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BACKGROUND: To retain the spread of SARS-CoV-2, fast, sensitive and cost-effective testing is essential, particularly in resource limited settings (RLS). Current standard nucleic acid-based RT-PCR assays, although highly sensitive and specific, require transportation of samples to specialised laboratories, trained staff and expensive reagents. The latter are often not readily available in low- and middle-income countries and this may significantly impact on the successful disease management in these settings. Various studies have suggested a SARS-CoV-2 loop mediated isothermal amplification (LAMP) assay as an alternative method to RT-PCR. METHODS: Four previously published primer pairs were used for detection of SARS-CoV-2 in the LAMP assay. To determine optimal conditions, different temperatures, sample input and incubation times were tested. Ninety-three extracted RNA samples from St. George's Hospital, London, 10 non-extracted nasopharyngeal swab samples from Great Ormond Street Hospital for Children, London, and 92 non-extracted samples from Queen Elisabeth Central Hospital (QECH), Malawi, which have previously been tested for SARS-Cov-2 by quantitative reverse-transcription RealTime PCR (qRT-PCR), were analysed in the LAMP assay. RESULTS: In this study we report the optimisation of an extraction-free colourimetric SARS-CoV-2 LAMP assay and demonstrated that a lower limit of detection (LOD) between 10 and 100 copies/µL of SARS-CoV-2 could be readily detected by a colour change of the reaction within as little as 30 min. We further show that this assay could be quickly established in Malawi, as no expensive equipment is necessary. We tested 92 clinical samples from QECH and showed the sensitivity and specificity of the assay to be 86.7% and 98.4%, respectively. Some viral transport media, used routinely to stabilise RNA in clinical samples during transportation, caused a non-specific colour-change in the LAMP reaction and therefore we suggest collecting samples in phosphate buffered saline (which did not affect the colour) as the assay allows immediate sample analysis on-site. CONCLUSION: SARS-CoV-2 LAMP is a cheap and reliable assay that can be readily employed in RLS to improve disease monitoring and management.
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COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Criança , Humanos , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA , SARS-CoV-2/genéticaRESUMO
The respiratory epithelium comprises polarized cells at the interface between the environment and airway tissues. Polarized apical and basolateral protein secretions are a feature of airway epithelium homeostasis. Human respiratory syncytial virus (hRSV) is a major human pathogen that primarily targets the respiratory epithelium. However, the consequences of hRSV infection on epithelium secretome polarity and content remain poorly understood. To investigate the hRSV-associated apical and basolateral secretomes, a proteomics approach was combined with an ex vivo pediatric human airway epithelial (HAE) model of hRSV infection (data are available via ProteomeXchange and can be accessed at https://www.ebi.ac.uk/pride/ with identifier PXD013661). Following infection, a skewing of apical/basolateral abundance ratios was identified for several individual proteins. Novel modulators of neutrophil and lymphocyte activation (CXCL6, CSF3, SECTM1 or CXCL16), and antiviral proteins (BST2 or CEACAM1) were detected in infected, but not in uninfected cultures. Importantly, CXCL6, CXCL16, CSF3 were also detected in nasopharyngeal aspirates (NPA) from hRSV-infected infants but not healthy controls. Furthermore, the antiviral activity of CEACAM1 against RSV was confirmed in vitro using BEAS-2B cells. hRSV infection disrupted the polarity of the pediatric respiratory epithelial secretome and was associated with immune modulating proteins (CXCL6, CXCL16, CSF3) never linked with this virus before. In addition, the antiviral activity of CEACAM1 against hRSV had also never been previously characterized. This study, therefore, provides novel insights into RSV pathogenesis and endogenous antiviral responses in pediatric airway epithelium.
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Antivirais/metabolismo , Quimiocinas/metabolismo , Proteoma/metabolismo , Mucosa Respiratória/virologia , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/fisiologia , Brônquios/patologia , Linhagem Celular , Criança , Células Epiteliais/patologia , Células Epiteliais/virologia , Células Caliciformes/metabolismo , Células Caliciformes/virologia , Homeostase , Humanos , Lactente , Cinética , Nasofaringe/virologia , Mucosa Respiratória/metabolismo , Vírus Sincicial Respiratório Humano/crescimento & desenvolvimento , Tropismo , Proteínas Virais/metabolismoRESUMO
Background: Adenoviruses are significant pathogens for the immunocompromised, arising from primary infection or reinfection. Serotyping is insufficient to support nosocomial transmission investigations. We investigate whether whole-genome sequencing (WGS) provides clinically relevant information on transmission among patients in a pediatric tertiary hospital. Methods: We developed a target-enriched adenovirus WGS technique for clinical samples and retrospectively sequenced 107 adenovirus-positive residual diagnostic samples, including viremias (>5 × 104 copies/mL), from 37 patients collected January 2011-March 2016. Whole-genome sequencing was used to determine genotype and for phylogenetic analysis. Results: Adenovirus sequences were recovered from 105 of 107 samples. Full genome sequences were recovered from all 20 nonspecies C samples and from 36 of 85 species C viruses, with partial genome sequences recovered from the rest. Whole-genome phylogenetic analysis suggested linkage of 3 genotype A31 cases and uncovered an unsuspected epidemiological link to an A31 infection first detected on the same ward 4 years earlier. In 9 samples from 1 patient who died, we identified a mixed genotype adenovirus infection. Conclusions: Adenovirus WGS from clinical samples is possible and useful for genotyping and molecular epidemiology. Whole-genome sequencing identified likely nosocomial transmission with greater resolution than conventional genotyping and distinguished between adenovirus disease due to single or multiple genotypes.
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Adenoviridae/genética , Infecções por Adenovirus Humanos/virologia , Infecção Hospitalar/virologia , Genótipo , Hospedeiro Imunocomprometido , Sequenciamento Completo do Genoma , Adenoviridae/classificação , Infecções por Adenovirus Humanos/transmissão , Adolescente , Criança , Pré-Escolar , Infecção Hospitalar/transmissão , Genômica , Humanos , Lactente , Epidemiologia Molecular , FilogeniaRESUMO
Clostridioides difficile is a well-recognized healthcare-associated pathogen, with its significance widely recognized in adult populations. Despite this, there is limited data on the significance of detection within paediatric populations, both for individual patient management and wider transmission risk-based considerations. High rates of colonization are understood to occur in infants, with increasing levels up to 11 months, and colonization rates similar to adults by 8 years old. Sources of C. difficile are ubiquitous, with detection in companion animals and food sources, as well as within the clinical and wider environment. Due to the close interactions that occur between children and the environment, it is understandable that increasing recognition is afforded to the community acquisition of C. difficile in children. Other risk factors for the detection of C. difficile in children are similar to those observed in adults, including prior hospitalization and underlying conditions affecting gut health and motility. Recent studies have shown rising awareness of the role of asymptomatic carriage of C. difficile in healthcare transmission. Prior to this, paediatric patient populations were less likely to be screened due to uncertainty regarding the significance of detection; however, this increased awareness has led to a review of possible carriage testing pathways. Despite this increased attention, C. difficile infection remains poorly defined in paediatric populations, with limited dedicated paediatric data sets making comparison challenging. This is further complicated by the fact that infection in children frequently self resolves without additional therapies. Due to this, C. difficile remains a management challenge in paediatric settings.
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Clostridioides difficile , Infecções por Clostridium , Lactente , Adulto , Animais , Humanos , Criança , Hospitalização , Fatores de Risco , Infecções por Clostridium/diagnósticoRESUMO
INTRODUCTION: Healthcare associated pathogens, including Staphylococcus capitis, can contaminate incubator surfaces and are of significant concern in neonatal intensive care units (NICUs). Effective incubator decontamination is essential for infection prevention and control, with submersion decontamination often recommended. This may not always be achievable, with wipe decontamination seen as an alternative. Here we compare the ability of a two-step (submersion in enzymatic detergent followed by wiping with hypochlorite-based wipes) with a one-step (wiping with quaternary ammonium compound-impregnated wipes) decontamination procedure to remove microbial surrogate markers from neonatal incubator surfaces. METHODS: Three Cauliflower Mosaic Virus derived microbial surrogate markers were inoculated onto the fan, a mattress seam and the external arm port door clips of two Giraffe™ Omnibed™ Carestation™ incubators. Incubators were decontaminated either by the one-step or two-step decontamination process. Swab samples were collected from 28 sites on each incubator and surrounding environment, with marker presence determined by qPCR. RESULTS: Following two-step decontamination, 3/28 (11%) sample sites were positive for any marker, compared to 12/28 (43%) after one-step decontamination. Markers were transferred to several incubator surfaces and recovered from the originally inoculated sites following one-step decontamination, with the marker inoculated on door clips having the greatest transfer. Markers inoculated onto the mattress persisted through both decontamination strategies. DISCUSSION: Microbial surrogate markers were not completely removed from incubator surfaces by one-step decontamination alone. Two-step decontamination was the most effective method and removed markers from submergible surfaces, but not from the mattress. These findings indicate microorganisms can persist after incubator terminal decontamination, particularly on mattresses and when a two-step decontamination process is not used. This highlights the importance of effective decontamination practices to mitigate microorganism persistence on incubator surfaces.
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Successful multidrug-resistant clones are increasing in prevalence globally, which makes the ability to identify these clones urgent. However, adequate, easy-to-perform, and reproducible typing methods are lacking. We investigated whether DiversiLab (DL), an automated repetitive-sequence-based PCR bacterial typing system (bioMérieux), is suitable for comparing isolates analyzed at different geographic centers. A total of 39 Escherichia coli and 39 Klebsiella species isolates previously typed by the coordinating center were analyzed. Pulsed-field gel electrophoresis (PFGE) confirmed the presence of one cluster of 6 isolates, three clusters of 3 isolates, and three clusters of 2 isolates for each set of isolates. DL analysis was performed in 11 centers in six different countries using the same protocol. The DL profiles of 425 E. coli and 422 Klebsiella spp. were obtained. The DL system showed a lower discriminatory power for E. coli than did PFGE. The local DL data showed a low concordance, as indicated by the adjusted Rand and Wallace coefficients (0.132 to 0.740 and 0.070 to 1.0 [E. coli] and 0.091 to 0.864 and 0.056 to 1.0 [Klebsiella spp.], respectively). The central analysis showed a significantly improved concordance (0.473 to 1.0 and 0.290 to 1.0 [E. coli] and 0.513 to 0.965 and 0.425 to 1.0 [Klebsiella spp.], respectively). The misclassifications of profiles for individual isolates were mainly due to inconsistent amplification, which was most likely due to variations in the quality and amounts of the isolated DNA used for amplification. Despite local variations, the DL system has the potential to indicate the occurrence of clonal outbreaks in an international setting, provided there is strict adherence to standardized, reproducible DNA isolation methods and analysis protocols, all supported by a central database for profile comparisons.
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Escherichia coli/classificação , Klebsiella/classificação , Tipagem Molecular/métodos , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Escherichia coli/genética , Humanos , Cooperação Internacional , Klebsiella/genética , Reação em Cadeia da Polimerase/métodos , Reprodutibilidade dos TestesRESUMO
Antimicrobial resistance (AMR) is now regarded as one of the greatest global challenges of the 21st century. The complexity, urgent timeframe, and lack of clear solution to AMR have contributed to its classification as a 'super wicked problem'. Yet knowledge surveys of the general public have found that they still harbour numerous misconceptions linked to both the sources and impact of AMR. This confusion is compounded by AMR being a One Health issue, and therefore a factor in not just human health but in other industries, such as farming. This can further inhibit understanding and knowledge transfer around AMR for those without a prior knowledge base. In order to address the escalating risk that AMR presents, however, it is essential to address this knowledge gap and engage with the public to support wide scale changes in behaviour and consumer choice. The WHO now requires national action plans tackling AMR to include patient and public involvement/engagement (PPI/E) to support changing the trajectory of AMR. Despite this, little detail is available as part of strategic plans on how PPI/E should be undertaken in order to aid implementation. This paper discusses a number of approaches to support the design and delivery of PPI/E in relation to AMR, including the different social behaviour models underlying successful PPI/E strategies, and key considerations linked to specific activity types. The framework produced includes features for steps from initial planning and design through to evaluation. The aim is to help improve the ability of scientists and healthcare professionals to produce high quality AMR PPI/E.
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In June 2021, a national incident team was formed due to an increased detection of Staphylococcus capitis in samples from hospitalised infants. Staphylococcus capitis has been known to cause outbreaks in neonatal units across the globe, but the extent of the UK spread was unclear. A literature review was undertaken to support case identification, clinical management and environmental infection control. A literature search was undertaken on multiple databases from inception to 24 May 2021, using keywords such as "Staphylococcus capitis", "NRCS-A", "S. capitis", "neonate", "newborn" and "neonatal intensive care unit" (NICU). After screening, 223 articles of relevance were included. Results show incidences of S. capitis outbreaks have frequently been associated with the outbreak clone (NRCS-A) and environmental sources. The NRCS-A harbours a multidrug resistance profile that includes resistance to beta-lactam antibiotics and aminoglycosides, with several papers noting resistance or heteroresistance to vancomycin. The NRCS-A clone also harbours a novel SCCmec-SCCcad/ars/cop composite island and increased vancomycin resistance. The S. capitis NRCS-A clone has been detected for decades, but the reasons for the potentially increased frequency are unclear, as are the most effective interventions to manage outbreaks associated with this clone. This supports the need for improvements in environmental control and decontamination strategies to prevent transmission.
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BACKGROUND: Mass drug administration (MDA) of azithromycin (AZI) has been shown to reduce under-5 mortality in some but not all sub-Saharan African settings. A large-scale cluster-randomized trial conducted in Malawi, Niger, and Tanzania suggested that the effect differs by country, may be stronger in infants, and may be concentrated within the first 3 months after treatment. Another study found no effect when azithromycin was given concomitantly with seasonal malaria chemoprevention (SMC). Given the observed heterogeneity and possible effect modification by other co-interventions, further trials are needed to determine the efficacy in additional settings and to determine the most effective treatment regimen. METHODS: LAKANA stands for Large-scale Assessment of the Key health-promoting Activities of two New mass drug administration regimens with Azithromycin. The LAKANA trial is designed to address the mortality and health impacts of 4 or 2 annual rounds of azithromycin MDA delivered to 1-11-month-old (29-364 days) infants, in a high-mortality and malaria holoendemic Malian setting where there is a national SMC program. Participating villages (clusters) are randomly allocated in a ratio of 3:2:4 to three groups: placebo (control):4-dose AZI:2-dose AZI. The primary outcome measured is mortality. Antimicrobial resistance (AMR) will be monitored closely before, during, and after the intervention and both among those receiving and those not receiving MDA with the study drugs. Other outcomes, from a subset of villages, comprise efficacy outcomes related to morbidity, growth and nutritional status, outcomes related to the mechanism of azithromycin activity through measures of malaria parasitemia and inflammation, safety outcomes (AMR, adverse and serious adverse events), and outcomes related to the implementation of the intervention documenting feasibility, acceptability, and economic aspects. The enrolment commenced in October 2020 and is planned to be completed by the end of 2022. The expected date of study completion is December 2024. DISCUSSION: If LAKANA provides evidence in support of a positive mortality benefit resulting from azithromycin MDA, it will significantly contribute to the options for successfully promoting child survival in Mali, and elsewhere in sub-Saharan Africa. TRIAL REGISTRATION: ClinicalTrials.gov NCT04424511. Registered on 11 June 2020.
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Azitromicina , Administração Massiva de Medicamentos , Humanos , Lactente , Antibacterianos/efeitos adversos , Azitromicina/efeitos adversos , Mortalidade Infantil , Malária/prevenção & controle , Mali/epidemiologia , Administração Massiva de Medicamentos/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
BACKGROUND: The Large-scale Assessment of the Key health-promoting Activities of two New mass drug administration regimens with Azithromycin (LAKANA) trial in Mali aims to evaluate the efficacy and safety of azithromycin (AZI) mass drug administration (MDA) to 1-11-month-old infants as well as the impact of the intervention on antimicrobial resistance (AMR) and mechanisms of action of azithromycin. To improve the transparency and quality of this clinical trial, we prepared this statistical analysis plan (SAP). METHODS/DESIGN: LAKANA is a cluster randomized trial that aims to address the mortality and health impacts of biannual and quarterly AZI MDA. AZI is given to 1-11-month-old infants in a high-mortality setting where a seasonal malaria chemoprevention (SMC) program is in place. The participating villages are randomly assigned to placebo (control), two-dose AZI (biannual azithromycin-MDA), and four-dose AZI (quarterly azithromycin-MDA) in a 3:4:2 ratio. The primary outcome of the study is mortality among the intention-to-treat population of 1-11-month-old infants. We will evaluate relative risk reduction between the study arms using a mixed-effects Poisson model with random intercepts for villages, using log link function with person-years as an offset variable. We will model outcomes related to secondary objectives of the study using generalized linear models with considerations on clustering. CONCLUSION: The SAP written prior to data collection completion will help avoid reporting bias and data-driven analysis for the primary and secondary aims of the trial. If there are deviations from the analysis methods described here, they will be described and justified in the publications of the trial results. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT04424511 . Registered on 11 June 2020.
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Azitromicina , Malária , Humanos , Lactente , Antibacterianos/efeitos adversos , Quimioprevenção , Malária/tratamento farmacológico , Malária/prevenção & controle , Malária/epidemiologia , Mali , Administração Massiva de Medicamentos , Método Duplo-CegoRESUMO
Escherichia coli is a leading cause of invasive bacterial infections in humans. Capsule polysaccharide has an important role in bacterial pathogenesis, and the K1 capsule has been firmly established as one of the most potent capsule types in E. coli through its association with severe infections. However, little is known about its distribution, evolution and functions across the E. coli phylogeny, which is fundamental to elucidating its role in the expansion of successful lineages. Using systematic surveys of invasive E. coli isolates, we show that the K1-cps locus is present in a quarter of bloodstream infection isolates and has emerged in at least four different extraintestinal pathogenic E. coli (ExPEC) phylogroups independently in the last 500 years. Phenotypic assessment demonstrates that K1 capsule synthesis enhances E. coli survival in human serum independent of genetic background, and that therapeutic targeting of the K1 capsule re-sensitizes E. coli from distinct genetic backgrounds to human serum. Our study highlights that assessing the evolutionary and functional properties of bacterial virulence factors at population levels is important to better monitor and predict the emergence of virulent clones, and to also inform therapies and preventive medicine to effectively control bacterial infections whilst significantly lowering antibiotic usage.
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Infecções por Escherichia coli , Proteínas de Escherichia coli , Humanos , Escherichia coli , Infecções por Escherichia coli/microbiologia , Virulência/genética , Fatores de Virulência/genética , Proteínas de Escherichia coli/genética , FilogeniaRESUMO
BACKGROUND: The near-patient environment is often heavily contaminated, yet the decontamination of near-patient surfaces and equipment is often poor. The Nanoclave Cabinet produces large amounts of ultraviolet-C (UV-C) radiation (53 W/m2) and is designed to rapidly disinfect individual items of clinical equipment. Controlled laboratory studies were conducted to assess its ability to eradicate a range of potential pathogens including Clostridium difficile spores and Adenovirus from different types of surface. METHODS: Each test surface was inoculated with known levels of vegetative bacteria (10(6) cfu/cm(2)), C. difficile spores (10(2)-10(6) cfu/cm(2)) or Adenovirus (10(9) viral genomes), placed in the Nanoclave Cabinet and exposed for up to 6 minutes to the UV-C light source. Survival of bacterial contaminants was determined via conventional cultivation techniques. Degradation of viral DNA was determined via PCR. Results were compared to the number of colonies or level of DNA recovered from non-exposed control surfaces. Experiments were repeated to incorporate organic soils and to compare the efficacy of the Nanoclave Cabinet to that of antimicrobial wipes. RESULTS: After exposing 8 common non-critical patient care items to two 30-second UV-C irradiation cycles, bacterial numbers on 40 of 51 target sites were consistently reduced to below detectable levels (≥ 4.7 log10 reduction). Bacterial load was reduced but still persisted on other sites. Objects that proved difficult to disinfect using the Nanoclave Cabinet (e.g. blood pressure cuff) were also difficult to disinfect using antimicrobial wipes. The efficacy of the Nanoclave Cabinet was not affected by the presence of organic soils. Clostridium difficile spores were more resistant to UV-C irradiation than vegetative bacteria. However, two 60-second irradiation cycles were sufficient to reduce the number of surface-associated spores from 10(3) cfu/cm(2) to below detectable levels. A 3 log10 reduction in detectable Adenovirus DNA was achieved within 3 minutes; after 6 minutes, viral DNA was undetectable. CONCLUSION: The results of this study suggest that the Nanoclave Cabinet can provide rapid and effective disinfection of some patient-related equipment. However, laboratory studies do not necessarily replicate 'in-use' conditions and further tests are required to assess the usability, acceptability and relative performance of the Nanoclave Cabinet when used in situ.
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Adenoviridae/efeitos da radiação , Clostridioides difficile/efeitos da radiação , Desinfecção/métodos , Microbiologia Ambiental , Equipamentos e Provisões/microbiologia , Equipamentos e Provisões/virologia , Raios Ultravioleta , Contagem de Colônia Microbiana , DNA Viral/efeitos da radiação , Humanos , Viabilidade Microbiana/efeitos da radiação , Reação em Cadeia da Polimerase , Esporos Bacterianos/efeitos da radiaçãoRESUMO
BACKGROUND: Haematopoietic stem cell transplantation is a curative procedure for a variety of conditions. Despite major advances, a plethora of adverse clinical outcomes can develop post-transplantation including graft-versus-host disease and infections, which remain the major causes of morbidity and mortality. There is increasing evidence that the gastrointestinal microbiota is associated with clinical outcomes post-haematopoietic stem cell transplantation. Herein, we investigated the longitudinal dynamics of the gut microbiota and metabolome and potential associations to clinical outcomes in paediatric haematopoietic stem cell transplantation at a single centre. RESULTS: On admission (baseline), the majority of patients presented with a different gut microbial composition in comparison with healthy control children with a significantly lower alpha diversity. A further, marked decrease in alpha diversity was observed immediately post-transplantation and in most microbial diversity, and composition did not return to baseline status whilst hospitalised. Longitudinal trajectories identified continuous fluctuations in microbial composition, with the dominance of a single taxon in a significant proportion of patients. Using pam clustering, three clusters were observed in the dataset. Cluster 1 was common pre-transplantation, characterised by a higher abundance of Clostridium XIVa, Bacteroides and Lachnospiraceae; cluster 2 and cluster 3 were more common post-transplantation with a higher abundance of Streptococcus and Staphylococcus in the former whilst Enterococcus, Enterobacteriaceae and Escherichia predominated in the latter. Cluster 3 was also associated with a higher risk of viraemia. Likewise, further multivariate analysis reveals Enterobacteriaceae, viraemia, use of total parenteral nutrition and various antimicrobials contributing towards cluster 3, Streptococcaceae, Staphylococcaceae, Neisseriaceae, vancomycin and metronidazole contributing towards cluster 2. Lachnospiraceae, Ruminococcaceae, Bifidobacteriaceae and not being on total parenteral nutrition contributed to cluster 1. Untargeted metabolomic analyses revealed changes that paralleled fluctuations in microbiota composition; importantly, low faecal butyrate was associated with a higher risk of viraemia. CONCLUSIONS: These findings highlight the frequent shifts and dominations in the gut microbiota of paediatric patients undergoing haematopoietic stem cell transplantation. The study reveals associations between the faecal microbiota, metabolome and viraemia. To identify and explore the potential of microbial biomarkers that may predict the risk of complications post-HSCT, larger multi-centre studies investigating the longitudinal microbial profiling in paediatric haematopoietic stem cell transplantation are warranted. Video abstract.
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Microbioma Gastrointestinal , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Criança , Clostridiales , Enterobacteriaceae , Fezes , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Metaboloma , Viremia/etiologiaRESUMO
Rapid identification of potentially life-threatening blood stream infections (BSI) improves clinical outcomes, yet conventional blood culture (BC) identification methods require ~24-72 hours of liquid culture, plus 24-48 hours to generate single colonies on solid media suitable for identification by mass spectrometry (MS). Newer rapid centrifugation techniques, such as the Bruker MBT-Sepsityper® IVD, replace culturing on solid media and expedite the diagnosis of BCs but frequently demonstrate reduced sensitivity for identifying clinically significant Gram-positive bacterial or fungal infections. This study introduces a protocol that utilises the broad-range binding properties of an engineered version of mannose-binding lectin linked to the Fc portion of immunoglobulin (FcMBL) to capture and enrich pathogens combined with matrix-assisted laser desorption-ionisation time-of-flight (MALDI-TOF) MS for enhanced infection identification in BCs. The FcMBL method identified 94.1% (64 of 68) of clinical BCs processed, with a high sensitivity for both Gram-negative and Gram-positive bacteria (94.7 and 93.2%, respectively). The FcMBL method identified more patient positive BCs than the Sepsityper® (25 of 25 vs 17 of 25), notably with 100% (3/3) sensitivity for clinical candidemia, compared to only 33% (1/3) for the Sepsityper®. Additionally, during inoculation experiments, the FcMBL method demonstrated a greater sensitivity, identifying 100% (24/24) of candida to genus level and 9/24 (37.5%) top species level compared to 70.8% (17/24) to genus and 6/24 to species (25%) using the Sepsityper®. This study demonstrates that capture and enrichment of samples using magnetic FcMBL-conjugated beads is superior to rapid centrifugation methods for identification of BCs by MALDI-TOF MS. Deploying the FcMBL method therefore offers potential clinical benefits in sensitivity and reduced turnaround times for BC diagnosis compared to the standard Sepsityper® kit, especially for fungal diagnosis.
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Bacteriemia , Sepse , Humanos , Criança , Hemocultura , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Técnicas Bacteriológicas/métodos , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Bactérias Gram-Positivas , Fenômenos MagnéticosRESUMO
OBJECTIVE: To estimate the degree of SARS-CoV-2 transmission among healthcare workers (HCWs) and general population in Kita region of Mali. DESIGN: Routine surveillance in 12 health facilities, HCWs serosurvey in five health facilities and community serosurvey in 16 villages in or near Kita town, Mali. SETTING: Kita region, western Mali; local health centres around the central (regional) referral health centre. PARTICIPANTS: Patients in routine surveillance, HCWs in local health centres and community members of all ages in populations associated with study health centres. MAIN OUTCOME MEASURES: Seropositivity of ELISA test detecting SARS-CoV-2-specific total antibodies and real-time RT-PCR confirmed SARS-CoV-2 infection. RESULTS: From 2392 routine surveillance samples, 68 (2.8%, 95% CI: 2.2% to 3.6%) tested positive for SARS-CoV-2 by RT-PCR. The monthly positivity rate was 0% in June-August 2020 and gradually increased to 6% by December 2020 and 6.2% by January 2021, then declined to 5.5%, 3.3%, 3.6% and 0.8% in February, March, April and May 2021, respectively. From 397 serum samples collected from 113 HCWs, 175 (44.1%, 95% CI: 39.1% to 49.1%) were positive for SARS-CoV-2 antibodies. The monthly seroprevalence was around 10% from September to November 2020 and increased to over 40% from December 2020 to May 2021. For community serosurvey in December 2020, overall seroprevalence of SARS-CoV-2 antibodies was 27.7%. The highest age-stratified seroprevalence was observed in participants aged 60-69 years (45.5%, 95% CI: 32.3% to 58.6%). The lowest was in children aged 0-9 years (14.0%, 95% CI: 7.4% to 20.6%). CONCLUSIONS: SARS-CoV-2 in rural Mali is much more widespread than assumed by national testing data and particularly in the older population and frontline HCWs. The observation is contrary to the widely expressed view, based on limited data, that COVID-19 infection rates were lower in 2020-2021 in West Africa than in other settings.
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COVID-19 , Anticorpos Antivirais , COVID-19/diagnóstico , COVID-19/epidemiologia , Criança , Pessoal de Saúde , Humanos , Mali/epidemiologia , SARS-CoV-2 , Estudos SoroepidemiológicosRESUMO
Infections are frequently experienced complications for patients undergoing haematopoietic cell transplant (HCT). To assess current infection prevention strategies, an international survey among HCT nurses was conducted by the Nurses Group and IDWP of the EBMT. Nurse representatives from all EBMT transplant centres were invited to complete an online questionnaire on protective environment in adult and paediatric HCT units. A total of 141 complete questionnaires were returned for the isolation section and 26 for the paediatric section, the majority of respondents (89.4%) being nurses. A small number of centres (7.1%) reported not allowing visitors, the rest have rules for entering patient rooms. Most HCT units (99.3%) indicated that nurses play a critical role in infection prevention and measures differed between bacterial infections and viral infections. Many of the paediatric units (57.7%) had a play area, applying rules of entry. To our knowledge, this is the first survey on protective environment directed at nurses within HCT centres. Despite having different practices, most HCT units tend to decrease isolation procedures and the use of PPE for multi-drug resistant organisms. This must concur with an increase of hand hygiene compliance, for which our data show that there is still room for improvement.
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Transplante de Células-Tronco Hematopoéticas , Enfermeiras e Enfermeiros , Adulto , Medula Óssea , Criança , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Quartos de Pacientes , Inquéritos e QuestionáriosRESUMO
BACKGROUND: The objectives of this study were to assess the number of organisms present on different surfaces within a clinical environment before and after cleaning took place, and to identify the impact of cleaning. The study involved extensive 2-week microbiological environmental monitoring of an entire ward before and after cleaning; the ward was located within a pediatric hematology-oncology ward comprised of a day unit and outpatient ward. METHODS: Tryptone soya agar contact plates were used to take a total of 1,160 surface samples before and after cleaning from 55 predetermined sites. Samples were taken from representative surfaces throughout the ward representing a variety of materials, surface heights, functions, and distances from patients, as well as both high-touch and infrequently touched surfaces. RESULTS: After surface cleaning was undertaken within the ward, there was a significant difference between the amount of colony-forming units (CFUs) recovered before and after cleaning (P < .0001). Cleaning produced an average CFU reduction of 68% throughout the ward environment. The corridor was the most contaminated area within the ward. There were differences in the CFUs among the various areas within the ward, which were cleaned with varying efficiency. The surface material, who interacted with the surface, levels of initial contamination, perceived risk, and perceived cleanability were all found to have a varying impact on the cleaning effectiveness. CONCLUSIONS: To the authors' current knowledge, this is the only study to assess cleaning within a pediatric ward by taking samples directly before and after cleaning. The standard of cleaning undertaken within the ward is open for discussion, and these data highlight the need for an improved cleaning intervention and can provide insight into the multitude of factors that must be considered when designing an effective training protocol.
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Contaminação de Medicamentos , Hospitais , Criança , HumanosRESUMO
Background: Cleaning is a critical tool for infection prevention and control, and is a key intervention for preventing healthcare associated infections (HCAIs) and controlling intermediate transmission routes between patient and environment. This study sought to identify potential areas of weakness in clinical surface cleaning, and assess the effectiveness of a staff group specific training intervention. Observations: One-hundred hours of audit observations in a paediatric cardiac intensive care unit (CICU) assessed surface cleaning technique of healthcare staff within bedspaces. Cleaning was assessed with a 5-component bundle, with each cleaning opportunity scored out of five. Training Intervention: Fifty hours of audit observations before and after a training intervention tested the efficacy of a staff group specific education intervention. The intervention was developed and implemented for 69% of nurses and 100% of cleaners. Results: One hundred and eighteen cleaning opportunities were observed before training, and scored an average of 2.4. One hundred and twenty-one cleaning opportunities were observed after training and scored an average 3.0. On average, before training, each cleaning opportunity by nurses and cleaners fulfilled 2.4 and 2.5, respectively, of the 5 bundle components. Following training, this improved to 3.3 and 2.9 respectively. There was a statistically significant improvement in bundle scores for nurses (P=.004) and cleaners (P=.0003). Conclusions: Surface wipe methods were inconsistent between all staff groups. The education based intervention resulted in a small improvement in most of the cleaning components. This study has identified how a small but targeted cleaning training intervention can have a significant (P= <.0001) impact on cleaning bundle compliance for both nurses and cleaners.
RESUMO
BACKGROUND: Hospital-acquired Legionnaires' disease is associated with the presence of Legionella pneumophila in hospital water systems. In the United Kingdom, the Department of Health recommends maintaining hot water temperatures >55°C and cold water temperatures <20°C at the point of delivery to prevent proliferation of L pneumophila in water systems. In this study, we evaluated the efficacy of copper and silver ionization to control L pneumophila at deliberately reduced hot water temperatures (43°C) within a newly installed water system in a new building linked to a large health care facility in the United Kingdom. METHODS: One thousand, five hundred ninety-eight water samples were collected between September 2011 and June 2017. Samples were tested using accredited methods for L pneumophila, copper and silver ion levels, and total viable counts. Energy consumption and water usage data were also collected to permit carbon emission calculations. RESULTS: The results of 1,598 routine samples from September 2011 to June 2017, and the recordings of temperatures at outlets in this facility, demonstrated effective (100%) L pneumophila control throughout the study period with an average hot water temperature of 42°C. The energy savings and reduction of carbon emissions were calculated to amount to 33% and 24%, respectively, compared to an equivalent temperature-controlled system. Water system management interventions were required to achieve consistently adequate levels of copper and silver across outlets. CONCLUSIONS: This study demonstrated that it is possible to control L pneumophila independent of temperature when copper and silver ionization is introduced into a new building in conjunction with an appropriately managed water system.
Assuntos
Cobre/farmacologia , Desinfecção/métodos , Legionella pneumophila/efeitos dos fármacos , Doença dos Legionários/prevenção & controle , Prata/farmacologia , Cátions Monovalentes , Hospitais , Temperatura Alta , Humanos , Legionella pneumophila/crescimento & desenvolvimento , Doença dos Legionários/microbiologia , Doença dos Legionários/transmissão , Engenharia Sanitária/instrumentação , Reino Unido , Microbiologia da Água , Purificação da Água/métodos , Abastecimento de Água/métodosRESUMO
Human respiratory syncytial virus (HRSV) is a major cause of pediatric infection and also causes disease in the elderly and those with underlying respiratory problems. There is no vaccine for HRSV and anti-viral therapeutics are not broadly applicable. To investigate the effect of HRSV biology in children, nasopharyngeal aspirates were taken from children with different viral loads and a combined high throughput RNAseq and label free quantitative proteomics approach was used to characterize the nucleic acid and proteins in these samples. HRSV proteins were identified in the nasopharyngeal aspirates from infected children, and their abundance correlated with viral load (Ct value), confirming HRSV infection. Analysis of the HRSV genome indicated that the children were infected with sub-group A virus and that minor variants in nucleotide frequency occurred in discrete clusters along the HRSV genome, and within a patient clustered distinctly within the glycoprotein gene. Data from the samples were binned into four groups; no-HRSV infection (control), high viral load (Ct < 20), medium viral load (Ct = 20-25), and low viral load (Ct > 25). Cellular proteins associated with the anti-viral response (e.g., ISG15) were identified in the nasopharyngeal aspirates and their abundance was correlated with viral load. These combined approaches have not been used before to study HRSV biology in vivo and can be readily applied to the study the variation of virus host interactions.