Streptococcus Pyogenes Isolates Research Articles

Streptococcus pyogenes carriage rate, associated factors and antimicrobial susceptibility profiles among urban and rural schoolchildren at Gondar city, Northwest Ethiopia

Streptococcus pyogenes remains one of the top ten causes of mortality from infectious diseases. Children in low-income nations have high carrier rates of Streptococcus pyogenes, which can serve as a source of infections, including simple superficial infections that may lead to invasive and post-streptococcal diseases, particularly among schoolchildren. This study aimed to assess the prevalence of Streptococcus pyogenes, associated factors, and antimicrobial susceptibility profiles among urban and rural public schoolchildren in Gondar City, Northwest Ethiopia. A school-based comparative cross-sectional study was conducted via a multistage sampling technique among elementary schoolchildren from April to June 2022 in Gondar City. Sociodemographic and clinical data were collected via a pretested structured questionnaire. Standard microbiological methods were used to collect and process throat swabs to isolate Streptococcus pyogenes. An antimicrobial susceptibility test was performed via the disk diffusion method. Epi-Info version 7.2.5 was used to enter the data, which were then exported to SPSS version 25 for analysis. Logistic regression analysis was used to determine the strength of associations between variables, and p < 0.05 was considered statistically significant. The overall prevalence of Streptococcus pyogenes in 438 children was 11.2% (n = 49), with 71.43% (35/49) being urban and 28.57% (14/49) being rural. Low-income parents, hospital admission history, and cigarette smoking in the home were found to be substantially linked with Streptococcus pyogenes carriage among students (p < 0.05). All the Streptococcus pyogenes isolates were susceptible (100%) to penicillin and cefotaxime, but 18.8% and 12.25% of the isolates were resistant to amoxicillin and tetracycline, respectively. The prevalence of Streptococcus pyogenes throat carriage among was intermediate. All the isolates were sensitive to penicillin and cefotaxime, but 18.8% and 12.25% of the isolates were resistant to amoxicillin and tetracycline, respectively. Thus, regular screening and surveillance of Streptococcus pyogenes among schoolchildren should be conducted to minimize carriage or infections and maintain the rational use of antimicrobials. Health education about cigarette smoking in the house also needs to be provided to and the community.

Nationwide upsurge in invasive disease in the context of longitudinal surveillance of carriage and invasive Streptococcus pyogenes 2009-2023, the Netherlands: a molecular epidemiological study.

Since 2022, many countries have reported an upsurge in invasive group A streptococcal (iGAS) infections. We explored whether changes in Streptococcus pyogenes carriage rates or emergence of strains with potentially altered virulence, such as emm1 variants M1UK and M1DK, contributed to the 2022/2023 surge in the Netherlands. We determined emm (sub)type distribution for 2,698 invasive and 351 S. pyogenes carriage isolates collected between January 2009 and March 2023. Genetic evolution of emm1 was analyzed by whole-genome sequencing of 497 emm1 isolates. The nationwide iGAS upsurge coincided with a sharp increase of emm1.0 from 18% (18/100) of invasive isolates in Q1 2022 to 58% (388/670) in Q1 2023 (Fisher's exact test, P < 0.0001). M1UK became dominant among invasive emm1 isolates in 2016 and further expanded from 72% in Q1 2022 to 96% in Q1 2023. Phylogenetic comparison revealed evolution and clonal expansion of four new M1UK clades in 2022/2023. DNase Spd1 and superantigen SpeC were acquired in 9% (46/497) of emm1 isolates. S. pyogenes carriage rates and emm1 proportions in carriage isolates remained stable during this surge, and the expansion of M1UK in iGAS was not reflected in carriage isolates. During the 2022/2023 iGAS surge in the Netherlands, expansion of four new M1UK clades was observed among invasive isolates, but not carriage isolates, suggesting increased virulence and fitness of M1UK compared to contemporary M1 strains. The emergence of more virulent clades has important implications for public health strategies such as antibiotic prophylaxis for close contacts of iGAS patients.IMPORTANCEThis study describes the molecular epidemiology of invasive group A streptococcal (iGAS) infections in the Netherlands based on >3,000 Streptococcus pyogenes isolates from both asymptomatic carriers and iGAS patients collected before, during, and after the COVID-19 pandemic period (2009-2023) and is the first to assess whether changes in carriage rates or carried emm types contributed to the alarming post-COVID-19 upsurge in iGAS infections. We show that the 2022/2023 iGAS surge coincided with a sharp increase of emm1, particularly the toxicogenic M1UK variant, in invasive isolates, but not in carriage isolates. These findings suggest that increased virulence and fitness of M1UK likely contributes to an increased dissemination between hosts. The emergence of a more virulent and fit lineage has important implications for iGAS control interventions such as antibiotic prophylaxis for close contacts of iGAS patients and calls for a reappraisal of iGAS control interventions and guidelines.

Loratadine Derivative Lo-7: A Weapon against Drug-Resistant Enterococcus and Streptococcal Infections.

The primary obstacles in the management of Enterococcus and Streptococcal infections are drug resistance and biofilm formation. Our study revealed that loratadine at a concentration of ≥25 μM exhibited significant inhibitory effects on biofilm formation in 167 clinical strains of Enterococcus faecalis and 15 clinical isolates of Streptococcus agalactiae, Streptococcus pyogenes, and Streptococcus pneumoniae. Additionally, the antibiofilm activity against E. faecalis and Streptococcal was demonstrated by several loratadine derivatives with altered side-chain carbamate moieties. This study investigated the antibacterial activity of the loratadine derivative Lo-7 against clinical strains of S. agalactiae and S. pyogenes, with minimum inhibitory concentrations ranging from 12.5 to 25 μM. The findings revealed that a low concentration of loratadine derivative Lo-7 (3.125 μM) significantly augmented the bactericidal efficacy of vancomycin against multidrug-resistant (MDR) S. agalactiae, both in vitro and in vivo. The loratadine derivative Lo-7, even at low concentrations, demonstrated significant efficacy in eliminating intracellular MDR S. agalactiae within macrophages, potentially indicating a unique advantage over vancomycin, linezolid, and loratadine. Mechanistically, exposure to the loratadine derivative Lo-7 resulted in membrane depolarization without affecting membrane permeability in S. agalactiae. The potential targeting of the SecG subunit of the SecYEG membrane-embedded channel by the loratadine derivative Lo-7 in S. agalactiae was identified through quantitative proteomics, a drug affinity responsive target stability assay, and molecular docking.

Estimation of the of Beta-Lactamase Production in Staphylococcus aureus Isolates from Blepharitis Patients

In this study, 90 eyelid swabs were obtained from patients with blepharitis of both sexes and various age groups who were admitted to various hospitals, and other primary healthcare centers between September 2023 and February 2024, in Babylon governorate. It was found that blepharitis occurs in all age groups and affects both sexes without any differences between them, but it is clear that blepharitis is more prevalent in the age range of (20 to 49) years old. It was discovered that out of the 90 samples, 75 (83.3%) had positive bacterial cultures, and 15 (16.7%) had no growth at all. Also, Staphylococcus aureus was the most common bacteria 39 (52%), followed by Haemophilus influenzae 17 (22.7%), Streptococcus pneumoniae 10 (13.3%), Klebsiella pneumoniae 7 (9.3%), and only 2 isolates of Streptococcus pyogenes (2.7%). The rapid iodometric method has been employed to investigate the production of beta-lactamase enzyme by the common bacteria Staphylococcus aureus, which was isolated from the eyelid's margin of patients with blepharitis. It was found that 36 (92.3%) of the 39 Staphylococcus aureus isolates had the ability to produce β-lactamase. A number of common beta-lactam antibiotics, such as penicillin, amoxicillin, ampiclox cephalexin, and cefazolin have also been used to investigate the ability of Staphylococcus aureus to produce the β-lactamase enzyme. The results showed that all isolates of Staphylococcus aureus were 100% resistant to penicillin, cephalexin and cefazolin. whereas some isolates 30 isolates were resistant to ampiclox (77%), and only 23 isolates were resistant to amoxicillin (59%).

New Enriched Culture Media for Culturing Streptococcus pyogenes by using Spirulina Powder

Background and Aim: Fastidious bacteria require special nutrients and growth factors to grow on enriched culture media. Many enriched culture media were developed for culturing and isolating fastidious bacteria in pure cultures. The present study investigates the ability of spirulina powder to support the fastidious bacteria growth in pure culture compared to ordinary enriched media, e.g., Blood agar and Chocolate agar.&#x0D; Methods: Spirulina powder was used as a nutrient source with some additives to prepare different types of Spirulina media. Reference strain ATCC (19615) and three clinical isolates of Streptococcus pyogenes were examined for their growth on the developed candidate medium. Three formulations of spirulina powder were used: Medium 1, Medium 2, and Medium 3.&#x0D; Results: All spirulina media supported the growth of streptococcus pyogenes and there was no significant difference in the morphology and cultural characteristics on the blood agar and chocolate agar media. Colonies size of streptococcus pyogenes were slightly smaller size on spirulina media.&#x0D; Conclusion: Spirulina media is a possible candidate that can be used as enriched culture media for culturing and isolating fastidious bacteria such as Streptococcus pyogenes.&#x0D; Keyword: Spirulina powder, enriched culture media, Streptococcus pyogenes.

Insights gained from sequencing Australian non-invasive and invasive Streptococcus pyogenes isolates.

Epidemiological data have indicated that invasive infections caused by the Gram-positive cocci Streptococcus pyogenes (group A streptococcus, GAS) have increased in many Australian states over the past two decades. In July 2022, invasive GAS (iGAS) infections became nationally notifiable in Australia via public-health agencies. Surveillance for S. pyogenes infections has been sporadic within the state of New South Wales (NSW). This has led to a lack of genetic data on GAS strains in circulation, particularly for non-invasive infections, which are the leading cause of GAS's burden on the Australian healthcare system. To address this gap, we used whole-genome sequencing to analyse the genomes of 318 S. pyogenes isolates collected within two geographical regions of NSW. Invasive isolates were collected in 2007-2017, whilst non-invasive isolates were collected in 2019-2021. We found that at least 66 different emm-types were associated with clinical disease within NSW. There was no evidence of any Australian-specific clones in circulation. The M1UK variant of the emm1 global pandemic clone (M1global) has been detected in our isolates from 2013 onwards. We detected antimicrobial-resistance genes (mainly tetM, ermA or ermB genes) in less than 10 % of our 318 isolates, which were more commonly associated with non-invasive infections. Superantigen virulence gene carriage was reasonably proportionate between non-invasive and invasive infection isolates. Our study adds rich data on the genetic makeup of historical S. pyogenes infections within Australia. Ongoing surveillance of invasive and non-invasive GAS infections within NSW by whole-genome sequencing is warranted to inform on outbreaks, antimicrobial resistance and vaccine coverage.

Isolation and Characterization of Streptococcus pyogenes from Iraqi Children with Pharyngotonsillitis

Background: Streptococcus pyogenes known as group A streptococci (GAS) is the main causative agent of pharyngotonsillitis in children younger than 12 years old. The infection appears mostly in winter and spring. Signs and symptoms of patients with a beta-hemolytic GAS infection, include tonsillar exudate, fever, painful anterior cervical adenopathy, and the lack of a cough. Penicillin and ampicillin are the preferred clinical therapy choice for GAS pharyngitis treatment. Objectives: Isolate and identify GAS in throat swabs among children suffering from acute pharyngotonsillitis to estimate the prevalence rate of bacterial isolates associated with age, sex, and months variation of GAS infection. Also, it is to determine the antibiotic sensitivity patterns such as penicillin, ampicillin, erythromycin, azithromycin, ofloxacin, clindamycin, and rifampicin, which are used for the treatment of GAS associated with the acute pharyngotonsillitis in children. Materials and Methods: Four hundred and ten throat swabs have been obtained from patients who were clinically diagnosed as having acute pharyngotonsillitis of age ranging from (1–12) years of both sexes were admitted to various hospitals and enrolled in a sequential manner from November 2021 to April 2022 in two Governorates (Baghdad and Babylon), Iraq. These throat swabs were exposed to the bacterial culturing, and some other tests. Streptococcus pyogenes isolates were identified depending on the colony properties, beta-hemolysis on sheep blood agar plate, Gram’s stain, catalase production test, in addition to a sensitivity to bacitracin and Pyrrolidinyl arylamidase test to confirm the identification of GAS. Results: The prevalence of identifying GAS isolates was 140 (34.1%) out of 410 samples. GAS strains can cause acute pharyngotonsillitis in children of all ages, but it most frequently occurred between 1 and 6 year age groups, and it was more in men 80 (57.1%) than in women 60 (42.9%). Likewise, it was found that GAS associated with acute pharyngotonsillitis with a high incidence in winter and in early spring, in which the peak of GAS infection has been seen in January (30.7%). On the other hand, some antibiotics were used to show their effect on these GAS isolates. The findings revealed that all isolates were sensitive (100%) to penicillin and ampicillin, and (83.6%) of isolates were sensitive to clindamycin, whereas some isolates shown a lesser degree of sensitivity (75% and 60%) to rifampicin and ofloxacin. However, only 49.3% of the isolates were sensitive to erythromycin, and (46.4%) were sensitive to azithromycin. Conclusion: GAS strains can cause acute pharyngotonsillitis in children of all ages, but it most frequently occurred in the age groups (1–6) year, and more predominant in men than in women. High percentage of infections with GAS have been noticed in winter and spring to reach its peak in January. Additionally, penicillin and ampicillin are preferred antibiotic for treatment, whereas in the most serious cases clindamycin was added to the treatment plan.

Consecutive Seven Serious Cases with Invasive Group A Streptococcal Infections at December 2022-January 2023.

To the Editors: During the second and third year of the COVID pandemic, an increased number of serious cases due to different microorganisms have been reported. In the second half of 2022, it has been reported that there has been an increase in invasive group A streptococcal (iGAS) infections in many countries including England, the Netherlands and others.1–3 iGAS is defined as a life-threatening invasive infection characterized by the isolation of Streptococcus pyogenes from normally sterile body fluids with culture or by pathogen-specific polymerase chain reaction (PCR). If GAS has grown from a probable carrier location, such as the throat, and the clinical course is compatible with GAS disease and no other causing organism has been found, these patients need to be handled as iGAS.4 Before the pandemic, GAS was the most common pathogen among children in Europe who had to be hospitalized for a community-acquired bacterial infection. Patients with GAS infection had a 12% impairment at discharge and a 2% fatality rate. Increases in toxic shock syndrome, necrotizing fasciitis and pleural empyema have all been linked to increased mortality.4 In UK, during the last couple of months, the rate per 100,000 population of iGAS is higher among children.1 Between December 2022 and January 2023, in our tertiary care facility, we followed up 7 consecutive cases of iGAS infection—3 boys and 4 girls, ages 37–96 months—without any relation to one another (Table 1). All children were previously healthy. Five children were admitted to the pediatric intensive care unit, including 1 with toxic shock syndrome and 4 with pleural effusion/empyema. In 6 out of 7 children, the diagnosis of iGAS infection was made based on a positive culture and/or PCR from a typically sterile place, with the pleural fluid being the most frequent site. iGAS infection was defined in a child with toxic shock syndrome based on positive throat culture. In Table 1, antibiotic therapy is displayed. Each patient received clindamycin and 1 patient received intravenous immunoglobulin (IVIG). Due to empyema, thoracic tubes had to be inserted in 5 patients. In 2 of the pleural empyema cases, tube thoracostomy was carried out; in the third video assisted thoracostomy and in the fourth, thoracotomy and decortication were carried out. One child with GAS bacteremia required surgery for mastoiditis, and throughout the course of the investigation, sinus venous thrombosis was detected. Five children required pediatric intensive care unit stay. The length of hospital stay ranged from 7 to 21 days. TABLE 1. - Clinical Characteristics of 7 Children with Invasive Group A Streptococcal Infection Patient Age (month) Gender Diagnosis Culture Multiplex PCR Treatment PICU Stay Length of hospital stay (day) 1 37 Girl Pleural Empyema - Pleural fluid Streptococcus pyogenes Meropenem + vancomycin + clindamycin IVIG Thoracotomy and decortication + 14 2 40 Girl Pleural Empyema Throat Streptococcus pyogenes Pleural fluid Streptococcus pyogenes Tube thoracostomy Ceftriaxone + clindamycin + 9 3 96 Girl Pleural Empyema - Pleural fluid Streptococcus pyogenes Meropenem + vancomycin + clindamycin Tube thoracostomy Video assisted thoracostomy + 15 4 62 Boy Bacteremia, Mastoiditis, Sinus vein thrombosis Blood Streptococcus pyogenes - Meropenem + vancomycin + clindamycin Mastoidectomy - 21 5 48 Boy Pleural Empyema - Pleural fluid Streptococcus pyogenes Ceftriaxone + vancomycin + clindamycin Tube thoracostomy + 10 6 59 Boy Toxic Shock Syndrome Throat Streptococcus pyogenes - Ceftriaxone + vancomycin + clindamycin + 7 7 42 Girl Bacteremia, Pleural Empyema Blood Streptococcus pyogenes - Ceftriaxone + clindamycin - 10 IVIG, intravenous immune globulin; PICU, pediatric intensive care unit. Both the frequency and morbidity of iGAS infections increased after the COVID-19 pandemic as before. While there was only one iGAS case during the previous 3 years, 7 patients in a row were hospitalized during a 2-month period in our setting. Clindamycin would be efficient to deactivate M-protein and these exotoxins because S. pyogenes has the cell wall M-protein that prevents complement activation and reduces phagocytosis. This would produce a positive outcome similar to our case series.4,5 Although culture is the gold standard method for diagnosis, molecular methods such as multiplex PCR are important in identifying the causative agent. Despite treatment, we have seen serious complications in our case series, such as pleural decortication, mastoiditis, sinus venous thrombosis and toxic shock syndrome. Early diagnosis of patients (using molecular techniques included) and the initiation of appropriate treatment including clindamycin, are crucial. To comprehend the postpandemic condition, it is essential to monitor the clinical findings and prognosis of iGAS cases from various countries.

Respiratory culture organism isolation and test characteristics in children with tracheostomies with and without acute respiratory infection.

Among children with tracheostomies, little is known about how respiratory culture results differ between states with and without acute respiratory infections (ARI), or the overall test performance of respiratory cultures. To determine the association of respiratory culture organism isolation with diagnosis of ARI in children with tracheostomies, and assess test characteristics of respiratory cultures in the diagnosis of bacterial ARI (bARI). This single-center, retrospective cohort study included respiratory cultures of children with tracheostomies obtained between 2010 and 2018. The primary predictor was ARI diagnosis code at the time of culture; the primary outcomes were respiratory culture organism isolation and species identified. Generalized estimating equations were used to assess for association between ARI diagnosis and isolation of any organism while controlling for potential confounders and accounting for within-patient clustering. A multinomial logistic regression equation assessed for association with specific species. Test characteristics were calculated using bARI diagnosis as the reference standard. Among 3578 respiratory cultures from 533 children (median 4 cultures/child, interquartile range (IQR): 1-9), 25.9% were obtained during ARI and 17.2% had ≥1 organism. Children with ARI diagnosis had higher odds of organism identification (adjusted odds ratio 1.29, 95% confidence interval [CI] 1.16-1.44). When controlling for covariates, ARI was associated with isolation of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Streptococcus pyogenes. Test characteristics revealed a 24.3% sensitivity, 85.2% specificity, 36.5% positive predictive value, and 76.3% negative predictive value in screening for bARI. The utility of respiratory culture testing to screen for, diagnose, and direct treatment of ARI in children with tracheostomies is limited.

Nowadays a New MIS-C Mimicker: Group A Streptococcal Infections.

To the Editors: We show severe streptococcal infections in this report that mimicked the multisystem inflammatory syndrome in children (MIS-C) clinical presentation. At the start of December 2022, the cases were concurrently admitted to our hospital. We would want to share our study considering the Streptococcus pyogenes-related death cases that have recently been reported in many parts of Europe. An 8-year-old female patient complained of chest pain, headaches and fever for 3 days. The patient exhibited a maculopapular rash on the trunk, strawberry tongue, bilateral conjunctivitis, tonsillar hyperemia and cervical lymphadenopathy. Acute phase reactants were noticeably greater and acute renal failure was found in addition to the patient’s lymphopenia (C-reactive protein: 503 mg/L, procalcitonin: 49 μg/L, leucocyte count: 14.700 × 103/μL, lymphocyte count: 100 × 103/μL). The patient was receiving inotropic treatment because of hypotension. A prediagnosis of septic shock and MIS-C was made, and she was monitored in the critical care unit. Treatments with cefotaxime and clindamycin began. Intravenous immunoglobulin (IVIG) (1 g/kg/d for 2 days) and steroid (2 mg/kg/d) treatments were used when the SARS-CoV-2 antibodies were positive. The echocardiogram was normal. Streptococcus pyogenes was produced in the case’s blood culture during the follow-up, confirming the diagnosis of toxic shock syndrome. A 10-year-old female patient presented with complaints of fever, headache, vomiting and weakness for 2 days. The patient with weakness appearance had hyperemic tonsils and bilateral conjunctivitis. In the laboratory results at admission, lymphopenia and increased B-type natriuretic peptide were evident. In the acute phase reactants, the procalcitonin level was 3.7 μg/L and the CRP level was 41 mg/L. The patient had multiorgan involvement, which included the Centers for Disease Control and Prevention case description, thus treatment for MIS-C was initiated in addition to antibiotherapy even though there had been no appreciable increase in inflammatory markers. The patient showed clinical improvement within hours after fluid resuscitation and antibiotic therapy. Influenza was detected in the respiratory viral panel. Upon isolation of Streptococcus pyogenes in the throat culture during the follow-up, the diagnosis was finalized and MIS-C treatment was discontinued and targeted antibiotherapy was continued. This report was presented to highlight severe streptococcal infections mimicking MIS-C. Today, MIS-C, which is characterized by fever, elevated inflammatory markers and multisystem organ involvement, is seen in children following SARS-CoV-2 infection.1 MIS-C is an excluding diagnosis, careful consideration should go into the differential diagnosis. Given that it is overlapped with other prevalent diseases, it is a challenging process for the doctor to treat. In instances with fever, organ involvement and elevated inflammatory markers, empirical antibiotic therapy for potential bacterial agents should be started. In fact, if clinical suspicion is high, antibiotic therapy may be extended. By carefully observing the outcomes of the culture, antibiotherapy can be terminated early in instances where it is not necessary. Viral infections, such as influenza, facilitate the development of group a streptococcal infection, and this increase may have occurred due to the influenza epidemic in the northern hemisphere. The presence of SARS-CoV-2 antibodies in our case with streptococcal toxic shock syndrome increased the suspicion of MIS-C. However, it remains unclear how the antibody test should be interpreted. Because of the increasing prevalence of infection in the community, the usefulness of SARS-CoV-2 antibody testing seems to be limited.2 Therefore, cases with suspected MIS-C should be evaluated from a broad perspective in terms of bacterial infections. Delayed administration of antibiotics may result in mortality.

Characterization of group A beta-haemolytic streptococcus with mucoid phenotype isolated in a tertiary hospital

IntroductionThe objective of this study is to characterize Streptococcus pyogenes isolates with a mucoid phenotype and to compare them with non-mucoid isolates obtained between April and August 2016. Material and methodsIdentification and antimicrobial susceptibility were performed in all isolates. The emm type and exotoxin genes speA, speB, speC, speF, speG, speH, speJ, speZ and ssa were analyzed. Clinical and demographic data were collected. ResultsFrom 96 isolates analyzed, 47% had a mucoid phenotype and 95.5% of them presented speA-speB-speF-speG-ssa genes and emm3 genotype. The main clinical manifestation was pharyngotonsillitis (77.1%) evolving to scarlet fever in 67.5% of the cases. ConclusionThis study describes the circulation of a mucoid phenotype strain with a speA-speB-speF-speG-ssa toxin profile and emm3.1 genotype considered one of the most frequent and virulent of SGA.

Cluster Transmission Drives Invasive Group A Streptococcus Disease Within the United States and Is Focused on Communities Experiencing Disadvantage.

Group A streptococci (GAS), although usually responsible for mild infections, can sometimes spread into normally sterile sites and cause invasive GAS disease (iGAS). Because both the risk of iGAS disease and occurrence of outbreaks are elevated within certain communities, such as those comprising people who inject drugs (PWID) and people experiencing homelessness (PEH), understanding the transmission dynamics of GAS is of major relevance to public health. We used a cluster detection tool to scan genomes of 7552 Streptococcus pyogenes isolates acquired through the population-based Active Bacterial Core surveillance (ABCs) during 2015-2018 to identify genomically related clusters representing previously unidentified iGAS outbreaks. We found that 64.6% of invasive isolates were included within clusters of at least 4 temporally related isolates. Calculating a cluster odds ratio (COR) for each emm type revealed that types vary widely in their propensity to form transmission clusters. By incorporating additional epidemiological metadata for each isolate, we found that emm types with a higher proportion of cases occurring among PEH and PWID were associated with higher CORs. Higher CORs were also correlated with emm types that are less geographically dispersed. Early identification of clusters with implementation of outbreak control measures could result in significant reduction of iGAS.

Invasive group A streptococcal disease in pregnant women and young children: a systematic review and meta-analysis

SummaryBackgroundThe incidence of invasive disease caused by group A streptococcus (GAS) has increased in multiple countries in the past 15 years. However, despite these reports, to the best of our knowledge, no systematic reviews and combined estimates of the incidence of invasive GAS have been done in key high-risk groups. To address this, we estimated the incidence of invasive GAS disease, including death and disability outcomes, among two high-risk groups—namely, pregnant women and children younger than 5 years.MethodsWe did a systematic review and meta-analyses on invasive GAS outcomes, including incidence, case fatality risks, and neurodevelopmental impairment risk, among pregnant women, neonates (younger than 28 days), infants (younger than 1 year), and children (younger than 5 years) worldwide and by income region. We searched several databases for articles published from Jan 1, 2000, to June 3, 2020, for publications that reported invasive GAS outcomes, and we sought unpublished data from an investigator group of collaborators. We included studies with data on invasive GAS cases, defined as laboratory isolation of Streptococcus pyogenes from any normally sterile site, or isolation of S pyogenes from a non-sterile site in a patient with necrotising fasciitis or streptococcal toxic shock syndrome. For inclusion in pooled incidence estimates, studies had to report a population denominator, and for inclusion in pooled estimates of case fatality risk, studies had to report aggregate data on the outcome of interest and the total number of cases included as a denominator. We excluded studies focusing on groups at very high risk (eg, only preterm infants). We assessed heterogeneity with I2.FindingsOf the 950 published articles and 29 unpublished datasets identified, 20 studies (seven unpublished; 3829 cases of invasive GAS) from 12 countries provided sufficient data to be included in pooled estimates of outcomes. We did not identify studies reporting invasive GAS incidence among pregnant women in low-income and middle-income countries (LMICs) nor any reporting neurodevelopmental impairment after invasive GAS in LMICs. In nine studies from high-income countries (HICs) that reported invasive GAS in pregnancy and the post-partum period, invasive GAS incidence was 0·12 per 1000 livebirths (95% CI 0·11 to 0·14; I2=100%). Invasive GAS incidence was 0·04 per 1000 livebirths (0·03 to 0·05; I2=100%; 11 studies) for neonates, 0·13 per 1000 livebirths (0·10 to 0·16; I2=100%; ten studies) for infants, and 0·09 per 1000 person-years (95% CI 0·07 to 0·10; I2=100%; nine studies) for children worldwide; 0·12 per 1000 livebirths (95% CI 0·00 to 0·24; I2=100%; three studies) in neonates, 0·33 per 1000 livebirths (−0·22 to 0·88; I2=100%; two studies) in infants, and 0·22 per 1000 person-years (0·13 to 0·31; I2=100%; two studies) in children in LMICs; and 0·02 per 1000 livebirths (0·00 to 0·03; I2=100%; eight studies) in neonates, 0·08 per 1000 livebirths (0·05 to 0·11; I2=100%; eight studies) in infants, and 0·05 per 1000 person-years (0·03 to 0·06; I2=100%; seven studies) in children for HICs. Case fatality risks were high, particularly among neonates in LMICs (61% [95% CI 33 to 89]; I2=54%; two studies).InterpretationWe found a substantial burden of invasive GAS among young children. In LMICs, little data were available for neonates and children and no data were available for pregnant women. Incidences of invasive GAS are likely to be underestimates, particularly in LMICs, due to low GAS surveillance. It is essential to improve available data to inform development of prevention and management strategies for invasive GAS.FundingWellcome Trust.

Streptococcal Pyrogenic Exotoxin Genes SpeA and SpeB in Isolates of &amp;lt;i&amp;gt;Streptococcus pyogenes&amp;lt;/i&amp;gt; from Children with Pharyngitis, Gezira State, Sudan

Background: Streptococcus pyogenes (group A streptococcus, GAS) is an important human bacterial pathogen. This organism possesses many virulence factors, Streptococcal pyrogenic exotoxinone of these. Aim: Detection of Streptococcal pyrogenic exotoxin SpeA and SpeB in isolated Streptococcus pyogenes. Methods: Tow hundred throat swab samples were collected from children with pharyngitis referred to Pediatric Teaching hospital and ENT hospital Wad medani, Sudan, from January to November 2021. The questionnaire was filled out to collect clinical and demographic data. Throat swabs were collected and processed with the standard microbiological procedure to isolate Streptococcus pyogenes. Antimicrobial susceptibility testing was done on all GAS isolates using the Kirby Bauer disk diffusion method according to clinical laboratory standard institute (CLSI) guidelines. Detection of Spy 1258 gene and Streptococcal pyrogenic exotoxins SpeA and SpeB were done by using Multiplex PCR. Results: Amongst the Tow hundred collected samples fifty-one isolates (25.5%) were identified as S. pyogenes. Antibiotic susceptibility testing showed that all the GAS isolates were sensitive to Azithromycin and Penicillin. Sensitivity to Erythromycin, Gentamicin, Clarithromycin, Amoxicillin and Cephalexin were 88.2%, 86.3%, 45.1%, 41.2%, 13.7%, respectively. SpeA was detected in 17 (33.3%) and SpeB in 48 (94.1%). Conclusion: Streptococcal pyrogenic exotoxin genes SpeA and SpeB were detected in 17 (33.3%) and 48 (94.1%) respectively of Streptococcus pyogenes isolates.

Isolation of Group A Streptococci with Reduced In Vitro β-Lactam Susceptibility Harboring Amino Acid Substitutions in Penicillin-Binding Proteins in Japan.

Streptococcus pyogenes (group A Streptococcus [GAS]) has long been regarded as being susceptible to β-lactams. However, amino acid substitutions in penicillin-binding protein 2X (PBP2X) conferring reduced in vitro β-lactam susceptibility have been indicated since 2019 in the United States and Iceland. Here, we report the first isolation of Streptococcus pyogenes possessing the PBP2X substitution conferring reduced in vitro β-lactam susceptibility in Asia; however, the MICs were below the susceptible breakpoint of the CLSI.

Isolation and Identification of Streptococcus pyogenes from Patients and Objects in Hospital Environment in Thi-Qarcity in Iraq

This study aimed to screen Streptococcus pyogenes in the hospital and investigate the incidence of thisbacteria. The genotypes of the S.pyogenes in the study samples will be determined using 16Sr RNA and somevirulence factors(emm, scpA, speA genes).The majority of the samples (74.1%) were isolated from patientsat the emergency room and (25.9%) were from hospital environment (objects).The current study showed thatthe total of 215 patients with pharyngitis were included 118 (55%) males higher than 97 (45%) females. Thepatients’ ages ranged from 2 to 62 years, which were divided into four categories. The majority of patients65 (30.1%) of patients from 3 to 6 years old, 54 (25%) of patients less than 3years, 51 (23.6%) from 7 to 11years old, and 46 (21.3%) more than 12years. Six isolates sent for sequencing were after that submission inNCBI-GenBank database. The results of nucleotide sequence alignment of the isolates revealed that thereare multiple point mutations, four of them appeared as a single nucleotide polymorphism (SNP) and twoappeared in duplicate. Polymorphic sites (Mutations) of 6 S.pyogenes isolates.

Determination of antimicrobial action of "Apicold oral spray"

Introduction: The causative agents of acute tonsillopharyngitis are viruses and bacterial flora. Treatment of acute pharyngitis is mainly local, which includes aerosols with antiseptics. Aim: Study of antimicrobial action of "Apicold oral spray" on clinical isolates of microorganisms Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis and Candida albicans isolated from patients' oropharynx in patients. Material and methods: The effect of Apicold Oral Spray (manufactured by APIPHARMA doo) on clinical isolates of Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, and Candida albicans in Ukrainian patients was studied. Antimicrobial activity was assessed after 5, 10 and 20 minutes of action of one dose of "Apicold oral spray" on microorganisms. Bactericidal and fungicidal action (inhibition of cell growth of microorganisms) is expressed as a percentage according to the control. Results and discussion: Apicold Oral Spray has a 100% antimicrobial effect after 5 minutes on clinical isolates of Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis and Candida albicans (complete growth inhibition of all 5 clinical isolates after 20 minutes). Conclusion: "Apicold oral spray" has a high antimicrobial effect on clinical isolates of Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis and Candida albicans, which is confirmed by 100% inhibition of the growth of all bacteria after 5 minutes

Survival Strategies of Streptococcus pyogenes in Response to Phage Infection.

Bacteriophages exert strong evolutionary pressure on their microbial hosts. In their lytic lifecycle, complete bacterial subpopulations are utilized as hosts for bacteriophage replication. However, during their lysogenic lifecycle, bacteriophages can integrate into the host chromosome and alter the host’s genomic make-up, possibly resulting in evolutionary important adjustments. Not surprisingly, bacteria have evolved sophisticated immune systems to protect against phage infection. Streptococcus pyogenes isolates are frequently lysogenic and their prophages have been shown to be major contributors to the virulence of this pathogen. Most S. pyogenes phage research has focused on genomic prophages in relation to virulence, but little is known about the defensive arsenal of S. pyogenes against lytic phage infection. Here, we characterized Phage A1, an S. pyogenes bacteriophage, and investigated several mechanisms that S. pyogenes utilizes to protect itself against phage predation. We show that Phage A1 belongs to the Siphoviridae family and contains a circular double-stranded DNA genome that follows a modular organization described for other streptococcal phages. After infection, the Phage A1 genome can be detected in isolated S. pyogenes survivor strains, which enables the survival of the bacterial host and Phage A1 resistance. Furthermore, we demonstrate that the type II-A CRISPR-Cas system of S. pyogenes acquires new spacers upon phage infection, which are increasingly detectable in the absence of a capsule. Lastly, we show that S. pyogenes produces membrane vesicles that bind to phages, thereby limiting the pool of phages available for infection. Altogether, this work provides novel insight into survival strategies employed by S. pyogenes to combat phage predation.

In vitro activity and resistance rates of topical antimicrobials fusidic acid, mupirocin and ozenoxacin against skin and soft tissue infection pathogens obtained across Canada (CANWARD 2007-18).

Current antimicrobial susceptibility/resistance data versus skin and soft tissue infection (SSTI) pathogens help to guide empirical treatment using topical antimicrobials. To assess the in vitro activity and resistance rates of fusidic acid, mupirocin, ozenoxacin and comparator agents against pathogens isolated from patients with SSTIs in Canada. SSTI isolates of MSSA (n = 422), MRSA (n = 283) and Streptococcus pyogenes (n = 46) obtained from CANWARD 2007-18 were tested using CLSI broth microdilution. Fusidic acid low-level resistance was defined as an MIC of ≥2 mg/L and high-level resistance as an MIC ≥512 mg/L. Mupirocin high-level resistance was defined as an MIC ≥512 mg/L and low-level resistance was an MIC of 2-256 mg/L. Low-level and high-level fusidic acid resistance in MSSA was 10.9% and 1.7%, respectively. Low-level and high-level fusidic acid resistance in MRSA was 10.6% and 3.5%, respectively. High-level mupirocin resistance was identified in 1.4% of MSSA and 14.1% of MRSA, respectively. Versus MSSA, ozenoxacin demonstrated MIC50 and MIC90 of 0.004 and 0.25 mg/L, respectively. Against MRSA, ozenoxacin inhibited all isolates at an MIC of ≤0.5 mg/L, including isolates with ciprofloxacin MICs >2 mg/L, clarithromycin-resistant, clindamycin-resistant, high-level fusidic acid-resistant and high-level mupirocin-resistant isolates. We conclude that fusidic acid low-level resistance exceeded 10% for both MSSA and MRSA while fusidic acid high-level resistance was ≤3.5%. Mupirocin high-level resistance exceeded 10% in MRSA. Ozenoxacin is active versus SSTI pathogens including MRSA resistant to fluoroquinolones, macrolides, clindamycin, fusidic acid and mupirocin.

Caracterización de estreptococos beta-hemolíticos del grupo A con fenotipo mucoide aislados en un hospital de tercer nivel

IntroductionThe objective of this study is to characterize Streptococcus pyogenes isolates with a mucoid phenotype and to compare them with non-mucoid isolates obtained between April and August 2016. Material and methodsIdentification and antimicrobial susceptibility were performed in all isolates. The emm type and exotoxin genes speA, speB, speC, speF, speG, speH, speJ, speZ and ssa were analyzed. Clinical and demographic data were collected. ResultsFrom 96 isolates analyzed, 47% had a mucoid phenotype and 95.5% of them presented speA-speB-speF-speG-ssa genes and emm3 genotype. The main clinical manifestation was pharyngotonsillitis (77.1%) evolving to scarlet fever in 67.5% of the cases. ConclusionThis study describes the circulation of a mucoid phenotype strain with a speA-speB-speF-speG-ssa toxin profile and emm3.1 genotype considered one of the most frequent and virulent of SGA.