Search

Purpose: The incidence of invasive Streptococcus dysgalactiae subsp. equisimilis (iSDSE) infections is increasing in developed countries, but studies on the risk factors for death in iSDSE infections are scant. Here, we aimed to clarify risk factors and predictors of mortality in adults with iSDSE infections. Methods: A multicentre observational study of adults with iSDSE infections was conducted to investigate the effects of host factors, disease severity, biomarkers, and antibiotic regimens, and bacterial factors on 28-day mortality. Results: The overall mortality rate of 588 patients was 10.4%, with a significant increase in those aged ≥ 60 years. Most of the patients (97.4%) had underlying diseases. The mortality rate (70.4%) of patients with severe disease was significantly higher than that of patients with mild-to-moderate disease (4.3%; p < 0.001). The risk factors for death identified using multivariable analysis were age ≥ 60 years (hazard ratio [HR], 3.4; 95% confidence interval [CI], 1.0–11.3, p = 0.042); severe disease (HR, 15.0; 95% CI 7.7–29.2, p < 0.001); bacteraemia without primary focus (HR, 20.5; 95% CI 2.8–152.3, p = 0.003); serum creatinine ≥ 2.0 mg/dL (HR, 2.2; 95% CI 1.2–4.0, p = 0.010); serum creatine kinase ≥ 300 IU/L (HR, 2.1; 95% CI 1.1–3.8, p = 0.019); and macrolide resistance (HR, 1.8; 95% CI 1.0–3.3, p = 0.048). Treatment regimens and emm types were not associated with poor outcomes. Conclusion: Evaluation of clinical manifestations and biomarkers on admission is important to predict invasive SDSE infection prognosis. [ABSTRACT FROM AUTHOR]

Purpose: Hypertoxigenic Streptococcus pyogenes emm1 lineage M1UK has recently been associated with upsurges of invasive infections and scarlet fever in several countries, but whole-genome sequencing surveillance data of lineages circulating in Germany is lacking. In this study, we investigated recent iGAS isolates from our laboratory at a German tertiary care center for the presence of the M1UK lineage. Methods: Whole-genome sequencing was employed to characterize a collection of 47 consecutive non-copy isolates recovered from blood cultures (21) and tissue samples (26) in our laboratory between October 2022 and April 2023. Results: M protein gene (emm) typing distinguished 14 different emm types, with emm1 (17) being the dominant type. Single-nucleotide polymorphism (SNP) analysis confirmed the presence of all 27 SNPs characteristic for the M1UK lineage in 14 of 17 emm1 isolates. Conclusion: This study has shown for the first time that M1UK is present in Germany and might constitute a driving force in the observed surge of GAS infections. This observation mirrors developments in the UK and other countries and underscores the importance of WGS surveillance to understand the epidemiology of GAS. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

High-level levofloxacin-resistant group A Streptococcus emerged in Taiwan in 2012. Among the 24 isolates identified, 23 belonged to emm12/ST36, most harbored the same GyrA and ParC mutations and were highly clonal. wgMLST showed them to be closely related to the Hong Kong scarlet fever outbreak strains. Continuous surveillance is warranted.

Abstract Background Group A streptococcus is human-restricted gram-positive pathogen, responsible for various clinical presentations from mild epidermis infections to life threatened invasive diseases. Under COVID-19 pandemic,. the characteristics of the epidemic strains of GAS could be different. Purpose To investigate epidemiological and molecular features of isolates from GAS infections among children in Beijing, China between January 2020 and December 2021. Antimicrobial susceptibility profiling was performed based on Cinical Laboratory Sandards Institute. Distribution of macrolide-resistance genes, emm types, and superantigens was examined by polymerase chain reaction. Results 114 GAS isolates were collected which were frequent resistance against erythromycin (94.74%), followed by clindamycin (92.98%), tetracycline (87.72%). Emm12 (46.49%), emm1 (25.44%) were dominant emm types. Distribution of ermB, ermA, and mefA gene was 93.85%, 2.63%, and 14.04%, respectively. Frequent superantigenes identified were smeZ (97.39%), speG (95.65%), and speC (92.17%). Emm1 strains possessed smeZ, ssa, and speC, while emm12 possessed smeZ, ssa, speG, and speC. Erythromycin resistance was predominantly mediated by ermB. Scarlet fever strains harbored smeZ (98.81%), speC (94.05%). Impetigo strains harbored smeZ (88.98%), ssa (88.89%), and speC (88.89%). Psoriasis strains harbored smeZ (100%). Conclusions Under COVID-19 pandemic, our collections of GAS infection cutaneous diseases decreased dramatically. Epidemiological analysis of GAS infections among children during COVID-19 pandemic was not significantly different from our previous study. There was a correlation among emm, superantigen gene and disease manifestations. Long-term surveillance and investigation of emm types and superantigens of GAS prevalence are imperative.

Beginning in October 2022, we observed a substantial increase in the total number of cases of invasive group A Streptococcus (GAS) disease in the pediatric population in Houston, Texas. Emm12 GAS strains were disproportionately represented but the overall proportion of invasive GAS infections observed during the current spike was similar to prepandemic years. [ABSTRACT FROM AUTHOR]

Assess the incidence, risk factors, clinical and microbiological features, and outcome of both probable invasive and invasive group A Streptococcus (GAS) infections in children and adults in the BrusselsCapital Region between 2005 and 2020. A retrospective, multicentric study was performed in three university hospitals in Brussels. Patients were identified through the centralized laboratory information system. Epidemiological and clinical data were collected from patients' hospital records. A total of 467 cases were identified. Incidence has increased from 2.1 to 10.9/100,000 inhabitants between 2009 and 2019 in non-homeless adults while it was above 100/100,000 on homeless in years with available denominators. Most of GAS were isolated from blood (43.6%), and the most common clinical presentation was skin and soft tissue infections (42.8%). A third of all the patients needed surgery, a quarter was admitted to the intensive care unit, and 10% of the adult patients died. Wounds and chickenpox disease were the main risk factors for children. Tobacco, alcohol abuse, wounds or chronic skin lesion, being homeless, and diabetes were identified as major predisposing factors for adults. The most common emm clusters were D4, E4, and AC3; 64% of the isolates were theoretically covered by the 30-valent M-protein vaccine. The burden of invasive and probable invasive GAS infections is on the rise in the studied adult population. We identified potential interventions that could contribute to decrease this burden: appropriate care of wounds, specifically among homeless and patients with risk factors such as diabetes and systematic chickenpox vaccination for children. [ABSTRACT FROM AUTHOR]

(1) Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an important β-hemolytic pathogen historically described as mainly affecting animals. Studies epidemiologically assessing the pathogenicity in the human population in Germany are rare. (2) Methods: the present study combines national surveillance data from 2010 to 2022 with a single-center clinical study conducted from 2016 to 2022, focusing on emm type, Lancefield antigen, antimicrobial resistance, patient characteristics, disease severity, and clinical infection markers. (3) Results: The nationwide reported invasive SDSE infections suggest an increasing infection burden for the German population. One particular emm type, stG62647, increased over the study period, being the dominant type in both study cohorts, suggesting a mutation-driven outbreak of a virulent clone. The patient data show that men were more affected than women, although in the single-center cohort, this trend was reversed for patients with stG62647 SDSE. Men affected by stG62647 developed predominantly fascial infections, whereas women suffering from superficial and fascial non-stG62647 SDSE infections were significantly younger than other patients. Increasing age was a general risk factor for invasive SDSE infections. (4) Conclusions: further studies are needed to further elucidate the raised questions regarding outbreak origin, underlying molecular mechanisms as well as sex-dependent pathogen adaptation. [ABSTRACT FROM AUTHOR]

ABSTRACT: Objectives: This study aimed to investigate the annual incidence, molecular epidemiological characteristics, and antimicrobial resistance of group A Streptococcus (GAS) clinical isolates from paediatric patients at Shenzhen Children's Hospital during 2016–2020. Methods: Clinical samples were collected from paediatric patients with a suspected diagnosis of GAS infections. We studied the annual incidence and characteristics of GAS infections using the GAS antigen detection method. Additionally, 250 GAS isolates were randomly selected for genotyping of the emm gene, and antimicrobial susceptibility assay was performed using the Kirby-Bauer paper dispersion strategy. Results: Among 43 593 collected samples, 9313 were positive for the GAS antigen. The main emm type was emm12, followed by emm1, emm6, and emm 4, which were used for distinguishing 90% of the scarlet fever isolated strains. The percentage of emm1 increased from 36% in 2016 to 44% in 2019, whereas the percentage of emm12 decreased from 62% to 50%. Several unusual emm types isolated from scarlet fever patients showed an increase in proportions from 2016 to 2020. These GAS isolates were sensitive to penicillin, ceftriaxone, and vancomycin and were highly resistant to erythromycin and clindamycin. Conclusion: There was a high incidence of GAS infections during 2016–2020 in Shenzhen, China. The GAS isolates had a high resistance rate to erythromycin and clindamycin; penicillin was the antibiotic of choice for GAS infections. The common emm types were emm12 and emm1. Future studies should investigate the clonal structure and superantigen profiles of the population of GAS isolates associated with scarlet fever.

BackgroundThe recent increase of group A Streptococcus (GAS) infections in Europe has aroused global concern. We aim to provide molecular biological data for GAS prevention and control in China by analyzing the temporal shift of emm type.MethodsWe collected studies reporting GAS emm types in China from 1990 to 2020 by PRISMA statement and established a summary database including emm types and literature quality assessment. Based on the database we analyzed the geographic distribution of emm types from 1990 to 2020 and assessed the coverage of the known GAS 30-valent vaccine. Outbreak-associated emm types that had been reported over the past 30 years were also included.Results47 high quality studies were included for a systematic analysis of emm type distribution. This generated a database including totally 12,347 GAS isolates and 85 emm types. Shift of dominant emm type was witnessed during the past 30 years in China. In mainland China, dominant types changed from emm3, emm1, emm4, emm12 in 1990s to emm12 and emm1 in 2000s and 2010s. Hong Kong and Taiwan were dominated by emm12, emm4 and emm1, of which emm4 reduced but emm12 increased in 2010s significantly. From 1990 to 2020, newly found emm types were increasingly reported in various regions of China. The reported 30-valent M protein vaccine covered 26 M types prevalent in China, including all dominant types.

Background: Group A streptococcus is human-restricted gram-positive pathogen, responsible for various clinical presentations from mild epidermis infections to life threatened invasive diseases. Under COVID-19 pandemic,. the characteristics of the epidemic strains of GAS could be different. Purpose: To investigate epidemiological and molecular features of isolates from GAS infections among children in Beijing, China between January 2020 and December 2021. Antimicrobial susceptibility profiling was performed based on Cinical Laboratory Sandards Institute. Distribution of macrolide-resistance genes, emm types, and superantigens was examined by polymerase chain reaction. Results: 114 GAS isolates were collected which were frequent resistance against erythromycin (94.74%), followed by clindamycin (92.98%), tetracycline (87.72%). Emm12 (46.49%), emm1 (25.44%) were dominant emm types. Distribution of ermB, ermA, and mefA gene was 93.85%, 2.63%, and 14.04%, respectively. Frequent superantigenes identified were smeZ (97.39%), speG (95.65%), and speC (92.17%). Emm1 strains possessed smeZ, ssa, and speC, while emm12 possessed smeZ, ssa, speG, and speC. Erythromycin resistance was predominantly mediated by ermB. Scarlet fever strains harbored smeZ (98.81%), speC (94.05%). Impetigo strains harbored smeZ (88.98%), ssa (88.89%), and speC (88.89%). Psoriasis strains harbored smeZ (100%). Conclusions: Under COVID-19 pandemic, our collections of GAS infection cutaneous diseases decreased dramatically. Epidemiological analysis of GAS infections among children during COVID-19 pandemic was not significantly different from our previous study. There was a correlation among emm, superantigen gene and disease manifestations. Long-term surveillance and investigation of emm types and superantigens of GAS prevalence are imperative. [ABSTRACT FROM AUTHOR]

Background: This work reports on antimicrobial resistance data for invasive Streptococcus pyogenes in Spain, collected by the 'Surveillance Program for Invasive Group A Streptococcus', in 2007–2020. Methods: emm typing was determined by sequencing. Susceptibility to penicillin, tetracycline, erythromycin, and clindamycin was determined via the E-test. tetM, tetO, msrD, mefA, ermB, ermTR, and ermT were sought by PCR. Macrolide-resistant phenotypes (M, cMLSB, and iMLSB) were detected using the erythromycin–clindamycin double-disk test. Resistant clones were identified via their emm type, multilocus sequence type (ST), resistance genotype, and macrolide resistance phenotype. Results: Penicillin susceptibility was universal. Tetracycline resistance was recorded for 237/1983 isolates (12.0%) (152 carried only tetM, 48 carried only tetO, and 33 carried both). Erythromycin resistance was detected in 172/1983 isolates (8.7%); ermB was present in 83, mefA in 58, msrD in 51, ermTR in 46, and ermT in 36. Clindamycin resistance (methylase-mediated) was present in 78/1983 isolates (3.9%). Eight main resistant clones were identified: two that were tetracycline-resistant only (emm22/ST46/tetM and emm77/ST63/tetO), three that were erythromycin-resistant only (emm4/ST39/mefA-msrD/M, emm12/ST36/mefA-msrD/M, and emm28/ST52/ermB/cMLSB), and three that were tetracycline–erythromycin co-resistant (emm11/ST403/tetM-ermB/cMLSB, emm77/ST63/tetO-ermTR/iMLSB, and emm77/ST63/tetM-tetO-ermTR/iMLSB). Conclusions: Tetracycline, erythromycin, and clindamycin resistance rates declined between 2007 and 2020. Temporal variations in the proportion of resistant clones determined the change in resistance rates. [ABSTRACT FROM AUTHOR]

ABSTRACT The human pathogen Streptococcus pyogenes causes substantial morbidity and mortality. It is unclear if antibodies developed after infections with this pathogen are opsonic and if they are strain specific or more broadly protective. Here, we quantified the opsonic-antibody response following invasive S. pyogenes infection. Four patients with S. pyogenes bacteremia between 2018 and 2020 at Skåne University Hospital in Lund, Sweden, were prospectively enrolled. Acute- and convalescent-phase sera were obtained, and the S. pyogenes isolates were genome sequenced (emm118, emm85, and two emm1 isolates). Quantitative antibody binding and phagocytosis assays were used to evaluate isolate-dependent opsonic antibody function in response to infection. Antibody binding increased modestly against the infecting isolate and across emm types in convalescent- compared to acute-phase sera for all patients. For two patients, phagocytosis increased in convalescent-phase serum both for the infecting isolate and across types. The increase was only across types for one patient, and one had no improvement. No correlation to the clinical outcomes was observed. Invasive S. pyogenes infections result in a modestly increased antibody binding with differential opsonic capacity, both nonfunctional binding and broadly opsonic binding across types. These findings question the dogma that an invasive infection should lead to a strong type-specific antibody increase rather than a more modest but broadly reactive response, as seen in these patients. Furthermore, our results indicate that an increase in antibody titers might not be indicative of an opsonic response and highlight the importance of evaluating antibody function in S. pyogenes infections. IMPORTANCE The bacterium Streptococcus pyogenes is a common cause of both mild and severe human diseases resulting in substantial morbidity and mortality each year. No vaccines are available, and our understanding of the antibody response to this human pathogen is still incomplete. Here, we carefully analyzed the opsonic antibody response following invasive infection in four patients. Unexpectedly, the patients did not always generate opsonic antibodies against the specific infecting strain. Instead, we found that some patients could generate cross-opsonic antibodies, leading to phagocytosis of bacteria across strains. The emergence of cross-opsonic antibodies is likely important for long-term immunity against S. pyogenes. Our findings question the dogma that mostly strain-specific immunity is developed after infection and add to our overall understanding of how immunity to S. pyogenes can evolve.

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.

(1) Background: Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an important β-hemolytic pathogen historically described as mainly affecting animals. Studies epidemiologically assessing the pathogenicity in the human population in Germany are rare. (2) Methods: the present study combines national surveillance data from 2010 to 2022 with a single-center clinical study conducted from 2016 to 2022, focusing on emm type, Lancefield antigen, antimicrobial resistance, patient characteristics, disease severity, and clinical infection markers. (3) Results: The nationwide reported invasive SDSE infections suggest an increasing infection burden for the German population. One particular emm type, stG62647, increased over the study period, being the dominant type in both study cohorts, suggesting a mutation-driven outbreak of a virulent clone. The patient data show that men were more affected than women, although in the single-center cohort, this trend was reversed for patients with stG62647 SDSE. Men affected by stG62647 developed predominantly fascial infections, whereas women suffering from superficial and fascial non-stG62647 SDSE infections were significantly younger than other patients. Increasing age was a general risk factor for invasive SDSE infections. (4) Conclusions: further studies are needed to further elucidate the raised questions regarding outbreak origin, underlying molecular mechanisms as well as sex-dependent pathogen adaptation.

Group A streptococcal or Streptococcus pyogenes infections have been increasing post-COVID-19 pandemic. We describe the epidemiology of S. pyogenes pharyngitis and invasive disease in Alberta, Canada 2018-2023. Positive pharyngitis specimens were identified from throat swabs collected from pharyngitis patients. Invasive S. pyogenes was defined as the isolation of S. pyogenes from a normally sterile site or severe skin infection. S. pyogenes isolates were emm typed. Pharyngitis and invasive disease displayed seasonal trends preceding the COVID-19 pandemic followed by a sharp decrease during COVID-19 intervention measures. After the lifting of interventions, rates of pharyngitis and invasive disease rose. There were 182 983 positive pharyngitis specimens between 2018 and 2023 for a positivity rate of 17.6%. The highest rates occurred in the 0-9 age group in 2023 (41.5%). Invasive disease increased in 2022-2023 driven by emm 1 and 12 types. M1 UK strain was the most frequent M1 type associated with invasive disease (59% of M1 isolates sequenced). Notably, out of 182 983 pharyngitis cases, there were 111 cases of invasive S. pyogenes detected for an invasive disease rate of 0.06%. This descriptive epidemiology of S. pyogenes pharyngitis and invasive S. pyogenes disease highlights the rapid increase in cases of S. pyogenes occurring in western Canada and illustrates the critical need for a vaccine.

Streptococcus pyogenes is a bacterial pathogen that causes a wide spectrum of clinical diseases exclusively in humans. The distribution of emm type, antibiotic resistance and virulence gene expression for S. pyogenes varies temporally and geographically, resulting in distinct disease spectra. In this study, we analyzed antibiotic resistance and resistance gene expression patterns among S. pyogenes isolates from pediatric patients in China and investigated the relationship between virulence gene expression, emm type, and disease categories. Forty-two representative emm 1.0 and emm 12.0 strains (n = 20 and n = 22, respectively) isolated from patients with scarlet fever or obstructive sleep apnea-hypopnea syndrome were subjected to whole-genome sequencing and phylogenetic analysis. These strains were further analyzed for susceptibility to vancomycin. We found a high rate and degree of resistance to macrolides and tetracycline in these strains, which mainly expressed ermB and tetM. The disease category correlated with emm type but not superantigens. The distribution of vanuG and virulence genes were associated with emm type. Previously reported important prophages, such as φHKU16.vir, φHKU488.vir, Φ5005.1, Φ5005.2, and Φ5005.3 encoding streptococcal toxin, and integrative conjugative elements (ICEs) such as ICE-emm12 and ICE-HKU397 encoding macrolide and tetracycline resistance were found present amongst emm 1 or emm 12 clones from Shenzhen, China. [ABSTRACT FROM AUTHOR]

Introduction: Biofilm is one of the important virulence factors that is responsible for the severity and progression of the Streptococcus pyogenes diseases. M-protein is involved in the irreversible attachment of S. pyogenes to surfaces during biofilm development. This study aims to determine the propensity of S. pyogenes to form biofilms and the molecular epidemiology of S. pyogenes isolates by emm typing. Methods: We screened 45 S. pyogenes isolates for the biofilm formation by Congo red agar (CRA) and quantified the biofilms by crystal violet microtiter-plate methods (CVMtP). The emm typing of all isolates was performed by conventional PCR with established primers according to the CDC protocol. Results: Majorities of S. pyogenes were isolated from non-invasive, 27 (60.0%) than invasive sources, 18 (40.0%). Regardless of invasiveness, 40 (88.9%) S. pyogenes isolates formed black colonies on CRA, while 43 (95.6%) of the isolates demonstrated various degrees of biofilm formation by CVMtP method. A total of 30 different emm types and subtypes were identified. No new emm types/subtypes were detected. The predominant emm types/subtypes were emm1, emm63, emm18.21, emm91, and emm97.4 which each gene accounted for 7.0%. All emm types/subtypes of S. pyogenes produced biofilms by CVMtP method except emm17.2 and emm57 which were isolated from non-invasive sources. Conclusions: Biofilm-producing S. pyogenes strains of various sources are genetically diverse and biofilm phenotypes are inherent to individual characteristic rather than specific emm type. Nonetheless, higher propensity of GAS to form biofilms warrants better management strategies to avoid treatment failures in the future. [ABSTRACT FROM AUTHOR]

IntroductionStreptococcus dysgalactiae can cause severe recurrent infections. This study aimed to investigate antibody responses following S. dysgalactiae bacteraemia and possible development of protective immunity.Materials and MethodsPatients with S. dysgalactiae bacteraemia in the county of Skåne between 2017 and 2018 were prospectively included. Acute and convalescent sera were obtained. All isolates were emm typed and enzyme-linked immunosorbent assay (ELISA) was utilised to analyse specific antibody responses to bacteria and antigens. Bactericidal- and phagocytosis assays were applied to further establish antibody function.ResultsSixteen patients with S. dysgalactiae bacteraemia were included of whom one had recurrent episodes of bacteraemia. Using ELISA with S. dysgalactiae isolates and mutants, development of IgG antibodies was demonstrated in few patients. Type-specific antibodies were demonstrated in one patient when recombinant M proteins as antigens, were applied. The type-specific serum mediated a small increase in phagocytosis but did not facilitate increased killing of the S. dysgalactiae isolate, carrying that M protein, in blood or by phagocytic cells.ConclusionS. dysgalactiae bacteraemia sometimes results in increased levels of antibodies to the infecting pathogen. We did not find evidence that these antibodies are effectively opsonising. Apparent failure to produce opsonising antibodies might partially explain why S. dysgalactiae can cause recurrent invasive infections in the same host.

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and puerperal sepsis and shows high mortality. Its primary cause is group A streptococcus (GAS, Streptococcus pyogenes). In this study, we genotyped the cell-surface M virulence protein gene (emm) from 621 GAS isolates obtained from patients with STSS in Japan in 2013–2018 and performed antimicrobial susceptibility testing using the broth microdilution method. The predominant emm type was found to be 1, followed by 89, 12, and 3, which were identified in more than 70 % of STSS isolates. The proportions of emm3 and emm89 increased from 2.4 % and 12.0 %, respectively, during 2010–2012 to 5.6 % and 23.3 % during 2013–2018. In contrast, the proportion of emm1 decreased from 60.6 % to 39.3 % during the same two periods. Some emm types showed increasing proportions and were not isolated from patients with STSS in 2010–2012. Among these, an emm76 type increased in prevalence and was not included in the 30-valent M protein-based vaccine. Continual investigation of changes in the epidemiology of GAS which causes STSS can provide useful monitoring information such as future vaccination strategies and the emergence status of antimicrobial-resistant bacteria.

The purpose of this study was to characterize the antibiotic resistance, virulence, and genetic diversity among invasive and non-invasive Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates. SDSE were isolated from clinical samples of outpatients and inpatients cares in La Rioja region (Spain) during 2012–2015. The analyses performed were susceptibility testing by disc diffusion, resistance and virulence genes by PCR, emm typing by PCR and sequencing, and other molecular typing by SmaI-PFGE and MLST. Forty-two SDSE isolates were recovered (64.3% non-invasive, 35.7% invasive) that were grouped in 31 PFGE patterns, 17 ST, and 14 emm types, being stC1400, stG6792, and stG62647 the most frequent, and stC74a and stC5345 exclusive in invasive SDSE. Twenty-one SDSE were resistant to at least one antibiotic. The erm(TR) and erm(B) genes were linked with resistance to macrolides; tet(M) and tet(T) to tetracycline; dfrF to trimethoprim; ant(6)-Ia and aph(3′)-IIIa to aminoglycosides; and the substitutions Asp80Ala in GyrA and Ser79Phe in ParC with resistance to levofloxacin. The sagA, slo, scpA, and ska virulence genes were amplified in 93% SDSE. Streptococcal superantigenic speGdys gene was identified in 80% of invasive and 63% of non-invasive SDSE and correlated with certain emm types (e.g., stG62647 or stG6792). SDSE invasive infections were most frequent in elderly patients, and half of our SDSE were resistant to at least one antibiotic tested. This work is the first detection of tet(T), dfrF, and new substitution in GyrA protein in SDSE. A high diversity of circulating genetic lineages was found among our SDSE. [ABSTRACT FROM AUTHOR]

Introduction: Streptococcus dysgalactiae can cause severe recurrent infections. This study aimed to investigate antibody responses following S. dysgalactiae bacteraemia and possible development of protective immunity. Materials and Methods: Patients with S. dysgalactiae bacteraemia in the county of Skåne between 2017 and 2018 were prospectively included. Acute and convalescent sera were obtained. All isolates were emm typed and enzyme-linked immunosorbent assay (ELISA) was utilised to analyse specific antibody responses to bacteria and antigens. Bactericidal- and phagocytosis assays were applied to further establish antibody function. Results: Sixteen patients with S. dysgalactiae bacteraemia were included of whom one had recurrent episodes of bacteraemia. Using ELISA with S. dysgalactiae isolates and mutants, development of IgG antibodies was demonstrated in few patients. Type-specific antibodies were demonstrated in one patient when recombinant M proteins as antigens, were applied. The type-specific serum mediated a small increase in phagocytosis but did not facilitate increased killing of the S. dysgalactiae isolate, carrying that M protein, in blood or by phagocytic cells. Conclusion: S. dysgalactiae bacteraemia sometimes results in increased levels of antibodies to the infecting pathogen. We did not find evidence that these antibodies are effectively opsonising. Apparent failure to produce opsonising antibodies might partially explain why S. dysgalactiae can cause recurrent invasive infections in the same host. [ABSTRACT FROM AUTHOR]

Abstract Background Infective endocarditis (IE) is defined as endocarditis caused by microorganisms (bacteria or fungi) involving either the heart or great vessels. The clinical course of IE can be complicated by cardiac dysfunction and bacterial embolization to virtually any organ. Staphylococcus aureus and viridans group streptococci are the most common causative organisms, whereas group A Streptococcus (GAS) is less common. Although some GAS serotypes have been associated with severe disease, there are few reports of IE associated with GAS serotypes. Here, we report two cases of GAS endocarditis and review the associated literature. Case presentations Patient 1 was a previously healthy 14-year-old girl who developed bacteremia and disseminated intravascular coagulation secondary to left foot cellulitis. She was administered intravenous antibiotics. Two of three blood cultures grew Streptococcus pyogenes (T6 M6, emm6.104). Three days later, a new systolic ejection murmur was heard and echocardiography showed mitral regurgitation with mitral valve vegetation. Because of the resultant severity of the mitral regurgitation, she underwent mitral valve repair after 10 weeks of antibiotic treatment. Patient 2 was a 17-month old boy who presented with a fever. He had a history of spontaneous closure of a ventricular septal defect (VSD). He was started on intravenous antibiotics for possible bacteremia. Two consecutive blood cultures with an interval of more than 12 h grew S. pyogenes (T4 M4, emm4.0). Five days later, echocardiography showed vegetation on a membranous ventricular septal aneurysm. The patient responded well to antibiotics, and recovered fully with no complications. Conclusions Although both patients developed GAS endocarditis, patient 1 did not have any predisposing conditions for IE, and patient 2 had a only a low-risk predisposing condition, a VSD that had closed spontaneously at five months of age. We found twelve reports in the literature of GAS endocarditis with information on serotypes. All patients in these reports had GAS endocarditis caused by serotypes generally associated with milder infections, but no specific risk trends were identified. A greater accumulation of cases is necessary to more clearly elucidate the association between GAS IE and specific serotypes.

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. [ABSTRACT FROM AUTHOR]

In England, notifications of invasive group A streptococcal (iGAS) infections have increased since 2015. We describe time trends, risk factors, as well as clinical and infection characteristics amongst iGAS cases in North West England, focussing on people who inject drugs (PWIDs), prisoners and homeless populations (referred to as risk groups), and analyse factors for fatal infection. The study design used was a cross-sectional study. Data for all iGAS cases notified to Public Health England North West between January 2016 and May 2019 were used. Analysis consisted of time trend analysis, descriptive statistics, hypothesis testing to investigate differences in clinical and infection characteristics between risk and non-risk groups and binary logistic regression to identify factors associated with fatal infection. There were 1353 cases. Two hundred and two were amongst risk groups, who were predominantly PWIDs in Greater Manchester. Soft tissue risk factors were widespread. There were differences in strain-type between risk and non-risk groups. Female gender, cancer, emm 1.0 and emm 5.23 were associated with increased odds of death, whilst cellulitis was associated with reduced odds. The relationship between age and death was U-shaped. iGAS has increased in North West England since 2016, including amongst PWIDs. This may be due to emm -type replacement, barriers to good hygiene and increasing colonisation. • Incidence of invasive group A streptococcal has increased across North West England since 2016. • This has been across the general population and amongst people who inject drugs (PWIDs). • Skin lesions and soft tissue infections were common risk factors across all patients. • There were significant differences in strain types between PWIDs and non-PWIDs. • Factors associated with fatal infection have been identified. [ABSTRACT FROM AUTHOR]

The annual rates of group A Streptococcus bacteremia per 100 000 children in southern Israel declined after introduction of the varicella vaccine to the national immunization program, from 2.43 (95% confidence interval, 1.73–3.13) in 1995–2002 to 1.30 (95% confidence interval, 0.91–1.72) in 2010–2016 (P =.04). This reduction correlated with the disappearance of varicella rash as a predisposing factor. [ABSTRACT FROM AUTHOR]

Background Bacterial infections caused by group A Streptococcus (GAS) are common in childhood. Few study reports have provided data on pediatric-specific trends in the epidemiology and bacterial strain characteristics of GAS infections. Methods We prospectively collected GAS isolates from the clinical microbiology laboratory at Texas Children's Hospital between July 1, 2013, and June 30, 2017. Patient characteristics and GAS disease categories were determined through chart review. GAS isolates were obtained from patients in either the inpatient or outpatient setting, and cases were defined as pharyngeal disease, skin and soft-tissue infection (SSTI), or invasive disease on the basis of predefined criteria. All isolates were emm typed to determine trends over time. Results We identified 930 cases over the 4-year period, including 432 (46.4%) pharyngeal, 235 (25.3%) SSTI, and 263 (28.3%) invasive disease types. The most frequently encountered emm types were emm1 (21.4%), emm12 (15.7%), emm89 (14.6%), emm4 (9.2%), and emm3 (8.2%). We observed significant changes over the 4-year period in the relative frequency of infections caused by emm1 (−17.7%; P =.046), emm4 (8.7%; P =.023), or emm6 (−7.9%; P =.024). Using bioinformatic analyses and targeted gene sequencing, we also discovered that all GAS emm28 and emm87 types harbored mutations that rendered them incapable of producing capsule. The relative frequency of GAS disease cases caused by capsule-negative GAS emm types (emm4 , emm22 , emm28 , emm87 , and emm89) increased over the 4-year period (32.2%–44.4%), although the difference was statistically significant for only nonpharyngeal disease types (27.1%–43.9%; P =.038). Conclusions Our data suggest an evolving epidemiology of GAS in the Houston pediatric population characterized by an increase in the frequency of capsule-negative emm types. [ABSTRACT FROM AUTHOR]

We report here 18 cases of pediatric group A streptococcal toxic shock syndrome, associated clinical findings, and bacterial molecular genetic characteristics discovered through whole-genome sequencing. This comparative whole-genome sequencing revealed unique gene content (speK) and polymorphisms (dpiB) in emm 87 group A Streptococcus , the relative contributions of which, in combination with the host response, in the development of streptococcal toxic shock syndrome remain to be elucidated. [ABSTRACT FROM AUTHOR]

Globally, Streptococcus pyogenes poses a continuous burden on human health, causing both self-limiting and life-threatening diseases. Therefore, studying the profile of virulence genes and their combinations is essential to monitor the epidemiology and pathogenic potential of this important species. Thus, the aim of this study was to analyze related genetic features of clinical strains collected in Italy in 2012 in order to obtain a valid picture of their virulence profile that could be compared to similar studies made in other countries approximately in the same period. We conducted emm typing and fibronectin-collagen-T antigen (FCT) region typing in 122 Streptococcus pyogenes strains. Furthermore, several additional virulence genes were screened by polymerase chain reaction. We found correlations between emm types and FCT region profiles. emm1 strains were mainly associated with FCT2 and FCT6, while emm89 and emm12 strains were associated with FCT4. FCT5 was mainly represented in emm4, emm6, and emm75 strains. Significantly, we defined subtypes for each FCT type based on the differences in single and double loci compared to the reference scheme used for the classification of the FCT region. In addition, new FCT-region variants with differences in multiple loci were also recorded. Cluster analysis based on virulence gene profiling showed a non-random distribution within each emm type. This study added new data to existing studies conducted worldwide and revealed new variability scores in circulating Streptococcus pyogenes strains and new assortments in well-established virulence gene signatures.

We collected β-hemolytic streptococci (1,611 isolates) from patients with invasive streptococcal infections in Japan during April 2010–March 2013. Streptococcus dysgalactiae subsp. equisimilis (SDSE) was most common (n = 693); 99% of patients with SDSE infections were elderly (mean age 75 years, SD ±15 years). We aimed to clarify molecular and epidemiologic characteristics of SDSE isolates and features of patient infections. Bacteremia with no identified focus of origin and cellulitis were the most prevalent manifestations; otherwise, clinical manifestations resembled those of S. pyogenes infections. Clinical manifestations also differed by patient’s age. SDSE isolates were classified into 34 emm types; stG6792 was most prevalent (27.1%), followed by stG485 and stG245. Mortality rates did not differ according to emm types. Multilocus sequence typing identified 46 sequence types and 12 novel types. Types possessing macrolide- and quinolone-resistance genes were 18.4% and 2.6%, respectively; none showed β-lactam resistance. Among aging populations, invasive SDSE infections are an increasing risk.

Globally, Streptococcus pyogenes poses a continuous burden on human health, causing both self-limiting and life-threatening diseases. Therefore, studying the profile of virulence genes and their combinations is essential to monitor the epidemiology and pathogenic potential of this important species. Thus, the aim of this study was to analyze related genetic features of clinical strains collected in Italy in 2012 in order to obtain a valid picture of their virulence profile that could be compared to similar studies made in other countries approximately in the same period. We conducted emm typing and fibronectin-collagen-T antigen (FCT) region typing in 122 Streptococcus pyogenes strains. Furthermore, several additional virulence genes were screened by polymerase chain reaction. We found correlations between emm types and FCT region profiles. emm1 strains were mainly associated with FCT2 and FCT6, while emm89 and emm12 strains were associated with FCT4. FCT5 was mainly represented in emm4, emm6, and emm75 strains. Significantly, we defined subtypes for each FCT type based on the differences in single and double loci compared to the reference scheme used for the classification of the FCT region. In addition, new FCT-region variants with differences in multiple loci were also recorded. Cluster analysis based on virulence gene profiling showed a non-random distribution within each emm type. This study added new data to existing studies conducted worldwide and revealed new variability scores in circulating Streptococcus pyogenes strains and new assortments in well-established virulence gene signatures. [ABSTRACT FROM AUTHOR]

Background: Infective endocarditis (IE) is defined as endocarditis caused by microorganisms (bacteria or fungi) involving either the heart or great vessels. The clinical course of IE can be complicated by cardiac dysfunction and bacterial embolization to virtually any organ. Staphylococcus aureus and viridans group streptococci are the most common causative organisms, whereas group A Streptococcus (GAS) is less common. Although some GAS serotypes have been associated with severe disease, there are few reports of IE associated with GAS serotypes. Here, we report two cases of GAS endocarditis and review the associated literature.Case Presentations: Patient 1 was a previously healthy 14-year-old girl who developed bacteremia and disseminated intravascular coagulation secondary to left foot cellulitis. She was administered intravenous antibiotics. Two of three blood cultures grew Streptococcus pyogenes (T6 M6, emm6.104). Three days later, a new systolic ejection murmur was heard and echocardiography showed mitral regurgitation with mitral valve vegetation. Because of the resultant severity of the mitral regurgitation, she underwent mitral valve repair after 10 weeks of antibiotic treatment. Patient 2 was a 17-month old boy who presented with a fever. He had a history of spontaneous closure of a ventricular septal defect (VSD). He was started on intravenous antibiotics for possible bacteremia. Two consecutive blood cultures with an interval of more than 12 h grew S. pyogenes (T4 M4, emm4.0). Five days later, echocardiography showed vegetation on a membranous ventricular septal aneurysm. The patient responded well to antibiotics, and recovered fully with no complications.Conclusions: Although both patients developed GAS endocarditis, patient 1 did not have any predisposing conditions for IE, and patient 2 had a only a low-risk predisposing condition, a VSD that had closed spontaneously at five months of age. We found twelve reports in the literature of GAS endocarditis with information on serotypes. All patients in these reports had GAS endocarditis caused by serotypes generally associated with milder infections, but no specific risk trends were identified. A greater accumulation of cases is necessary to more clearly elucidate the association between GAS IE and specific serotypes. [ABSTRACT FROM AUTHOR]

Knowledge of infective endocarditis (IE) caused by Streptococcus dysgalactiae (SD) is limited. This study aimed to identify the clinical and microbiological features of SD-caused IE and to investigate any possible synergy between penicillin and gentamicin on SD isolates. Cases of IE 2008-2016 due to SD reported to the Swedish Registry of Infective Endocarditis (SRIE) were identified. Isolates were emm typed and synergy between antibiotics was determined in time-kill experiments. Medical records were reviewed and SD-cases were compared to cases of IE due to other pathogens reported to the SRIE. Fifty cases of SD-caused IE were confirmed. emm types stC74a, stG62647, and stG643 were most commonly encountered. The patients had a median age of 74 years (range 38-93) and were significantly older compared to patients with Staphylococcus aureus-caused IE, (65 years (p = 0.003)). The median time to diagnosis from symptom onset was 1 day for patients with SD-caused IE which was less compared to patients with IE due to the other pathogens (2-15 days). Embolization was seen in 46% and the in-hospital mortality was 8%. Etest-based methods did not indicate any synergy between penicillin and gentamicin whereas synergy was noted for four out of nine isolates applying time-kill assays. This is the largest study of SD-caused IE, a condition with an acute onset predominantly affecting elderly people. Synergy between penicillin and gentamicin against some SD isolates was distinguished but the potential benefit of this must be weighed against the risk of aminoglycoside side effects. [ABSTRACT FROM AUTHOR]

Scarlet fever is one of a variety of diseases caused by group A Streptococcus (GAS). During 2011, a scarlet fever epidemic characterized by peak monthly incidence rates 2.9–6.7 times higher than those in 2006–2010 occurred in Beijing, China. During the epidemic, hospital-based enhanced surveillance for scarlet fever and pharyngitis was conducted to determine characteristics of circulating GAS strains. The surveillance identified 3,359 clinical cases of scarlet fever or pharyngitis. GAS was isolated from 647 of the patients; 76.4% of the strains were type emm12, and 17.1% were emm1. Almost all isolates harbored superantigens speC and ssa. All isolates were susceptible to penicillin, and resistance rates were 96.1% to erythromycin, 93.7% to tetracycline, and 79.4% to clindamycin. Because emm12 type GAS is not the predominant type in other countries, wider surveillance for the possible spread of emm12 type GAS from China to other countries is warranted.

More than 900 cases of scarlet fever were recorded in Hong Kong during January–July, 2011. Six cases were complicated by toxic shock syndrome, of which 2 were fatal. Pulsed-field gel electrophoresis patterns suggested a multiclonal epidemic; emm12 was the predominant circulating type. We recommend genetic testing of and antimicrobial resistance monitoring for this reportable disease.

We conducted a retrospective population-based study of 140 episodes of Streptococcus dysgalactiae subsp. equisimilis bacteremia occurring in Finland during 1995–2004. Rare emm types were associated with more severe disease and increased mortality rates. Skin and soft tissue infections were more frequent clinical signs among cases caused by common emm types.

Since autumn 2022, observed numbers of paediatric invasive group A Streptococcus infections in Portugal (n = 89) were higher than in pre-COVID-19 seasons. Between September 2022 and May 2023, the dominant diagnoses were pneumonia (25/79), mostly with empyema (20/25), and sepsis (22/79). A number of cases required admission to intensive care (27/79) and surgery (35/79), and the case fatality rate was 5.1% (4/79). Genomic sequencing (n = 55) revealed multiple genetic lineages, dominated by the M1 UK sublineage (26/55) and more diverse emm 12 isolates (12/55).

Background:  Many countries worldwide have reported increasing numbers of emm89 group A Streptococcus (GAS) infections during last decade. Pathogen genetic factors linked to this increase need assessment.Methods:  We investigated epidemiological characteristics of emm89 GAS bacteremic infections, including 7-day and 30-day case-fatality rates, in Finland during 2004-2014 and linked them to whole-genome sequencing data obtained from corresponding strains. The Fisher exact test and exact logistic regression were used to compare differences between bacteremic infections due to emm89 GAS belonging to different genetic clades and subclades.Results:  Out of 1928 cases of GAS bacteremic infection, 278 were caused by emm89 GAS. We identified 2 genetically distinct clades, arbitrarily designated clade 2 and clade 3. Both clades were present during 2004-2008, but clade 3 increased rapidly from 2009 onward. Six subclades (designated subclades A-F) were identified within clade 3, based on phylogenetic core genome analysis. The case-fatality rate differed significantly between subclades (P < .05), with subclade D having the highest 30-day estimated case-fatality rate (19% vs 3%-14%).Conclusions:  A new emm89 clone, clade 3, emerged in 2009 and spread rapidly in Finland. Patients infected with certain subclades of clade 3 were significantly more likely to die. A specific polymerase chain reaction assay was developed to follow the spread of subclade D in 2015. [ABSTRACT FROM AUTHOR]

This study targeted patients in the Department of Pediatrics, Asahikawa Kosei Hospital, between January 2002 and December 2013. In patients suspected of having hemolytic streptococcal infection, Group A Streptococcus (GAS) strains isolated from a throat swab were examined for antimicrobial susceptibility testing. The MICs were measured by the broth microdilution method. The annual number of GAS strains examined for antimicrobial susceptibility testing ranged from 28 to 65 strains, for a total of 574 strains. Some of the isolates obtained from 2006 to 2009 and from 2011 to 2013 were analyzed to determine their emm types. An erythromycin (EM) resistant strain was not detected until 2004, but one EM-resistant strain appeared in 2005. Subsequently, EM-resistant strains rapidly increased, and 48 of 65 strains (73.8%) examined in 2009 were resistant. In 2010, the number of EM-resistant strains decreased to 12 of 36 strains (33.3%). However, it gradually increased afterwards, and 37 of 60 strains (61.7%) were resistant in 2013. Out of 574 strains examined, 184 exhibited EM-resistance, and the overall resistance rate was 31.9%. Partitioning the 124 strains examined between 2006 and 2008 according to emm types, only emm 28 strains, which exhibited a high resistance rate, and emm 12 strains demonstrated resistance. For the 142 strains examined between 2011 and 2013, the resistance rate of emm 28 strains was similarly high; the resistance of emm 12 strains significantly increased, and emm 1 strains exhibited a high resistance rate. The number of emm types associated with the resistant strains increased. [ABSTRACT FROM AUTHOR]

Distribution of virulence factors and association with emm polymorphism or isolation site among beta-hemolytic group G Streptococcus dysgalactiae subspecies equisimilis. Streptococcus dysgalactiae subspecies equisimilis ( SDSE), the dominant human pathogenic species among group G streptococci, is the causative agent of several invasive and non-invasive diseases worldwide. However, limited information is available about the distribution of virulence factors among SDSE isolates, or their association with emm types and the isolation sites. In this study, 246 beta-hemolytic group G SDSE isolates collected in central Taiwan between February 2007 and August 2011 were under investigation. Of these, 66 isolates were obtained from normally sterile sites and 180 from non-sterile sites. emm typing revealed 32 types, with the most prevalent one being stG10.0 (39.8%), followed by stG245.0 (15.4%), stG840.0 (12.2%), stG6.1 (7.7%), and stG652.0 (4.1%). The virulence genes lmb (encoding laminin-binding protein), gapC (glyceraldehyde 3-phosphate dehydrogenase), sagA (streptolysin S), and hylB (hyaluronidase) existed in all isolates. Also, 99.2% of the isolates possessed slo (streptolysin O) and scpA (C5a peptidase) genes. In addition, 72.8%, 14.6%, 9.4%, and 2.4% of the isolates possessed the genes ska (streptokinase), cbp (putative collagen-binding protein, SDEG_1781), fbp (putative fibronectin-binding protein, SDEG_0161), and sicG (streptococcal inhibitor of complement), respectively. The only superantigen gene detected was spegg (streptococcus pyrogenic exotoxin Gdys), which was possessed by 74.4% of the isolates; these isolates correlated with non-sterile sites. Positive correlations were observed between the following emm types and virulence genes: stG10.0 and stG840.0 with spegg, stG6.1 and stG652.0 with ska, and stG840.0 with cbp. On the other hand, negative correlations were observed between the following: stG245.0, stG6.1, and stG652.0 types with spegg, stG10.0 with ska, and stG10.0, stG245.0, and stG6.1 types with cbp. The prevalence of emm types of SDSE in central Taiwan was investigated for the first time. Moreover, the distribution of virulence factors among beta-hemolytic group G SDSE isolates, as well as their association with emm types or isolation sites were also examined. [ABSTRACT FROM AUTHOR]