A Novel Human Cytomegalovirus Locus Modulates Cell Type-Specific Outcomes of Infection

Clinical strains of HCMV encode 20 putative ORFs within a region of the genome termed ULb′ that are postulated to encode functions related to persistence or immune evasion. We have previously identified ULb′-encoded pUL138 as necessary, but not sufficient, for HCMV latency in CD34+ hematopoietic progenitor cells (HPCs) infected in vitro. pUL138 is encoded on polycistronic transcripts that also encode 3 additional proteins, pUL133, pUL135, and pUL136, collectively comprising the UL133-UL138 locus. This work represents the first characterization of these proteins and identifies a role for this locus in infection. Similar to pUL138, pUL133, pUL135, and pUL136 are integral membrane proteins that partially co-localized with pUL138 in the Golgi during productive infection in fibroblasts. As expected of ULb′ sequences, the UL133-UL138 locus was dispensable for replication in cultured fibroblasts. In CD34+ HPCs, this locus suppressed viral replication in HPCs, an activity attributable to both pUL133 and pUL138. Strikingly, the UL133-UL138 locus was required for efficient replication in endothelial cells. The association of this locus with three context-dependent phenotypes suggests an exciting role for the UL133-UL138 locus in modulating the outcome of viral infection in different contexts of infection. Differential profiles of protein expression from the UL133-UL138 locus correlated with the cell-type dependent phenotypes associated with this locus. We extended our in vitro findings to analyze viral replication and dissemination in a NOD-scid IL2Rγcnull-humanized mouse model. The UL133-UL138NULL virus exhibited an increased capacity for replication and/or dissemination following stem cell mobilization relative to the wild-type virus, suggesting an important role in viral persistence and spread in the host. As pUL133, pUL135, pUL136, and pUL138 are conserved in virus strains infecting higher order primates, but not lower order mammals, the functions encoded likely represent host-specific viral adaptations

Aetiology of acute respiratory infection in preschool children requiring hospitalisation in Europe-results from the PED-MERMAIDS multicentre case-control study.

BACKGROUND: Both pathogenic bacteria and viruses are frequently detected in the nasopharynx (NP) of children in the absence of acute respiratory infection (ARI) symptoms. The aim of this study was to estimate the aetiological fractions for ARI hospitalisation in children for respiratory syncytial virus (RSV) and influenza virus and to determine whether detection of specific respiratory pathogens on NP samples was associated with ARI hospitalisation. METHODS: 349 children up to 5 years of age hospitalised for ARI (following a symptom-based case definition) and 306 hospital controls were prospectively enrolled in 16 centres across seven European Union countries between 2016 and 2019. Admission day NP swabs were analysed by multiplex PCR for 25 targets. RESULTS: RSV was the leading single cause of ARI hospitalisations, with an overall population attributable fraction (PAF) of 33.4% and high seasonality as well as preponderance in younger children. Detection of RSV on NP swabs was strongly associated with ARI hospitalisation (OR adjusted for age and season: 20.6, 95% CI: 9.4 to 45.3). Detection of three other viral pathogens showed strong associations with ARI hospitalisation: influenza viruses had an adjusted OR of 6.1 (95% CI: 2.5 to 14.9), parainfluenza viruses (PIVs) an adjusted OR of 4.6 (95% CI: 1.8 to 11.3) and metapneumoviruses an adjusted OR of 4.5 (95% CI: 1.3 to 16.1). Influenza viruses had a PAF of 7.9%, PIVs of 6.5% and metapneumoviruses of 3.0%. In contrast, most other pathogens were found in similar proportions in cases and controls, including Streptococcus pneumoniae, which was weakly associated with case status, and endemic coronaviruses. CONCLUSION: RSV is the predominant cause of ARI hospitalisations in young children in Europe and its detection, as well as detection of influenza virus, PIV or metapneumovirus, on NP swabs can establish aetiology with high probability. PAFs for RSV and influenza virus are highly seasonal and age dependent

Impact of infection on proteome-wide glycosylation revealed by distinct signatures for bacterial and viral pathogens

Mechanisms of infection and pathogenesis have predominantly been studied based on differential gene or protein expression. Less is known about posttranslational modifications, which are essential for protein functional diversity. We applied an innovative glycoproteomics method to study the systemic proteome-wide glycosylation in response to infection. The protein site-specific glycosylation was characterized in plasma derived from well-defined controls and patients. We found 3862 unique features, of which we identified 463 distinct intact glycopeptides, that could be mapped to more than 30 different proteins. Statistical analyses were used to derive a glycopeptide signature that enabled significant differentiation between patients with a bacterial or viral infection. Furthermore, supported by a machine learning algorithm, we demonstrated the ability to identify the causative pathogens based on the distinctive host blood plasma glycopeptide signatures. These results illustrate that glycoproteomics holds enormous potential as an innovative approach to improve the interpretation of relevant biological changes in response to infection

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Relationship between molecular pathogen detection and clinical disease in febrile children across Europe: a multicentre, prospective observational study

BackgroundThe PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice.MethodsFebrile children and controls were recruited on presentation to hospital in 9 European countries 2016-2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed.FindingsOf 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92-5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07-7.59), Group A streptococcus (OR 2.73, 95% CI 1.13-6.09) and E. coli (OR 2.7, 95% CI 1.02-6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11-0.46), influenza B (OR 0.12, 95% CI 0.02-0.37) and RSV (OR 0.16, 95% CI: 0.06-0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23-0.72) and EBV (OR 0.71, 95% CI 0.56-0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively.InterpretationMost febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics.FundingEU Horizon 2020 grant 668303

Acute otitis media in neonatal life: A review

Acute otitis media is frequently encountered by general practitioners and pediatricians. In the neonatal period acute otitis media may present as an isolated local infection or as part of septicemia. Diagnosis of the condition by otoscopy is difficult. Considering the wide spectrum of middle ear disorders (acute otitis media, otitis media with effusion, chronic suppurative otitis media) one can appreciate why opinions on the management of the condition are diverse. This is a review of the literature on clinical presentation, etiology, risk factors, treatment and prevention of acute otitis media in neonatal life

Acute otitis media in neonatal life: A review

Acute otitis media is frequently encountered by general practitioners and pediatricians. In the neonatal period acute otitis media may present as an isolated local infection or as part of septicemia. Diagnosis of the condition by otoscopy is difficult. Considering the wide spectrum of middle ear disorders (acute otitis media, otitis media with effusion, chronic sup-purative otitis media) one can appreciate why opinions on the management of the condition are diverse. This is a review of the literature on clinical presentation, etiology, risk factors, treatment and prevention of acute otitis media in neonatal life. © E.S.I.F.T.srl frenze

The use of sildenafil in the treatment of persistent pulmonary hypertension of the newborn: A review of the literature

Persistent pulmonary hypertension of the newborn (PPHN) is a serious and potentially fatal condition, characterized by hypoxemia due to increased pulmonary vascular resistance (PVR) with resultant shunting of pulmonary blood to the systemic circulation. Inhaled nitric oxide (iNO) has been considered a revolutionary treatment of PPHN. Data show that the use of iNO has reduced the need of ECMO in neonates with severe PPHN, while in moderate PPHN, iNO administration has been associated with a significant decrease in ventilatory support and prevented progression to severe PPHN. Not all neonates respond to iNO therapy though, and phosphodiesterase (PDE) inhibitors with their potent vasodilator properties have evolved as an alternative therapy or as an adjunct to the treatment of PPHN with iNO. There are ten families of PDE isoenzymes. PDE 5 is particularly prevalent in vascular smooth muscle (VSM) and PDE 5 inhibitors, such as sildenafil, have been used in clinical practice. This review provides a comprehensive account of existing data in the literature, from animal and clinical studies, on the use of sildenafil for the treatment of PPHN. Sildenafil may also have a role as a single mode of therapy, since in resource-limited settings the cost of iNO is a serious concer

Research in human resuscitation: What we learn from animals

Aim: It was not until the 18th century that scientists throughout Europe established humane societies to develop resuscitation techniques and to keep registries of successful and unsuccessful cases. Since then, the science and art of cardiopulmonary resuscitation have flourished, multiple international organizations were found, and guidelines are proposed every 5 years in an everlasting attempt to improve the outcome of cardiac arrest victims. The aim of this article is to present the role of animal models in resuscitation research. Methods: A comprehensive search in PubMed, CINAHL, Cochrane Library, and Scopus databases was performed. Results: Mice, rats, and swine have been established as experimental models for conducting resuscitation research. The choice of the animal model is not a simple task, as there are multiple parameters that have to be considered when designing an experiment. Conclusion: Animal models are used extensively in resuscitation research and possess a central role in the effort towards a better understanding of the underlying mechanisms. However, experimental results should always be cautiously extrapolated in humans. © 2012 Informa UK, Ltd

Drugs in Newborn resuscitation: The more we learn the least we use

Temperature control, airway management and support of circulation remain the gold-standards for the majority of neonates requiring resuscitation at birth. For the minority of neonates in which the basic steps of resuscitation fail to reverse an adverse situation, drug administration is justifiable. The 2010 International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn resuscitation state: "Drugs are rarely indicated in resuscitation of the newly born infant. Bradycardia in the newborn infant is usually caused by inadequate lung inflation or profound hypoxia, and establishing adequate ventilation is the most important step to correct it. However, if the HR remains less than 60 min-1 despite adequate ventilation and chest compressions, it is reasonable to consider the use of drugs. These are best given via an umbilical venous catheter". Even though drugs have been used in neonatal resuscitation for long, their doses, order and route of administration have been issues of debate among neonatologists, mainly due to the lack of data in human studies. This review will examine existing evidence behind the medications currently used in neonatal resuscitation. © 2012 Bentham Science Publishers