first line cell phenotype involved in the clearance of infection. Upon parasite uptake, these cells increase inflammatory mediators like NO, TNF-α, IL-1ß and IL-6, leading to parasite killing. Although desired, inflammatory response perpetuation and exacerbation may lead to tissue damage. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent nuclear transcription factors that, besides regulating lipid and carbohydrate metabolism, have a significant anti-inflammatory effect. This is mediated through the interaction of the receptors with their ligands. PPARγ, one of the PPAR isoforms, has been implicated in macrophage polarization from M1, the classically activated phenotype, to M2, the alternatively activated phenotype, in different models of metabolic disorders and infection. In this study, we show for the first time that, besides PPARγ, PPARα is also involved in the in vitro polarization of macrophages isolated from T. cruzi-infected mice. Polarization was evidenced by a decrease in the expression of NOS2 and proinflammatory cytokines and the increase in M2 markers like Arginase I, Ym1, mannose receptor and TGF-ß. Besides, macrophage phagocytic activity was significantly enhanced, leading to increased parasite load. We suggest that modulation of the inflammatory response by both PPARs might be due, at least in part, to a change in the profile of inflammatory macrophages. The potential use of PPAR agonists as modulators of overt inflammatory response during the course of Chagas' disease deserves further investigation.

Disease disclosure, treatment adherence, and behavioural profile in a cohort of vertically acquired HIV-infected adolescents. NeuroCoRISpeS study.

UNLABELLED: Advances in care and antiretroviral treatment, improved life expectancy and quality of life in children with perinatally-acquired human immunodeficiency virus (HIV) infection. There is increasing interest in the chronic effects of growing up with HIV. The aim of this study was to assess the psychosocial, emotional and behavioural functioning in a cohort of perinatally-acquired HIV-infected adolescents. Data were obtained through semi-structured interviews and the Strengths and Difficulties Questionnaire (SDQ) for emotional and behavioural disorders screening. RESULTS: A total of 95 patients (58% women) were assessed with a median age of 15 years (11-19.1) and a median age at diagnosis of 1.7 years (0-12.2). The median CD4 count, at the inclusion, was 626 cells/mm(3) (132-998), with 34% (10-52%). Viral load was <50 copies/ml in 72% of patients. Eighty-one per cent knew their diagnosis and optimal adherence was achieved in 53%. Passive coping was reported in 58.4% of the adolescents. Only 7.7% of teenagers had a complete and adequate knowledge of their disease and only 18.2% had shared it with their friends. Six unwanted pregnancies occurred (11% of women). Most of them (90%) attended school but 60% had been held back one or more school years. Overall, SDQ scored a risk of behavioural and emotional problems in 24.5%. The report of behaviours associated with hyperactivity was high in 14.9% of the population and borderline in 18.1%. Adolescents with encephalopathy accounted for 44% of those whose total scores fell in either the abnormal and borderline ranges for emotional difficulties (p = .038). CONCLUSION: Perinatally-acquired HIV-infected adolescents showed significant psychosocial and behavioural health risks that should bring attention to prevention and health care programmes. An earlier disclosure to children could favour a better psychological adjustment and a better treatment adherence. Future studies are needed to assess the relationship between vertically acquired HIV-infection and hyperactivity.

Leaf expansion in Arabidopsis is controlled by a TCP-NGA regulatory module likely conserved in distantly related species.

The NGATHA (NGA) clade of transcription factors (TFs) forms a small subfamily of four members in Arabidopsis thaliana. NGA genes act redundantly to direct the development of apical tissues in the gynoecium, where they have been shown to be essential for style and stigma specification. In addition, NGA genes have a more general role in controlling lateral organ growth. The four NGA genes in Arabidopsis are expressed in very similar domains, although little is known about the nature of their putative regulators. Here, we have identified a conserved region within the four NGA promoters that we have used as a bait to screen a yeast library, aiming to identify such NGA regulators. Three members of the TCP family of TFs, named after the founding factors TEOSINTE BRANCHED 1, CYCLOIDEA and PROLIFERATING CELL FACTOR 1 AND 2), were recovered from this screening, of which two [TCP2 and TCP3, members of the CINCINNATA (CIN) family of TCP genes (CIN-TCP) subclade] were shown to activate the NGA3 promoter in planta. We provide evidence that support that CIN-TCP genes are true regulators of NGA gene expression, and that part of the CIN-TCP role in leaf development is mediated by NGA upregulation. Moreover, we have found that this TCP-NGA regulatory interaction is likely conserved in angiosperms, including important crop species, for which the regulation of leaf development is a target for biotechnological improvement.

Isolation and characterization of onion degrading bacteria from onion waste produced in South Buenos Aires province, Argentina.

Onion production in Argentina generates a significant amount of waste. Finding an effective method to recycle it is a matter of environmental concern. Among organic waste reuse techniques, anaerobic digestion could be a valuable alternative to current practices. Substrate inoculation with appropriate bacterial strains enhances the rate-limiting step (hydrolysis) of anaerobic digestion of biomass wastes. Selection of indigenous bacteria with the ability to degrade onion waste could be a good approach to find a suitable bioaugmentation or pretreatment agent. We isolated bacterial strains from onion waste in different degradation stages and from different localities. In order to characterize and select the best candidates, we analyzed the growth patterns of the isolates in a medium prepared with onion juice as the main source of nutrients and we evaluated carbon source utilization. Nine strains were selected to test their ability to grow using onion tissue and the five most remarkable ones were identified by 16S rRNA gene sequencing. Strains belonged to the genera Pseudoxanthomonas, Bacillus, Micrococcus and Pseudomonas. Two strains, Bacillus subtilis subsp. subtillis MB2-62 and Pseudomonas poae VE-74 have characteristics that make them promising candidates for bioaugmentation or pretreatment purposes.

[Psychosocial aspects in a cohort of vertically transmitted human immunodeficiency virus-infected adolescents]. / Aspectos psicosociales en una cohorte de adolescentes con infección por el virus de la inmunodeficiencia humana por transmisión vertical. NeuroCoRISpeS.

INTRODUCTION: Thanks to advances in antiretroviral treatment, children with HIV infections through vertical transmission have improved their life expectancy. However, new challenges have emerged. We propose this study in order to determine the psychosocial aspects and knowledge of infections in a cohort of adolescents with vertically transmitted HIV infections. METHODS: Patients with vertically-acquired HIV infection between 12 and 19 years old were included. Data were obtained through semi-structured interviews and a Strengths and Difficulties Questionnaire for emotional and behavioral disorders screening. RESULTS: We evaluated 96 patients (58% females) with a median age of 15 years (11-19.1) and a median age at diagnosis of 1.70 years (0-12.2). The median CD4 count was 626cells/mm(3) (132-998), and the viral load was<50cp/ml in 72% of patients. Among them, 90% attended school and 60% repeated at least one course. Although 81% of them knew of their diagnosis, only 30% understood their disease, with 18.2% having discussed it with friends. Six unwanted pregnancies occurred during the study period. Strengths and Difficulties Questionnaire showed hyperactivity risk in 33%. CONCLUSION: A high percentage of adolescents show difficulties in several areas (disease knowledge, peer relationship, school failure...) that can have an impact on their adult lives. Further studies are needed to evaluate their origin and development in depth, as well as interventions to modify this situation.

Immunisation schedule of the Spanish Association of Pediatrics: 2024 recommendations.

The AEP Immunization Calendar for 2024, with its immunization recommendations for pregnant women, children and adolescents residing in Spain, marks the 25th edition since the first one was introduced in 1995, being annual since 2003, as a vaccination calendar, and since 2023 as immunization schedule due to the inclusion of a monoclonal antibody for the prevention of RSV disease. Novelties for this year include the following: The rest of the recommendations from the previous calendar remain unchanged.

Vaccination against seasonal flu in childhood and adolescence. Recommendations of the Advisory Committee on Vaccines and Immunizations of the Spanish Association of Pediatrics (CAV-AEP) for the 2024-2025 season.

The flu is a constant threat that can sometimes cause severe forms of disease. The highest incidence rates by age group occur in children under 15 years of age, especially in those under 5 years, in whom the rate of hospitalization is also similar to the population aged 65 years and older. In addition, children are the main transmitters of the infection. In Spain, 5 influenza vaccines are authorized for the paediatric age group: three inactivated tetravalent vaccines harvested from fertilised eggs, one tetravalent inactivated vaccine obtained from cell cultures and one attenuated tetravalent vaccine for intranasal administration, which will become trivalent in the 2024-2025 season by excluding the B Yamagata lineage as recommended by the WHO. The CAV-AEP recommends systematic vaccination in children aged 6-59 months, children and adolescents belonging to risk groups, people who can transmit the flu to groups at risk of complicated flu, and household contacts or close family of infants under 6 months. From 2 years of age, the intranasal attenuated vaccine is preferred due to its greater acceptability and thus contribution to greater vaccination coverage. The CAV-AEP also considers that vaccination against influenza of healthy children and adolescents aged 5-18 years is advisable, as it provides individual protection and promotes protection at the family and community levels. It is especially important to vaccinate all health care professionals against influenza as well as pregnant women at any time during pregnancy.

Effectiveness and Safety of Direct-acting Antivirals for Treatment of Adolescents With HCV/HIV Coinfection: Real-world Data From Europe.

We evaluated the effectiveness and safety of direct-acting antivirals in adolescents with hepatitis C (HCV)/HIV coinfection using pooled individual patient-level data from 5 European cohorts. Of 122 participants in follow-up from November 2013 to August 2021, 19 were treated <18 years of age; of 15 with HCV RNA available at/after 12 weeks post-treatment, all had sustained virologic response with acceptable safety. This evidence addresses an important gap in knowledge of treatment outcomes in adolescents with HCV/HIV coinfection in real-life settings.

Shedding of tumor necrosis factor receptor 1 induced by protein A decreases tumor necrosis factor alpha availability and inflammation during systemic Staphylococcus aureus infection.

Staphylococcus aureus infections are an important public health concern due to their increasing incidence and high rates of mortality. The success of S. aureus as a pathogen is highly related to its enormous capacity to evade the host immune response. The critical role of tumor necrosis factor alpha (TNF-α) in the initial host defense against systemic staphylococcal infection has been demonstrated in experimental models and may partially explain the lack of significant benefits observed in clinical trials attempting to neutralize this cytokine in septic patients. S. aureus protein A plays a key role in regulating inflammation through its ability to bind and signal through the TNF-α receptor 1 (TNFR1). In this study, we demonstrate that S. aureus, via protein A-mediated signaling, induces early shedding of TNFR1, which precedes the secretion of TNF-α in vitro and in vivo. The results obtained using a protein A-deficient mutant and tnfr1(-/-) mice strongly suggest that the increased levels of soluble TNFR1 present during experimental S. aureus infection may neutralize circulating TNF-α and impair the host inflammatory response. Early shedding of TNFR1 induced by protein A may constitute a novel mechanism by which S. aureus subverts the host immune response.

The length of the Staphylococcus aureus protein A polymorphic region regulates inflammation: impact on acute and chronic infection.

Staphylococcus aureus protein A (SpA) plays a critical role in the induction of inflammation. This study was aimed to determine whether the number of short sequence repeats (SSRs) present in the polymorphic region modulates the inflammatory response induced by SpA. We demonstrated that there is a dose-response effect in the activation of interferon (IFN)-ß signaling in airway epithelial and immune cells, depending on the number of SSRs, which leads to differences in neutrophil recruitment. We also determined that a significant proportion of isolates from patients with chronic infections such as osteomyelitis and cystic fibrosis carry fewer SSRs than do isolates from patients with acute infections or healthy carriers and that there was an inverse correlation between the number of SSRs and the length of disease course. Given the importance of IFN signaling in eradication of S. aureus, loss of SSRs may represent an advantageous mechanism to adapt to and persist in the host.

Staphylococcus aureus Adaptation to the Skin in Health and Persistent/Recurrent Infections.

Staphylococcus aureus is a microorganism with an incredible capability to adapt to different niches within the human body. Approximately between 20 and 30% of the population is permanently but asymptomatically colonized with S. aureus in the nose, and another 30% may carry S. aureus intermittently. It has been established that nasal colonization is a risk factor for infection in other body sites, including mild to severe skin and soft tissue infections. The skin has distinct features that make it a hostile niche for many bacteria, therefore acting as a strong barrier against invading microorganisms. Healthy skin is desiccated; it has a low pH at the surface; the upper layer is constantly shed to remove attached bacteria; and several host antimicrobial peptides are produced. However, S. aureus is able to overcome these defenses and colonize this microenvironment. Moreover, this bacterium can very efficiently adapt to the stressors present in the skin under pathological conditions, as it occurs in patients with atopic dermatitis or suffering chronic wounds associated with diabetes. The focus of this manuscript is to revise the current knowledge concerning how S. aureus adapts to such diverse skin conditions causing persistent and recurrent infections.

New Weapons to Fight against Staphylococcus aureus Skin Infections.

The treatment of Staphylococcus aureus skin and soft tissue infections faces several challenges, such as the increased incidence of antibiotic-resistant strains and the fact that the antibiotics available to treat methicillin-resistant S. aureus present low bioavailability, are not easily metabolized, and cause severe secondary effects. Moreover, besides the susceptibility pattern of the S. aureus isolates detected in vitro, during patient treatment, the antibiotics may never encounter the bacteria because S. aureus hides within biofilms or inside eukaryotic cells. In addition, vascular compromise as well as other comorbidities of the patient may impede proper arrival to the skin when the antibiotic is given parenterally. In this manuscript, we revise some of the more promising strategies to improve antibiotic sensitivity, bioavailability, and delivery, including the combination of antibiotics with bactericidal nanomaterials, chemical inhibitors, antisense oligonucleotides, and lytic enzymes, among others. In addition, alternative non-antibiotic-based experimental therapies, including the delivery of antimicrobial peptides, bioactive glass nanoparticles or nanocrystalline cellulose, phototherapies, and hyperthermia, are also reviewed.

A plant small polypeptide is a novel component of DNA-binding protein phosphatase 1-mediated resistance to plum pox virus in Arabidopsis.

DNA-binding protein phosphatases (DBPs) have been identified as a novel class of plant-specific regulatory factors playing a role in plant-virus interactions. NtDBP1 from tobacco (Nicotiana tabacum) was shown to participate in transcriptional regulation of gene expression in response to virus infection in compatible interactions, and AtDBP1, its closest relative in the model plant Arabidopsis (Arabidopsis thaliana), has recently been found to mediate susceptibility to potyvirus, one of the most speciose taxa of plant viruses. Here, we report on the identification of a novel family of highly conserved small polypeptides that interact with DBP1 proteins both in tobacco and Arabidopsis, which we have designated DBP-interacting protein 2 (DIP2). The interaction of AtDIP2 with AtDBP1 was demonstrated in vivo by bimolecular fluorescence complementation, and AtDIP2 was shown to functionally interfere with AtDBP1 in yeast. Furthermore, reducing AtDIP2 gene expression leads to increased susceptibility to the potyvirus Plum pox virus and to a lesser extent also to Turnip mosaic virus, whereas overexpression results in enhanced resistance. Therefore, we describe a novel family of conserved small polypeptides in plants and identify AtDIP2 as a novel host factor contributing to resistance to potyvirus in Arabidopsis.