Streptococcus Pyogenes Research Articles

Epidemiology of Streptococcus pyogenes Disease before, during, and after COVID-19 Pandemic, Germany, 2005-2023.

We analyzed 3,081 invasive and noninvasive Streptococcus pyogenes cases (January 2005-December 2023) at a tertiary care hospital in southwest Germany. Absolute numbers of case-patients increased each year from 2005 until the COVID-19 pandemic. Odds ratios for invasive streptococcal disease were significantly influenced by year, male sex, and older age.

PhieDBEs: a DBD-containing, PAM-flexible, high-efficiency dual base editor toolbox with wide targeting scope for use in plants.

Dual base editors (DBEs) enable simultaneous A-to-G and C-to-T conversions, expanding mutation types. However, low editing efficiency and narrow targeting range limit the widespread use of DBEs in plants. The single-strand DNA binding domain of RAD51 DBD can be fused to base editors to improve their editing efficiency. However, it remains unclear how the DBD affects dual base editing performance in plants. In this study, we generated a series of novel plant DBE-SpGn tools consisting of nine constructs using the high-activity cytidine deaminase evoFERNY, adenosine deaminase TadA8e and DBD in various fusion modes with the PAM-flexible Streptococcus pyogenes Cas9 (SpCas9) nickase variant SpGn (with NG-PAM). By analysing their editing performance on 48 targets in rice, we found that DBE-SpGn constructs containing a single DBD and deaminases located at the N-terminus of SpGn exhibited the highest editing efficiencies. Meanwhile, constructs with deaminases located at the C-terminus and/or multiple DBDs failed to function normally and exhibited inhibited editing activity. We identified three particularly high-efficiency dual base editors (C-A-SpGn, C-A-D-SpGn and A-C-D-SpGn), named PhieDBEs (Plant high-efficiency dual base editors), capable of producing efficient dual base conversions within a narrow editing window (M5 ~ M9, M = A/C). The editing efficiency of C-A-D-SpGn was as high as 95.2% at certain target sites, with frequencies of simultaneous C-to-T and A-to-G conversions as high as 81.0%. In summary, PhieDBEs (especially C-A-D-SpGn) can produce diverse mutants and may prove useful in a wide variety of applications, including plant functional genomics, precise mutagenesis, directed evolution and crop genetic improvement, among others.

A novel methionyl-tRNA synthetase inhibitor targeting gram-positive bacterial pathogens.

New antibiotics are needed to treat gram-positive bacterial pathogens. MRS-2541 is a novel inhibitor of methionyl-tRNA synthetase with selective activity against gram-positive bacteria. The minimum inhibitory concentrations (MICs) against Staphylococcus aureus, Streptococcus pyogenes, and Enterococcus species range from 0.063 to 0.5 µg/mL. Given orally to mice at 50 mg/kg every 8 hours, MRS-2541 shows sustained plasma levels well above these MICs. In the mouse thigh infection model, MRS-2541 decreased methicillin-resistant Staphylococcus aureus and Streptococcus pyogenes bacterial loads to the same degree as linezolid. MRS-2541 is a promising new antibiotic for development against skin and soft tissue infections.

Necrotizing fasciitis: treatment concepts & clinical outcomes – an institutional experience

BackgroundA severe infection of the skin and soft tissues, Necrotizing Fasciitis (NF), spreads quickly along the deep fascia. This study aimed to characterize the clinicopathological features, analyze the implicated bacteria’s antibiotic sensitivity, evaluate surgical management, and assess the diagnostic accuracy of the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score in Necrotizing Soft Tissue Infection (NST).MethodsThis single-center prospective observational study was conducted in the Department of General Surgery, Kasturba Medical College, Manipal, with 171 proven cases of NSTI between 2019 and 2021. Clinico-demographic data and laboratory investigation values were collected at two-time points (at admission and 72 h after admission). Imaging data, LRINEC score, culture results, and antibiotic sensitivity were recorded. Appropriate descriptive and analytical statistics were used for the statistical analysis.ResultsOf the 171 patients, 150 were male (87.7%). The mean age was 57.6 ± 13.1 years. The presenting features in all the cases were pain, swelling, and fever. Diabetes mellitus (DM) is the most common comorbidity. The lower extremities were the most commonly affected sites. Streptococcus pyogenes showed significant growth in 25.41% of the samples. Ceftriaxone sensitivity was seen in 41/141. A score of ≥ 8 was obtained in 118/171 (69%) patients, suggesting a higher severity and significant risk for NSTI. The Area Under the Curve of Receiver Operating characteristic Curve (ROC) for establishing diagnostic accuracy for LRINEC was 0.694. Mortality was significantly higher in the patients with higher LRINEC scores and elevated procalcitonin. The mortality rate was higher in patients who underwent surgery within 12 h.ConclusionNecrotizing fasciitis is a soft tissue infection with a high mortality rate. The clinical features and determinants of mortality in patients with NF are highlighted in this study. At the outset, a high index of suspicion was critical. Using prognostic evaluation techniques in daily clinical practice will assist medical professionals in providing adequate on-time care and significantly lowering mortality. The AUC for LRINEC score, although significant, is low. LRINEC score is not to be used to determine whether surgical intervention should be expedited or anticipated. Its role is to aid in prognosticating the outcome of the individual patient. Our study concludes that early extensive surgical debridement remains the single most crucial intervention in patients diagnosed with necrotizing fasciitis (NF), regardless of disease severity and the LRINEC score.

Insertion sequence elements and unique symmetrical genomic regions mediate chromosomal inversions in Streptococcus pyogenes.

Chromosomal inversions are a phenomenon in many bacterial species, often across the axis of replication. Inversions have been shown to alter gene expression, changing persistence of colonisation and infection following environmental stresses. In Streptococcus pyogenes, inversions have been reported. However, frequency and molecular markers of inversions have not been systematically examined. Here, 249 complete S.pyogenes genomes were analysed using a pangenomic core gene synteny framework to identify sequences associated with inversions. 47% of genomes (118/249) contained at least one inversion, from 23 unique inversion locations. Chromosomal locations enabling inversions were usually associated with mobile elements (insertion sequences n=9 and prophages n=7). Two insertion sequences, IS1548 and IS1239, accounted for>80% of insertion sequences and were the only insertion sequences associated with inversions. The most observed inversion location (n=104 genomes, 88% of genomes with an inversion) occurs between two conserved regions encoding rRNAs, tRNAsand sigma factor genes. The regions are symmetrically placed around the origin of replication forming a unique chromosomal structure inS. pyogenes, relative to other streptococci. Cataloging of thechromosomal location and frequency of inversions can direct dissection of phenotypic changes following chromosomal inversions. The framework used here can be transferred to other bacterial species to characterise chromosomal inversions.

The heart of the matter: a re-iteration of the role of the social determinants of health in addressing health inequity in Central Australia.

The persisting life-expectancy 'gap' between First Nations and non-First Nations Australians is fundamentally driven by the social determinants of health. These include income and social protection, access to adequate housing and food security, among others. These factors are particularly prominent in Central Australia. Inadequate housing has led to some of the highest rates of Streptococcus pyogenes infection in the world, which in turn drives an extremely high prevalence of rheumatic heart disease. Food insecurity and inadequate social protection manifesting as energy insecurity result in inadequate nutrition and have resulted in a huge burden of diabetes in Central Australia. These factors, combined with social exclusion, racism and the pervasive effect of colonisation, also drive a high rate of alcohol misuse. Only by prioritising equity in these 'social determinants' and emphasising the importance of First Nations leadership in formulating and implementing solutions will health inequity be addressed.

Antimicrobial and antioxidant activities of Bromelin Propolis Spray

The indiscriminate use of antibiotics over the last 60 years has led to the development of resistant strains, leading an urgent need for new treatments, new molecules or combinations of products, safety and effective. In this regard, propolis has been used in traditional medicine due its therapeutic effects, such as antibacterial, antifungal and antiseptic, tested in vitro, in vivo and clinically. The aim of this study is to evaluate the antimicrobial and antioxidant activities of a commercial oral flavoring product against bacterial strains of clinical interest from the upper respiratory tract. Bacteria sensitivity against Bromelin Propolis Sprayâ (BPS) was evaluated using macrodilution in broth and no turbid tubes plated on TSA to confirm the results. Tested bacteria were Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa. BPS showed antimicrobial activity for all tested strains and the MBC was 2.5mg/mL. Moreover, the antioxidant activity was determined by the ability to scavenge the stable radical DPPH. 0.007% of BPS showed the maximum antioxidant effect, of 6.63mM, which demonstrate its high antioxidant effect. Therefore, these results indicate that the commercial product BPS at 0.7% can be a potential candidate as adjuvant in antibiotic therapy for upper respiratory tract disorders, due possible antimicrobial effect and its high antioxidant potential.

Impact of the COVID-19 Pandemic on Pediatric Bacterial Community-Acquired Pneumonia: A Multicenter Retrospective Study in Madrid (Spain).

This study conducted in Madrid (Spain) between 2018 and 2023 shows a significant decrease in the pediatric bacterial community-acquired pneumonia cases during the COVID-19 pandemic, followed by a notable postpandemic increase surpassing prepandemic incidence. Streptococcus pneumoniae remains predominant, with an increasing prevalence of serotype 3, while Streptococcus pyogenes was the second most common pathogen.

ICESp1109, a novel hybrid Integrative Conjugative Element of macrolide-resistant Streptococcus pyogenes serotype M77 collected between 2003 and 2017 in Poland.

Genetic characterization of the antibiotic resistance determinants and associated mobile genetic elements (MGEs) among Streptococcus pyogenes [Group A streptococci (GAS)] clinical isolates of an M77 serotype collected in Poland between 2003 and 2017. The genomes of 136 M77 GAS isolates were sequenced using Illumina, and selected with long-read approach (Oxford Nanopore). Whole genome sequences were analyzed to determine the presence of macrolide resistance determinants, and their genetic context. The strains used in the study were collected in the two multicenter surveys from in- and outpatients. Sequencing data analysis revealed that all strains carried the tet(O) gene (100%, N=136). They were classified as a single sequence type ST63. For erythromycin resistance, the unique determinant was erm(TR) detected in 76.5% (N=104) isolates. A single appearance of tet(M) and erm(B) on Tn3872 was noticed. The mefA, mefE, and msr(D) genes were detected in neither of the genomes. This correlated with the detected strain phenotypes - 11 exhibited cMLSB, 93 - iMLSB, and no M phenotype.The erm(TR) gene was predominantly (N=74) found within a novel hybrid Integrative Conjugative Element composed of the ICESp1108-like sequence and ICESp2906 variant which was then named ICESp1109. However, in strains isolated before 2008, erm(TR) was located within ICESp2905 (N=27). The erm(TR) gene was detected within stand-alone ICESp1108-like sequences in 3 strains. Based on phylogenetic analysis results the clonal dissemination of the macrolide-resistant S. pyogenes M77/ST63 strain with hybrid ICESp1109 was observed between 2008 and 2017. ICESp1109 is the novel hybrid ICE in Gram-positive bacteria.

In vitro antioxidant and antibacterial activities of Ajuga integrifolia leaf extracts obtained with different solvents

BackgroundMany diseases are increasingly recognized as public health concerns worldwide because of the increasing incidence of multidrug-resistant bacteria. Recently, interest in the use of indigenous medicinal plants to treat infectious illnesses has increased, highlighting the need to find new bioactive phytochemicals. Ajuga integrifolia is a plant commonly utilized in traditional drugs to treat a wide range of diseases, although its effectiveness has not been scientifically validated. The present study aimed to evaluate the total phenolic and flavonoid contents and assess the biological activities of A. integrifolia leaf extracts produced via different solvent systems.MethodsSoxhlet extraction was employed to obtain crude extracts from different solvents (methanol, ethanol and water). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing power assays were used to measure the antioxidant activity, and the antibacterial activity of the extract was evaluated on the basis of its minimum inhibitory concentration (MIC) against two gram-negative bacteria (Escherichia coli (ATCC-25922) and Pseudomonas aeruginosa (ATCC-43495)) and two gram-positive bacteria (Staphylococcus aureus (ATCC-25923) and Streptococcus pyogenes (ATCC-19615)) via the agar disk-diffusion technique.ResultsA significant amount of total phenolic content (TPC) and flavonoid content (TFC) were present in all the extracts. The extracts presented powerful antioxidant activity in all the assays. The disc diffusion and MIC results revealed the ability of the methanol and ethanol extracts of A. integrifolia leaves to inhibit S. aureus growth at a concentration of 3.125 mg/mL. However, the water extracts were ineffective against E. coli and P. aeruginosa.ConclusionsThese findings indicate that A. integrifolia leaf extracts have reasonable biological activities. These findings underscore the importance of A. integrifolia leaves as a source of health benefits.

Novel motif associated with carbon catabolite repression in two major Gram-positive pathogen virulence regulatory proteins.

Carbon catabolite repression (CCR) is a widely conserved regulatory process that ensures enzymes and transporters of less-preferred carbohydrates are transcriptionally repressed in the presence of a preferred carbohydrate. This phenomenon can be regulated via a CcpA-dependent or CcpA-independent mechanism. The CcpA-independent mechanism typically requires a transcriptional regulator harboring a phosphotransferase regulatory domain (PRD) that interacts with phosphotransferase system (PTS) components. PRDs contain a conserved histidine residue that is phosphorylated by the PTS-associated HPr-His15~P protein. PRD-containing regulators often harbor additional domains that resemble PTS-associated EIIB protein domains with a conserved cysteine residue that can be phosphorylated by cognate PTS components. We noted that Mga, the PRD-containing central virulence regulator of Streptococcus pyogenes, has an EIIBGat domain containing a cysteine that, based on the presence of a similar motif in glycerol kinase, could be a target for phosphorylation. Using site-directed mutagenesis, we constructed phospho-ablative and phospho-mimetic substitutions of this cysteine and found that these substitutions modify the CCR of the Rgg2/3 quorum-sensing system. Moreover, we provide genetic evidence that the phospho-donor of this cysteine residue is likely to be ManL, the EIIA/B subunit of the mannose PTS system. Interestingly, a structurally distinct virulence gene regulator, PrfA of Listeria monocytogenes, harbors a similar cysteine-containing motif, and phospho-ablative and phospho-mimetic substitutions of the cysteine-altered CCR of PrfA-dependent virulence gene expression. Collectively, our data suggest that phosphorylation of a cysteine within the shared novel motif in Mga and PrfA may be a heretofore missing link between cellular metabolism and virulence.IMPORTANCEIn this study, we identified a novel cysteine-containing motif within the amino acid sequence of two structurally distinct transcriptional regulators of virulence in two Gram-positive pathogens that appears to link carbon metabolism with virulence gene expression. The results also highlight the potential post-translational modification of cysteine in bacterial species, a rare and understudied modification.

Etiology, Clinical Profiles, and Outcomes of Acute Encephalitis Syndrome Cases Admitted to a Tertiary Care Center in Myanmar in 2023.

The diagnosis of encephalitis is a challenging problem due to the heterogeneity of clinical presentations. The objective was to determine the etiology, clinical features, laboratory parameters, radiological findings, and in-hospital outcome of acute encephalitis syndrome (AES) cases in Myanmar. A prospective descriptive study was conducted at the Neuromedical Ward of Yangon General Hospital from March to August 2023. Eighty-one AES cases were enrolled, and cerebrospinal fluid (CSF) samples were collected. A Qiastat ME Panel was used to detect viral, bacterial, and fungal pathogens. Seventeen out of eighty-one (21%) cases were non-encephalitis with alternative definite diagnosis. Among the remaining 64 encephalitis cases, the exact infectious and immune etiologies were identified in 31 of 64 cases (48.4%); 26 of these (83.9%) were due to infectious causes and 5 (16.1%) were immune encephalitis. Among the infectious causes, six Herpes Simplex Virus-1-, one bacteriologically confirmed and seven probable Mycobacterium tuberculosis-, three Haemophilus influenzae-, two Streptococcus pneumoniae-, one Streptococcus pyogenes-, one Varicella-Zoster Virus (Ramsay Hunt Syndrome with meningoencephalitis)-, and two Cryptococcus neoformans-infected patients and rare causes such as Listeria monocytogenes, Burkholdelria cepacia, Sphingomonas paucimobilis, and Aspergillus were identified. One case was a dual infection with Haemophilus influenzae and Cryptococcus neformans. Abnormal protein levels and CSF pleocytosis were significantly higher among bacterial causes (p < 0.05). In total, 6.45% (2/31) of encephalitis patients with identified causes and 12.12% (4/33) of those without an identified organism had poor outcome. Herpes encephalitis and tuberculous meningoencepalitis were the commonest. This study highlighted that molecular testing with a multidisciplinary approach is required to ensure the right treatment on time.

Serological responses to target Streptococcus pyogenes vaccine antigens in patients with proven invasive beta-haemolytic streptococcal infections.

Rising incidence of invasive beta-haemolytic streptococcal (iBHS) infections has prompted consideration of vaccination as a preventative strategy for at-risk populations. The benefits of a vaccine targeting Lancefield group A (Streptococcus pyogenes; Strep A) would increase if cross-species immunity against Lancefield groups C/G (Streptococcus dysgalactiae subspecies equisimilis; SDSE) and B (Streptococcus agalactiae; GBS) was demonstrated. A prospective, observational study of adult patients with iBHS infections due to Strep A, SDSE or GBS. Antibody responses to six Strep A candidate antigens were assayed on acute and convalescent sera. A serological response was defined as an increase of >0.2log10 arbitrary units/mL (AU/mL). Sixty-seven participants were enrolled. Thirty-three participants were included in the final analysis (12, 11 and 10 with Strep A, SDSE and GBS, respectively). The median serological response for participants with Strep A was significant for all tested antigens (median >0.2log10 difference between acute and convalescent samples; P<0.05 for all). Those with SDSE had comparable and significant median (IQR) responses to streptolysin-O (0.65 [0.36-1.67], P=0.004), S. pyogenes adhesion and division protein (0.68 [0.36-1.63], P=0.005) and C5a peptidase (ScpA; 0.30 [0.23-1.06]), P=0.004). GBS responses were limited to ScpA only (0.34 [0.08-0.52], P=0.05). Patients with invasive Strep A infection mount robust antibody responses to six non-M protein vaccine candidate antigens. Similar significant responses to C5a peptidase in those with invasive SDSE and GBS infection highlight the importance of further research into cross-species protection and immunological correlates of vaccine efficacy.

Bakteri Penyebab Gingivitis dan Sensitivitas Antibiotik Pada Pasien Diabetes Melitus

Gingivitis is an inflammation of the gingiva caused by plaque and poor oral hygiene, including in patients with long-term diabetes mellitus and uncontrolled blood glucose. Gingivitis is caused by various bacteria such as Streptococcus sp, Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and also the Enterobacteriaceae family, Haemophilus influenzae and Actinomycetes. Management of infection with antibiotics, especially beta-lactam class. The study aimed to determine the characteristics of the research subjects, the type of bacteria, and their sensitivity to the bacteria that cause gingivitis in diabetes mellitus (DM) patients. The research was a cross-sectional descriptive study at the internal medicine polyclinic at Arifin Achmad Hospital, Riau Province, and the Microbiology Laboratory of Medical Faculty, Universitas Riau. The research sample was a gingivitis plaque swab in DM patients who signed an informed consent. Samples were cultured, identified, and tested for antibiotic sensitivity. The results of the study obtained 34 samples with characteristics aged 33-67 years, most of them were women, high school education/equivalent, civil servants/army/police/retired. Most aerobic bacteria Klebsiella sp. The highest sensitivity to levofloxacin, amikacin, ciprofloxacin, trimethoprim-sulfamethoxazole, and meropenem, the lowest sensitivity to amoxicillin, ceftazidim, and amoxicillin-clavulanic acid.

Synthesis, Physicochemical Characterization, and Antimicrobial Evaluation of Halogen-Substituted Non-Metal Pyridine Schiff Bases

Four synthetic Schiff bases (PSB1 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4,6-dibromophenol], PSB2 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4,6-diiodophenol], PSB3 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4-iodophenol], and PSB4 [(E)-2-(((4-aminopyridin-3-yl)imino)methyl)-4-chloro-6-iodophenol]) were fully characterized. These compounds exhibit an intramolecular hydrogen bond between the hydroxyl group of the phenolic ring and the nitrogen of the azomethine group, contributing to their stability. Their antimicrobial activity was evaluated against various Gram-negative and Gram-positive bacteria, and it was found that the synthetic pyridine Schiff bases, as well as their precursors, showed no discernible antimicrobial effect on Gram-negative bacteria, including Salmonella Typhi (and mutant derivatives), Salmonella Typhimurium, Escherichia coli, and Morganella morganii. In contrast, a more pronounced biocidal effect against Gram-positive bacteria was found, including Bacillus subtilis, Streptococcus agalactiae, Streptococcus pyogenes, Enterococcus faecalis, Staphylococcus aureus, and Staphylococcus haemolyticus. Among the tested compounds, PSB1 and PSB2 were identified as the most effective against Gram-positive bacteria, with PSB2 showing the most potent biocidal effects. Although the presence of reactive oxygen species (ROS) was noted after treatment with PSB2, the primary mode of action for PSB2 does not appear to involve ROS generation. This conclusion is supported by the observation that antioxidant treatment with vitamin C only partially mitigated bacterial inhibition, indicating an alternative biocidal mechanism.

The double-edged role of FASII regulator FabT in Streptococcus pyogenes infection.

In Streptococcus pyogenes, the type II fatty acid (FA) synthesis pathway FASII is feedback-controlled by the FabT repressor bound to an acyl-Acyl carrier protein. Although FabT defects confer reduced virulence in animal models, spontaneous fabT mutants arise in vivo. We resolved this paradox by characterizing the conditions and mechanisms requiring FabT activity, and those promoting fabT mutant emergence. The fabT defect leads to energy dissipation, limiting mutant growth on human tissue products, which explains the FabT requirement during infection. Conversely, emerging fabT mutants show superior growth in biotopes rich in saturated FAs, where continued FASII activity limits their incorporation. We propose that membrane alterations and continued FASII synthesis are the primary causes for increased fabT mutant mortality in nutrient-limited biotopes, by failing to stop metabolic consumption. Our findings elucidate the rationale for emerging fabT mutants that improve bacterial survival in lipid-rich biotopes, but lead to a genetic impasse for infection.

Parasitological prevalence of scabies and secondary bacterial infections among scabies suspected patients at Borumeda General Hospital, Northeast Ethiopia

BackgroundScabies disproportionately affects people in resource-poor areas. Clinical diagnosis risks misdiagnosis due to resemblance to other skin diseases, but laboratory confirmation improves accuracy. Scabies allow for secondary bacterial infections. Associated bacteria exacerbate scabies and antibiotic resistance. Ethiopian scabies diagnosis relies solely on clinical exams without confirming parasites or investigating secondary bacterial infections. This study aims to identify parasites via scraping, isolate secondary bacteria, and evaluate their antibiotic susceptibility profiles.MethodsA hospital based cross-sectional study was conducted from September 2022 to July 2023 among scabies suspected patients who visited the dermatology clinic at Borumeda General Hospital in Northeast Ethiopia. A systematic random sampling technique was used to select 422 study participants. Socio-demographic, hygiene, and clinical characteristics data were collected via face-to-face interviews and observation. Skin scrapings for parasitological investigations and swab samples for microbiological investigations were collected and transported for analysis and drug susceptibility testing. Descriptive statistics and logistic regression analysis were employed to assess risk factors.ResultAmong 422 skin scraping samples, 156 (37.0%) cases of scabies were microscopically confirmed. Bed-sharing and having contact history were independent predictors of microscopically confirmed scabies. The prevalence of secondary bacterial infections among scabies-confirmed patients was 35.9% (56/156). The most prevalent bacterial species were Staphylococcus aureus, coagulase-negative staphylococci, and Streptococcus pyogenes. Tetracycline for Gram-positive bacteria and ampicillin for Gram-negative bacteria showed the highest rate of resistance. In both Gram-positive and Gram-negative strains, multidrug resistance was also observed.ConclusionThis study found that over one-third of skin scrapings tested positive for scabies. Additionally, more than one-third of scabies cases were complicated by secondary bacterial infections. Improved scabies diagnosis and consideration of secondary bacterial infections are important for better controlling this neglected tropical disease.

Impact of COVID-19 health precautions on asymptomatic Streptococcus pyogenes carriage in palestinian children: a pre- and post-pandemic study

BackgroundStreptococcus pyogenes (Group A Streptococcus, GAS) is a significant pathogen that causes diverse infections, ranging from pharyngitis to severe invasive diseases. Asymptomatic carriage in children is pivotal for transmission. The COVID-19 pandemic’s health measures, including mask wearing and enhanced hand hygiene, likely influenced GAS transmission dynamics. This study evaluated the impact of these precautions on the prevalence of asymptomatic pharyngeal GAS carriage among schoolchildren in the southern West Bank, Palestine.MethodsThis cross-sectional study was conducted in two phases: pre-COVID-19 (November 2019–January 2020) and post-COVID-19 (November 2023–April 2024). Throat swabs were collected from 701 children (345 pre-COVID-19, 356 post-COVID-19) via cluster sampling. The samples were tested with the ABON Strep A rapid test and confirmed by culture. Sociodemographic, health, and household data were also collected. The statistical analyses included descriptive statistics, chi-square tests, and binary logistic regression.ResultsThe prevalence of asymptomatic pharyngeal GAS carriage declined from 15.7% pre-COVID-19 to 10.4% post-COVID-19 (p = 0.038). Significant reductions were observed among urban residents (23.5–10.1%, p = 0.003) and those from medium socioeconomic backgrounds (16.0–9.1%, p = 0.008). Compared with urban residents, rural residents had lower GAS carriage rates (adjusted OR = 0.505, p = 0.023). Carriage rates also decreased among children with frequent sore throats (17.6–7.3%, p = 0.007) and those using private wells (52.5–14.9%, p < 0.001). Higher BMI was a significant risk factor (adjusted OR = 17.68, p < 0.001), whereas frequent tooth brushing (adjusted OR = 0.055, p < 0.001) and hand washing (adjusted OR = 0.367, p < 0.001) were protective factors.ConclusionsCOVID-19-related health precautions were correlated with a significant reduction in asymptomatic GAS carriage among Palestinian children. These findings suggest that public health measures, such as mask wearing and hand hygiene, can influence the transmission of respiratory pathogens. Ongoing surveillance and targeted interventions are essential for managing GAS infections, particularly in resource-limited settings.

The efficacy of antimicrobial solutions against multispecies bacterial biofilm with or without negative pressure wound therapy in an in vitro wound model.

Biofilm is the major challenge in chronic wound management. Instilling a wound cleansing solution aids in wound bed cleaning and infectious pathogen elimination. Negative pressure wound therapy (NPWT) improves the wound-healing process. This study investigated the efficacy of two antimicrobials (Vashe Wound Cleanser and Prontosan Wound Irrigation Solution) against a multispecies bacterial biofilm with or without NPWT in an in vitro wound model. A mixed multispecies biofilm containing Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, and Acinetobacter baumannii was developed and verified by scanning electron microscopy and fluorescent in situ hybridization. The efficacy of Vashe and Prontosan against multispecies biofilm with or without NPWT was evaluated by colony-forming unit (cfu) of each species and total bacterial number, and visually confirmed by live/dead stain and confocal microscopy. Prontosan reduced biofilm cell numbers significantly: 6 instils over 24 h resulting in 3.86 ± 0.14 cfu log10 reduction without NPWT and 4.75 ± 0.13 cfu log10 reduction combined with NPWT (P < 0.01) and 12 instils over 48 h resulting in 5.24 ± 0.11 cfu log10 reduction without NPWT and biofilm eradication with NPWT (P < 0.001). NPWT alone or combined with Vashe failed to reduce multispecies biofilm numbers significantly over 24 or 48 h. Prontosan significantly reduced biofilm cell numbers, with better efficacy over 48 than 24 h, emphasizing the necessity for persistent and robust treatment. NPWT enhanced the effectiveness of Prontosan instillation. However, NPWT alone or combined with Vashe showed limited efficacy and difficulty when combating the multispecies biofilm in vitro.

Inhibition of Streptococcus pyogenes biofilm by Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus.

The human pathobiont Streptococcus pyogenes forms biofilms and causes infections, such as pharyngotonsillitis and necrotizing fasciitis. Bacterial biofilms are more resilient to antibiotic treatment, and new therapeutic strategies are needed to control biofilm-associated infections, such as recurrent pharyngotonsillitis. Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus are two bacterial commensals used for their probiotic properties. This study aimed to elucidate the anti-biofilm properties of L. plantarum and L. rhamnosus cell-free supernatants (LPSN and LRSN, respectively) on S. pyogenes biofilms grown in vitro in supplemented minimal medium. When planktonic or biofilm S. pyogenes were exposed to LPSN or LRSN, S. pyogenes survival was reduced significantly in a concentration-dependent manner, and the effect was more pronounced on preformed biofilms. Enzymatic digestion of LPSN and LRSN suggested that glycolipid compounds might cause the antimicrobial effect. In conclusion, this study indicates that L. plantarum and L. rhamnosus produce glycolipid bioactive compounds that reduce the viability of S. pyogenes in planktonic and biofilm cultures.IMPORTANCEStreptococcus pyogenes infections are a significant concern for populations at risk, such as children and the elderly, as non-invasive conditions such as impetigo and strep throat can lead to severe invasive diseases such as necrotizing fasciitis. Despite its susceptibility to current antibiotics, the formation of biofilm by this pathogen decreases the efficacy of antibiotic treatment alone. The ability of commensal lactobacillus to kill S. pyogenes has been documented by previous studies using in vitro settings. The relevance of our study is in using a physiological setup and a more detailed understanding of the nature of the lactobacillus molecule affecting the viability of S. pyogenes. This additional knowledge will help for a better comprehension of the molecules' characteristics and kinetics, which in turn will facilitate new avenues of research for its translation to new therapies.