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BMC Oral Health May 2024In this study, the antimicrobial activity of three different cleanser tablets on S. mutans and C. albicans adhesion to PMMA, polyamide and 3D printed resin was...
BACKGROUND
In this study, the antimicrobial activity of three different cleanser tablets on S. mutans and C. albicans adhesion to PMMA, polyamide and 3D printed resin was investigated.
METHODS
40 samples were prepared for PMMA (SR Triplex Hot), polyamide (Deflex) and 3D printed resin (PowerResins Denture) materials and divided into four subgroups for cleansers (Aktident™, Protefix™, Corega™ tablets and distilled water) (n = 5). After the surface preparations were completed, the samples were immersed separately in tubes containing the prepared microorganism suspension and incubated at 37˚C for 24 h. After the incubation, the samples were kept in the cleanser solutions. The samples were then transferred to sterile saline tubes. All the tubes were vortexed and 10 µl was taken from each of them. Sheep blood agar was inoculated for colony counting. The inoculated plates were incubated for 48 h for S. mutans and 24 h for C. albicans. After incubation, colonies observed on all plates were counted. Statistical analyses were done with three-way ANOVA and Tukey's multiple comparison test.
RESULTS
Polyamide material registered the highest colony count of S. mutans, whereas PMMA registered the lowest. Significant differences in S. mutans adherence (p = 0.002) were found between the three denture base materials, but no such difference in C. albicans adherence (p = 0.221) was identified between the specimens. All three cleanser tablets eliminated 98% of S. mutans from all the material groups. In all these groups, as well, the antifungal effect of Corega™ on C. albicans was significantly higher than those of the other two cleanser tablets.
CONCLUSIONS
According to the study's results, it may be better to pay attention to surface smoothness when using polyamide material to prevent microorganism retention. Cleanser tablets are clinically recommended to help maintain hygiene in removable denture users, especially Corega tablets that are more effective on C. albicans.
Topics: Candida albicans; Streptococcus mutans; Denture Bases; Denture Cleansers; Polymethyl Methacrylate; Nylons; Tablets; Colony Count, Microbial; Dental Materials; Bacterial Adhesion; Anti-Infective Agents; Materials Testing
PubMed: 38811903
DOI: 10.1186/s12903-024-04403-6 -
Science Advances May 2024[group B (GBS)] is a leading cause of neonatal meningitis, with late-onset disease (LOD) occurring after gastrointestinal tract colonization in infants. Bacterial...
[group B (GBS)] is a leading cause of neonatal meningitis, with late-onset disease (LOD) occurring after gastrointestinal tract colonization in infants. Bacterial membrane lipids are essential for host-pathogen interactions, and the functions of glycolipids are yet to be fully elucidated. GBS synthesizes three major glycolipids: glucosyl-diacylglycerol (Glc-DAG), diglucosyl-DAG (Glc-DAG), and lysyl-Glc-DAG (Lys-Glc-DAG). Here, we identify the enzyme, IagB, as responsible for biosynthesis of Glc-DAG, the precursor for the two other glycolipids in GBS. To examine the collective role of glycolipids to GBS virulence, we adapted a murine model of neonatal meningitis to simulate LOD. The GBS∆ mutant traversed the gut-epithelial barrier comparable to wild type but was severely attenuated in bloodstream survival, resulting in decreased bacterial loads in the brain. The GBS∆ mutant was more susceptible to neutrophil killing and membrane targeting by host antimicrobial peptides. This work reveals an unexplored function of GBS glycolipids with their ability to protect the bacterial cell from host antimicrobial killing.
Topics: Streptococcus agalactiae; Animals; Glycolipids; Mice; Virulence; Streptococcal Infections; Humans; Disease Models, Animal; Host-Pathogen Interactions; Neutrophils; Mutation
PubMed: 38809989
DOI: 10.1126/sciadv.adn7848 -
ImmunoHorizons May 2024The mammalian Siglec receptor sialoadhesin (Siglec1, CD169) confers innate immunity against the encapsulated pathogen group B Streptococcus (GBS). Newborn lung...
The mammalian Siglec receptor sialoadhesin (Siglec1, CD169) confers innate immunity against the encapsulated pathogen group B Streptococcus (GBS). Newborn lung macrophages have lower expression levels of sialoadhesin at birth compared with the postnatal period, increasing their susceptibility to GBS infection. In this study, we investigate the mechanisms regulating sialoadhesin expression in the newborn mouse lung. In both neonatal and adult mice, GBS lung infection reduced Siglec1 expression, potentially delaying acquisition of immunity in neonates. Suppression of Siglec1 expression required interactions between sialic acid on the GBS capsule and the inhibitory host receptor Siglec-E. The Siglec1 gene contains multiple STAT binding motifs, which could regulate expression of sialoadhesin downstream of innate immune signals. Although GBS infection reduced STAT1 expression in the lungs of wild-type newborn mice, we observed increased numbers of STAT1+ cells in Siglece-/- lungs. To test if innate immune activation could increase sialoadhesin at birth, we first demonstrated that treatment of neonatal lung macrophages ex vivo with inflammatory activators increased sialoadhesin expression. However, overcoming the low sialoadhesin expression at birth using in vivo prenatal exposures or treatments with inflammatory stimuli were not successful. The suppression of sialoadhesin expression by GBS-Siglec-E engagement may therefore contribute to disease pathogenesis in newborns and represent a challenging but potentially appealing therapeutic opportunity to augment immunity at birth.
Topics: Animals; Mice; Streptococcus agalactiae; Animals, Newborn; N-Acetylneuraminic Acid; Sialic Acid Binding Ig-like Lectin 1; Streptococcal Infections; STAT1 Transcription Factor; Mice, Knockout; Immunity, Innate; Mice, Inbred C57BL; Lung; Macrophages, Alveolar; Female; Macrophages; Lectins; Sialic Acid Binding Immunoglobulin-like Lectins; Antigens, CD; Antigens, Differentiation, B-Lymphocyte
PubMed: 38809232
DOI: 10.4049/immunohorizons.2300076 -
Frontiers in Public Health 2024is one of the porcine pathogens that have recently emerged as a pathogen capable of causing zoonoses in some humans. Patients infected with can present with sepsis,...
INTRODUCTION
is one of the porcine pathogens that have recently emerged as a pathogen capable of causing zoonoses in some humans. Patients infected with can present with sepsis, meningitis, or arthritis. Compared to common pathogens, such as , , and , infections in humans have been reported only rarely.
METHODS
This case report described a 57-year-old man who presented with impaired consciousness and fever following several days of backache. He was a butcher who worked in an abattoir and had wounded his hands 2 weeks prior. The patient was dependent on alcohol for almost 40 years. was detected in the cerebrospinal fluid by metagenomic next-generation sequencing. Although he received adequate meropenem and low-dose steroid therapy, the patient suffered from bilateral sudden deafness after 5 days of the infection. The final diagnosis was meningitis and sepsis.
RESULTS
The patient survived with hearing loss in both ears and dizziness at the 60-day follow-up.
DISCUSSION
We reported a case of infection manifested as purulent meningitis and sepsis. Based on literature published worldwide, human meningitis shows an acute onset and rapid progression in the nervous system. Similar to bacterial meningitis, effective antibiotics, and low-dose steroids play important roles in the treatment of human meningitis.
Topics: Humans; Streptococcus suis; Male; Middle Aged; Streptococcal Infections; China; Meningitis, Bacterial; Anti-Bacterial Agents; Sepsis; Hearing Loss, Sudden
PubMed: 38808002
DOI: 10.3389/fpubh.2024.1369703 -
Critical Care (London, England) May 2024Streptococcus pneumoniae is the most common bacterial cause of community acquired pneumonia and the acute respiratory distress syndrome (ARDS). Some clinical trials have...
BACKGROUND
Streptococcus pneumoniae is the most common bacterial cause of community acquired pneumonia and the acute respiratory distress syndrome (ARDS). Some clinical trials have demonstrated a beneficial effect of corticosteroid therapy in community acquired pneumonia, COVID-19, and ARDS, but the mechanisms of this benefit remain unclear. The primary objective of this study was to investigate the effects of corticosteroids on the pulmonary biology of pneumococcal pneumonia in a mouse model. A secondary objective was to identify shared transcriptomic features of pneumococcal pneumonia and steroid treatment in the mouse model and clinical samples.
METHODS
We carried out comprehensive physiologic, biochemical, and histological analyses in mice to identify the mechanisms of lung injury in Streptococcus pneumoniae with and without adjunctive steroid therapy. We also studied lower respiratory tract gene expression from a cohort of 15 mechanically ventilated patients (10 with Streptococcus pneumoniae and 5 controls) to compare with the transcriptional studies in the mice.
RESULTS
In mice with pneumonia, dexamethasone in combination with ceftriaxone reduced (1) pulmonary edema formation, (2) alveolar protein permeability, (3) proinflammatory cytokine release, (4) histopathologic lung injury score, and (5) hypoxemia but did not increase bacterial burden. Transcriptomic analyses identified effects of steroid therapy in mice that were also observed in the clinical samples.
CONCLUSIONS
In combination with appropriate antibiotic therapy in mice, treatment of pneumococcal pneumonia with steroid therapy reduced hypoxemia, pulmonary edema, lung permeability, and histologic criteria of lung injury, and also altered inflammatory responses at the protein and gene expression level. The transcriptional studies in patients suggest that the mouse model replicates some of the features of pneumonia in patients with Streptococcus pneumoniae and steroid treatment. Overall, these studies provide evidence for the mechanisms that may explain the beneficial effects of glucocorticoid therapy in patients with community acquired pneumonia from Streptococcus Pneumoniae.
Topics: Animals; Pneumonia, Pneumococcal; Mice; Disease Models, Animal; Adrenal Cortex Hormones; Humans; Dexamethasone; Female; Male; Streptococcus pneumoniae
PubMed: 38807178
DOI: 10.1186/s13054-024-04956-6 -
Protein Science : a Publication of the... Jun 2024The bacteriophage protein paratox (Prx) blocks quorum sensing in its streptococcal host by directly binding the signal receptor and transcription factor ComR. This...
The bacteriophage protein paratox (Prx) blocks quorum sensing in its streptococcal host by directly binding the signal receptor and transcription factor ComR. This reduces the ability of Streptococcus to uptake environmental DNA and protects phage DNA from damage by recombination. Past work characterizing the Prx:ComR molecular interaction revealed that paratox adopts a well-ordered globular fold when bound to ComR. However, solution-state biophysical measurements suggested that Prx may be conformationally dynamic. To address this discrepancy, we investigated the stability and dynamic properties of Prx in solution using circular dichroism, nuclear magnetic resonance, and several fluorescence-based protein folding assays. Our work shows that under dilute buffer conditions Prx is intrinsically disordered. We also show that the addition of kosmotropic salts or protein stabilizing osmolytes induces Prx folding. However, the solute stabilized fold is different from the conformation Prx adopts when it is bound to ComR. Furthermore, we have characterized Prx folding thermodynamics and folding kinetics through steady-state fluorescence and stopped flow kinetic measurements. Our results show that Prx is a highly dynamic protein in dilute solution, folding and refolding within the 10 ms timescale. Overall, our results demonstrate that the streptococcal phage protein Prx is an intrinsically disordered protein in a two-state equilibrium with a solute-stabilized folded form. Furthermore, the solute-stabilized fold is likely the predominant form of Prx in a solute-crowded bacterial cell. Finally, our work suggests that Prx binds and inhibits ComR, and thus quorum sensing in Streptococcus, by a combination of conformational selection and induced-fit binding mechanisms.
Topics: Intrinsically Disordered Proteins; Protein Folding; Viral Proteins; Streptococcus Phages; Streptococcus
PubMed: 38801244
DOI: 10.1002/pro.5037 -
Medicina (Kaunas, Lithuania) Apr 2024We present a case of endogenous endophthalmitis with urinary tract infection (UTI) caused by group B Streptococcus (GBS). An 86-year-old female initially presented with...
We present a case of endogenous endophthalmitis with urinary tract infection (UTI) caused by group B Streptococcus (GBS). An 86-year-old female initially presented with ocular pain and sudden visual disturbance of the left eye. The patient did not complain of other symptoms and had no history of recent ocular surgery or trauma. Endogenous endophthalmitis was clinically diagnosed based on ophthalmic examination, history, and lab results showing systemic infection. A few days later, GBS was identified in her aqueous humor, blood, and urine cultures. Intravitreal ceftazidime and vancomycin injections, as well as fortified ceftazidime and vancomycin eye drops, were used immediately after clinical diagnosis. However, the symptoms worsened despite repeated intravitreal injections, so evisceration was performed. Endogenous endophthalmitis caused by GBS is very virulent and may present without evident systemic symptoms. The early recognition of the disease and systemic work up, followed by prompt treatment, is necessary.
Topics: Humans; Female; Urinary Tract Infections; Aged, 80 and over; Endophthalmitis; Streptococcus agalactiae; Streptococcal Infections; Anti-Bacterial Agents; Vancomycin; Ceftazidime
PubMed: 38792883
DOI: 10.3390/medicina60050700 -
International Journal of Molecular... May 2024The gene cluster for Type IV pilus (Tfp) biosynthesis is commonly present and highly conserved in . Nevertheless, Tfp-mediated twitching motility is less common among...
The gene cluster for Type IV pilus (Tfp) biosynthesis is commonly present and highly conserved in . Nevertheless, Tfp-mediated twitching motility is less common among strains, and the factors determining twitching activity are not fully understood. Here, we analyzed the functions of three major pilin proteins (PilA1, PilA2, and PilA3) in the assembly and activity of Tfp in motile CGMH010. Using various recombinant deletion strains, we found that Tfp composed of different PilA proteins varied morphologically and functionally. Among the three PilA proteins, PilA1 was most critical in the assembly of twitching-active Tfp, and recombinant strains expressing motility generated more structured biofilms under constant shearing forces compared to the non-motile recombinant strains. Although PilA1 and PilA3 shared 94% identity, PilA3 could not compensate for the loss of PilA1, suggesting that the nature of PilA proteins plays an essential role in twitching activity. The single deletion of individual genes had little effect on the invasion of host endothelia by CGMH010. In contrast, the deletion of all three genes or , encoding the retraction ATPase, abolished Tfp-mediated invasion. Tfp- and PilT-dependent invasion were also detected in the non-motile SK36, and thus, the retraction of Tfp, but not active twitching, was found to be essential for invasion.
Topics: Fimbriae Proteins; Streptococcus sanguis; Fimbriae, Bacterial; Biofilms; Bacterial Proteins
PubMed: 38791440
DOI: 10.3390/ijms25105402 -
PloS One 2024In 2012, Botswana introduced 13-valent pneumococcal conjugate vaccine (PCV-13) to its childhood immunization program in a 3+0 schedule, achieving coverage rates of above...
BACKGROUND
In 2012, Botswana introduced 13-valent pneumococcal conjugate vaccine (PCV-13) to its childhood immunization program in a 3+0 schedule, achieving coverage rates of above 90% by 2014. In other settings, PCV introduction has been followed by an increase in carriage or disease caused by non-vaccine serotypes, including some serotypes with a high prevalence of antibiotic resistance.
METHODS
We characterized the serotype epidemiology and antibiotic resistance of pneumococcal isolates cultured from nasopharyngeal samples collected from infants (≤12 months) in southeastern Botswana between 2016 and 2019. Capsular serotyping was performed using the Quellung reaction. E-tests were used to determine minimum inhibitory concentrations for common antibiotics.
RESULTS
We cultured 264 pneumococcal isolates from samples collected from 150 infants. At the time of sample collection, 81% of infants had received at least one dose of PCV-13 and 53% had completed the three-dose series. PCV-13 serotypes accounted for 27% of isolates, with the most prevalent vaccine serotypes being 19F (n = 20, 8%), 19A (n = 16, 6%), and 6A (n = 10, 4%). The most frequently identified non-vaccine serotypes were 23B (n = 29, 11%), 21 (n = 12, 5%), and 16F (n = 11, 4%). Only three (1%) pneumococcal isolates were resistant to amoxicillin; however, we observed an increasing prevalence of penicillin resistance using the meningitis breakpoint (2016: 41%, 2019: 71%; Cochran-Armitage test for trend, p = 0.0003) and non-susceptibility to trimethoprim-sulfamethoxazole (2016: 55%, 2019: 79%; p = 0.04). Three (1%) isolates were multi-drug resistant.
CONCLUSIONS
PCV-13 serotypes accounted for a substantial proportion of isolates colonizing infants in Botswana during a four-year period starting four years after vaccine introduction. A low prevalence of amoxicillin resistance supports its continued use as the first-line agent for non-meningeal pneumococcal infections. The observed increase in penicillin resistance at the meningitis breakpoint and the low prevalence of resistance to ceftriaxone supports use of third-generation cephalosporins for empirical treatment of suspected bacterial meningitis.
Topics: Humans; Streptococcus pneumoniae; Botswana; Infant; Pneumococcal Infections; Pneumococcal Vaccines; Serogroup; Female; Microbial Sensitivity Tests; Anti-Bacterial Agents; Male; Drug Resistance, Bacterial; Serotyping; Nasopharynx; Prevalence
PubMed: 38787847
DOI: 10.1371/journal.pone.0302400 -
Biosensors May 2024Loop-mediated isothermal amplification (LAMP) technology is extensively utilized for the detection of infectious diseases owing to its rapid processing and high...
Loop-mediated isothermal amplification (LAMP) technology is extensively utilized for the detection of infectious diseases owing to its rapid processing and high sensitivity. Nevertheless, conventional LAMP signaling methods frequently suffer from a lack of sequence specificity. This study integrates a triplex-forming oligonucleotide (TFO) probe into the LAMP process to enhance sequence specificity. This TFO-LAMP technique was applied for the detection of Group B (GBS). The TFO probe is designed to recognize a specific DNA sequence, termed the TFO targeting sequence (TTS), within the amplified product, facilitating detection via fluorescent instrumentation or lateral flow biosensors. A screening method was developed to identify TFO sequences with high affinity to integrate TFO into LAMP, subsequently incorporating a selected TTS into an LAMP primer. In the TFO-LAMP assay, a FAM-labeled TFO is added to target the TTS. This TFO can be captured by an anti-FAM antibody on lateral flow test strips, thus creating a nucleic acid testing biosensor. The efficacy of the TFO-LAMP assay was confirmed through experiments with specimens spiked with varying concentrations of GBS, demonstrating 85% sensitivity at 300 copies and 100% sensitivity at 30,000 copies. In conclusion, this study has successfully developed a TFO-LAMP technology that offers applicability in lateral flow biosensors and potentially other biosensor platforms.
Topics: Biosensing Techniques; Nucleic Acid Amplification Techniques; Oligonucleotides; Streptococcus; Humans; DNA, Bacterial; Molecular Diagnostic Techniques
PubMed: 38785731
DOI: 10.3390/bios14050257