Age-dependent differences in efferocytosis determine the outcome of opsonophagocytic protection from invasive pathogens.

In early life, susceptibility to invasive infection skews toward a small subset of microbes, whereas other pathogens associated with diseases later in life, including Streptococcus pneumoniae (Spn), are uncommon among neonates. To delineate mechanisms behind age-dependent susceptibility, we compared age-specific mouse models of invasive Spn infection. We show enhanced CD11b-dependent opsonophagocytosis by neonatal neutrophils improved protection against Spn during early life. The augmented function of neonatal neutrophils was mediated by higher CD11b surface expression at the population level due to dampened efferocytosis, which also resulted in more CD11bhi "aged" neutrophils in peripheral blood. Dampened efferocytosis during early life could be attributed to the lack of CD169+ macrophages in neonates and reduced systemic expressions of multiple efferocytic mediators, including MerTK. On experimentally impairing efferocytosis later in life, CD11bhi neutrophils increased and protection against Spn improved. Our findings reveal how age-dependent differences in efferocytosis determine infection outcome through the modulation of CD11b-driven opsonophagocytosis and immunity.

Oral streptococci S. anginosus and S. mitis induce distinct morphological, inflammatory, and metabolic signatures in macrophages.

Oral streptococci, key players in oral biofilm formation, are implicated in oral dysbiosis and various clinical conditions, including dental caries, gingivitis, periodontal disease, and oral cancer. Specifically, Streptococcus anginosus is associated with esophageal, gastric, and pharyngeal cancers, while Streptococcus mitis is linked to oral cancer. However, no study has investigated the mechanistic links between these Streptococcus species and cancer-related inflammatory responses. As an initial step, we probed the innate immune response triggered by S. anginosus and S. mitis in RAW264.7 macrophages. These bacteria exerted time- and dose-dependent effects on macrophage morphology without affecting cell viability. Compared with untreated macrophages, macrophages infected with S. anginosus exhibited a robust proinflammatory response characterized by significantly increased levels of inflammatory cytokines and mediators, including TNF, IL-6, IL-1ß, NOS2, and COX2, accompanied by enhanced NF-κB activation. In contrast, S. mitis-infected macrophages failed to elicit a robust inflammatory response. Seahorse Xfe96 analysis revealed an increased extracellular acidification rate in macrophages infected with S. anginosus compared with S. mitis. At the 24-h time point, the presence of S. anginosus led to reduced extracellular itaconate, while S. mitis triggered increased itaconate levels, highlighting distinct metabolic profiles in macrophages during infection in contrast to aconitate decarboxylase expression observed at the 6-h time point. This initial investigation highlights how S. anginosus and S. mitis, two Gram-positive bacteria from the same genus, can prompt distinct immune responses and metabolic shifts in macrophages during infection.IMPORTANCEThe surge in head and neck cancer cases among individuals devoid of typical risk factors such as Human Papilloma Virus (HPV) infection and tobacco and alcohol use sparks an argumentative discussion around the emerging role of oral microbiota as a novel risk factor in oral squamous cell carcinoma (OSCC). While substantial research has dissected the gut microbiome's influence on physiology, the oral microbiome, notably oral streptococci, has been underappreciated during mucosal immunopathogenesis. Streptococcus anginosus, a viridans streptococci group, has been linked to abscess formation and an elevated presence in esophageal cancer and OSCC. The current study aims to probe the innate immune response to S. anginosus compared with the early colonizer Streptococcus mitis as an important first step toward understanding the impact of distinct oral Streptococcus species on the host immune response, which is an understudied determinant of OSCC development and progression.

Evaluation of the HANDOC Score and the 2023 International Society of Cardiovascular Infectious Diseases and European Society of Cardiology Duke Clinical Criteria for the Diagnosis of Infective Endocarditis Among Patients With Streptococcal Bacteremia.

BACKGROUND: Streptococci are a common cause of infective endocarditis (IE). We aimed to evaluate the performance of the HANDOC score to identify patients at high risk for IE and the Duke clinical criteria of the European Society of Cardiology (ESC; 2015 and 2023 versions) and the 2023 version from the International Society of Cardiovascular Infectious Diseases (ISCVID) in diagnosing IE among patients with streptococcal bacteremia. METHODS: This retrospective study included adult patients with streptococcal bacteremia hospitalized at Lausanne University Hospital. Episodes were classified as IE by the Endocarditis Team. A HANDOC score >2 classified patients as high risk for IE. RESULTS: Among 851 episodes with streptococcal bacteremia, IE was diagnosed in 171 episodes (20%). Among 607 episodes with non-ß-hemolytic streptococci, 213 (35%) had HANDOC scores >2 points; 132 (22%) had IE. The sensitivity of the HANDOC score to identify episodes at high risk for IE was 95% (95% confidence interval [CI], 90%-98%), the specificity 82% (95% CI, 78%-85%), and the negative predictive value (NPV) 98% (95% CI, 96%-99%). 2015 Duke-ESC, 2023 Duke-ISCVID, and 2023 Duke-ESC clinical criteria classified 114 (13%), 145 (17%), and 126 (15%) episodes as definite IE, respectively. Sensitivity (95% CI) for the 2015 Duke-ESC, 2023 Duke-ISCVID, and 2023 Duke-ESC clinical criteria was calculated at 65% (57%-72%), 81% (74%-86%), and 73% (65%-79%), respectively, with specificity (95% CI) at 100% (98%-100%), 99% (98%-100%), and 99% (98%-100%), respectively. CONCLUSIONS: The HANDOC score showed an excellent NPV to identify episodes at high risk for IE. Among the different versions of the Duke criteria, the 2023 Duke-ISCVID version fared better for the diagnosis of IE among streptococcal bacteremia.

Predictors of Mortality of Streptococcal Bacteremia and the Role of Infectious Diseases Consultation: A Retrospective Cohort Study.

BACKGROUND: Streptococcal bacteremia is associated with high mortality. Thia study aims to identify predictors of mortality among patients with streptococcal bacteremia. METHODS: This retrospective study was conducted at the Lausanne University Hospital, Switzerland, and included episodes of streptococcal bacteremia among adult patients from 2015 to 2023. RESULTS: During the study period, 861 episodes of streptococcal bacteremia were included. The majority of episodes were categorized in the Mitis group (348 episodes; 40%), followed by the Pyogenic group (215; 25%). Endocarditis was the most common source of bacteremia (164; 19%). The overall 14-day mortality rate was 8% (65 episodes). The results from the Cox multivariable regression model showed that a Charlson comorbidity index >4 (P .001; hazard ratio [HR], 2.87; confidence interval [CI]: 1.58-5.22), Streptococcus pyogenes (P = .011; HR, 2.54;CI: 1.24-5.21), sepsis (P < .001; HR, 7.48; CI: 3.86-14.47), lower respiratory tract infection (P = .002; HR, 2.62; CI: 1.42-4.81), and absence of source control interventions within 48 hours despite being warranted (P = .002; HR, 2.62; CI: 1.43-4.80) were associated with 14-day mortality. Conversely, interventions performed within 48 hours of bacteremia onset, such as infectious diseases consultation (P < .001; HR, 0.29; CI: .17-.48) and appropriate antimicrobial treatment (P < .001; HR, .28; CI: .14-.57), were associated with improved outcome. CONCLUSIONS: Our findings underscore the pivotal role of infectious diseases consultation in guiding antimicrobial treatment and recommending source control interventions for patients with streptococcal bacteremia.

Group B Streptococcus Sequence Type 103 as Human and Bovine Pathogen, Brazil.

Group B Streptococcus sequence type 103 is known primarily as a bovine mastitis pathogen. In Brazil, it has circulated in cattle and humans since the 1990s. It lacks scpB and, in humans, was found only among carriage isolates. Bovine-human interspecies transmission may have contributed to its evolution and spread.

Follow-Up Study of Effectiveness of 23-Valent Pneumococcal Polysaccharide Vaccine Against All-Type and Serotype-Specific Invasive Pneumococcal Disease, Denmark.

As a follow-up to a previous study, we investigated vaccine effectiveness (VE) of 23-valent pneumococcal polysaccharide vaccine (PPSV23) against invasive pneumococcal disease (IPD) among 1,254,498 persons >65 years of age as part of a vaccination program in Denmark during April 2020-January 2023. We assessed VE by using a Cox regression model and adjusted for age, sex, and underlying conditions. Using nationwide data, we estimated a VE of PPSV23 against all-type IPD of 32% and against PPSV23-serotype IPD of 41%. Because this follow-up study had more statistical power than the original study, we also estimated VE against IPD caused by PPSV23-serotypes excluding serotype 3; serotype 3; serotype 8; serotype 22F; PPSV23 non-PCV15 serotypes; PPSV23 non-PCV20 serotypes; and IPD over time. Our findings suggest PPSV23 vaccination can protect persons >65 years of age against IPD caused by all serotypes or serotype groupings, except serotype 3.

Identification and characterization of a novel α-haemolytic streptococci, Streptococcus parapneumoniae sp. nov., which caused bacteremia with pyelonephritis.

OBJECTIVES: We report a case of bacteremia with pyelonephritis in an adult male with an underlying disease caused by α-hemolytic streptococci. α-Hemolytic streptococci were isolated from blood, but it was challenging to identify its species. This study aimed to characterize the causative bacterium SP4011 and to elucidate its species. METHODS: The whole-genome sequence and biochemical characteristics of SP4011 were determined. Based on the genome sequence, phylogenetic analysis was performed with standard strains of each species of α-hemolytic streptococci. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were calculated. RESULTS: SP4011 showed optochin susceptibility and bile solubility, but did not react with pneumococcal omni antiserum. Phylogenetic analysis of the whole-genome sequence showed that SP4011 clustered with S. pneumoniae and S. pseodopneumoniae and was most closely related to S. pseodopneumoniae. Genomic analysis revealed that ANI and dDDH values between SP4011 and S. pseodopneumoniae were 94.0 % and 56.0 %, respectively, and between SP4011 and S. pneumoniae were 93.3 % and 52.2 %, respectively. Biochemical characteristics also showed differences between SP4011 and S. pseodopneumoniae and between SP4011 and S. pneumoniae. These results indicate that SP4011 is a novel species. CONCLUSION: Our findings indicate that SP4011 is a novel species of the genus Streptococcus. SP4011 has biochemical characteristics similar to S. pneumoniae, making it challenging to differentiate and requiring careful clinical diagnosis. This isolate was proposed to be a novel species, Streptococcus parapneumoniae sp. nov. The strain type is SP4011T (= JCM 36068T = KCTC 21228T).

Genomic analysis of conjugative and chromosomally integrated mobile genetic elements in oral streptococci.

This study aimed to investigate the diversity of conjugative and chromosomally integrated mobile genetic elements (cciMGEs) within six oral streptococci species. cciMGEs, including integrative and conjugative elements (ICEs) and integrative and mobilizable elements (IMEs), are stably maintained on the host cell chromosome; however, under certain conditions, they are able to excise, form extrachromosomal circles, and transfer via a conjugation apparatus. Many cciMGEs encode "cargo" functions that aid survival in new niches and evolve new antimicrobial resistance or virulence properties, whereas others have been shown to influence host bacterial physiology. Here, using a workflow employing preexisting bioinformatics tools, we analyzed 551 genomes for the presence of cciMGEs across six common health- and disease-associated oral streptococci. We identified 486 cciMGEs, 173 of which were ICEs and 233 of which were IMEs. The cciMGEs were diverse in size, cargo genes, and relaxase types. We identified several novel relaxase proteins and a widespread IME carrying a small multidrug resistance transporter. Additionally, we provide evidence that several of the bioinformatically predicted cciMGEs encoded within various Streptococcus mutans strains are capable of excision and circularization, a critical step for cciMGE conjugative transfer. These findings highlight the significance and potential impact of MGEs in shaping the genetic landscape, pathogenicity, and antimicrobial resistance profiles of the oral microbiota.IMPORTANCEOral streptococci are important players in the oral microbiome, influencing both health and disease states within dental bacterial communities. Evolutionary adaptation, shaped in a major part by the horizontal transfer of genes, is essential for their survival in the oral cavity and within new environments. Conjugation is a significant driver of horizontal gene transfer; however, there is limited information regarding this process in oral bacteria. This study utilizes publicly available genome sequences to identify conjugative and chromosomally integrated mobile genetic elements (cciMGEs) across several species of oral streptococci and presents the preliminary characterization of these elements. Our findings significantly enhance our understanding of the mobile genomic landscape of oral streptococci critical for human health, with valuable insights into how cciMGEs might influence the survival and pathogenesis of these bacteria in the oral microbiome.

Unveiling the genetic landscape of Streptococcus agalactiae bacteremia: emergence of hypervirulent CC1 strains and new CC283 strains in Tehran, Iran.

BACKGROUND: The emergence of Streptococcus agalactiae infections in patients with bacteremia is increasing. It is crucial to investigate the epidemiology, molecular characteristics, biofilm status, and virulence analysis of Streptococcus agalactiae in these patients. METHODS: In this cross-sectional study, 61 S. agalactiae isolated from blood infection were subjected to characterization through antimicrobial susceptibility tests, biofilm formation, multilocus sequence typing (MLST), and PCR analysis for detecting resistance (tet and erm family) and virulence genes (alp2/3, alp4, bca, bac, eps, rib, lmb, cylE, and pilus island genes). RESULTS: Overall, 32.7% of the isolates demonstrated an inducible clindamycin resistance phenotype. The results showed that 49.2, 24.6, and 8.2% of confirmed Streptococcus agalactiae strains were classified as strong, intermediate, and weak biofilm-forming strains, respectively. tet(M) (57.1%) was recovered most, followed by tet(M) + tet(L) (14.3%), tet(S) + tet(K) (10.7%), tet(M) + tet(K) (8.9%), tet(M) + tet(K) + tet(O) (5.4%), and tet(S) + tet(L) + tet(O) (3.6%). Three virulence gene profiles of cylE, lmb, bca, rib (24.6%; 15/61), cylE, lmb, rib, alp3 (19.7%; 12/61), and cylE, lmb, bac, rib (16.4%; 10/61) were detected in approximately two-thirds of the isolates. MLST revealed that the 61 isolates belonged to six clonal complexes, including CC1 (49.2%), followed by CC12 (18%), CC19 (13.1%), CC22 (9.8%), CC17 (6.6%), and CC283 (3.3%), and 11 different sequence types (STs), including ST1 (24.6%), ST7 (14.8%), ST918 (13.1%), ST2118 (9.8%), ST19 (9.8%), ST48 (6.6%), ST1372 (4.9%), ST22 (4.9%), ST40 (4.9%), ST734 (3.3%), and ST283 (3.3%). Remarkably, all CC1 and CC12 isolates, three-fourths of CC19, and half of CC22 were confirmed as biofilm producers. Conversely, CC17 and CC28 isolates were found to be nonproducers. The occurrence of strong biofilm formation was limited to specific CCs, namely CC1 (34.4%), CC12 (8.2%), CC19 (3.3%), and CC22 (3.3%). CONCLUSION: The high prevalence of CC1 and CC12 clones among S. agalactiae strains reflects the emergence of these lineages as successful clones in Iran, which is a serious concern and poses a potential threat to patients.

The complement system as a key modulator of the oral microbiome in health and disease.

In this review, we address the interplay between the complement system and host microbiomes in health and disease, focussing on oral bacteria known to contribute to homeostasis or to promote dysbiosis associated with dental caries and periodontal diseases. Host proteins modulating complement activities in the oral environment and expression profiles of complement proteins in oral tissues were described. In addition, we highlight a sub-set of bacterial proteins involved in complement evasion and/or dysregulation previously characterized in pathogenic species (or strains), but further conserved among prototypical commensal species of the oral microbiome. Potential roles of these proteins in host-microbiome homeostasis and in the emergence of commensal strain lineages with increased virulence were also addressed. Finally, we provide examples of how commensal bacteria might exploit the complement system in competitive or cooperative interactions within the complex microbial communities of oral biofilms. These issues highlight the need for studies investigating the effects of the complement system on bacterial behaviour and competitiveness during their complex interactions within oral and extra-oral host sites.

Competitive dynamics and balance between Streptococcus mutans and commensal streptococci in oral microecology.

Dental caries, as a biofilm-related disease, is closely linked to dysbiosis in microbial ecology within dental biofilms. Beyond its impact on oral health, bacteria within the oral cavity pose systemic health risks by potentially entering the bloodstream, thereby increasing susceptibility to bacterial endocarditis, among other related diseases. Streptococcus mutans, a principal cariogenic bacterium, possesses virulence factors crucial to the pathogenesis of dental caries. Its ability to adhere to tooth surfaces, produce glucans for biofilm formation, and metabolize sugars into lactic acid contributes to enamel demineralization and the initiation of carious lesions. Its aciduricity and ability to produce bacteriocins enable a competitive advantage, allowing it to thrive in acidic environments and dominate in changing oral microenvironments. In contrast, commensal streptococci, such as Streptococcus sanguinis, Streptococcus gordonii, and Streptococcus salivarius, act as primary colonizers and compete with S. mutans for adherence sites and nutrients during biofilm formation. This competition involves the production of alkali, peroxides, and antibacterial substances, thereby inhibiting S. mutans growth and maintaining microbial balance. This dynamic interaction influences the balance of oral microbiota, with disruptions leading to shifts in microbial composition that are marked by rapid increases in S. mutans abundance, contributing to the onset of dental caries. Thus, understanding the dynamic interactions between commensal and pathogenic bacteria in oral microecology is important for developing effective strategies to promote oral health and prevent dental caries. This review highlights the roles and competitive interactions of commensal bacteria and S. mutans in oral microecology, emphasizing the importance of maintaining oral microbial balance for health, and discusses the pathological implications of perturbations in this balance.

Evaluation of the main disorders and microbiota of the oral cavity of capuchin monkeys (Sapajus apella) under human care.

BACKGROUND: Although critical to the overall condition of animals under human care, there is still limited information about oral health in neotropical primates. METHODS: We analyzed the main oral conditions and microbiota using mass spectrometry from 13 capuchin monkeys (Sapajus apella) under human care. The findings were registered on odontograms following the Triadan system. RESULTS: The most prevalent conditions were dental fractures (n = 9), mainly enamel fractures, and periodontal disease (n = 8), mainly grade 1 calculi. When exanimating teeth, alterations were identified in 90 out of the 416 evaluated pieces, being periodontal disease the most common (n = 60), followed by enamel fracture (n = 15) and missing teeth (n = 10). In the oral microbiota analyses, Staphylococcus and Streptococcus species were the most prevalent, although no obvious association was observed between isolated organisms and oral conditions. CONCLUSIONS: These findings hold the potential to prevent oral disorders, including fractures and periodontal diseases, contribute to molecular identification of oral microbiota, and to improve the well-being of primates under human care.

Epidemiology, clinical characteristics, and outcome of infective endocarditis due to Abiotrophia and Granulicatella in a Tertiary Hospital in China, 2015-2023: a retrospective study.

BACKGROUND: Abiotrophia (ABI) and Granulicatella (GRA) are rare causative pathogens in infective endocarditis (IE). This study aims to describe the epidemiology, clinical characteristics, and outcome of ABI/GRA-IE. The main features of ABI/GRA-IE were compared with Viridans group streptococci (VGS) IE. METHODS: From January 2015 to December 2023, a total of 1531 definite IE in Zhongshan Hospital, Fudan University, Shanghai, China were retrospectively enrolled in this study. Clinical and laboratory data were collected. RESULTS: Forty-five ABI/GRA-IE cases were identified, representing 2.9% of all IE cases in Zhongshan Hospital between 2015 and 2023, compared to 20.1% of VGS-IE. ABI and GRA IE shared similar clinical characteristics. Congenital valvulopathy was reported in 21 (46.7%) ABI/GRA-IE and 85 (28.8%) VGS-IE (P = 0.025). Pulmonary valve was more frequently affected in ABI/GRA-IE (6 [13.3%]) than VGS-IE (7 [2.4%]) (P = 0.002). Congestive heart failure was observed in 30 (66.7%) ABI/GRA-IE and 103 (34.9%) VGS-IE (P < 0.001). Systemic embolization excluding central nervous system (CNS) occurred in 13 (28.9%) ABI/GRA-IE and 39 (13.2%) VGS-IE (P = 0.012). In-hospital mortality was reported as 4.4% in ABI/GRA-IE and 3.7% in VGS-IE (P = 0.854). CONCLUSION: GRA/ABI-IE was approximately one-seventh as prevalent as VGS-IE. Congestive heart failure and systemic embolization (excluding CNS) were more frequent in GRA/ABI-IE compared to VGS-IE. Mortality of ABI/GRA-IE in this study was comparable to that of VGS-IE and lower than previously reported results.

Outcomes in orthopedic device infections due to Streptococcus agalactiae: a retrospective cohort study.

BACKGROUND: Group B streptococci (Streptococcus agalactiae) (GBS) is a rare cause of prosthetic joint infection (PJI) occurring in patients with comorbidities and seems to be associated with a poor outcome. Depiction of GBS PJI is scarce in the literature. METHODS: A retrospective survey in 2 referral centers for bone joint infections was done Patients with a history of PJI associated with GBS between 2014 and 2019 were included. A descriptive analysis of treatment failure was done. Risk factors of treatment failure were assessed. RESULTS: We included 61 patients. Among them, 41 had monomicrobial (67%) infections. The median duration of follow-up was 2 years (interquartile range 2.35) Hypertension, obesity, and diabetes mellitus were the most reported comorbidities (49%, 50%, and 36% respectively). Death was observed in 6 individuals (10%) during the initial management. The rate of success was 63% (26/41). Removal of the material was not associated with remission (p = 0.5). We did not find a specific antibiotic regimen associated with a better outcome. CONCLUSION: The results show that S. agalactiae PJIs are associated with high rates of comorbidities and a high treatment failure rate with no optimal treatment so far.

The bacterial and fungal profiles of patients hospitalized with non-COVID-19 lower respiratory tract infections in Wuhan, China, 2019-2021.

AIMS: A severe lockdown occurred in Wuhan during the COVID-19 pandemic, followed by a remission phase in the pandemic's aftermath. This study analyzed the bacterial and fungal profiles of respiratory pathogens in patients hospitalized with non-COVID-19 lower respiratory tract infections (LRTIs) during this period to determine the pathogen profile distributions in different age groups and hospital departments in Wuhan. METHODS AND RESULTS: We collected reports of pathogen testing in the medical records of patients hospitalized with non-COVID-19 LRTI between 2019 and 2021. These cases were tested for bacterial and fungal pathogens using 16S and internal transcribed spacer sequencing methods on bronchoalveolar lavage fluid samples. The study included 1368 cases. The bacteria most commonly identified were Streptococcus pneumoniae (12.50%) and Mycoplasma pneumoniae (8.33%). The most commonly identified fungi were Aspergillus fumigatus (2.49%) and Pneumocystis jirovecii (1.75%). Compared to 2019, the S. pneumoniae detection rates increased significantly in 2021, and those of M. pneumoniae decreased. Streptococcus pneumoniae was detected mainly in children. The detection rates of almost all fungi were greater in the respiratory Intensive Care Unit compared to respiratory medicine. Streptococcus pneumoniae and M. pneumoniae were detected more frequently in the pediatric department. CONCLUSIONS: Before and after the COVID-19 outbreak, a change in the common pathogen spectrum was detected in patients with non-COVID-19 in Wuhan, with the greatest change occurring among children. The major pathogens varied by the patient's age and the hospital department.

A 6-year review of acute post-streptococcal glomerulonephritis at a public children's hospital in Cape Town, South Africa.

BACKGROUND: Acute post-streptococcal glomerulonephritis (APSGN) is the most common cause of acute nephritis in children globally and, in some cases, may be associated with progressive kidney injury and failure, cumulating in the need for long-term dialysis and/or kidney transplantation. METHODS: Our retrospective study describes the occurrence of APSGN among children (< 14 years) admitted to a tertiary children's hospital in Cape Town, South Africa, from January 2015 to December 2020. RESULTS: Of 161 children who presented with acute nephritis (haematuria, oedema, oliguria, and hypertension), 100 met the inclusion criteria. Demographic, clinical features, laboratory findings, management, and outcome data were collected. APSGN was defined by the clinical presentation of at least two clinical signs of acute nephritis, and low serum complement 3 (C3) level or evidence of a recent streptococcal infection. Most cases of APSGN were associated with streptococcal skin infections: 55/100 (55%); 10/100 (10%) children presented with hypertensive seizures; C3 levels were low in 86/92 (93.5%) children; 94/94 (100%) children had elevated anti-deoxyribonuclease-B (anti-DNase-B) levels; and 80/94 (85%) also had elevated anti-streptolysin O titre (ASOT) at presentation. Eleven (11%) children had a percutaneous kidney biopsy; 4/11 (36%) showed histological features of post-infectious nephritis, and 7/11(64%) also had crescentic glomerulonephritis with immune complex deposits. Sixty-two (62%) children confirmed recovered, and five (5%) progressed to kidney failure, but 29 presumed recovered as they did not return for follow-up to our institution. CONCLUSIONS: Childhood APSGN remains an important health problem in South Africa (SA) with favourable outcomes in most, apart from those with crescentic glomerulonephritis who progressed to kidney failure.

Antimicrobial effects of surface pre-reacted glass-ionomer (S-PRG) eluate against oral microcosm biofilm.

This study investigated the antimicrobial activity of surface pre-reacted glass ionomer eluate (S-PRG) against oral microcosm biofilms collected from the oral cavity of patients. Dental biofilm samples were collected from three volunteers to form microcosm biofilms in vitro. Initially, screening tests were carried out to determine the biofilm treatment conditions with S-PRG eluate. The effects of a daily treatment for 5 min using three microcosm biofilms from different patients was then evaluated. For this, biofilms were formed on tooth enamel specimens for 120 h. Biofilms treated with 100% S-PRG for 5 min per day for 5 days showed a reduction in the number of total microorganisms, streptococci and mutans streptococci. SEM images confirmed a reduction in the biofilm after treatment. Furthermore, S-PRG also reduced lactic acid production. It was concluded that S-PRG eluate reduced the microbial load and lactic acid production in oral microcosm biofilms, reinforcing its promising use as a mouthwash agent.

Abiotrophia defectiva triple threat: A rare case of infective spondylodiscitis, endocarditis, and brain abscess.

Abiotrophia defectiva is a pathogen of the oral, gastrointestinal, and urinary tracts that can cause significant systemic disease with uniquely negative blood cultures depending on the growth medium. Prior cases note possible seeding from relatively common procedures such as routine dental work and prostate biopsies, however case literature describes prior infectious complications to include infective endocarditis, brain abscess formation, and spondylodiscitis. While prior cases describe some aspects of these presentations, we highlight a case of a 64-year-old male who presented to the emergency department (ED) f5or acute onset of low back pain with fever symptoms four days after an outpatient transrectal ultrasound-guided needle biopsy of the prostate, with a prior dental extraction described four weeks prior to arrival. Findings on initial ED presentation and subsequent hospitalization revealed infective spondylodiscitis, endocarditis, and brain abscess formation. This is the only cases noted in literature with all three infection locations with dual risk factors of dental and prostate procedures prior to symptom onset. This case highlights the multifocal illness that can complicate Abiotrophia defectiva infections, and the importance of thorough ED evaluation and multiservice approach for consultation and treatment.

The impact of national guidelines on the diagnostics of sore throat in children.

BACKGROUND: The Finnish treatment guidelines for sore throat were updated in June 2020. The aim of this study was to determine how the publication of these guidelines affected the treatment of pediatric patients, particularly through the use of the Centor criteria, C-reactive protein tests, and microbiological testing in the diagnosis of Group A ß-hemolytic streptococci tonsillitis. METHODS: We conducted a retrospective single-center before-and-after cohort study in Finland from 2019 to 2022. We included all patients who visited the pediatric emergency department and were diagnosed with tonsillitis or pharyngitis. RESULTS: We included 246 patients who were admitted before the guidelines were updated and 219 patients after. Only two patients in the after group had a Centor score reported in their patient records. Rapid antigen tests were administered to 231 patients (93.9%) before the update and 202 patients (92.2%) after (proportion difference of 1.7%, CI -3.0-6.6%). C-reactive protein was taken from 193 patients (78.5%) before the update and 189 patients (86.3%) after (proportion difference of 7.8%, CI 0.1-14.7%). CONCLUSIONS: Centor scores were not used as recommended in the guidelines and did not impact the use of microbiological or C-reactive protein testing. More education and examining the preconceptions of health care personnel is required to implement the updated treatment guidelines in clinical practice.

Time-lapse confocal microscopy to study in vitro Streptococcus mutans surface colonization.

The cariogenicity of Streptococcus mutans relates to its ability to form biofilms on dental surfaces. The aim of this work was to develop a flowcell system compatible with time-lapse confocal microscopy to compare the adhesion and accumulation of S. mutans cells on surfaces in unsupplemented media against media containing sucrose or sucralose (a non-metabolized sweetener) over a short period of time. Fluorescent S. mutans 3209/pVMCherry was suspended in unsupplemented media or media supplemented with 1% sucrose or 1% sucralose and passed through a 3D-printed flowcell system. Flowcells were imaged over 60 minutes using a confocal microscope. Image analysis was performed, including a newly developed object-movement-based method to measure biomass adhesion. Streptococcus mutans 3209/pVMCherry grown in 1% sucrose-supplemented media formed small, dense, relatively immobile clumps in the flowcell system measured by biovolume, surface area, and median object centroid movement. Sucralose-supplemented and un-supplemented media yielded large, loose, mobile aggregates. Architectural metrics and per-object movement were significantly different (P < 0.05) when comparing sucrose-supplemented media to either unsupplemented or sucralose-supplemented media. These results demonstrate the utility of a flowcell system compatible with time-lapse confocal microscopy and image analysis when studying initial biofilm formation and adhesion under different nutritional conditions.