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Scientific Reports Dec 2021As a conserved defense mechanism, many bacteria produce antimicrobial peptides, called bacteriocins, which provide a colonization advantage in a multispecies...
As a conserved defense mechanism, many bacteria produce antimicrobial peptides, called bacteriocins, which provide a colonization advantage in a multispecies environment. Here the first bacteriocin of Streptococcus anginosus, designated Angicin, is described. S. anginosus is commonly described as a commensal, however it also possesses a high pathogenic potential. Therefore, understanding factors contributing to its host colonization and persistence are important. A radial diffusion assay was used to identify S. anginosus BSU 1211 as a potent bacteriocin producer. By genetic mutagenesis the background of bacteriocin production and the bacteriocin gene itself were identified. Synthetic Angicin shows high activity against closely related streptococci, listeria and vancomycin resistant enterococci. It has a fast mechanism of action and causes a membrane disruption in target cells. Angicin, present in cell free supernatant, is insensitive to changes in temperature from - 70 to 90 °C and pH values from 2 to 10, suggesting that it represents an interesting compound for potential applications in food preservation or clinical settings.
Topics: Bacterial Proteins; Bacteriocins; Gene Expression Regulation, Bacterial; Listeria; Streptococcus anginosus; Vancomycin-Resistant Enterococci
PubMed: 34934110
DOI: 10.1038/s41598-021-03797-5 -
The Journal of Infection Aug 2022To describe the clinical characteristics and outcome of Abiotrophia and Granulicatella infective endocarditis and compare them with Viridans group streptococci infective...
OBJECTIVE
To describe the clinical characteristics and outcome of Abiotrophia and Granulicatella infective endocarditis and compare them with Viridans group streptococci infective endocarditis.
METHODS
All patients in the International Collaboration on Endocarditis (ICE) - prospective cohort study (PCS) and the ICE-PLUS cohort were included (n = 8112). Data from patients with definitive or possible IE due to Abiotrophia species, Granulicatella species and Viridans group streptococci was analyzed. A propensity score (PS) analysis comparing the ABI/GRA-IE and VGS-IE groups according to a 1:2 ratio was performed.
RESULTS
Forty-eight (0.64%) cases of ABI/GRA-IE and 1,292 (17.2%) VGS-IE were included in the analysis. The median age of patients with ABI/GRA-IE was lower than VGS-IE (48.1 years vs. 57.9 years; p = 0.001). Clinical features and the rate of in-hospital surgery was similar between ABI/GRA-IE and VGS-IE (52.1% vs. 45.4%; p = 0.366). Unadjusted in-hospital death was lower in ABI/GRA-IE than VGS-IE (2.1% vs. 8.8%; p = 0.003), and cumulative six-month mortality was lower in ABI/GRA-IE than VGS-IE (2.1% vs. 11.9%; p<0.001). After PS analysis, in-hospital mortality was similar in both groups, but six-month mortality was lower in the ABI/GRA IE group (2.1% vs. 10.4%; p = 0.029).
CONCLUSIONS
Patients with ABI/GRA-IE were younger, had similar clinical features and rates of surgery and better prognosis than VGS-IE.
Topics: Abiotrophia; Endocarditis; Endocarditis, Bacterial; Hospital Mortality; Humans; Middle Aged; Prospective Studies; Viridans Streptococci
PubMed: 35618152
DOI: 10.1016/j.jinf.2022.05.023 -
Oral Health & Preventive Dentistry Jan 2021Purpose: The aim of this study was to verify how the prevalence of viridans-streptococci is changed by two appointments of professional prophylaxis and after the...
Purpose: The aim of this study was to verify how the prevalence of viridans-streptococci is changed by two appointments of professional prophylaxis and after the subgingival instrumentation via scaling and root planing (SRP). Material and Methods: Samples of the subgingival biofilm were collected from 19 individuals with periodontitis receiving two appointments of professional prophylaxis and SRP before and after the treatment procedures and the presence of viridans-streptococci was analysed by microbiological cultivation. Non-parametric statistical testing using Friedman/Wilcoxon tests and chi-square testing was used for statistical analysis. Results: No statistically significant changes over time were found for the mutans-group. The prevalence of Streptococcus mitis decreased after two appointments of professional prophylaxis (p = 0.013). The prevalence of S. mitis decreased again after SRP (p <0.001). The prevalence of Streptococcus anginosus decreased after two appointments of professional prophylaxis (p = 0.002). After SRP five positive results for S. anginosus were detected (p = 0.026). For Streptococcus oralis and Streptococcus gordonii tendencies to statistical significance were found. The number of positive results for S. oralis increased after the first appointment of professional oral prophylaxis (p = 0.055). The number of positive results for S. gordonii increased after the first appointment of professional oral prophylaxis (p = 0.055). Conclusion: The step-wise periodontal therapy influences the prevalence of viridans-streptococci, especially S. mitis and S. anginosus. No tremendous increase of streptococci especially related to the carious process occurs in the subgingival biofilm. Clinical Relevance: The study reveals knowledge on changes of the composition of the subgingival biofilm due to different steps of periodontal therapy.
Topics: Biofilms; Dental Scaling; Humans; Periodontitis; Root Planing; Streptococcus oralis
PubMed: 33491375
DOI: 10.3290/j.ohpd.b875517 -
Journal of Periodontology Jun 2024This study determined the prevalence of aggressive (molar-incisor pattern) (Ag/MI) periodontitis and assessed the associated subgingival bacterial-herpesvirus microbiota...
BACKGROUND
This study determined the prevalence of aggressive (molar-incisor pattern) (Ag/MI) periodontitis and assessed the associated subgingival bacterial-herpesvirus microbiota in Pueblo Indian adolescents in the southwestern United States.
METHODS
The study included 240 Pueblo Indian adolescents, aged 13-20 years old, residing in three Rio Grande River villages in New Mexico and the Hopi Pueblo reservation in Arizona. Adolescents with Ag/MI periodontitis or periodontal health provided subgingival samples for culture of bacterial pathogens and for polymerase chain reaction detection of periodontal herpesviruses.
RESULTS
Ag/MI periodontitis was detected in 22 (9.2%) Pueblo Indian adolescents, with 21 exhibiting a localized molar-incisor breakdown pattern. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and other red/orange complex bacterial pathogens predominated in Ag/MI periodontitis, whereas periodontal health yielded mainly viridans streptococci and Actinomyces species. Periodontal herpesviruses demonstrated a 3.5 odds ratio relationship with Ag/MI periodontitis. The only adolescent with generalized Ag/MI periodontitis harbored viral co-infection by cytomegalovirus plus Epstein-Barr virus Type 1, in addition to A. actinomycetemcomitans, P. gingivalis, and several other periodontopathic bacteria.
CONCLUSIONS
Pueblo Indian adolescents showed an unusually high prevalence of early-age Ag/MI periodontitis predominated by periodontopathic bacteria and herpesviruses suspected to be major etiologic agents of the disease.
Topics: Humans; Adolescent; Young Adult; Male; Female; Aggressive Periodontitis; Indians, North American; Aggregatibacter actinomycetemcomitans; Porphyromonas gingivalis; Arizona; New Mexico; Cytomegalovirus; Actinomyces; Viridans Streptococci; Prevalence; Coinfection; Herpesvirus 4, Human; Herpesviridae
PubMed: 37910464
DOI: 10.1002/JPER.23-0410 -
Nature Chemical Biology May 2021Genome mining of clinical samples led to the identification of a structurally unique polyketide/non-ribosomal peptide, mutanofactin-697, that promotes biofilm...
Genome mining of clinical samples led to the identification of a structurally unique polyketide/non-ribosomal peptide, mutanofactin-697, that promotes biofilm formation. This study highlights the unexplored functional potential of secondary metabolites and opens new avenues for inhibiting pathogenic processes.
Topics: Biofilms; Mining; Mouth; Streptococcus mutans
PubMed: 33767389
DOI: 10.1038/s41589-021-00784-9 -
Critical Reviews in Microbiology Aug 2020Despite the substantial research advancements on oral diseases, dental caries remains a major healthcare burden. A disease of microbial dysbiosis, dental caries is... (Review)
Review
Despite the substantial research advancements on oral diseases, dental caries remains a major healthcare burden. A disease of microbial dysbiosis, dental caries is characterised by the formation of biofilms that assist demineralisation and destruction of the dental hard tissues. While it is well understood that this is a multi-kingdom biofilm-mediated disease, it has been elucidated that acid producing and acid tolerant bacteria play pioneering roles in the process. Specifically, houses major virulence pathways that enable it to thrive in the oral cavity and cause caries. This pathogen adheres to the tooth substrate, forms biofilms, resists external stress, produces acids, kills closely related species, and survives the acid as well as the host clearance mechanisms. For an organism to be able to confer such virulence, it requires a large and complex gene network which synergise to establish disease. In this review, we have charted how these multi-faceted genes control several caries-related functions of . In a futuristic thinking approach, we also briefly discuss the potential roles of omics and machine learning, to ease the study of non-functional genes that may play a major role and enable the integration of experimental data.
Topics: Animals; Bacterial Proteins; Biofilms; Dental Caries; Gene Expression Regulation, Bacterial; Humans; Mouth; Streptococcus mutans; Virulence
PubMed: 32720594
DOI: 10.1080/1040841X.2020.1796579 -
Journal of Dental Research Jan 2021Biofilm-mediated oral diseases such as dental caries and periodontal disease remain highly prevalent in populations worldwide. Biofilm formation initiates with the...
Biofilm-mediated oral diseases such as dental caries and periodontal disease remain highly prevalent in populations worldwide. Biofilm formation initiates with the attachment of primary colonizers onto surfaces, and in the context of caries, the adhesion of oral streptococci to dentinal collagen is crucial for biofilm progression. It is known that dentinal collagen suffers from glucose-associated crosslinking as a function of aging or disease; however, the effect of collagen crosslinking on the early adhesion and subsequent biofilm formation of relevant oral streptococci remains unknown. Therefore, the aim of this work was to determine the impact of collagen glycation on the initial adhesion of primary colonizers such as UA159 and SK 36, as well as its effect on the early stages of streptococcal biofilm formation in vitro. Type I collagen matrices were crosslinked with either glucose or methylglyoxal. Atomic force microscopy nanocharacterization revealed morphologic and mechanical changes within the collagen matrix as a function of crosslinking, such as a significantly increased elastic modulus in crosslinked fibrils. Increased nanoadhesion forces were observed for on crosslinked collagen surfaces as compared with the control, and retraction curves obtained for both streptococcal strains demonstrated nanoscale unbinding behavior consistent with bacterial adhesin-substrate coupling. Overall, glucose-crosslinked substrates specifically promoted the initial adhesion, biofilm formation, and insoluble extracellular polysaccharide production of , while methylglyoxal treatment reduced biofilm formation for both strains. Changes in the adhesion behavior and biofilm formation of oral streptococci as a function of collagen glycation could help explain the biofilm dysbiosis seen in older people and patients with diabetes. Further studies are necessary to determine the influence of collagen crosslinking on the balance between acidogenic and nonacidogenic streptococci to aid in the development of novel preventive and therapeutic treatment against dental caries in these patients.
Topics: Biofilms; Collagen; Dental Caries; Humans; Streptococcus; Streptococcus mutans; Streptococcus sanguis
PubMed: 32758105
DOI: 10.1177/0022034520946320 -
Journal of Cardiothoracic Surgery Jun 2020The aim of this study was to describe the clinical features and outcome of infective endocarditis at a general hospital in China and to identify the risk factors...
BACKGROUND
The aim of this study was to describe the clinical features and outcome of infective endocarditis at a general hospital in China and to identify the risk factors associated with in-hospital mortality.
METHODS
A retrospective study was conducted and all patients diagnosed with definite or possible infective endocarditis between January 2013 and June 2018 according to the modified Duke criteria were included.
RESULTS
A total of 381 patients were included. The mean age was 46 years old and 66.9% patients were male patients. Community acquired IE was the most common type of infective endocarditis and Viridans Group Streptococci (37.5%) was still the most common causative pathogen. The microbial etiology of infective endocarditis varied with location of acquisition. 97 (25.5%) patients had culture-negative infective endocarditis. Vegetations were detected in 85% patients and mitral valve was the most common involved valve. Operations were performed in 72.7% patients and in-hospital mortality rate was 8.4%. The risk factors of in-hospital mortality were age old than 70 years old, heart failure, stroke and medical therapy.
CONCLUSIONS
Older age, heart failure, stroke and medical therapy were risk factors of in-hospital mortality. Infective endocarditis, were mainly caused by Viridans Group Streptococci, characterized by younger patients and lower mortality rate in China.
Topics: Adult; Age Factors; Aged; China; Community-Acquired Infections; Endocarditis, Bacterial; Female; Heart Failure; Hospital Mortality; Humans; Male; Middle Aged; Retrospective Studies; Risk Factors; Streptococcal Infections; Stroke; Tertiary Care Centers; Viridans Streptococci
PubMed: 32522279
DOI: 10.1186/s13019-020-01183-2 -
Clinical Microbiology and Infection :... Aug 2020Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is becoming the method of choice for bacterial identification. However,...
OBJECTIVES
Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is becoming the method of choice for bacterial identification. However, correct identification by MALDI-TOF of closely related microorganisms such as viridans streptococci is still cumbersome, especially in the identification of S. pneumoniae. By making use of additional spectra peaks for S. pneumoniae and other viridans group streptococci (VGS). We re-identified viridans streptococci that had been identified and characterized by molecular and phenotypic techniques by MALDI-TOF.
METHODS
VGS isolates (n = 579), 496 S. pneumoniae and 83 non-S. pneumoniae were analysed using MALDI-TOF MS and the sensitivity and specificity of MALDI-TOF MS was assessed. Hereafter, mass spectra analysis was performed. Presumptive identification of proteins represented by discriminatory peaks was performed by molecular weight matching and the corresponding nucleotides sequences against different protein databases.
RESULTS
Using the Bruker reference library, 495 of 496 S. pneumoniae isolates were identified as S. pneumoniae and one isolate was identified as non-S. pneumoniae. Of the 83 non-S. pneumoniae isolates, 37 were correctly identified as non-S. pneumoniae, and 46 isolates as S. pneumoniae. The sensitivity of the MALDI-TOF MS was 99.8% (95% confidence interval (CI) 98.9-100) and the specificity was 44.6% (95% CI 33.7-55.9). Eight spectra peaks were mostly present in one category (S. pneumoniae or other VGS) and absent in the other category and inversely. Two spectra peaks of these (m/z 3420 and 3436) were selected by logistic regression to generate three identification profiles. These profiles could differentiate between S. pneumoniae and other VGS with high sensitivity and specificity (99.4% and 98.8%, respectively).
CONCLUSIONS
Spectral peaks analysis based identification is a powerful tool to differentiate S. pneumoniae from other VGS species with high specificity and sensitivity and is a useful method for pneumococcal identification in carriage studies. More research is needed to further confirm our findings. Extrapolation of these results to clinical strains need to be deeply investigated.
Topics: Bacterial Typing Techniques; Diagnosis, Differential; Humans; Molecular Typing; Sensitivity and Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptococcal Infections; Streptococcus pneumoniae; Viridans Streptococci
PubMed: 31811915
DOI: 10.1016/j.cmi.2019.11.024 -
Journal of Dental Research Apr 2023As oral bacteria grow and persist within biofilms attached to the tooth's surface, they interact with other species to form synergistic or antagonistic exchanges that...
As oral bacteria grow and persist within biofilms attached to the tooth's surface, they interact with other species to form synergistic or antagonistic exchanges that govern homeostasis for the overall population. One example are the interactions between the cariogenic species and oral commensal streptococci. Previously, we showed that the cell-cell signaling pathways of were inhibited during coculture with other oral streptococci species, leading us to posit that the transcriptome and behaviors are broadly altered during growth with these species. To test this hypothesis, we performed whole transcriptome sequencing (RNA-seq) on cocultures of with either , , or and a quadculture containing all 4 species in comparison to grown alone. Our results reveal that in addition to species-dependent changes to the transcriptome, a conserved response to oral streptococci in general can be observed. We monitored the behavior of by both microscopy imaging of biofilms and in a bacteriocin overlay assay and verified that acts similarly with each of these species but noted divergences in phenotypes when cocultured with another cariogenic () or with oral nonstreptococci species. RNA-seq with oral nonstreptococci showed lack of a consistent gene expression profile and overlap of differentially expressed genes found with commensal streptococci. Finally, we investigated the role of upregulated genes within our data sets to determine if they provided a fitness benefit during interspecies interactions. Eleven total genes were studied, and we found that a majority impacted the fitness of in various assays, highlighted by increased biomass of commensal streptococci in mixed-species biofilms. These results confirm a common, species-independent modification of behaviors with oral commensal streptococci that emphasizes the need to further evaluate oral bacteria within multispecies settings.
Topics: Streptococcus mutans; Streptococcus sanguis; Streptococcus gordonii; Symbiosis; Microbiota; Biofilms
PubMed: 36688378
DOI: 10.1177/00220345221145906