The pathogenicity of Plasmopara viticola: a review of evolutionary dynamics, infection strategies and effector molecules.

Oomycetes are filamentous organisms that resemble fungi in terms of morphology and life cycle, primarily due to convergent evolution. The success of pathogenic oomycetes lies in their ability to adapt and overcome host resistance, occasionally transitioning to new hosts. During plant infection, these organisms secrete effector proteins and other compounds during plant infection, as a molecular arsenal that contributes to their pathogenic success. Genomic sequencing, transcriptomic analysis, and proteomic studies have revealed highly diverse effector repertoires among different oomycete pathogens, highlighting their adaptability and evolution potential.The obligate biotrophic oomycete Plasmopara viticola affects grapevine plants (Vitis vinifera L.) causing the downy mildew disease, with significant economic impact. This disease is devastating in Europe, leading to substantial production losses. Even though Plasmopara viticola is a well-known pathogen, to date there are scarce reviews summarising pathogenicity, virulence, the genetics and molecular mechanisms of interaction with grapevine.This review aims to explore the current knowledge of the infection strategy, lifecycle, effector molecules, and pathogenicity of Plasmopara viticola. The recent sequencing of the Plasmopara viticola genome has provided new insights into understanding the infection strategies employed by this pathogen. Additionally, we will highlight the contributions of omics technologies in unravelling the ongoing evolution of this oomycete, including the first in-plant proteome analysis of the pathogen.

Uncovering the burden of Influenza in children in Portugal, 2008-2018.

BACKGROUND: Despite their higher risk of developing severe disease, little is known about the burden of influenza in Portugal in children aged < 5 years old. This study aims to cover this gap by estimating the clinical and economic burden of severe influenza in children, in Portugal, during ten consecutive influenza seasons (2008/09-2017/18). METHODS: We reviewed hospitalizations in children aged < 5 years old using anonymized administrative data covering all public hospitals discharges in mainland Portugal. The burden of hospitalization and in-hospital mortality directly coded as due to influenza was supplemented by the indirect burden calculated from excess hospitalization and mortality (influenza-associated), estimated for four groups of diagnoses (pneumonia or influenza, respiratory, respiratory or cardiovascular, and all-cause), through cyclic regression models integrating the incidence of influenza. Means were reported excluding the H1N1pdm09 pandemic (2009/10). RESULTS: The mean annual number of hospitalizations coded as due to influenza was 189 (41.3 cases per 100,000 children aged < 5 years old). Hospitalization rates decreased with increasing age. Nine-in-ten children were previously healthy, but the presence of comorbidities increased with age. Children stayed, on average, 6.1 days at the hospital. Invasive mechanical ventilation was used in 2.4% of hospitalizations and non-invasive in 3.1%. Influenza-associated excess hospitalizations between 2008 and 2018 were estimated at 1,850 in pneumonia or influenza, 1,760 in respiratory, 1,787 in respiratory or cardiovascular, and 1,879 in all-cause models. A total of 95 influenza-associated excess deaths were estimated in all-cause, 14 in respiratory or cardiovascular, and 9 in respiratory models. Over ten years, influenza hospitalizations were estimated to have cost the National Health Service at least €2.9 million, of which 66.5% from healthy children. CONCLUSIONS: Influenza viruses led to a high number of hospitalizations in children. Most were previously healthy. Results should lead to a reflection on the adequate preventive measures to protect this age group.

Sustained increase of paediatric invasive Streptococcus pyogenes infections dominated by M1UK and diverse emm12 isolates, Portugal, September 2022 to May 2023.

Since autumn 2022, observed numbers of paediatric invasive group A Streptococcus infections in Portugal (n = 89) were higher than in pre-COVID-19 seasons. Between September 2022 and May 2023, the dominant diagnoses were pneumonia (25/79), mostly with empyema (20/25), and sepsis (22/79). A number of cases required admission to intensive care (27/79) and surgery (35/79), and the case fatality rate was 5.1% (4/79). Genomic sequencing (n = 55) revealed multiple genetic lineages, dominated by the M1UK sublineage (26/55) and more diverse emm12 isolates (12/55).

A comprehensive analysis of copy number variation in a Turkish dementia cohort.

BACKGROUND: Copy number variants (CNVs) include deletions or multiplications spanning genomic regions. These regions vary in size and may span genes known to play a role in human diseases. As examples, duplications and triplications of SNCA have been shown to cause forms of Parkinson's disease, while duplications of APP cause early onset Alzheimer's disease (AD). RESULTS: Here, we performed a systematic analysis of CNVs in a Turkish dementia cohort in order to further characterize the genetic causes of dementia in this population. One hundred twenty-four Turkish individuals, either at risk of dementia due to family history, diagnosed with mild cognitive impairment, AD, or frontotemporal dementia, were whole-genome genotyped and CNVs were detected. We integrated family analysis with a comprehensive assessment of potentially disease-associated CNVs in this Turkish dementia cohort. We also utilized both dementia and non-dementia individuals from the UK Biobank in order to further elucidate the potential role of the identified CNVs in neurodegenerative diseases. We report CNVs overlapping the previously implicated genes ZNF804A, SNORA70B, USP34, XPO1, and a locus on chromosome 9 which includes a cluster of olfactory receptors and ABCA1. Additionally, we also describe novel CNVs potentially associated with dementia, overlapping the genes AFG1L, SNX3, VWDE, and BC039545. CONCLUSIONS: Genotyping data from understudied populations can be utilized to identify copy number variation which may contribute to dementia.

Osteoarticular infections in infants under 3 months of age.

BACKGROUND: Acute osteoarticular infections (OAI) in infants under 3 months of age (≤3M) are rare and remain a diagnostic challenge. Orthopedic complications and functional sequelae have been less well described in this age group. Our aims were to evaluate trends in aetiology, management, and outcomes of OAI ≤ 3M, and to compare these younger children who have OAI with older children. METHODS: A longitudinal observational study was conducted of OAI cases admitted to tertiary care pediatric hospital from 2008 to 2018. OAI ≤ 3M was compared with children above 3 months. Clinical, microbiological, imaging, and outcome data were analyzed. RESULTS: We identified 24 (9.1%) of the 263 OAI in children under 3 months. Analyzing OAI ≤ 3M there was a twofold increase since 2014; 54% were males with a median age of 28 days (IQR: 13.5-60.0), 10 (41.7%) were premature and nine (37.5%) had healthcare-associated infections. Microbiological causes were identified in 87.5%, mostly Staphylococcus aureus (57.1%) and Group B Streptococcus (23.8%), and 25% were multidrug-resistant (5 methicillin-resistant S. aureus and 1 Enterobacter cloacae). Bacteremia (100% vs 36.8%, P = 0.037), multidrug resistant bacteria (75% vs 16, P = 0.04), and healthcare-associated infections (100% vs 26.3%, P = 0.014) were associated with sequelae. Comparing OAI ≤ 3M with older children, OAI ≤ 3M were treated with longer antibiotic courses, had more complications and sequelae (17.4% vs 3.2%, P = 0.002). CONCLUSIONS: S. aureus is still the most common cause of OAI ≤ 3M, and 25% of causative bacteria were multidrug-resistant bacteria. Complications and sequelae were more frequent in OAI ≤ 3M when compared with older children.

Comparison of nasopharyngeal samples for SARS-CoV-2 detection in a paediatric cohort.

AIM: The diagnosis of coronavirus disease 2019 (COVID-19) depends on accurate and rapid testing. Choosing an appropriate sample may impact diagnosis. Naso-oropharyngeal swabs (NOS) are most frequently used, despite several limitations. Since studies suggest nasopharyngeal aspirate (NPA) as a superior alternative in children, we hypothesised collecting both nasopharyngeal swab and aspirate would improve our diagnostic accuracy. METHODS: Observational, longitudinal, prospective study from 7 March to 7 May in a tertiary paediatric hospital in Lisbon. The objective was to compare the rate of detection of SARS-CoV-2 between NOS and NPA samples collected simultaneously. RESULTS: A total of 438 samples collected from 85 patients with confirmed COVID-19. There were 47.7% overall positive specimens - 32% (70/219) positive NOS and 63.5% (139/219) positive NPA. The tests were 67.6% concordant (k = 0.45). 50.3% had positive NPA with negative NOS, while 1.3% had positive NOS with negative NPA. NPA proved to be more sensitive (98.6% with 95% confidence interval 91.2-99.9% vs. 49.6% with 95% confidence interval 41.1-58.2%, P < 0.001). Additionally, the difference between NPA and NOS positive samples was statistically significant across all population groups (age, health condition, clinical presentation, contact with COVID-19 patients or need for hospitalisation), meaning NPA is more sensitive overall. CONCLUSIONS: Nasopharyngeal aspirates had greater sensitivity than naso-oropharyngeal swabs in detecting SARS-CoV-2. Our results suggest paediatric patients would benefit from collecting nasopharyngeal aspirates in hospital settings, whenever feasible, to improve diagnosis of COVID-19.

Atypical bartonellosis in children: What do we know?

AIM: To characterise Bartonella infections in a paediatric population requiring hospital admission and review its treatment. METHODS: Longitudinal observational retrospective data analysis of children and adolescents admitted with Bartonella infection at a paediatric tertiary hospital from 2010 to 2019. RESULTS: We identified 16 cases of bartonellosis, with a mean age of 8.0 ± 4.5 years old, no sex predominance and 14 had contact with cats. Most of the cases occurred in fall and winter. Clinical presentations included osteomyelitis/arthritis (n = 9), hepatosplenic disease (n = 2), lymphadenitis (n = 2), neuroretinitis (n = 2) and encephalitis (n = 1). Clinical diagnosis was confirmed by serology (n = 16) and Bartonella DNA detection in patient's lymph nodes/hepatic lesion (n = 3). Therapeutic approach varied according to the clinical presentation: azithromycin in lymphadenitis, rifampicin plus ciprofloxacin in hepatosplenic disease, rifampicin and doxycycline in neuroretinitis, ceftriaxone in encephalitis and azithromycin, cotrimoxazole or rifampicin plus azithromycin, cefuroxime, ciprofloxacin or doxycycline in osteomyelitis/arthritis. Immunodeficiency was excluded in seven patients. Seven patients' cats were screened by veterinarians and treated when infected (n = 5). CONCLUSIONS: In these clinical presentations, where other infections may be involved, a high index of suspicion is necessary, with emphasis on the epidemiological context. The association of systemic forms with immunodeficiency did not occur in our study. The lack of recommendations for treatment of atypical infection makes the approach of these cases a challenge. Randomised control studies are essential to define the best approach in each case.

Should patients with symptomatic cholelithiasis before 30 years of age be tested for ABCB4 gene mutations?

BACKGROUND AND AIMS: Low phospholipid-associated cholelithiasis syndrome (LPAC) is characterized by recurrent symptomatic cholelithiasis in young adults associated with ABCB4 gene mutations. Current diagnosing criteria are complex and heterogeneous, making this a largely underdiagnosed entity. Also, although recommended, genetic testing is not necessary for the diagnosis and its real advantages are not clear. The aim of our study was to explore the prevalence of ABCB4 mutations in symptomatic patients with cholelithiasis before the age of 30. METHODS: We conducted a multicentric prospective cohort study including patients with symptomatic cholelithiasis presenting before 30 years of age in 4 Portuguese centres between January 2017 and December 2019. ABCB4 gene was analyzed by next generation sequencing (NGS) including all exons and flanking regions. In 17/32 patients ABCB11 and ATP8B1 variants were also analyzed by NGS. RESULTS: Thirty-two patients were included (75% females, median age of symptom onset was 23 ± 5 years). We found that 8/32 (25%) patients had mutations in ABCB4 gene, 3/17 (18%) in ATP8B1 gene and 1/17 (6%) in ABCB11 gene. 44% (8/18) of patients with LPAC syndrome criteria had identified variants, while the prevalence of mutations in patients with symptoms onset before 30 as sole criteria was 29%. CONCLUSION: Our results suggest that LPAC should be systematically suspected and investigated in patients with symptomatic cholelithiasis before age of thirty, but genetic testing should only be attempted in patients complying with the more stringent LPAC criteria.

Arthritis in Kawasaki disease: A poorly recognised manifestation.

AIM: To determine the prevalence of arthritis in Kawasaki disease (KD) and the clinical characteristics of children with KD and arthritis. METHODS: This was a single-centre, 15-year, retrospective study of children admitted with KD. Clinical features (including coronary involvement), laboratory results and treatment response were evaluated. RESULTS: Of 63 children with KD, 60.3% were male, with a median of age of 2.0 years. Complete KD was found in 68.3%. The time from symptom onset to treatment was 7.0 days (median); 30.7% had coronary artery aneurysms, from which 82.5% responded to intravenous immunoglobulin. During the course of their illness, eight children developed arthritis (12.7%), which was early onset in six (75%) and oligoarticular in five (62.5%). The median number of joints was 3.5 (P25 = 1.3, P75 = 17.0), and at least one large joint was affected. In all cases, the arthritis was self-limited and left no sequelae, lasting a median of 14 days and no longer than 22 days. KD children with arthritis were older (P = 0.025), and those with early-onset arthritis responded to first-line therapy, unlike the late-onset group (P = 0.018). CONCLUSIONS: This study emphasises the value of a systematic articular examination of joints in KD. Refractory KD was observed in children with late-onset arthritis.

Severe Stevens-Johnson syndrome/toxic epidermal necrolysis overlap syndrome-beyond skin involvement.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but serious dermatologic diseases with many potential multisystem complications. We describe the case of an 8-year-old girl who developed severe SJS/TEN overlap syndrome (25% of her body surface area was affected) complicated by pancreatitis and bronchiolitis obliterans. These rare complications emphasize the need for careful, intensive monitoring of possible complications and an interdisciplinary team approach to provide optimal treatment and follow-up.

Pantoea Species Bacteremia in a Child With Sickle Cell Disease: Looking for a Culprit.

Pantoea agglomerans has been classically associated with cellulitis or synovitis secondary to penetrating trauma by vegetation. It is an infrequent cause of systemic infections. We describe the case of a 5-year-old girl with sickle cell disease with P. agglomerans bacteremia and review its potential causes.

Cold Agglutinin Syndrome and Hemophagocytic Lymphohistiocytosis: An Unusual Combination Caused by Epstein-Barr Virus Infection.

Autoimmune hemolytic anemia (AIHA) and hemophagocytic lymphohistiocytosis (HLH) are rare complications of infectious mononucleosis. The authors describe a 12-year-old male with acute infectious mononucleosis, hepatitis, cholestasis, and an autoimmune hemolytic disorder caused by cold agglutinins IgM (anti-i specificity). Clinical deterioration with persistent fever, anemia, and hepatosplenomegaly was consistent with cold AIHA plus concomitant HLH. The patient was treated with corticosteroids and acyclovir, with an uneventful recovery. Although rare, cold agglutinin syndrome and HLH can complicate infectious mononucleosis and should be considered in a patient with clinical deterioration. Corticosteroids are the mainstay treatment of HLH and may be beneficial in infection-associated cold agglutinin syndrome.

Elbow septic arthritis in an infant: an unusual presentation of invasive pneumococcal disease.

Acute septic arthritis is a rare, potentially severe infection that requires immediate treatment to avoid long-term morbidity. Most common aetiological agents are commonly used for empirical treatment, but the choice of antibiotics may be influenced by other factors, such as the patient's age and the epidemiological context.We report an infant with elbow arthritis, whose treatment was changed after Streptococcus pneumoniae serotype 9N was isolated in the blood and synovial fluid. The child underwent arthrocentesis and received intravenous ampicillin followed by oral amoxicillin, with a favourable response and no sequelae at 1-year follow-up.We report an uncommon manifestation of invasive pneumococcal disease in a young immunised healthy infant caused by a non-vaccine serotype. The presence of S. pneumoniae should be considered in joint infections, especially in infants and those with a history of respiratory symptoms.

Grapevine-Associated Lipid Signalling Is Specifically Activated in an Rpv3 Background in Response to an Aggressive P. viticola Pathovar.

Vitis vinifera L. is highly susceptible to the biotrophic pathogen Plasmopara viticola. To control the downy mildew disease, several phytochemicals are applied every season. Recent European Union requirements to reduce the use of chemicals in viticulture have made it crucial to use alternative and more sustainable approaches to control this disease. Our previous studies pinpoint the role of fatty acids and lipid signalling in the establishment of an incompatible interaction between grapevine and P. viticola. To further understand the mechanisms behind lipid involvement in an effective defence response we have analysed the expression of several genes related to lipid metabolism in three grapevine genotypes: Chardonnay (susceptible); Regent (tolerant), harbouring an Rpv3-1 resistance loci; and Sauvignac (resistant) that harbours a pyramid of Rpv12 and Rpv3-1 resistance loci. A highly aggressive P. viticola isolate was used (NW-10/16). Moreover, we have characterised the grapevine phospholipases C and D gene families and monitored fatty acid modulation during infection. Our results indicate that both susceptible and resistant grapevine hosts did not present wide fatty acid or gene expression modulation. The modulation of genes associated with lipid signalling and fatty acids seems to be specific to Regent, which raises the hypothesis of being specifically linked to the Rpv3 loci. In Sauvignac, the Rpv12 may be dominant concerning the defence response, and, thus, this genotype may present the activation of other pathways rather than lipid signalling.

Osteoarticular Infections: Younger Children With Septic Arthritis and Low Inflammatory Patterns Have a Better Prognosis in a European Cohort.

BACKGROUND: Osteoarticular infections (OAI) are associated with complications and sequelae in children, whose prediction are of great importance in improving outcomes. We aimed to design risk prediction models to identify early complications and sequelae in children with OAI. METHODS: This observational study included children (>3 months-17 years old) with acute OAI admitted to a tertiary-care pediatric hospital between 2008 and 2018. Clinical treatment, complications and sequelae were recorded. We developed a multivariable logistic predictive model for an acute complicated course (ACC) and another for sequelae. RESULTS: A total of 240 children were identified, 17.5% with ACC and 6.0% and 3.6% with sequelae at 6 and 12 months of follow-up, respectively. In the multivariable logistic predictive model for ACC, predictors were fever at admission [adjusted odds ratio (aOR): 2.98; 95% confidence interval (CI): 1.10-8.12], C-reactive protein ≥100 mg/L (aOR: 2.37; 95% CI: 1.05-5.35), osteomyelitis (aOR: 4.39; 95% CI: 2.04-9.46) and Staphylococcus aureus infection (aOR: 3.50; 95% CI: 1.39-8.77), with an area under the ROC curve of 0.831 (95% CI: 0.767-0.895). For sequelae at 6 months, predictors were age ≥4 years (aOR: 4.08; 95% CI: 1.00-16.53), C-reactive protein ≥110 mg/L (aOR: 4.59; 95% CI: 1.25-16.90), disseminated disease (aOR: 9.21; 95% CI: 1.82-46.73) and bone abscess (OR: 5.46; 95% CI: 1.23-24.21), with an area under the ROC curve of 0.887 (95% CI: 0.815-0.959). CONCLUSIONS: In our model we could identify patients at low risk for complications and sequelae, probably requiring a less aggressive approach.