Streptococcus Research Articles

PREVALENCE OF BOVINE MASTITIS AND THE FIRST DETECTION OF MYCOPLASMA BOVIS IN VIETNAM’S DAIRY FARMS

Mastitis still remains an economic disease in dairy farms all over the world. This study aimed to report the prevalence of this disease in large-scale farms in Vietnam, the pathogens profile, and first report the detection of Mycoplasma bovis (M. bovis) by applying conventional culture and real-time PCR (polymerase chain reaction) methods. We examined 64,802 enrolled dairy cows from six farms in Vietnam, yielding 1,874 (2.9%) total cases of clinical mastitis. The majority of the 14 pathogens were identified. Klebsiella spp. accounted for 21.0% of the total isolates. Streptococcus uberis (S. uberis), Escherichia coli (E. coli), other Streptococcus spp, and Coagulase-Negative Staphylococci (CNS), followed at 12.6, 7.6, 6.0, and 5.5 percent, respectively. The rest pathogens include Pseudomonas spp., Enterococcus faecalis, Enterobacter spp., Bacillus spp., Citrobacter spp., Pasteurella spp., Proteus spp., and Staphylococcus aureus were isolated with less than 1% each. To the best of our knowledge, this is the first report for detecting M. bovis in mastitis milk samples in Vietnam, where 35 out of 1,422 samples submitted in 2022 were M. bovis positive. Moreover, of the 35 positive cases, 11 cases had only M. bovis, while 24 cases had M. bovis and other pathogens, including 13 Enterobacteriaceae, 7 Streptococcus spp., and 4 CNS.

Gestational diabetes augments group B Streptococcus infection by disrupting maternal immunity and the vaginal microbiota

Group B Streptococcus (GBS) is a pervasive perinatal pathogen, yet factors driving GBS dissemination in utero are poorly defined. Gestational diabetes mellitus (GDM), a complication marked by dysregulated immunity and maternal microbial dysbiosis, increases risk for GBS perinatal disease. Using a murine GDM model of GBS colonization and perinatal transmission, we find that GDM mice display greater GBS in utero dissemination and subsequently worse neonatal outcomes. Dual-RNA sequencing reveals differential GBS adaptation to the GDM reproductive tract, including a putative glycosyltransferase (yfhO), and altered host responses. GDM immune disruptions include reduced uterine natural killer cell activation, impaired recruitment to placentae, and altered maternofetal cytokines. Lastly, we observe distinct vaginal microbial taxa associated with GDM status and GBS invasive disease status. Here, we show a model of GBS dissemination in GDM hosts that recapitulates several clinical aspects and identifies multiple host and bacterial drivers of GBS perinatal disease.

Fulminant invasive group A streptococcal infection in children

Group A streptococcal infections dominate among invasive streptococcal infections, with the major causative agent, Streptococcus pyogenes, being quite stable in the environment and bearing a large number of chromosome encoded pathogenicity factors or transmitted by horizontal transfer through bacteriophages. Different genetic variants of S. pyogenes can have a different set of pathogenicity factors able to change during pathogen evolution and determine virulence level for specific isolate. With a short incubation period, the disease can proceed with developing invasive infection and toxic shock syndrome with unfavorable outcome within 7 days from disease onset. The purpose of this article is to increase the doctors’ alertness to early recognition and diagnosis, which directly affects adequate treatment in a timely manner and disease outcome. The data on streptococcal morbidity in Russia and worldwide, review of laboratory diagnostic methods and pathogen genetic typing are presented. The maximum number of cases of streptococcal septicemia in Russia was registered in 2022, which accounted for 69% of all cases during the 2014–2022 observation period. The article also describes two clinical cases of fulminant invasive group A streptococcal infection in children with symptoms of acute respiratory viral infections at the onset of the disease. The results of various laboratory diagnostics methods verifying the diagnosis are presented. The genetic characterization of microbial isolates was performed by deep DNA sequencing. In the biological material from patients (including autopsy in one case), S. pyogenes sequence type ST-28, serotypes emm-1.25 and emm-1.0 were identified. The increasing importance of invasive streptococcal infection for health care in Russia and other countries may be associated with a possible change in dominating S. pyogenes genetic variants. In this regard, the study on circulating S. pyogenes genotypes on an ongoing basis as part of surveillance of streptococcal infection and development of vaccine for specific prevention are required.

A rare case of streptococcal pharyngitis in an adult male causing hemophagocytic lymphohistiocytosis

Hyperinflammatory responses due to cytokine storms involve multiple systems in hemophagocytic lymphohistiocytosis (HLH) leading to morbidities. Multiple bacterial etiologies have been suggested as a cause of secondary HLH but streptococcal infection has only been reported in pediatric cases. Streptococcus has been considered a notorious pathogen due to its ability to interfere with host immunity through the phenomenon of molecular mimicry. This case report shows the sequence of events post-streptococcal pharyngitis in a 28-year-old male, which lead to HLH and fatality to life, and how a timely intervention of steroids salvaged the patient.

Genomically linked invasive Group A streptococcus infection within an extended household

Genomically linked invasive Group A streptococcus infection within an extended household

Neonatal Group B Streptococcus infection at a single center in Al-Madinah Al-Munawarah, Saudi Arabia.

To determine the occurrence of Group B Streptococcus (GBS) infection in neonates and its associated risk factors in Al-Madinah Al-Munawarah, Saudi Arabia. This retrospective study was carried out at the Maternity and Child Hospital in Al-Madinah Al-Munawarah, between 2017-2022. The laboratory and clinical data of 64 neonates were collected and analyzed using GraphPad Prism 7 software. Out of 16,022 neonates admitted to the nursery, 64 infants were diagnosed with GBS infection. Approximately 53.1% were male, 46.9% female, 15.6% were preterm, and 84.4% were full-term. Vaginal births accounted for 71.9%. The mean onset age was 10±12.4 days. Among the GBS patients, 53.1% had early-onset disease (EOD, 0-6 days), while 46.9% had late-onset disease (LOD, 7-90 days). Unexamined mothers had a higher incidence of GBS and EOD newborns (p=0.05). Meningitis was more common in LOD than EOD patients and correlated with illness onset (p=0.05). Early-onset disease patients had a higher incidence of sepsis. The mortality rate was 10.9%, while 89.1% were discharged from the hospital. Neonatal GBS infection is prevalent in Al-Madinah Al-Munawarah. Several risk factors may contribute to the occurrence of GBS infection including preterm labor, higher body temperature during delivery, prolonged premature rupture of membranes for more than 18 hours, and GBS bacteriuria. We recommend that larger multi-centric studies are needed in Al-Madinah Al-Munawarah, to study the magnitude of neonatal GBS infection and risk factors to develop a screening protocol in maternity and children's hospital.

Compartment syndrome due to group A streptococcal infection associated with intramuscular venous malformation.

Compartment syndrome due to group A streptococcal infection associated with intramuscular venous malformation.

Folate Receptor Alpha Autoantibodies in the Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) Population.

The folate receptor alpha autoantibodies (FRAAs) are associated with cerebral folate deficiency (CFD) and autism spectrum disorder (ASD). Both of these syndromes have overlapping characteristics with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) and Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS). Thus, we propose that the FRAAs may contribute to the symptomatology of PANS/PANDAS. To test this hypothesis, 1 mL of serum from 47 patients (age range = 6-18 years old) clinically diagnosed with PANS/PANDAS was sent to Vascular Strategies (Plymouth Meeting, PA, USA) for analysis of FRAAs. Moreover, 63.8% of PANS/PANDAS patients (male = 15; female = 15) were found to have either the blocking and/or blinding FRAAs, with 25 (83.3%; male = 14; female = 11) having binding FRAAs, two (6.7%; all female = 2) having blocking FRAAs, and 3 (10%; male = 1; female = 2) having both binding and blocking. Furthermore, surprisingly, ASD was associated with a 0.76 lower binding titer (p = 0.02), and severe tics were associated with a 0.90 higher binding titer (p = 0.01). A case of a FRAA-positive patient is provided to illustrate that a treatment plan including leucovorin can result in symptom improvement in patients with PANS/PANDAS who are FRAA-positive. These data, for the first time, demonstrate that PANS/PANDAS is associated with FRAAs and suggest folate metabolism abnormalities may contribute to PANS/PANDAS symptomatology. Further studies investigating the therapeutic nature of leucovorin in the treatment of PANS/PANDAS are needed. Such studies may open up an alternative, safe, and well-tolerated treatment for those with the PANS/PANDAS diagnosis.

Clinical and molecular epidemiological features of critically ill patients with invasive group A Streptococcus infections: a Belgian multicenter case-series

BackgroundRecent alerts have highlighted an increase in group A streptococcal (GAS) infections since 2022 in Europe and the United States. Streptococcus pyogenes can cause limited skin or mucosal disease, but can also present as severe invasive disease necessitating critical care. We performed a multicenter retrospective study of patients with GAS infections recently admitted to Belgian intensive care units (ICUs) since January 2022. We describe patient characteristics and investigate the molecular epidemiology of the S. pyogenes strains involved.ResultsBetween January 2022 and May 2023, a total of 86 cases (56 adults, 30 children) with GAS disease were admitted to critical care in the university hospitals of Leuven, Antwerp and Liège. We noted a strikingly high incidence of severe community-acquired pneumonia (sCAP) (45% of adults, 77% of children) complicated with empyema in 45% and 83% of adult and pediatric cases, respectively. Two-thirds of patients with S. pyogenes pneumonia had viral co-infection, with influenza (13 adults, 5 children) predominating. Other disease presentations included necrotizing fasciitis (23% of adults), other severe skin/soft tissue infections (16% of adults, 13% of children) and ear/nose/throat infections (13% of adults, 13% of children). Cardiogenic shock was frequent (36% of adults, 20% of children). Fifty-six patients (65%) had toxic shock syndrome. Organ support requirements were high and included invasive mechanical ventilation (77% of adults, 50% of children), renal replacement therapy (29% of adults, 3% of children) and extracorporeal membrane oxygenation (20% of adults, 7% of children). Mortality was 21% in adults and 3% in children. Genomic analysis of S. pyogenes strains from 55 out of 86 patients showed a predominance of emm1 strains (73%), with a replacement of the M1global lineage by the toxigenic M1UK lineage (83% of emm1 strains were M1UK).ConclusionsThe recent rise of severe GAS infections (2022–23) is associated with introduction of the M1UK lineage in Belgium, but other factors may be at play—including intense circulation of respiratory viruses and potentially an immune debt after the COVID pandemic. Importantly, critical care physicians should include S. pyogenes as causative pathogen in the differential diagnosis of sCAP.

The Canine Vaginal Flora: A Large-Cohort Retrospective Study.

Microbiological examinations are frequently performed as part of breeding management examinations in the bitch, but also in case of (suspected) reproductive tract problems. As most bacteria are opportunistic pathogens, evaluation of bacterial findings is challenging for veterinarians. Besides, breeders might request antimicrobial treatment in breeding bitches, fearing conception failure-even without medical indication. Considering the rising threat of antimicrobial resistance, gaining deeper insights into the bacterial findings from the vagina of healthy and (suspected) reproductive-diseased bitches might contribute to the knowledge of the canine aerobic vaginal flora and consequently improve the responsible use of antibiotics. We analyzed results from bacteriological cultures of 23,254 vaginal swabs sent in to three commercial laboratories in Germany between 2015 and 2021, where standard aerobic microbiological examination was carried out. We found a variety of 319 bacterial species that mostly grew in mixed cultures of two or more bacterial species. Commonly found species were Escherichia coli, beta-hemolytic Streptococci, coagulase-positive Staphylococci, Pasteurellales, and aerobic sporulators, as well as other Streptococcus spp. Our results showed a large diversity of the canine vaginal flora in healthy and (suspected) reproductive-diseased bitches. They largely support earlier findings of small studies on the physiological canine vaginal flora, emphasizing that solely the results of a bacterial evaluation should not be the base for antimicrobial treatment. Instead, bacterial findings should be evaluated with the results of a clinical gynecological examination.

The current status of Group B Streptococcus infection in the reproductive tract of late-pregnancy women and its impact on pregnancy outcomes.

Analyze Group B Streptococcus (GBS) infection in late-pregnancy pregnant women in Shanghai, the risk factors of GBS infection, and its impact on pregnancy outcomes, providing guidance for early prevention and treatment in clinical practice. We selected 12,132 late-pregnancy pregnant women admitted from January 2022 to December 2022 as the research subjects. Based on the GBS test results of reproductive tract secretion samples from pregnant women, 210 cases of GBS positive pregnant women were randomly selected as the observation group, and 200 cases of GBS negative pregnant women were selected as the control group. The risk factors of infection and the impact on pregnancy outcomes were compared between the two groups. The GBS colonization rate of pregnant women in this study was 6.52%; the incidence of Vaginal delivery and Neonatal infection in GBS positive group was significantly higher than that in GBS negative group (P < 0.05); with Neonatal infection as the dependent variable, and the GBS infection, Vaginal delivery and GDM of the elderly and women in late pregnancy as independent variables, the results showed that GBS infection of women in late pregnancy was an independent risk factor for Neonatal infection. Clinical practice should attach great importance to GBS infection in late pregnancy, strengthen GBS screening in late pregnancy, and actively implement the strategy of intrapartum antibiotic intervention (IAP), which is of great significance in reducing the vertical infection rate of maternal and infant GBS and improving the quality of newborn birth.

Myocardial dysfunction and thrombocytopenia, rare manifestations of acute post-streptococcal glomerulonephritis: case report

In this case report, we present two rare cases of acute post-streptococcal glomerulonephritis with unusual manifestations in the form of myocardial dysfunction and thrombocytopenia. APSGN typically follows Streptococcal infections and is characterized by inflammation of glomeruli. These cases, however, exhibited additional complexities. The first case involved a 12-year-old male with fever, shortness of breath, and cough. He presented with pedal edema, pallor, and hypertension. Laboratory findings revealed thrombocytopenia, anemia, and decreased C3 levels, while echocardiography indicated grade-3 diastolic dysfunction. The second case featured a 5-year-old female with icterus, fever, and body swelling. She had a palpable liver, pleural effusion, and thrombocytopenia. Both cases were diagnosed with APSGN, congestive heart failure, and thrombocytopenia. Thrombocytopenia is a rare finding in APSGN, and its etiology remains debated. Treatment included decongestive therapy and antihypertensive medication. Notably, thrombocytopenia in both cases improved without specific intervention, challenging the necessity of steroids or IVIg therapy. This report illuminates on the atypical presentation of APSGN, highlighting the potential coexistence of glomerulonephritis and thrombocytopenia. It underscores the need for further research to better understand this association and determine appropriate treatment protocols. These cases emphasize the importance of considering diverse clinical manifestations in the context of APSGN, calling for a broader understanding of this condition.

Postpandemic Rebound in Noninvasive Group a Streptococcal Disease is not Synchronous with Winter RSV and Influenza Epidemics.

An increase in invasive group A Streptococcus infections was reported in 2022, associated with intense respiratory virus circulation. We describe a marked increase of noninvasive group A Streptococcus infections. Although the rise coincided with epidemics of respiratory syncytial virus and influenza, it continued after detection of these viruses fell to low levels, suggesting that other factors have contributed to this epidemiologic change.

Early-onset group B streptococcal infections in five Nordic countries with different prevention policies, 1995 to 2019.

BackgroundNeonatal early-onset disease caused by group B Streptococcus (GBS) is a leading cause of infant morbidity. Intrapartum antibiotic prophylaxis (IAP) is effective in preventing early-onset GBS disease, but there is no agreement on the optimal strategy for identifying the pregnant women requiring this treatment, and both risk-based prophylaxis (RBP) and GBS screening-based prophylaxis (SBP) are used.AimThe aim of this study was to evaluate the effect of SBP as a public health intervention on the epidemiology of early-onset GBS infections.MethodsIn 2012, Finland started the universal SBP, while Denmark, Iceland, Norway and Sweden continued with RBP. We conducted an interrupted time series analysis taking 2012 as the intervention point to evaluate the impact of this intervention. The incidences of early- and late-onset GBS infections during Period I (1995-2011) and Period II (2012-2019) were collected from each national register, covering 6,605,564 live births.ResultsIn Finland, a reduction of 58% in the incidence of early-onset GBS disease, corresponding to an incidence rate ratio (IRR) of 0.42 (95% CI: 0.34-0.52), was observed after 2012. At the same time, the pooled IRR of other Nordic countries was 0.89 (95% CI: 0.80-1.0), specifically 0.89 (95% CI: 0.70-1.5) in Denmark, 0.34 (95% CI: 0.15-0.81) in Iceland, 0.72 (95% CI: 0.59-0.88) in Norway and 0.97 (95% CI: 0.85-1.1) in Sweden.ConclusionsIn this ecological study of five Nordic countries, early-onset GBS infections were approximately halved following introduction of the SBP approach as compared with RBP.

Toxic Shock Syndrome: A Literature Review.

Toxic shock syndrome (TSS) is a rare, life-threatening, toxin-mediated infectious process linked, in the vast majority of cases, to toxin-producing strains of Staphylococcus aureus or Streptococcus pyogenes. The pathophysiology, epidemiology, clinical presentation, microbiological features, management and outcome of TSS are described in this review. Bacterial superantigenic exotoxins induces unconventional polyclonal lymphocyte activation, which leads to rapid shock, multiple organ failure syndrome, and death. The main described superantigenic exotoxins are toxic shock syndrome toxin-1 (TSST-1) and enterotoxins for Staphylococcus aureus and Streptococcal pyrogenic exotoxins (SpE) A, B, and C and streptococcal superantigen A (SsA) for Streptococcus pyogenes. Staphylococcal TSS can be menstrual or nonmenstrual. Streptococcal TSS is linked to a severe group A streptococcal infection and, most frequently, to a necrotizing soft tissue infection. Management of TSS is a medical emergency and relies on early detection, immediate resuscitation, source control and eradication of toxin production, bactericidal antibiotic treatment, and protein synthesis inhibiting antibiotic administration. The interest of polyclonal intravenous immunoglobulin G administration as an adjunctive treatment for TSS requires further evaluation. Scientific literature on TSS mainly consists of observational studies, clinical cases, and in vitro data; although more data on TSS are required, additional studies will be difficult to conduct due to the low incidence of the disease.

Green synthesized silver nanoparticles (AgNPs) using aqueous extract of &lt;i&gt;Calotropis procera&lt;/i&gt; and its antimicrobial activity on clinical bacteria isolates

The green synthesis of nanoparticles, utilizing aqueous plant extract as a capping and stabilizing agent, has attracted significant attention in various domains, particularly in pharmaceuticals and drug delivery. In this investigation, silver nitrate (AgNO3) salts were employed as precursors to fabricate silver nanoparticles using Calotropis procera (leaves/flower) extract, and the resulting nanoparticles were characterized. Fourier Transform Infrared (FTIR) spectroscopy revealed three primary functional groups at peaks of 2851.4 cm-1, 1543.1 cm-1, and 1323.2 cm-1, responsible for capping and stabilizing the synthesized C.p-AgNPs. Scanning Electron Microscopy (SEM) demonstrated that the synthesized C.p-AgNPs exhibited spherical shapes with an average particle size ranging from 20 nm to 30 nm. Energy-dispersive X-ray (EDX) analysis of the synthesized C.p-AgNPs indicated the presence of pure silver (Ag) at 54.32% in the region of 2.7 to 3.1 keV. Furthermore, the antimicrobial activity of C.p-AgNPs was examined, with the best inhibition observed at 0.5 mg/mL on Gram-negative bacteria S. aureus (12.0 mm) and Streptococcus spp (13.0 mm), and on Gram-positive bacteria E. coli (16.0 mm) and Salmonella spp (14.0 mm). The antimicrobial efficacy was dose-dependent, suggesting the potential for eradicating resistant human pathogenic bacteria. The antibacterial potential of C.p-AgNPs could be enhanced by increasing their concentration, depending on the specific application. Based on the study's findings, C.p-AgNPs derived from Calotropis procera can be employed for various biomedical purposes, such as textile coating by incorporating C.p-AgNPs in fibers and food storage by nanocapsulation of food items to extend their shelf life.

Influence of streptococcal infection on the appearance of caries in the background of chronic rheumatoid arthritis and the transmitted coronavirus infection COVID-19 (literature review)

Relevance. Caries of hard dental tissues is one of the most common diseases throughout the world. It affects not only the primary teeth of children, but also the permanent teeth of adults, which can lead to serious consequences for human health. In recent years, the dental community has paid special attention to the possible connection between streptococcal infection and the development of caries, and therefore this topic is extremely relevant and requires detailed consideration. Chronic rheumatoid arthritis (CRA) is one of the most common joint diseases, which is characterized by inflammation of the joint lining and destruction of cartilage. Patients with CPA are also at high risk of developing dental caries, which may be due to many factors, including changes in saliva composition and long-term use of medications.Purpose of the study: to study the effect of streptococcal infection on the occurrence of caries among patients suffering from chronic rheumatoid arthritis. To assess the incidence of caries complications caused by streptococcal infection among patients who have had COVID-19.Materials and methods of research. The authors analyzed domestic and foreign literature in order to conduct a literature review regarding the etiology of the occurrence and relationship of streptococcal infection and caries against the background of rheumatoid arthritis. The authors also analyze the incidence of caries complications caused by streptococcal infection as a consequence of COVID-19. Data from 160 patients, 100 men and 60 women, were studied.Conclusion. From the studies conducted, we can conclude that streptococcal infection is one of the factors influencing the development of caries. However, the exact mechanisms of interaction between bacteria and hard dental tissues have not yet been established. As a result of the analysis, it was revealed that the relationship between streptococcal infection and the occurrence of caries against the background of chronic rheumatoid arthritis is significant. The presence of streptococcal infections in patients with rheumatoid arthritis can lead to deterioration of oral health, which in turn contributes to the development of dental caries. Among patients who have had COVID-19, there is a fairly high percentage of caries, including those caused by streptococcal infection and a general deterioration in the health of the oral cavity and the body as a whole.

Microbiological Profile and Antimicrobial Susceptibility Patterns in Patients with Tinea Pedis at Diabetic Center In EL-Beyda City

The purpose of this study was to determine the microbiological profile and antimicrobial susceptibility patterns in patients with Tinea Pedis at the Diabetic Center in EL-Beyda City (Libya). Samples were collected from the diabetic patients with intertrigo of foot attending the out-patients’ department in the Diabetic Center from December 2020 to February 2021 by using sterile swabs. Samples were inoculated into blood and MacConkey agars for bacterial isolation. The microbiologic isolation and antimicrobial susceptibility tests were performed according to standard microbiological methods. Antibiotic susceptibility patterns of all the isolates to different antibiotics was determined by antimicrobial susceptibility testing. Overall, 50 patients (50% male and 50% female) had a mean age of 58.4 ± 9.4 years and a mean duration of diabetes of 14.6 ± 6.6 years. Most isolates (76.8 %) were Gram-negative bacilli (Escherichia coli, Pseudomonas aeruginosa, Klebsiella Spp and Proteus Spp), followed by Gram-positive cocci (23.2%) (Streptococci Spp and Staphylococcus aureus). Most bacteria were sensitive to Ciprofloxacin (84.0%) and resistant to Erythromycin (42.0%). The majority of isolated bacteria from patients were found to be multi-drug resistant. The results demonstrate the importance of time in the identification of the intertrigo sample collection for the identification of the pathogens and their antibiotic susceptibility pattern before initiating antimicrobial treatment.

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

Group A Streptococcus (GAS) causes multiple clinical manifestations, including invasive (iGAS) or even life-threatening (severe-iGAS) infections. After the drop in cases during COVID-19 pandemic, in 2022 a sharp increase of GAS was reported globally. GAS strains collected in 09/2022-03/2023 in two university hospitals in Milan, Italy were retrospectively analyzed. Clinical/epidemiological data were combined with whole-genome sequencing to: (i) define resistome/virulome, (ii) identify putative transmission chains, (iii) explore associations between emm-types and clinical severity. Twenty-eight isolates were available, 19/28 (67.9%) from adults and 9/28 (32.1%) from pediatric population. The criteria for iGAS were met by 19/28 cases (67.9%), of which 11/19 (39.3%) met the further criteria for severe-iGAS. Pediatric cases were mainly non-invasive infections (8/9, 88.9%), adult cases were iGAS and severe-iGAS in 18/19 (94.7%) and 10/19 (52.6%), respectively. Thirteen emm-types were detected, the most prevalent being emm1 and emm12 (6/28 strains each, 21.4%). Single nucleotide polymorphism (SNP) analysis of emm1.0 and emm12.0 strains revealed pairwise SNP distance always >10, inconsistent with unique transmission chains. Emm12.0-type, found to almost exclusively carry virulence factors speH and speI, was mainly detected in children and in no-iGAS infections (55.6 vs. 5.3%, p = 0.007 and 66.7 vs. 0.0%, p < 0.001, respectively), while emm1.0-type was mainly detected in severe-iGAS (0.0 vs. 45.5%, p = 0.045). This study showed that multiple emm-types contributed to a 2022/2023 GAS infection increase in two hospitals in Milan, with no evidence of direct transmission chains. Specific emm-types could be associated with disease severity or invasiveness. Overall, these results support the integration of classical epidemiological studies with genomic investigation to appropriately manage severe infections and improve surveillance.

Associations of &lt;i&gt;TLR&lt;/i&gt; gene polymorphism with the risk of rheumatic heart disease

Aim of the study was to investigate the associations between TLR gene polymorphism and the risk of rheumatic heart disease (RHD).Material and methods. 251 RHD patients (190 females and 61 males) and 300 healthy donors (190 females and 110 males), whose age was 57 [29; 77] and 53 [21; 80] years (median [lower quartile; upper quartile]), respectively, were recruited in the presented study. Eight polymorphic variants in the TLR gene were genotyped by realtime PCR.Results. We found no statistically significant differences in the frequency of eight polymorphic variants in the TLR1, TLR2, TLR4 and TLR6 genes in the general group of patients. Stratification by gender and age showed that the frequency of the C/C genotype of the TLR1 gene (rs5743551) was increased in females with RHD (11.6 %) compared to the control group (5.3 %); a risk effect was determined for recessive inheritance patterns (odds ratio 2.43, 95 % confidence interval 1.07–5.52, p = 0.029). Moreover, the combination of polymorphic variants TLR2 (rs5743708) – TLR4 (rs4689791) – TLR1 (rs5743551) – TLR2 (rs3804099) showed the greatest significance in RHD risk.Conclusions. Future research on the different populations will allow to discover the general patterns of RHD pathogenesis, which will finally lead to the establishment of therapeutic targets for treatment of streptococcal infection and RHD prevention.