Complicated pneumonia caused by group A Streptococcus in children - 2022/2023 infectious season outbreak and update on clinical characteristics

BACKGROUND

An increased incidence of group A Streptococcus (GAS) infections has been observed in pediatric population post-COVID-19 pandemic. While the majority of reports refer to scarlet fever or invasive GAS disease, detailed data on pulmonary manifestations such as complicated community-acquired pneumonia (CAP) are scarce. The aim of this study was to assess the contribution of GAS to complicated CAP in children during the 2022/2023 infectious season.

METHODS

We retrospectively analyzed the etiology and clinical presentation of complicated CAP patients hospitalized in our tertiary care center in Warsaw, Poland, between August 2022 and May 2023.

RESULTS

Among 91 patients with complicated CAP, GAS was the dominant cause constituting 24.2% (22/91; 95% CI 15.8-34.3%) of the study group. 68.2% of GAS pneumonia patients presented symptoms of scarlet fever, and 27.3% had preceding or concurrent viral infection. GAS complicated CAP was associated with longer hospitalization, higher incidence of chest tube insertion, but shorter duration of chest tube drainage than complicated CAP of other etiology. Children with GAS complicated CAP had higher procalcitonin concentration (28.1 vs. 1.5 ng/dL; p<0.0001) and a lower platelets level (254.5 vs. 422 × 103/μL; p = 0.0031) than those with non-GAS infection.

CONCLUSIONS

GAS is currently the predominant pathogen of complicated CAP in children. Clinicians should be aware of the current epidemiological situation and a more severe course of GAS pneumonia in this age group, and should monitor patients presenting with symptoms of scarlet fever and preceding viral infection closely.

Clinical, microbiological, and molecular characterization of pediatric invasive infections by Streptococcus pyogenes in Spain in a context of global outbreak

In December 2022, an alert was published in the UK and other European countries reporting an unusual increase in the incidence of Streptococcus pyogenes infections. Our aim was to describe the clinical, microbiological, and molecular characteristics of group A Streptococcus invasive infections (iGAS) in children prospectively recruited in Spain (September 2022-March 2023), and compare invasive strains with strains causing mild infections. One hundred thirty isolates of S. pyogenes causing infection (102 iGAS and 28 mild infections) were included in the microbiological study: emm typing, antimicrobial susceptibility testing, and sequencing for core genome multilocus sequence typing (cgMLST), resistome, and virulome analysis. Clinical data were available from 93 cases and 21 controls. Pneumonia was the most frequent clinical syndrome (41/93; 44.1%), followed by deep tissue abscesses (23/93; 24.7%), and osteoarticular infections (11/93; 11.8%). Forty-six of 93 cases (49.5%) required admission to the pediatric intensive care unit. iGAS isolates mainly belonged to emm1 and emm12; emm12 predominated in 2022 but was surpassed by emm1 in 2023. Spread of M1UK sublineage (28/64 M1 isolates) was communicated for the first time in Spain, but it did not replace the still predominant sublineage M1global (36/64). Furthermore, a difference in emm types compared with the mild cases was observed with predominance of emm1, but also important representativeness of emm12 and emm89 isolates. Pneumonia, the most frequent and severe iGAS diagnosed, was associated with the speA gene, while the ssa superantigen was associated with milder cases. iGAS isolates were mainly susceptible to antimicrobials. cgMLST showed five major clusters: ST28-ST1357/emm1, ST36-ST425/emm12, ST242/emm12.37, ST39/emm4, and ST101-ST1295/emm89 isolates.

IMPORTANCE

Group A Streptococcus (GAS) is a common bacterial pathogen in the pediatric population. In the last months of 2022, an unusual increase in GAS infections was detected in various countries. Certain strains were overrepresented, although the cause of this raise is not clear. In Spain, a significant increase in mild and severe cases was also observed; this study evaluates the clinical characteristics and the strains involved in both scenarios. Our study showed that the increase in incidence did not correlate with an increase in resistance or with an emm types shift. However, there seemed to be a rise in severity, partly related to a greater rate of pneumonia cases. These findings suggest a general increase in iGAS that highlights the need for surveillance. The introduction of whole genome sequencing in the diagnosis and surveillance of iGAS may improve the understanding of antibiotic resistance, virulence, and clones, facilitating its control and personalized treatment.

A systematic review of goal attainment scaling implementation practices by caregivers in randomized controlled trials

BACKGROUND

Goal attainment scaling (GAS), an established individualized, patient-centred outcome measure, is used to capture the patient's voice. Although first introduced ~60 years ago, there are few published guidelines for implementing GAS, and almost none for its use when caregivers GAS is implemented with caregiver input. We conducted a systematic review of studies that implemented GAS with caregiver input; and examined variations in GAS implementation, analysis, and reporting.

METHODS

Literature was retrieved from Medline, Embase, Cochrane, PsycInfo and CINAHL databases. We included randomized controlled trials (published between 1968 and November 2022) that used GAS as an outcome measure and involved caregiver input during goal setting.

RESULTS

Of the 2610 studies imported for screening, 21 met the inclusion criteria. Most studies employed GAS as a primary outcome. The majority (76%) had children as study participants. The most common disorders represented were cerebral palsy, developmental disorders, and dementia/Alzheimer's disease. The traditional five-point GAS scale, with levels from -2 to +2, was most often implemented, with -1 level typically being the baseline. However, most studies omitted essential GAS details from their reports including the number of goals set, number of attainment levels and whether any training was given to GAS facilitators.

CONCLUSIONS

GAS with caregiver input has been used in a limited number of randomized controlled trials, primarily in pediatric patients and adults with dementia. There is a variability in GAS implementation and many crucial details related to the specifics of GAS implementation are omitted from reports, which may limit reproducibility. Here we propose catalog that may be utilized when reporting research results pertaining to GAS with caregivers to enhance the application of this patient-centered outcome measure.

Epidemiology and emm types among group A streptococcal pharyngitis in Finland: a prospective laboratory-based study

PURPOSE

Streptococcus pyogenes (mostly termed group A Streptococcus - GAS) is the most important bacterial causative of pharyngitis. However, epidemiology of GAS pharyngitis is not widely established. This study describes GAS pharyngitis cases and emm-type distribution in a prospective study covering over 2 years in two Hospital Districts in Finland.

METHODS

A prospective, systematic collection of GAS pharyngitis isolates was conducted between March 2018 and December 2020 in two large Hospital Districts in Finland. Patient characteristics (age, gender) were included if available. All GAS isolates collected were emm typed.

RESULTS

Altogether 1320 GAS pharyngitis strains were collected, 904 in the Hospital District 1 (HD1) and 416 in Hospital District 2 (HD2). In HD1, age and gender data were available. Females were overrepresented (58% of all cases). In addition, the age and gender distributions were noted to be significantly different (p < 0.0001) with females having a more uniform distribution until age of 40. emm28 was common among the age group of 20-29-year-olds and emm89 in children under 10 years of age, respectively. In HD1, most of the isolates were collected during winter and autumn months. Significant differences by season in the frequency of emm12, emm89, emm75 and group of "others" were observed.

CONCLUSION

Age distribution among GAS pharyngitis cases was significantly different between genders (p < 0.0001). In addition, age group specific and seasonal variations in emm GAS types causing the disease were observed. These findings warrant further investigation, especially for understanding population-based spread of GAS even in more detail.

Invasive Group A Streptococcus in Infants Less Than 1-year of Age From 2012 to 2022: A Single-Center Experience

The incidence of invasive Group A Streptococcus (iGAS) has varied throughout the COVID-19 pandemic. We reviewed iGAS infections in infants ≤1 year from 2012 to 2022. Twenty-five percent of cases occurred in the last quarter of 2022. Pneumonia (21.8%) was the most common presentation. Twenty-one patients (65.6%) were successfully transitioned to oral antibiotics.

Increase in invasive group A streptococcal infections in Milan, Italy: a genomic and clinical characterization

Background

Group A Streptococcus (GAS) causes multiple clinical manifestations, including invasive (iGAS) or even life-threatening (severe-iGAS) infections. After the drop in cases during COVID-19 pandemic, in 2022 a sharp increase of GAS was reported globally.

Methods

GAS strains collected in 09/2022-03/2023 in two university hospitals in Milan, Italy were retrospectively analyzed. Clinical/epidemiological data were combined with whole-genome sequencing to: (i) define resistome/virulome, (ii) identify putative transmission chains, (iii) explore associations between emm-types and clinical severity.

Results

Twenty-eight isolates were available, 19/28 (67.9%) from adults and 9/28 (32.1%) from pediatric population. The criteria for iGAS were met by 19/28 cases (67.9%), of which 11/19 (39.3%) met the further criteria for severe-iGAS. Pediatric cases were mainly non-invasive infections (8/9, 88.9%), adult cases were iGAS and severe-iGAS in 18/19 (94.7%) and 10/19 (52.6%), respectively. Thirteen emm-types were detected, the most prevalent being emm1 and emm12 (6/28 strains each, 21.4%). Single nucleotide polymorphism (SNP) analysis of emm1.0 and emm12.0 strains revealed pairwise SNP distance always >10, inconsistent with unique transmission chains. Emm12.0-type, found to almost exclusively carry virulence factors speH and speI, was mainly detected in children and in no-iGAS infections (55.6 vs. 5.3%, p = 0.007 and 66.7 vs. 0.0%, p < 0.001, respectively), while emm1.0-type was mainly detected in severe-iGAS (0.0 vs. 45.5%, p = 0.045).

Conclusions

This study showed that multiple emm-types contributed to a 2022/2023 GAS infection increase in two hospitals in Milan, with no evidence of direct transmission chains. Specific emm-types could be associated with disease severity or invasiveness. Overall, these results support the integration of classical epidemiological studies with genomic investigation to appropriately manage severe infections and improve surveillance.

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) Syndrome: A 10-Year Retrospective Cohort Study in an Italian Centre of Pediatric Rheumatology

BACKGROUND

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) syndrome is a rare pediatric disorder consisting of a sudden onset of obsessive-compulsive disorder (OCD) and/or tics after a group A Streptococcus (GAS) infection.

METHODS

In the period between 2013 and 2023, 61 children presented to our Pediatric Rheumatology unit with a suspicion of PANDAS syndrome. Among these, a retrospective analysis was conducted, and 19 fulfilled the current classification criteria and were included in this study.

RESULTS

The male-to-female ratio was 14:5, the median age at onset was 7.0 (2.0-9.5) years, and the median age at diagnosis was 8.0 (3.0-10.4) years. The median follow-up period was 16.0 (6.0-72.0) months. Family and personal history were relevant in 7/19 and 6/19 patients. Tics were present in all patients. Details for motor tics were retrospectively available in 18/19 patients, with the eyes (11/18) and neck/head (10/18) being most often involved. Vocal tics were documented in 8/19, behavioral changes in 10/19, and OCD in 2/19. Regarding the therapeutic response, all patients responded to amoxicillin, 12/13 to benzathine benzylpenicillin, and 7/9 to azithromycin.

CONCLUSIONS

Our findings partially overlap with previous reports. Larger prospective studies are needed to improve treatment strategies and classification criteria.

Acute pharyngitis in children and adults: descriptive comparison of current recommendations from national and international guidelines and future perspectives

This study aims to provide a comparison of the current recommendations about the management of acute pharyngitis. A literature search was conducted from January 2009 to 2023. Documents reporting recommendations on the management of acute pharyngitis were included, pertinent data were extracted, and a descriptive comparison of the different recommendations was performed. The quality of guidelines was assessed through the AGREE II instrument. Nineteen guidelines were included, and an overall moderate quality was found. Three groups can be distinguished: one group supports the antibiotic treatment of group A β-hemolytic Streptococcus (GABHS) to prevent acute rheumatic fever (ARF); the second considers acute pharyngitis a self-resolving disease, recommending antibiotics only in selected cases; the third group recognizes a different strategy according to the ARF risk in each patient. An antibiotic course of 10 days is recommended if the prevention of ARF is the primary goal; conversely, some guidelines suggest a course of 5-7 days, assuming the symptomatic cure is the goal of treatment. Penicillin V and amoxicillin are the first-line options. In the case of penicillin allergy, first-generation cephalosporins are a suitable choice. In the case of beta-lactam allergy, clindamycin or macrolides could be considered according to local resistance rates.    Conclusion: Several divergencies in the management of acute pharyngitis were raised among guidelines (GLs) from different countries, both in the diagnostic and therapeutic approach, allowing the distinction of 3 different strategies. Since GABHS pharyngitis could affect the global burden of GABHS disease, it is advisable to define a shared strategy worldwide. It could be interesting to investigate the following issues further: cost-effectiveness analysis of diagnostic strategies in different healthcare systems; local genomic epidemiology of GABHS infection and its complications; the impact of antibiotic treatment of GABHS pharyngitis on its complications and invasive GABHS infections; the role of GABHS vaccines as a prophylactic measure. The related results could aid the development of future recommendations. What is Known: • GABHS disease spectrum ranges from superficial to invasive infections and toxin-mediated diseases. • GABHS accounts for about 25% of sore throat in children and its management is a matter of debate. What is New: • Three strategies can be distinguished among current GLs: antibiotic therapy to prevent ARF, antibiotics only in complicated cases, and a tailored strategy according to the individual ARF risk. • The impact of antibiotic treatment of GABHS pharyngitis on its sequelae still is the main point of divergence; further studies are needed to achieve a global shared strategy.

Selecting Goals and Target Muscles for Botulinum Toxin A Injection Using the Goal Oriented Facilitated Approach to Spasticity Treatment (GO-FAST) Tool

The objective of this article is to introduce the GO-FAST Tool (developed by the Toxnet group) to clinicians working in the field of neurological rehabilitation, specifically post-stroke spasticity management. The concepts utilized in the Tool and described in this article can be broadly grouped into five topics: the principles of patient-centred goal-setting; an algorithm for setting SMART (specific, measurable, attainable, realistic, and timed) treatment goals; goal-related target muscles and botulinum toxin type A dose determinants; goal attainment follow-up, scoring, and interpretation; and the multimodal approach to spasticity management. The Tool can enhance clinical practice by providing guided assistance with goal-setting and target muscle selection for botulinum toxin type A treatment. It also provides support with the follow-up evaluation of goal attainment and calculation of treatment success. The Tool is designed to be used by clinicians with varying levels of expertise in the field of neurological rehabilitation and post-stroke spasticity management, from those who are new to the field to those with many years of experience. A case study is presented in the Results Section of the article to illustrate the utility of the Tool in setting SMART treatment goals in the management of patients with post-stroke spasticity.

[The many faces of Group A Streptococcal infections, case-series of invasive infections in children in Iceland]

In recent months the incedence of invasive group A streptococcal infections (Streptococcus pyogenes) has increased worldwide. In the Children's Hospital Iceland 20 such cases were admitted during a four month period, until which time the avarage was one or two children admitted with an invasive GAS infection per year. To demonstrate the variability in the presentation of these invasive infections four cases were chosen for discussion in this case-series. Empyema with toxic shock syndrome, meningitis, orbital abscess and fascitis of the leg are reviewed.

State of the Art of Invasive Group A Streptococcus Infection in Children: A Scoping Review of the Literature with a Focus on Predictors of Invasive Infection

Currently, it remains unclear why some children develop invasive group A Streptococcus (iGAS) and how to manage this condition. Therefore, to explore available works in the literature, we performed a scoping review aiming to analyze the current literature on clinical presentation of different illnesses outcomes of iGAS, with a specific focus on predictors of invasive infection, including an assessment of the prodromal stages of the disease and the possible presence of previous non-invasive GAS infections in children that later developed iGAS.

METHODS

We conducted a systematic search on PubMed and SCOPUS of all pediatric studies reporting iGAS cases, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. For those studies in which multivariable analysis investigating iGAS risk factors was performed, a second review was performed and reported in detail.

RESULTS

A total of 209 studies were included. Five studies investigated risk factors for iGAS, the most relevant being varicella infection, chronic underlying illness, presence of the speC gene in GAS strains, acetaminophen and ibuprofen use, children nonwhite, living in low-income households, exposure to varicella at home, persistent high fever, having more than one other child in the home, and new use of NSAIDs. Although we observed a progressive increase in the number of papers published on this topic, no trials investigating the benefits of clindamycin or intravenous immunoglobulins were found and low-to-middle-income countries were found to be poorly represented in the current literature.

CONCLUSIONS

Our scoping review highlights important gaps regarding several aspects of iGAS in children, including prodromic presentation and optimal treatment strategies. There is also little representation of low-middle-income countries. The current literature does not allow the performance of systematic reviews or meta-analyses, but this work should inform healthcare professionals, policy makers, and funding agencies on which studies to prioritize on this topic.

Epidemiology of Group A Streptococcal bacteraemia in Hunter New England Local Health District, 2008 to 2019

Invasive Group A Streptococcal infection (iGAS) is an uncommon but serious infection with Streptococcus pyogenes in a normally sterile body site. Manifestations include bacteraemia, necrotising fasciitis and toxic shock syndrome with attendant serious morbidity and mortality. An increasing incidence of iGAS has been observed in some regions of Australia. iGAS became a nationally notifiable condition from 1 July 2021. To determine if regional incidence has increased, and to identify priority populations, we undertook a retrospective data analysis of Group A Streptococcal (GAS) bacteraemia cases in Hunter New England Local Health District (HNELHD), New South Wales, Australia, from 1 January 2008 to 31 December 2019, as identified by NSW Health Pathology, John Hunter Hospital. A total of 486 cases were identified (age-standardised rate: 4.05 cases per 100,000 population per year). Incidence in HNELHD gradually increased over the study period (adjusted incidence rate ratio: 1.04; 95% confidence interval: 1.01-1.07) and was significantly higher in children under 5 years of age; in adults over 70 years of age; in males; and in First Nations peoples. A significant peak occurred in 2017 (9.00 cases per 100,000 population), the cause of which remains unclear. GAS bacteraemia is uncommon but severe, and incidence in HNELHD has slowly increased. Public health and clinical guidelines must address the needs of priority populations, which include young children, older adults and First Nations peoples. Routine surveillance and genomic analysis will help improve our understanding of iGAS and inform best public health management.

Invasive beta-haemolytic streptococcal infections, Finland, 2006 to 2020: increase in Lancefield group C/G infections

BackgroundInvasive infections with beta-haemolytic streptococci of Lancefield groups A (iGAS), B (iGBS) and C/G (iGCGS) are a major cause of morbidity and mortality worldwide.AimWe studied incidence trends of invasive beta-haemolytic streptococcal infections in Finland, focusing on iGCGS.MethodsWe conducted a retrospective register-based study. Cases were defined as isolations from blood and/or cerebrospinal fluid and retrieved from the National Infectious Disease Register where all invasive cases are mandatorily notified.ResultsBetween 2006 and 2020, the mean annual incidence was 4.1 per 100,000 for iGAS (range: 2.1-6.7), 5.2 for iGBS (4.0-6.3) and 10.1 for iGCGS (5.4-17.6). The incidence displayed an increasing trend for all groups, albeit for iGBS only for individuals 45 years and older. The increase was particularly sharp for iGCGS (8% annual relative increase). The incidence rate was higher in males for iGCGS (adjusted incidence rate ratio (IRR) = 1.6; 95% confidence interval (CI): 1.5-1.8) and iGAS (adjusted IRR = 1.3; 95% CI: 1.1-1.4); for iGBS, the association with sex was age-dependent. In adults, iGCGS incidence increased significantly with age. Recurrency was seen for iGCGS and secondarily iGBS, but not for iGAS. Infections with iGCGS and iGBS peaked in July and August.ConclusionsThe incidence of invasive beta-haemolytic streptococcal infections in Finland has been rising since 2006, especially for iGCGS and among the elderly population. However, national surveillance still focuses on iGAS and iGBS, and European Union-wide surveillance is lacking. We recommend that surveillance of iGCGS be enhanced, including systematic collection and typing of isolates, to guide infection prevention strategies.

The role of CopA in Streptococcus pyogenes copper homeostasis and virulence

Maintenance of intracellular metal homeostasis during interaction with host niches is critical to the success of bacterial pathogens. To prevent infection, the mammalian innate immune response employs metal-withholding and metal-intoxication mechanisms to limit bacterial propagation. The first-row transition metal ion copper serves critical roles at the host-pathogen interface and has been associated with antimicrobial activity since antiquity. Despite lacking any known copper-utilizing proteins, streptococci have been reported to accumulate significant levels of copper. Here, we report that loss of CopA, a copper-specific exporter, confers increased sensitivity to copper in Streptococcus pyogenes strain HSC5, with prolonged exposure to physiological levels of copper resulting in reduced viability during stationary phase cultivation. This defect in stationary phase survival was rescued by supplementation with exogeneous amino acids, indicating the pathogen had altered nutritional requirements during exposure to copper stress. Furthermore, S. pyogenes HSC5 ΔcopA was substantially attenuated during murine soft-tissue infection, demonstrating the importance of copper efflux at the host-pathogen interface. Collectively, these data indicate that copper can severely reduce the viability of stationary phase S. pyogenes and that active efflux mechanisms are required to survive copper stress in vitro and during infection.

Detection of superantigens in Streptococcus pyogenes isolates based on whole genome sequencing data

Streptococcus pyogenes causes a variety of human diseases ranging from uncomplicated respiratory tract and skin infections to severe invasive diseases possibly involving toxic shock syndrome. Besides the emm gene-encoded M protein, important virulence factors are pyrogenic exotoxins, referred to as superantigens. The National Reference Laboratory for Streptococcal Infections has newly introduced bioinformatics tools for processing S. pyogenes whole genome sequencing data. Using the SRST2 software and BV-BRC platform, WGS data of 10 S. pyogenes isolates from patients with invasive disease were analysed, and emm type, sequence type, and superantigen encoding gene profiles were determined. The Unicycler assembly pipeline with the SPAdes de novo assembler was used to assemble genome sequences from short reads.

Goal attainment in individual and group-based neuropsychological interventions for young adults with dyslexia in a randomized controlled trial

In this study, we investigated the outcome of goal attainment in individual and group-based neuropsychological intervention for young adults with dyslexia. Participants (N = 120) were randomly assigned to individual intervention, group intervention, or wait-list control group. Attainment of goals set personally before the intervention was evaluated after the intervention using Goal Attainment Scaling. The participants were asked to report the number of concrete changes made in their study or working habits at five months (after intervention or wait-list control time), at ten months, and 15 months post-interventions. Potential predictive factors for predicting goal attainment were evaluated including background and cognitive variables, self-reported psychological variables (mood, cognitive and behavioral strategies, self-esteem, quality of life), and self-reported behavioral variables (concrete changes made, time used to work on intervention matters). Based on the results, personal goals were, on average, met especially in individual intervention. Nearly 50% of goal attainment was explained by intervention type, behavioral and cognitive strategies, concrete changes made, cognitive capacity, and used time. Concrete changes, e.g., adopting new strategies and methods in study or working habits, were reported in both interventions and more than during the wait-list control period. The changes seemed long-lasting as fifteen months post-intervention, 76.4% reported still using the learned strategies. A structured and relatively short neuropsychological intervention for dyslexia in either individual or group format can lead to attaining pre-set personal goals and positive behavioral changes that can last up to over a year post-intervention.

Preparation of gastrodin-modified dendrimer-entrapped gold nanoparticles as a drug delivery system for cerebral ischemia-reperfusion injury

OBJECTIVE

This study sought to evaluate the feasibility of multifunctional gastrodin (GAS)-containing nano-drug carrier system against cerebral ischemia-reperfusion injury (CIRI).

METHODS

The drug-loaded nanocomposite (Au-G5.NHAc-PS/GAS) with certain encapsulation efficiency (EE) was prepared by physical adsorption method using different proportions of GAS and drug-carrying system (Au-G5.NHAc-PS). High-performance liquid chromatography was used to determine the drug loading and EE. Cultured rat astrocytes and hypothalamic neurons were assigned into four groups: PBS, Au-G5.NHAc-PS, Au-G5.NHAc-PS/GAS, and GAS. CCK-8 assay, flow cytometry, and quantitative real-time PCR were performed to examine the cell viability, apoptosis, and the expression of tumor necrosis factor-α (TNF-α), IL-1β, and IL-6 in the astrocytes and hypothalamic neurons, respectively. Cellular uptake of GAS and Au-G5.NHAc-PS/GAS was analyzed by using Hoechst 33342 staining. The animal model with focal cerebral ischemia was generated by middle cerebral artery occlusion (MCAO) in healthy male Sprague Dawley (SD) rats, and pathological changes of brain tissue and major organs in the rats were identified by hematoxylin and eosin (HE) staining. Apoptosis in rat astrocytes and hypothalamic neurons was detected by TUNEL staining and flow cytometry.

RESULTS

Au-G5.NHAc-PS had a spherical shape with a uniform size of 157.3 nm. Among the nanoparticles, Au-G5.NHAc-PS/GAS with an EE of 70.3% displayed the best release delay effect. Moreover, we observed that in vitro cytotoxicity and cellular uptake of Au-G5.NHAc-PS/GAS were higher than those of GAS, whereas the expression of TNF-α, IL-1β, and IL-6 was significantly downregulated in Au-G5.NHAc-PS/GAS group as compared to G5.NHAc-PS group. Notably, HE staining revealed that although Au-G5.NHAc-PS/GAS had no toxic and side effects on the main organs of rats, it alleviated the damage of brain tissue in the MCAO rats. Besides, Au-G5.NHAc/GAS markedly reduced MCAO-induced apoptosis.

CONCLUSION

Au-G5.NHAc-PS showed favorable surface morphology, sustained drug release ability, no measurable toxicity, and good biocompatibility, indicating that GAS exerts anti-inflammatory and antiapoptotic effects on CIRI.

Foodborne streptococcal tonsillopharyngitis outbreak in a hospital

OBJECTIVE

Group A beta-haemolytic streptococci (GAS), which are responsible for most cases of acute bacterial tonsillopharyngitis, are transmitted from person to person and may rarely cause foodborne outbreaks. This study aims to report the epidemic caused by GAS in our hospital and to draw attention to the explosive outbreaks of the bacteria.

METHODS

Acute tonsillopharyngitis was seen in 201 of 450 hospital employees who ate in the hospital cafeteria on 4-5 June 2015.

RESULTS

GAS was detected in 106 (68%) of 157 cases and in 40 (63.5%) of 62 throat culture samples. The attack rate was 44.7%. The most suspected source of the outbreak was a food handler who had been showing signs of streptococcal tonsillopharyngitis for six days, and perhaps the food prepared by these staff.

CONCLUSION

It should not be forgotten that GAS can cause explosive outbreaks by infecting food through hand lesions or mouth secretions of food service personnel.

An Overview of Macrolide Resistance in Streptococci: Prevalence, Mobile Elements and Dynamics

Streptococcal infections are usually treated with beta-lactam antibiotics, but, in case of allergic patients or reduced antibiotic susceptibility, macrolides and fluoroquinolones are the main alternatives. This work focuses on studying macrolide resistance rates, genetic associated determinants and antibiotic consumption data in Spain, Europe and also on a global scale. Macrolide resistance (MR) determinants, such as ribosomal methylases (erm(B), erm(TR), erm(T)) or active antibiotic efflux pumps and ribosomal protectors (mef(A/E)-mrs(D)), are differently distributed worldwide and associated with different clonal lineages and mobile genetic elements. MR rates vary together depending on clonal dynamics and on antibiotic consumption applying selective pressure. Among Streptococcus, higher MR rates are found in the viridans group, Streptococcus pneumoniae and Streptococcus agalactiae, and lower MR rates are described in Streptococcus pyogenes. When considering different geographic areas, higher resistance rates are usually found in East-Asian countries and milder or lower in the US and Europe. Unfortunately, the availability of data varies also between countries; it is scarce in low- and middle- income countries from Africa and South America. Thus, surveillance studies of macrolide resistance rates and the resistance determinants involved should be promoted to complete global knowledge among macrolide resistance dynamics.

Loss of rpoE Encoding the δ-Factor of RNA Polymerase Impacts Pathophysiology of the Streptococcus pyogenes M1T1 Strain 5448

Streptococcus pyogenes, also known as the Group A Streptococcus (GAS), is a Gram-positive bacterial pathogen of major clinical significance. Despite remaining relatively susceptible to conventional antimicrobial therapeutics, GAS still causes millions of infections and hundreds of thousands of deaths each year worldwide. Thus, a need for prophylactic and therapeutic interventions for GAS is in great demand. In this study, we investigated the importance of the gene encoding the delta (δ) subunit of the GAS RNA polymerase, rpoE, for its impact on virulence during skin and soft-tissue infection. A defined 5448 mutant with an insertionally-inactivated rpoE gene was defective for survival in whole human blood and was attenuated for both disseminated lethality and lesion size upon mono-culture infection in mouse soft tissue. Furthermore, the mutant had reduced competitive fitness when co-infected with wild type (WT) 5448 in the mouse model. We were unable to attribute this attenuation to any observable growth defect, although colony size and the ability to grow at higher temperatures were both affected when grown with nutrient-rich THY media. RNA-seq of GAS grown in THY to late log phase found that mutation of rpoE significantly impacted (>2-fold) the expression of 429 total genes (205 upregulated, 224 downregulated), including multiple virulence and “housekeeping” genes. The arc operon encoding the arginine deiminase (ADI) pathway was the most upregulated in the rpoE mutant and this could be confirmed phenotypically. Taken together, these findings demonstrate that the delta (δ) subunit of RNA polymerase is vital in GAS gene expression and virulence.

Predictors of rebleeding in patients with acute non-variceal upper gastrointestinal bleeding

BACKGROUND

There is a risk of rebleeding after acute non-variceal upper gastrointestinal bleeding (ANVUGIB), and rebleeding increases the risk of poor prognosis. At present, there is no effective predictive method for such rebleeding. The changes of red blood cell distribution width as well as hemoglobin and gastrin levels are all related to bleeding diseases, which can provide a reference for clinical improvement of relevant mechanisms and prediction of bleeding.

AIM

To investigate the relationship of the red blood cell distribution width (RDW), hemoglobin (Hb), and gastrin (GAS) with Glasgow-Blatchford score (GBS) and AIMS65 score in patients with ANVUGIB and to explore their predictive value for rebleeding.

METHODS

A prospective cohort study was conducted on 122 ANVUGIB patients admitted to our hospital from August 2018 to February 2021, and they were divided into either a rebleeding group (n = 31) or a no-rebleeding group (n = 91) according to whether rebleeding occurred 7 d after onset. Baseline data, RDW, Hb, GAS, GBS score, and AIMS65 score were compared between the two groups. Pearson correlation analysis was performed to explore the relationship of each index with GBS and AIMS65 scores, and multi-factor logistic regression analysis was performed to identify the influencing factors of rebleeding. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to analyze the value of each index in predicting rebleeding, and to compare the incidence of rebleeding in patients with different levels of each index.

RESULTS

The proportion of patients with gastrointestinal bleeding in the rebleeding group was higher than that of the no-rebleeding group. The RDW, GAS, and GBS and AIMS65 scores were higher and Hb was lower in the rebleeding group than in the no-rebleeding group (P < 0.05). RDW and GAS were positively correlated with GBS and AIMS65 scores, and Hb was negatively correlated with GBS and AIMS65 scores (P < 0.05). Multivariate logistic regression analysis showed that after controlling for past gastrointestinal bleeding, GBS, and AIMS65 score, RDW, Hb, and GAS were still influencing factors of rebleeding (P < 0.05). The performance of RDW and Hb combined with GAS for predicting rebleeding (AUC = 0.850) was better than that of RDW (0.721), Hb (0.721), or GAS (0.806) alone. The rebleeding rate in patients with high levels of RDW and GAS was higher than that of patients with low levels, but patients with high levels of Hb had a lower rebleeding rate than those with low levels (P < 0.05).

CONCLUSION

RDW, Hb, and GAS are related to the risk of disease and rebleeding in patients with ANVUGIB. Combined detection of them may be a reliable method to assess the risk of disease and predict rebleeding.

COVID-19 and currency dependences: Empirical evidence from BRICS

The COVID-19 has caused dramatic fluctuations in international financial markets. This paper tests the effect of this pandemic on foreign exchange dependences within the BRICS economies. Upon dividing the COVID-19 episode into four stages, we document negative effects of the COVID-19 on dependences between CNY and other currencies in the BRICS across different stages. In addition, USD flows positively affect the dependencies of BRL-CNY, INR-CNY, and RUB-CNY pairs in response to the transition of the pandemic stages.

A remark on "COVID-19: Perturbation dynamics resulting chaos to stable with seasonality transmission" [Chaos, Solitons and Fractals 145 (2021) 110772]

In Batabyal (2021)[2], introducing an extension of the well-known susceptible-exposed-infected-recovered (SEIR) model with seasonality transmission of SARS-CoV-2, the author has derived and discussed various analytical and numerical results. Careful scrutiny of the said article brings about some genuine issues pertaining to the model formulation, analysis and numerical studies carried out in Batabyal (2021)[2]. Given the present pandemic and the havoc it has been causing throughout the world, and the responsibility of giving out rightful information/results backed by scientific proofs, there is a pressing need to address issues of such kind right away.

Detection of group A streptococcus in children with confirmed viral pharyngitis and antiviral host response

Our aim was to study the detection of group A streptococcus (GAS) with different diagnostic methods in paediatric pharyngitis patients with and without a confirmed viral infection. In this prospective observational study, throat swabs and blood samples were collected from children (age 1-16 years) presenting to the emergency department with febrile pharyngitis. A confirmed viral infection was defined as a positive virus diagnostic test (nucleic acid amplification test [NAAT] and/or serology) together with an antiviral immune response of the host demonstrated by elevated (≥ 175 µg/L) myxovirus resistance protein A (MxA) blood concentration. Testing for GAS was performed by a throat culture, by 2 rapid antigen detection tests (StrepTop and mariPOC) and by 2 NAATs (Simplexa and Illumigene). Altogether, 83 children were recruited of whom 48 had samples available for GAS testing. Confirmed viral infection was diagnosed in 30/48 (63%) children with febrile pharyngitis. Enteroviruses 11/30 (37%), adenoviruses 9/30 (30%) and rhinoviruses 9/30 (30%) were the most common viruses detected. GAS was detected by throat culture in 5/30 (17%) with and in 6/18 (33%) patients without a confirmed viral infection. Respectively, GAS was detected in 4/30 (13%) and 6/18 (33%) by StrepTop, 13/30 (43%) and 10/18 (56%) by mariPOC, 6/30 (20%) and 9/18 (50%) by Simplexa, and 5/30 (17%) and 6/18 (30%) patients by Illumigene.

CONCLUSION

GAS was frequently detected also in paediatric pharyngitis patients with a confirmed viral infection. The presence of antiviral host response and increased GAS detection by sensitive methods suggest incidental throat carriage of GAS in viral pharyngitis.

WHAT IS KNOWN

•The frequency and significance of GAS-virus co-detection are poorly characterised in children with pharyngitis. •Detection of a virus and the antiviral host response likely indicates symptomatic infection.

WHAT IS NEW

•Group A streptococcus (GAS) was detected in 17-43% of the children with confirmed viral pharyngitis depending on the GAS diagnostic method. •Our results emphasize the risk of detecting and treating incidental pharyngeal carriage of GAS in children with viral pharyngitis.

Dnmt3a is downregulated by Stat5a and mediates G0/G1 arrest by suppressing the miR-17-5p/Cdkn1a axis in Jak2V617F cells

Background

Despite of the frequently reported Dnmt3a abormality in classical myeloproliferative neoplasms (cMPNs) patients, few research explores how the Dnmt3a is regulated by Jak2^V617F mutation. In this study, we have investigated how the Dnmt3a is regulated by Jak2^V617F mutation and its effects on downstream signaling pathways in cMPNs.

Methods

Specimens of Jak2^V617F positive cMPN patients and normal controls were collected. Murine BaF3 cell line was used to construct cell models. Dual-Glo luciferase assays and chromatin immunoprecipitation (ChIP)-qPCR were performed to detect the impact of Stat5a on transcription activity of Dnmt3a. Soft agar colony formation assay and cell counting assay were performed to detect cell proliferation. BrdU staining and flow cytometry were used to investigate cell cycle distribution. Western blotting and quantitative reverse-transcription PCR (qPCR) were performed to detect the expression levels of genes.

Results

Firstly, the results of western blotting and qPCR revealed that compared with the control samples, Dnmt3a is downregulated in Jak2^V617F positive samples. Then we explored the mechanism behind it and found that Dnmt3a is a downstream target of Stat5a, the transcription and translation of Dnmt3a is suppressed by the binding of aberrantly activated Stat5a with Dnmt3a promoter in Jak2^V617F positive samples. We further revealed the region approximately 800 bp upstream of the first exon of the Dnmt3a promoter, which includes a gamma-activated sequence (GAS) motif of Stat5a, is the specific site that Stat5a binds to. Soft agar colony formation assay, cell counting assay, and BrdU staining and flow cytometry assay found that Dnmt3a in Jak2^V617F-BaF3 cells significantly affected the cell proliferation capacity and cell cycle distribution by suppressing Cdkn1a via miR-17-5p/Cdkn1a axis and mediated G0/G1 arrest.

Conclusions

Transcription and translation of Dnmt3a is downregulated by the binding of Stat5a with Dnmt3a promoter in Jak2^V617F cells. The GAS motif at promoter of Dnmt3a is the exact site where the Stat5a binds to. Dnmt3a conducted G0/G1 arrest through regulating miR-17-5p/Cdkn1a axis. The axis of Stat5a/Dnmt3a/miR-17-5p/Cdkn1a potentially provides a treatment target for cMPNs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08915-0.

[Patient-centered approach using COPM, GAS scores in medical rehabilitation of patients with tetraplegia after spinal cord injury]

OBJECTIVE

To study the efficacy of the patient- and task-oriented approach and specific therapeutic exercises (TE) for the arms in patients after spinal cord injury at the cervical level.

MATERIAL AND METHODS

The study included 119 patients with a history of spinal injury of more than one year. They were divided into three demographically comparable groups. Group 1 patients (control) received standard of care: TE, physiotherapeutic treatment, social adaptation (SA), and massage; Group 2-standard of care and specific TE for the arms as part of the SA; Group 3-the same as Group 2 combined with the patient- and task-oriented approach (patient-selected activities were trained). Outcomes were assessed at the beginning (T₁), end (T₂), and at 1 year (T₃) after a 30-day medical rehabilitation course.

RESULTS

No statistically significant differences between the groups in demographic, neurological (ISCSCI score), motor (FIMm, VLT scores), psychological parameters (depression, anxiety), quality of life (WHOQOL-BREF score) before the medical rehabilitation (T₁) were observed. At the end of the medical rehabilitation course (T₂), the increase in functional scores was 6.0±5.4 points of FIMm score, 6.0±4.6 points of VLT score in group 1; 8.0±7.6 points of FIMm score, 7.0±7.1 points of VLT score in group 2; 9.0±6.9 points of FIMm score, 8.0±7.6 points of VLT in group 3. Significant differences were found between groups 1 and 2 and 3 on the domains of «finger I» (13.6±9.64 points vs. 15.2±9.40 and 15.3±9.21 points respectively), «fingers II-V» (9.4±6.76 points vs. 11.3±6.41 and 11.6±6.76 points respectively) of VLT score; between groups 3 and 1 on the domains «self-care» (25.9±9.67 points vs. 23.1±9.8 points), «transfer» (11.7±6.21 points vs. 10.6±6.1 points) of the FIMm score, and also the group 3 patients had a higher quality of life by 3.0±1.8 points. At delayed follow-up (T₃-T₂), no changes of the FIMm and VLT scores were detected within groups. In group 3, 69% of problems were identified in self-care (COPM); subjective assessment of functional improvement for COPM (T₂-T₁) was as follows: «performance» 4.7±1.27 points, «satisfaction» 3.8±1.63 points; for GAS the T-score at the end of rehabilitation was 1.3±0.55 points, and the greatest significance of change was noted for COPM under «performance» (ES=0.73), with the correlation coefficient between FIMm and COPM being 0.55 and 0.63 for «performance» and «satisfaction» domains, respectively.

CONCLUSION

Patient- and task-oriented approach implemented by using COPM questionnaire and GAS score together with specific TE for arms is an effective method of motor medical rehabilitation of patients with posttraumatic cervical tetraplegia. This approach improves their quality of life, while parameters of subjective scores (COPM, GAS) have the same sensitivity in comparison with the conventional motor scores (FIMm, VLT).

Increasing Incidence of Invasive Group A Streptococcus Disease in First Nations Population, Alberta, Canada, 2003-2017

The incidence of invasive group A Streptococcus (iGAS) disease in the general population in Alberta, Canada, has been steadily increasing. To determine whether rates for specific populations such as First Nations are also increasing, we investigated iGAS cases among First Nations persons in Alberta during 2003-2017. We identified cases by isolating GAS from a sterile site and performing emm typing. We collected demographic, social, behavioral, and clinical data for patients. During the study period, 669 cases of iGAS in First Nations persons were reported. Incidence increased from 10.0 cases/100,000 persons in 2003 to 52.2 cases/100,000 persons in 2017. The 2017 rate was 6 times higher for the First Nations population than for non-First Nations populations (8.7 cases/100,000 persons). The 5 most common emm types from First Nations patients were 59, 101, 82, 41, and 11. These data indicate that iGAS is severely affecting the First Nations population in Alberta, Canada.

Structured review of primary interventions to reduce group A streptococcal infections, acute rheumatic fever and rheumatic heart disease

Rheumatic heart disease (RHD) is a large, preventable, global public health burden. In New Zealand (NZ), acute rheumatic fever (ARF) and RHD rates are highest for Māori and Pacific children. This structured review explores the evidence for primary prevention interventions to diagnose and effectively treat group A Streptococcus (GAS) pharyngitis and skin infections to reduce rates of ARF and RHD. Medline, EMBASE and Scopus databases were searched as well as other electronic publications. Included were 50 publications from 1980 onwards. This review has identified that there is little available evidence for effective primary prevention strategies to reduce ARF rates in NZ. However, two primary intervention strategies that should be considered by communities at high-risk of ARF are: the use of school-based clinics to identify and treat GAS pharyngitis and GAS skin infections; and intramuscular benzathine penicillin G with lignocaine analgesia in children who present with a GAS positive throat.

First Description of the Composition and the Functional Capabilities of the Skin Microbial Community Accompanying Severe Scabies Infestation in Humans

Epidemiological studies link Sarcoptes scabiei infection and impetigo. Scabies mites can promote Streptococcus pyogenes (Group A Streptococcus) and Staphylococcus aureus infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. However, little is known about the composition and the function of the scabies-associated microbiota. Here, high-throughput whole-metagenome sequencing was used to explore the scabies-associated microbiome. Scabies mites including their immediate microenvironments were isolated from two patients with severe scabies in Northern Australia. Two ~45–50 million paired-end reads Illumina libraries were generated of which ~2 (5.1%) and 0.7 million (1.3%) microbial reads were filtered out by mapping to human (hg19) and mite draft genomes. Taxonomic profiling revealed a microbial community dominated by the phylum Firmicutes (A: 79% and B: 59%) and genera that comprise Streptococcus, Staphylococcus, Acinetobacter, and Corynebacterium. Assembly of the metagenome reads resulted in genome bins representing reference genomes of Acinetobacter baumannii, Streptococcus dysgalactiae (Group C/G), Proteus mirablis and Staphylococcus aureus. The contigs contained genes relevant to pathogenicity and antibiotics resistance. Confocal microscopy of a patient skin sample confirmed A. baumannii, Streptococci and S. aureus in scabies mite gut and faeces and the surrounding skin. The study provides fundamental evidence for the association of opportunistic pathogens with scabies infection.

Native Human Antibody to Shr Promotes Mice Survival After Intraperitoneal Challenge With Invasive Group A Streptococcus

BACKGROUND

A vaccine against group A Streptococcus (GAS) has been actively pursued for decades. The surface receptor Shr is vital in GAS heme uptake and provides an effective target for active and passive immunization. Here, we isolated human monoclonal antibodies (mAbs) against Shr and evaluated their efficacy and mechanism.

METHODS

We used a single B-lymphocyte screen to discover the mAbs TRL186 and TRL96. Interactions of the mAbs with whole cells, proteins, and peptides were investigated. Growth assays and cultured phagocytes were used to study the mAbs' impact on heme uptake and bacterial killing. Efficacy was tested in prophylactic and therapeutic vaccination using intraperitoneal mAb administration and GAS challenge.

RESULTS

Both TRL186 and TRL96 interact with whole GAS cells, recognizing the NTR and NEAT1 domains of Shr, respectively. Both mAbs promoted killing by phagocytes in vitro, but prophylactic administration of only TRL186 increased mice survival. TRL186 improved survival also in a therapeutic mode. TRL186 but not TRL96 also impeded Shr binding to hemoglobin and GAS growth on hemoglobin iron.

CONCLUSIONS

Interference with iron acquisition is central for TRL186 efficacy against GAS. This study supports the concept of antibody-based immunotherapy targeting the heme uptake proteins to combat streptococcal infections.

LL-37-mediated activation of host receptors is critical for defense against group A streptococcal infection

Group A Streptococcus (GAS) causes diverse human diseases, including life-threatening soft-tissue infections. It is accepted that the human antimicrobial peptide LL-37 protects the host by killing GAS. Here, we show that GAS extracellular protease ScpC N-terminally cleaves LL-37 into two fragments of 8 and 29 amino acids, preserving its bactericidal activity. At sub-bactericidal concentrations, the cleavage inhibits LL-37-mediated neutrophil chemotaxis, shortens neutrophil lifespan, and eliminates P2X7 and EGF receptors' activation. Mutations at the LL-37 cleavage site protect the peptide from ScpC-mediated splitting, maintaining all its functions. The mouse LL-37 ortholog CRAMP is neither cleaved by ScpC nor does it activate P2X7 or EGF receptors. Treating wild-type or CRAMP-null mice with sub-bactericidal concentrations of the non-cleavable LL-37 analogs promotes GAS clearance that is abolished by the administration of either P2X7 or EGF receptor antagonists. We demonstrate that LL-37-mediated activation of host receptors is critical for defense against GAS soft-tissue infections.

A Review of Streptococcus pyogenes: Public Health Risk Factors, Prevention and Control

Streptococcus pyogenes, (colloquially named “group A streptococcus” (GAS)), is a pathogen of public health significance, infecting 18.1 million people worldwide and resulting in 500,000 deaths each year. This review identified published articles on the risk factors and public health prevention and control strategies for mitigating GAS diseases. The pathogen causing GAS diseases is commonly transmitted via respiratory droplets, touching skin sores caused by GAS or through contact with contaminated material or equipment. Foodborne transmission is also possible, although there is need for further research to quantify this route of infection. It was found that GAS diseases are highly prevalent in developing countries, and among indigenous populations and low socioeconomic areas in developed countries. Children, the immunocompromised and the elderly are at the greatest risk of S. pyogenes infections and the associated sequelae, with transmission rates being higher in schools, kindergartens, hospitals and residential care homes. This was attributed to overcrowding and the higher level of social contact in these settings. Prevention and control measures should target the improvement of living conditions, and personal and hand hygiene. Adherence to infection prevention and control practices should be emphasized in high-risk settings. Resource distribution by governments, especially in developed countries, should also be considered.

Prion protein oligomers cause neuronal cytoskeletal damage in rapidly progressive Alzheimer's disease

Background

High-density oligomers of the prion protein (HDPs) have previously been identified in brain tissues of patients with rapidly progressive Alzheimer’s disease (rpAD). The current investigation aims at identifying interacting partners of HDPs in the rpAD brains to unravel the pathological involvement of HDPs in the rapid progression.

Methods

HDPs from the frontal cortex tissues of rpAD brains were isolated using sucrose density gradient centrifugation. Proteins interacting with HDPs were identified by co-immunoprecipitation coupled with mass spectrometry. Further verifications were carried out using proteomic tools, immunoblotting, and confocal laser scanning microscopy.

Results

We identified rpAD-specific HDP-interactors, including the growth arrest specific 2-like 2 protein (G2L2). Intriguingly, rpAD-specific disturbances were found in the localization of G2L2 and its associated proteins i.e., the end binding protein 1, α-tubulin, and β-actin.

Discussion

The results show the involvement of HDPs in the destabilization of the neuronal actin/tubulin infrastructure. We consider this disturbance to be a contributing factor for the rapid progression in rpAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13024-021-00422-x.

A protracted iGAS outbreak in a long-term care facility 2014-2015: control measures and the use of whole-genome sequencing

BACKGROUND

In 2014, two residents of a long-term care facility (LTCF) developed invasive group A streptococcal (iGAS) infections with identical typing (emm 11), resulting in one death. The second resident recovered but had a subsequent episode of emm 11 iGAS infection 10 months later. This second episode was linked to a third case, within 12 days, leading to a further outbreak investigation.

AIM

To combine different techniques to establish whether this was a protracted outbreak, understand transmission pathways and inform appropriate control measures.

METHODS

Following a routine response to the first cluster, the second investigation included a care record review. This informed network analysis of case interactions with staff and visitors during 10 days prior to infection. These data were combined with post-outbreak whole-genome sequencing (WGS) using isolates from cases, and staff and resident screening (44 GAS isolates: 11 outbreak-related and 33 sporadic isolates).

FINDINGS

Two of the three confirmed iGAS cases died (one suffered two episodes). All iGAS cases, and six non-invasive isolates from 2015, were emm 11 (monophylogenetic WGS clade). Network analysis highlighted only indirect contact through staff-visitor interactions between iGAS cases in 2015. This suggested a common source and transmission propagation through carriage and/or environmental contamination over an 11-month period.

CONCLUSIONS

This outbreak highlighted benefits of staff/resident screening and typing as part of routine response. Network analysis and highly discriminatory WGS clarified the protracted nature of the outbreak, supporting findings of hygiene and infection control issues and adding to our understanding of the epidemiology.

Heme Binding to HupZ with a C-Terminal Tag from Group A Streptococcus

HupZ is an expected heme degrading enzyme in the heme acquisition and utilization pathway in Group A Streptococcus. The isolated HupZ protein containing a C-terminal V5-His6 tag exhibits a weak heme degradation activity. Here, we revisited and characterized the HupZ-V5-His6 protein via biochemical, mutagenesis, protein quaternary structure, UV-vis, EPR, and resonance Raman spectroscopies. The results show that the ferric heme-protein complex did not display an expected ferric EPR signal and that heme binding to HupZ triggered the formation of higher oligomeric states. We found that heme binding to HupZ was an O2-dependent process. The single histidine residue in the HupZ sequence, His111, did not bind to the ferric heme, nor was it involved with the weak heme-degradation activity. Our results do not favor the heme oxygenase assignment because of the slow binding of heme and the newly discovered association of the weak heme degradation activity with the His6-tag. Altogether, the data suggest that the protein binds heme by its His6-tag, resulting in a heme-induced higher-order oligomeric structure and heme stacking. This work emphasizes the importance of considering exogenous tags when interpreting experimental observations during the study of heme utilization proteins.

Peptide-Protein Conjugation and Characterization to Develop Vaccines for Group A Streptococcus

Peptide conjugates have been widely used for developing vaccines that prevent common bacterial infections for which peptides alone are either ineffective or provide only short-term protection. Among several carrier proteins, diphtheria toxoid and CRM₁₉₇ (a genetically detoxified diphtheria toxin) are considered safe and have been used in several licensed vaccines. For developing a vaccine against group A streptococcus (GAS), antigens from conserved region of M protein and the IL-8 protease, SpyCEP, have been identified. In this chapter, we describe a method for producing peptide-conjugate subunit GAS vaccines, which involves maleimide conjugation of peptides to a carrier protein and their subsequent characterization.

Effect of Paliperidone Palmitate 3-Month Formulation on Goal Attainment and Disability After 52 Weeks' Treatment in Patients with Clinically Stable Schizophrenia

PURPOSE

This pragmatic clinical study aimed to assess goal attainment among patients with schizophrenia treated with paliperidone palmitate 3-monthly (PP3M) and its relation to their level of disability, and whether patients achieved symptomatic remission at the study endpoint.

PATIENTS AND METHODS

Goal attainment was assessed as a secondary endpoint using Goal Attainment Scaling (GAS) within a 52-week, prospective, single-arm, non-randomized, open-label, international, multicenter study evaluating the impact of transitioning stable patients with schizophrenia from paliperidone palmitate 1-monthly (PP1M) to PP3M. Additional exploratory analyses were performed to investigate the relationship between disability and functioning as measured by the World Health Organization Disability Assessment Schedule (WHODAS), Version 2.0, symptomatic remission, and goal attainment.

RESULTS

Overall, 305 patients were enrolled, of whom 281 (92.1%) provided GAS data at baseline. Of these, 160 achieved symptomatic remission at the last observation carried forward (LOCF) endpoint. The most common category of goals was "self" related, of which work-related was most frequent. Two-thirds of patients (67.7%) achieved at least one goal at the LOCF endpoint. Goal achievement was positively associated with lower baseline symptoms and symptomatic remission at LOCF endpoint, and with lower WHODAS scores at baseline and LOCF endpoint and greater WHODAS score improvements from baseline. Age, duration of disease, and duration of PP1M treatment before the switch did not impact goal setting and goal attainment. The proportion of patients with remunerated work status increased by 11.3% at LOCF endpoint.

CONCLUSION

The results of this secondary endpoint analysis indicate that continued treatment of patients with schizophrenia with PP3M following stabilization with PP1M may facilitate attainment of patients' personal goals and reduce disability, especially, but not exclusively, in patients with symptomatic remission achieved at LOCF.

Gaming addiction, problematic gaming and engaged gaming - Prevalence and associated characteristics

Introduction

Gaming disorder was included in the 11th revision of the International Classification of Diseases (ICD 11) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) included Internet Gaming Disorder as a tentative diagnosis. Most scholars agree upon the potential risk for pathological use of video games. The primary aim of this study was to investigate the prevalence of engaged gamers, problem gamers and addicted gamers. The secondary aim was to describe these groups in terms of gender, age, social satisfaction, psychological wellbeing and hours spent chatting on internet/social media.

Methods

We used survey-based data for this population-based research. The data was collected online in two different settings in 2017. In total 2075 participants were included.

Results

4.5 percent met the criteria for highly engaged gaming, 5.3 percent were shown to be problem gamers and 1.2 percent met the cut off for game addiction. Young age, hours chatting on internet/social media, experiencing loneliness and considering seeking treatment for psychological distress were associated with both engaged, problematic and addictive gaming. Male gender was associated to problematic and addictive gaming. Hours spent chatting showed a greater correlation to problem/addictive gaming than to engaged gaming.

Conclusion

The results of this study indicate that both highly engaged gamers, problem gamers and addicted gamers all experience loneliness and psychological distress to a greater extent than the remaining study participants. This adds to the knowledge of prevalence and features of gaming disorder. Additionally, preferably longitudinal research is needed in order to understand causality.

Disparate Effects of Invasive Group A Streptococcus on Native Americans

Active surveillance of invasive group A Streptococcus (iGAS) disease indicates that its incidence in the US general population is low, but limited studies show rates for American Indians and Alaska Natives (AI/AN) are severalfold higher. Major disparities in rates of iGAS exist between Indigenous and non-Indigenous populations of Australia, New Zealand, and Canada, but much less is understood about iGAS among AI/AN in the United States. Although complex host-pathogen interactions influence the rates of iGAS, including strain variation and virulence, the number and type of concurrent conditions, and socioeconomic status, the relative contribution of each remains unclear. We highlight the poor correlation between the substantial effect of iGAS among Indigenous persons in industrialized countries and the current understanding of factors that influence iGAS disease in these populations. Prospective, large-scale, population-based studies of iGAS are needed that include AI/AN as a necessary first step to understanding the effects of iGAS.

Systematic Review and Meta-analysis of the Prevalence of Group A Streptococcal emm Clusters in Africa To Inform Vaccine Development

Low vaccine coverage is of grave public health concern, particularly in developing countries where epidemiological data are often absent. To inform vaccine development for group A Streptococcus (GAS), we report on the epidemiology of the M protein emm clusters from GAS infections in Africa, where GAS-related illnesses and their sequelae, including rheumatic fever and rheumatic heart disease, are of a high burden. This first report of emm clusters across the continent indicates a high probably of coverage by the M protein-based vaccine currently undergoing testing were an emm-cluster based approach to be used.

An emm-cluster based system was proposed as a standard typing scheme to facilitate and enhance future studies of group A Streptococcus (GAS) epidemiological surveillance, M protein function, and vaccine development strategies. We provide an evidence-based distribution of GAS emm clusters in Africa and assess the potential coverage of the new 30-valent vaccine in terms of an emm cluster-based approach. Two reviewers independently assessed studies retrieved from a comprehensive search and extracted relevant data. Meta-analyses were performed (random-effects model) to aggregate emm cluster prevalence estimates. Eight studies (n = 1,595 isolates) revealed the predominant emm clusters as E6 (18%; 95% confidence interval [CI], 12.6% to 24.0%), followed by E3 (14%; 95% CI, 11.2% to 17.4%) and E4 (13%; 95% CI, 9.5% to 16.0%). There was negligible variation in emm clusters with regard to regions, age, and socioeconomic status across the continent. Considering an emm cluster-based vaccine strategy, which assumes cross-protection within clusters, the 30-valent vaccine currently in clinical development would provide hypothetical coverage to 80.3% of isolates in Africa. This systematic review indicates the most predominant GAS emm cluster in Africa is E6 followed by E3, E4, and D4. The current 30-valent vaccine would provide considerable coverage across the diversity of emm cluster types in Africa. Future efforts could be directed toward estimating the overall potential coverage of the new 30-valent vaccine based on cross-opsonization studies with representative panels of GAS isolates from populations at highest risk for GAS diseases.

IMPORTANCE Low vaccine coverage is of grave public health concern, particularly in developing countries where epidemiological data are often absent. To inform vaccine development for group A Streptococcus (GAS), we report on the epidemiology of the M protein emm clusters from GAS infections in Africa, where GAS-related illnesses and their sequelae, including rheumatic fever and rheumatic heart disease, are of a high burden. This first report of emm clusters across the continent indicates a high probably of coverage by the M protein-based vaccine currently undergoing testing were an emm-cluster based approach to be used.

Is There Emergence of β-Lactam Antibiotic-Resistant Streptococcus pyogenes in China?

Streptococcus pyogenes is regarded as susceptible to β-lactam antibiotics. The guidelines of the Clinical and Laboratory Standards Institute (CLSI) are widely recognized and have long-recommended penicillin for treatment of S. pyogenes infections. There is no CLSI guideline for the treatment of S. pyogenes infections that have intermediate susceptibility or resistance to penicillin. However, there have been several reports of S. pyogenes isolates that are nonsusceptible or even resistant to β-lactam antibiotics, mostly from Chinese journals. The purpose of this commentary is to show data from the literature which suggests the presence of S. pyogenes isolates that are not susceptible to β-lactam antibiotics and whether these strains are really nonsusceptible to β-lactam antibiotics and the presence of mutation in the pbp2x gene requires further research and confirmation.

Molecular epidemiology and antimicrobial resistance of group a streptococcus recovered from patients in Beijing, China

BACKGROUND

Group A streptococcus (GAS) is an important human pathogen responsible for a broad range of infections. Epidemiological surveillance has been crucial to detect changes in the geographical and temporal variation of the disease pattern. The objective of this study was to investigate the molecular epidemiological characteristics and antimicrobial resistance of GAS isolates from patients in Children's Hospital in Beijing.

METHODS

From 2016 to 2017, pharyngeal swab samples were collected from the outpatients in Children's Hospital, Capital Institute of Pediatrics, who were diagnosed with scarlet fever. Antimicrobial susceptibility test was performed according to the distribution of conventional antibiotics and Clinical and Laboratory Standards Institute (CLSI) recommendations. The distribution of the macrolide-resistance genes (ermB, ermA, mefA), emm (M protein-coding gene) typing, and superantigens (SAg) gene profiling were examined by polymerase chain reaction (PCR).

RESULTS

A total of 297 GAS isolates were collected. The susceptibility of the isolates to penicillin, ceftriaxone, and levofloxacin was 100%. The resistance rate to erythromycin and clindamycin was 98.3 and 96.6%, respectively. The dominant emm types were emm12 (65.32%), emm1 (27.61%), emm75 (2.69%), and emm89 (1.35%). Of the 297 isolates, 290 (97.64%) carried the ermB gene, and 5 (1.68%) carried the mefA gene, while none carried the ermA gene. The most common superantigen genes identified from GAS isolates were smeZ (96.97%), speC (92.59%), speG (91.58%), ssa (85.52%), speI (54.55%), speH (52.19%), and speA (34.34%). Isolates with the genotype emm1 possessed speA, speC, speG, speJ, speM, ssa, and smeZ, while emm12 possessed speC, speG, speH, speI, speM, ssa, and smeZ superantigens.

CONCLUSIONS

The prevalent strain of GAS isolates in Beijing has a high resistance rate to macrolides; however, penicillin can still be the preferred antibiotic for treatment. Erythromycin resistance was predominantly mediated by ermB. The common emm types were emm12 and emm1. There was a correlation between emm and the superantigen gene. Thus, long-term monitoring and investigation of the emm types and superantigen genes of GAS prevalence are imperative.

Investigation of Ag/a-C:H Nanocomposite Coatings on Titanium for Orthopedic Applications

One of the leading causes of failure for any bone implant is implant-associated infections. The implant-bone interface is in fact the crucial site of infection where both the microorganisms and cells compete to populate the newly introduced implant surface. Most of the work dealing with this issue has focused on the design of implant coatings capable of preventing infection while ignoring cell proliferation or vice versa. The present study is therefore focused on investigating the antibacterial and biological properties of nanocomposite coatings based on an amorphous hydrocarbon (a-C:H) matrix containing silver nanoparticles (AgNPs). a-C:H coatings with varying silver concentrations were generated directly on medical grade titanium substrates using a combination of a gas aggregation source (GAS) and a plasma-enhanced chemical vapor deposition (PE-CVD) process. The obtained results revealed that the surface silver content increased from 1.3 at % to 5.3 at % by increasing the used DC magnetron current in the GAS from 200 to 500 mA. The in vitro antibacterial assays revealed that the nanocomposites with the highest number of silver content exhibited excellent antibacterial activities resulting in a 6-log reduction of Escherichia coli and a 4-log reduction of Staphylococcus aureus after 24 h of incubation. An MTT assay, fluorescence live/dead staining, and SEM microscopy observations of MC3T3 cells seeded on the uncoated and coated Ti substrates also showed that increasing the amount of AgNPs in the nanocomposites had no notable impact on their cytocompatibility, while improved cell proliferation was especially observed for the nanocomposites possessing a low amount of AgNPs. These controllable Ag/a-C:H nanocomposites on Ti substrates, which simultaneously provide an excellent antibacterial performance and good biocompatibility, could thus have promising applications in orthopedics and other biomedical implants.

Emerging erythromycin and clindamycin resistance in group A streptococci: Efficacy of linezolid and tedizolid in experimental necrotizing infection

OBJECTIVES

Clindamycin (CLI) and erythromycin (ERY) resistance is increasing among group A streptococci (GAS) causing invasive disease and alternative treatments are urgently required. In this study, the efficacy of the newer oxazolidinone tedizolid (TZD) was compared with the first drug in this class, linezolid (LNZ), in experimental murine myonecrosis caused by ERY-susceptible/CLI-susceptible (ERY^S/CLI^S) or ERY- resistant/CLI-resistant (ERY^R/CLI^R) GAS.

METHODS

Normal adult outbred Swiss Webster female mice (10 per group) were infected intramuscularly with ERY^S/CLI^S (ATCC 12384) or ERY^R/CLI^R (15-003) GAS. Treatments began 4 h post-infection and continued for 72 h. TZD and LNZ (10, 20 and 40 mg/kg) were given intraperitoneally every 12 h. Saline, penicillin (PEN), CLI and ERY were given every 6 h. Survival and infection severity signs and symptoms were followed for 12 days.

RESULTS

Both GAS strains were susceptible to LNZ, TZD and PEN; strain 15-003 was confirmed as constitutively resistant to ERY and CLI. Blood levels following a 40 mg/kg dose of LZD and TZD were 30.9 ± 4.0 μg/mL and 21.9 ± 5.3 μg/mL, respectively. Both TZD and LNZ were highly efficacious for the treatment of severe experimental myonecrosis caused by ERY^S/CLI^S and, importantly, ERY^R/CLI^R GAS.

CONCLUSION

In the current era of emerging macrolide/lincosamide resistance among GAS, these data support the use of TZD and LNZ as first-line antibiotics for the treatment of life-threatening GAS infections in humans.

Biphasic Outbreak of Invasive Group A Streptococcus Disease in Eldercare Facility, New Zealand

A 3-month outbreak of invasive group A Streptococcus disease at an eldercare facility, in which 5 persons died, was biphasic. Although targeted chemoprophylaxis contained the initial outbreak, a second phase of the outbreak occurred after infection control processes ended. To retrospectively investigate the genomic epidemiology of the biphasic outbreak, we used whole-genome sequencing and multiple bioinformatics approaches. Analysis of isolates from the outbreak and isolates prospectively collected during the outbreak response indicated a single S. pyogenes emm81 clone among residents and staff members. Outbreak isolates differed from nonoutbreak emm81 isolates by harboring an integrative conjugative genomic element that contained the macrolide resistance determinant erm(TR). This study shows how retrospective high-resolution genomic investigations identified rapid spread of a closed-facilty clonal outbreak that was controlled, but not readily cleared, by infection control management procedures.

LncRNA GAS5 exacerbates renal tubular epithelial fibrosis by acting as a competing endogenous RNA of miR-96-5p

Renal fibrosis is at the core of various renal diseases, including diabetic kidney disease (DKD). Long noncoding RNAs (lncRNAs) are known players in the regulation of renal fibrosis. However, their expression and function in DKD still need to be elucidated. The purpose of this study was to assess how lncRNA GAS5 regulates fibrosis and its mechanism in TGF-β1-treated renal proximal tubular cell.In this study, the lncRNA GAS5 was upregulated in both TGF-β1-treated HK-2 cells and the kidneys of HDF/STZ mice. Knockdown of GAS5 relieved renal tubular epithelial fibrosis. This effect was mediated by the downregulation and functional inactivation of miR-96-5p. Furthermore, miR-96-5p was downregulated in DKD mice, and this downregulation attenuated the repression of FN1(fibronectin, FN) and led to its upregulation. The decrease in miR-96-5p was partially attributed to the miRNA-sponge action of GAS5.Our research demonstrates that knockdown of lncRNA GAS5 leads to antifibrosis by competitively binding miR-96-5p, which inhibits the expression of FN1. These results indicate that targeting lncRNA GAS5 may be a promising therapeutic strategy for preventing DKD.

A novel genomic island harbouring lsa(E) and lnu(B) genes and a defective prophage in a Streptococcus pyogenes isolate resistant to lincosamide, streptogramin A and pleuromutilin antibiotics

A lincosamide-resistant and macrolide-susceptible phenotype has not been described to date in Streptococcus pyogenes [group A streptococcus (GAS)]. The aim of this study was to characterize a GAS isolate susceptible to macrolides but resistant to lincosamide, streptogramin A and pleuromutilin antibiotics. Antimicrobial susceptibility was tested using the microdilution broth method and the resistance phenotype was tested by D-test. The GAS2887HUB isolate was subjected to whole-genome sequencing. The isolate showed a positive Gots' test (clindamycin inactivation). Whole-genome sequencing revealed that the strain was ST10 and emm93, and had five resistance genes [lnu(B), ant(6)-Ia, aph(3')-III, tet(M) and dfrG]. The tet(M) gene was located in a Tn916-like transposon. The lsa(E)-lnu(B)-containing sequence (inserted downstream of the rumA gene) was formed by a 39.6-kb prophage, followed by a gene cluster encoding aminoglycoside-streptothricin resistance [ant(6)Ia-sat4-aph(3')III] and lsa(E)-lnu(B) genes. This structure was not transferred by conjugation. This study identified a new genetic element carrying a determinant of lincosamide resistance in a GAS. Further molecular epidemiological surveys are needed to determine the prevalence of this mechanism of resistance in GAS.

Evaluation of Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry and ClinPro Tools as a Rapid Tool for Typing Streptococcus pyogenes

Background

Timely strain typing of group A Streptococci (GAS) is necessary to guide outbreak recognition and investigation. We evaluated the use of (matrix-assisted laser desorption ionization time-of-flight mass spectrometry) combined with cluster analysis software to rapidly distinguish between related and unrelated GAS isolates in real-time.

Methods

We developed and validated a typing model using 177 GAS isolates with known emm types. The typing model was created using 43 isolates, which included 8 different emm types, and then validated using 134 GAS isolates of known emm types that were not included in model generation.

Results

Twelve spectra were generated from each isolate during validation. The overall accuracy of the model was 74% at a cutoff value of 80%. The model performed well with emm types 4, 59, and 74 but showed poor accuracy for emm types 1, 3, 12, 28, and 101. To evaluate the ability of this tool to perform typing in an outbreak situation, we evaluated a virtual outbreak model using a “virtual outbreak strain; emm74” compared with a non-outbreak group or an “outgroup “ of other emm types. External validation of this model showed an accuracy of 91.4%.

Conclusions

This approach has the potential to provide meaningful information that can be used in real time to identify and manage GAS outbreaks. Choosing isolates characterized by whole genome sequencing rather than emm typing for model generation should improve the accuracy of this approach in rapidly identifying related and unrelated GAS strains.